MODULE module_sf_noahlsm USE module_model_constants ! REAL, PARAMETER :: CP = 1004.5 REAL, PARAMETER :: RD = 287.04, SIGMA = 5.67E-8, & CPH2O = 4.218E+3,CPICE = 2.106E+3, & LSUBF = 3.335E+5, & EMISSI_S = 0.95 ! VEGETATION PARAMETERS INTEGER :: LUCATS , BARE integer, PARAMETER :: NLUS=50 CHARACTER*4 LUTYPE INTEGER, DIMENSION(1:NLUS) :: NROTBL real, dimension(1:NLUS) :: SNUPTBL, RSTBL, RGLTBL, HSTBL, LAITBL, & ALBTBL, Z0TBL, SHDTBL, MAXALB REAL :: TOPT_DATA,CMCMAX_DATA,CFACTR_DATA,RSMAX_DATA ! SOIL PARAMETERS INTEGER :: SLCATS INTEGER, PARAMETER :: NSLTYPE=30 CHARACTER*4 SLTYPE REAL, DIMENSION (1:NSLTYPE) :: BB,DRYSMC,F11, & MAXSMC, REFSMC,SATPSI,SATDK,SATDW, WLTSMC,QTZ ! LSM GENERAL PARAMETERS INTEGER :: SLPCATS INTEGER, PARAMETER :: NSLOPE=30 REAL, DIMENSION (1:NSLOPE) :: SLOPE_DATA REAL :: SBETA_DATA,FXEXP_DATA,CSOIL_DATA,SALP_DATA,REFDK_DATA, & REFKDT_DATA,FRZK_DATA,ZBOT_DATA, SMLOW_DATA,SMHIGH_DATA, & CZIL_DATA CHARACTER*256 :: err_message ! CONTAINS ! SUBROUTINE SFLX (FFROZP,ICE,DT,ZLVL,NSOIL,SLDPTH, & !C LOCAL, & !L LLANDUSE, LSOIL, & !CL LWDN,SOLDN,SOLNET,SFCPRS,PRCP,SFCTMP,Q2,SFCSPD, & !F COSZ,PRCPRAIN, SOLARDIRECT, & !F TH2,Q2SAT,DQSDT2, & !I VEGTYP,SOILTYP,SLOPETYP,SHDFAC,SHDMIN,SHDMAX, & !I ALB, SNOALB,TBOT, Z0BRD, Z0, EMISSI, EMBRD, & !S CMC,T1,STC,SMC,SH2O,SNOWH,SNEQV,ALBEDO,CH,CM, & !H ! ---------------------------------------------------------------------- ! OUTPUTS, DIAGNOSTICS, PARAMETERS BELOW GENERALLY NOT NECESSARY WHEN ! COUPLED WITH E.G. A NWP MODEL (SUCH AS THE NOAA/NWS/NCEP MESOSCALE ETA ! MODEL). OTHER APPLICATIONS MAY REQUIRE DIFFERENT OUTPUT VARIABLES. ! ---------------------------------------------------------------------- ETA,SHEAT, ETA_KINEMATIC,FDOWN, & !O EC,EDIR,ET,ETT,ESNOW,DRIP,DEW, & !O BETA,ETP,SSOIL, & !O FLX1,FLX2,FLX3, & !O SNOMLT,SNCOVR, & !O RUNOFF1,RUNOFF2,RUNOFF3, & !O RC,PC,RSMIN,XLAI,RCS,RCT,RCQ,RCSOIL, & !O SOILW,SOILM,Q1, & !D SMCWLT,SMCDRY,SMCREF,SMCMAX,NROOT) !P ! ---------------------------------------------------------------------- ! SUBROUTINE SFLX - UNIFIED NOAHLSM VERSION 1.0 JULY 2007 ! ---------------------------------------------------------------------- ! SUB-DRIVER FOR "Noah LSM" FAMILY OF PHYSICS SUBROUTINES FOR A ! SOIL/VEG/SNOWPACK LAND-SURFACE MODEL TO UPDATE SOIL MOISTURE, SOIL ! ICE, SOIL TEMPERATURE, SKIN TEMPERATURE, SNOWPACK WATER CONTENT, ! SNOWDEPTH, AND ALL TERMS OF THE SURFACE ENERGY BALANCE AND SURFACE ! WATER BALANCE (EXCLUDING INPUT ATMOSPHERIC FORCINGS OF DOWNWARD ! RADIATION AND PRECIP) ! ---------------------------------------------------------------------- ! SFLX ARGUMENT LIST KEY: ! ---------------------------------------------------------------------- ! C CONFIGURATION INFORMATION ! L LOGICAL ! CL 4-string character bearing logical meaning ! F FORCING DATA ! I OTHER (INPUT) FORCING DATA ! S SURFACE CHARACTERISTICS ! H HISTORY (STATE) VARIABLES ! O OUTPUT VARIABLES ! D DIAGNOSTIC OUTPUT ! P Parameters ! Msic Miscellaneous terms passed from gridded driver ! ---------------------------------------------------------------------- ! 1. CONFIGURATION INFORMATION (C): ! ---------------------------------------------------------------------- ! ICE SEA-ICE FLAG (=1: SEA-ICE, =0: LAND) ! DT TIMESTEP (SEC) (DT SHOULD NOT EXCEED 3600 SECS, RECOMMEND ! 1800 SECS OR LESS) ! ZLVL HEIGHT (M) ABOVE GROUND OF ATMOSPHERIC FORCING VARIABLES ! NSOIL NUMBER OF SOIL LAYERS (AT LEAST 2, AND NOT GREATER THAN ! PARAMETER NSOLD SET BELOW) ! SLDPTH THE THICKNESS OF EACH SOIL LAYER (M) ! ---------------------------------------------------------------------- ! 2. LOGICAL: ! ---------------------------------------------------------------------- ! LCH Exchange coefficient (Ch) calculation flag (false: using ! ch-routine SFCDIF; true: Ch is brought in) ! LOCAL Flag for local-site simulation (where there is no ! maps for albedo, veg fraction, and roughness ! true: all LSM parameters (inluding albedo, veg fraction and ! roughness length) will be defined by three tables ! LLANDUSE (=USGS, using USGS landuse classification) ! LSOIL (=STAS, using FAO/STATSGO soil texture classification) ! ---------------------------------------------------------------------- ! 3. FORCING DATA (F): ! ---------------------------------------------------------------------- ! LWDN LW DOWNWARD RADIATION (W M-2; POSITIVE, NOT NET LONGWAVE) ! SOLDN SOLAR DOWNWARD RADIATION (W M-2; POSITIVE, NOT NET SOLAR) ! SOLNET NET DOWNWARD SOLAR RADIATION ((W M-2; POSITIVE) ! SFCPRS PRESSURE AT HEIGHT ZLVL ABOVE GROUND (PASCALS) ! PRCP PRECIP RATE (KG M-2 S-1) (NOTE, THIS IS A RATE) ! SFCTMP AIR TEMPERATURE (K) AT HEIGHT ZLVL ABOVE GROUND ! TH2 AIR POTENTIAL TEMPERATURE (K) AT HEIGHT ZLVL ABOVE GROUND ! Q2 MIXING RATIO AT HEIGHT ZLVL ABOVE GROUND (KG KG-1) ! COSZ Solar zenith angle (not used for now) ! PRCPRAIN Liquid-precipitation rate (KG M-2 S-1) (not used) ! SOLARDIRECT Direct component of downward solar radiation (W M-2) (not used) ! FFROZP FRACTION OF FROZEN PRECIPITATION ! ---------------------------------------------------------------------- ! 4. OTHER FORCING (INPUT) DATA (I): ! ---------------------------------------------------------------------- ! SFCSPD WIND SPEED (M S-1) AT HEIGHT ZLVL ABOVE GROUND ! Q2SAT SAT SPECIFIC HUMIDITY AT HEIGHT ZLVL ABOVE GROUND (KG KG-1) ! DQSDT2 SLOPE OF SAT SPECIFIC HUMIDITY CURVE AT T=SFCTMP ! (KG KG-1 K-1) ! ---------------------------------------------------------------------- ! 5. CANOPY/SOIL CHARACTERISTICS (S): ! ---------------------------------------------------------------------- ! VEGTYP VEGETATION TYPE (INTEGER INDEX) ! SOILTYP SOIL TYPE (INTEGER INDEX) ! SLOPETYP CLASS OF SFC SLOPE (INTEGER INDEX) ! SHDFAC AREAL FRACTIONAL COVERAGE OF GREEN VEGETATION ! (FRACTION= 0.0-1.0) ! SHDMIN MINIMUM AREAL FRACTIONAL COVERAGE OF GREEN VEGETATION ! (FRACTION= 0.0-1.0) <= SHDFAC ! PTU PHOTO THERMAL UNIT (PLANT PHENOLOGY FOR ANNUALS/CROPS) ! (NOT YET USED, BUT PASSED TO REDPRM FOR FUTURE USE IN ! VEG PARMS) ! ALB BACKROUND SNOW-FREE SURFACE ALBEDO (FRACTION), FOR JULIAN ! DAY OF YEAR (USUALLY FROM TEMPORAL INTERPOLATION OF ! MONTHLY MEAN VALUES' CALLING PROG MAY OR MAY NOT ! INCLUDE DIURNAL SUN ANGLE EFFECT) ! SNOALB UPPER BOUND ON MAXIMUM ALBEDO OVER DEEP SNOW (E.G. FROM ! ROBINSON AND KUKLA, 1985, J. CLIM. & APPL. METEOR.) ! TBOT BOTTOM SOIL TEMPERATURE (LOCAL YEARLY-MEAN SFC AIR ! TEMPERATURE) ! Z0BRD Background fixed roughness length (M) ! Z0 Time varying roughness length (M) as function of snow depth ! ! EMBRD Background surface emissivity (between 0 and 1) ! EMISSI Surface emissivity (between 0 and 1) ! ---------------------------------------------------------------------- ! 6. HISTORY (STATE) VARIABLES (H): ! ---------------------------------------------------------------------- ! CMC CANOPY MOISTURE CONTENT (M) ! T1 GROUND/CANOPY/SNOWPACK) EFFECTIVE SKIN TEMPERATURE (K) ! STC(NSOIL) SOIL TEMP (K) ! SMC(NSOIL) TOTAL SOIL MOISTURE CONTENT (VOLUMETRIC FRACTION) ! SH2O(NSOIL) UNFROZEN SOIL MOISTURE CONTENT (VOLUMETRIC FRACTION) ! NOTE: FROZEN SOIL MOISTURE = SMC - SH2O ! SNOWH ACTUAL SNOW DEPTH (M) ! SNEQV LIQUID WATER-EQUIVALENT SNOW DEPTH (M) ! NOTE: SNOW DENSITY = SNEQV/SNOWH ! ALBEDO SURFACE ALBEDO INCLUDING SNOW EFFECT (UNITLESS FRACTION) ! =SNOW-FREE ALBEDO (ALB) WHEN SNEQV=0, OR ! =FCT(MSNOALB,ALB,VEGTYP,SHDFAC,SHDMIN) WHEN SNEQV>0 ! CH SURFACE EXCHANGE COEFFICIENT FOR HEAT AND MOISTURE ! (M S-1); NOTE: CH IS TECHNICALLY A CONDUCTANCE SINCE ! IT HAS BEEN MULTIPLIED BY WIND SPEED. ! CM SURFACE EXCHANGE COEFFICIENT FOR MOMENTUM (M S-1); NOTE: ! CM IS TECHNICALLY A CONDUCTANCE SINCE IT HAS BEEN ! MULTIPLIED BY WIND SPEED. ! ---------------------------------------------------------------------- ! 7. OUTPUT (O): ! ---------------------------------------------------------------------- ! OUTPUT VARIABLES NECESSARY FOR A COUPLED NUMERICAL WEATHER PREDICTION ! MODEL, E.G. NOAA/NWS/NCEP MESOSCALE ETA MODEL. FOR THIS APPLICATION, ! THE REMAINING OUTPUT/DIAGNOSTIC/PARAMETER BLOCKS BELOW ARE NOT ! NECESSARY. OTHER APPLICATIONS MAY REQUIRE DIFFERENT OUTPUT VARIABLES. ! ETA ACTUAL LATENT HEAT FLUX (W m-2: NEGATIVE, IF UP FROM ! SURFACE) ! ETA_KINEMATIC atctual latent heat flux in Kg m-2 s-1 ! SHEAT SENSIBLE HEAT FLUX (W M-2: NEGATIVE, IF UPWARD FROM ! SURFACE) ! FDOWN Radiation forcing at the surface (W m-2) = SOLDN*(1-alb)+LWDN ! ---------------------------------------------------------------------- ! EC CANOPY WATER EVAPORATION (W m-2) ! EDIR DIRECT SOIL EVAPORATION (W m-2) ! ET(NSOIL) PLANT TRANSPIRATION FROM A PARTICULAR ROOT (SOIL) LAYER ! (W m-2) ! ETT TOTAL PLANT TRANSPIRATION (W m-2) ! ESNOW SUBLIMATION FROM (OR DEPOSITION TO IF <0) SNOWPACK ! (W m-2) ! DRIP THROUGH-FALL OF PRECIP AND/OR DEW IN EXCESS OF CANOPY ! WATER-HOLDING CAPACITY (M) ! DEW DEWFALL (OR FROSTFALL FOR T<273.15) (M) ! ---------------------------------------------------------------------- ! BETA RATIO OF ACTUAL/POTENTIAL EVAP (DIMENSIONLESS) ! ETP POTENTIAL EVAPORATION (W m-2) ! SSOIL SOIL HEAT FLUX (W M-2: NEGATIVE IF DOWNWARD FROM SURFACE) ! ---------------------------------------------------------------------- ! FLX1 PRECIP-SNOW SFC (W M-2) ! FLX2 FREEZING RAIN LATENT HEAT FLUX (W M-2) ! FLX3 PHASE-CHANGE HEAT FLUX FROM SNOWMELT (W M-2) ! ---------------------------------------------------------------------- ! SNOMLT SNOW MELT (M) (WATER EQUIVALENT) ! SNCOVR FRACTIONAL SNOW COVER (UNITLESS FRACTION, 0-1) ! ---------------------------------------------------------------------- ! RUNOFF1 SURFACE RUNOFF (M S-1), NOT INFILTRATING THE SURFACE ! RUNOFF2 SUBSURFACE RUNOFF (M S-1), DRAINAGE OUT BOTTOM OF LAST ! SOIL LAYER (BASEFLOW) ! RUNOFF3 NUMERICAL TRUNCTATION IN EXCESS OF POROSITY (SMCMAX) ! FOR A GIVEN SOIL LAYER AT THE END OF A TIME STEP (M S-1). ! Note: the above RUNOFF2 is actually the sum of RUNOFF2 and RUNOFF3 ! ---------------------------------------------------------------------- ! RC CANOPY RESISTANCE (S M-1) ! PC PLANT COEFFICIENT (UNITLESS FRACTION, 0-1) WHERE PC*ETP ! = ACTUAL TRANSP ! XLAI LEAF AREA INDEX (DIMENSIONLESS) ! RSMIN MINIMUM CANOPY RESISTANCE (S M-1) ! RCS INCOMING SOLAR RC FACTOR (DIMENSIONLESS) ! RCT AIR TEMPERATURE RC FACTOR (DIMENSIONLESS) ! RCQ ATMOS VAPOR PRESSURE DEFICIT RC FACTOR (DIMENSIONLESS) ! RCSOIL SOIL MOISTURE RC FACTOR (DIMENSIONLESS) ! ---------------------------------------------------------------------- ! 8. DIAGNOSTIC OUTPUT (D): ! ---------------------------------------------------------------------- ! SOILW AVAILABLE SOIL MOISTURE IN ROOT ZONE (UNITLESS FRACTION ! BETWEEN SMCWLT AND SMCMAX) ! SOILM TOTAL SOIL COLUMN MOISTURE CONTENT (FROZEN+UNFROZEN) (M) ! Q1 Effective mixing ratio at surface (kg kg-1), used for ! diagnosing the mixing ratio at 2 meter for coupled model ! ---------------------------------------------------------------------- ! 9. PARAMETERS (P): ! ---------------------------------------------------------------------- ! SMCWLT WILTING POINT (VOLUMETRIC) ! SMCDRY DRY SOIL MOISTURE THRESHOLD WHERE DIRECT EVAP FRM TOP ! LAYER ENDS (VOLUMETRIC) ! SMCREF SOIL MOISTURE THRESHOLD WHERE TRANSPIRATION BEGINS TO ! STRESS (VOLUMETRIC) ! SMCMAX POROSITY, I.E. SATURATED VALUE OF SOIL MOISTURE ! (VOLUMETRIC) ! NROOT NUMBER OF ROOT LAYERS, A FUNCTION OF VEG TYPE, DETERMINED ! IN SUBROUTINE REDPRM. ! ---------------------------------------------------------------------- IMPLICIT NONE ! ---------------------------------------------------------------------- ! DECLARATIONS - LOGICAL AND CHARACTERS ! ---------------------------------------------------------------------- LOGICAL, INTENT(IN):: LOCAL LOGICAL :: FRZGRA, SNOWNG CHARACTER (LEN=4), INTENT(IN):: LLANDUSE, LSOIL ! ---------------------------------------------------------------------- ! 1. CONFIGURATION INFORMATION (C): ! ---------------------------------------------------------------------- INTEGER,INTENT(IN) :: ICE,NSOIL,SLOPETYP,SOILTYP,VEGTYP INTEGER,INTENT(OUT):: NROOT INTEGER KZ, K, iout ! ---------------------------------------------------------------------- ! 2. LOGICAL: ! ---------------------------------------------------------------------- REAL, INTENT(IN) :: SHDMIN,SHDMAX,DT,DQSDT2,LWDN,PRCP,PRCPRAIN, & Q2,Q2SAT,SFCPRS,SFCSPD,SFCTMP, SNOALB, & SOLDN,SOLNET,TBOT,TH2,ZLVL, & EMBRD, FFROZP REAL, INTENT(INOUT):: COSZ, SOLARDIRECT,ALBEDO,CH,CM, & CMC,SNEQV,SNCOVR,SNOWH,T1,XLAI,SHDFAC,Z0BRD,ALB,& EMISSI REAL, DIMENSION(1:NSOIL), INTENT(IN) :: SLDPTH REAL, DIMENSION(1:NSOIL), INTENT(OUT):: ET REAL, DIMENSION(1:NSOIL), INTENT(INOUT) :: SH2O, SMC, STC REAL,DIMENSION(1:NSOIL):: RTDIS, ZSOIL REAL,INTENT(OUT) :: ETA_KINEMATIC,BETA,DEW,DRIP,EC,EDIR,ESNOW,ETA, & ETP,FLX1,FLX2,FLX3,SHEAT,PC,RUNOFF1,RUNOFF2, & RUNOFF3,RC,RSMIN,RCQ,RCS,RCSOIL,RCT,SSOIL, & SMCDRY,SMCMAX,SMCREF,SMCWLT,SNOMLT, SOILM, & SOILW,FDOWN,Q1 REAL :: BEXP,CFACTR,CMCMAX,CSOIL,CZIL,DF1,DF1H,DF1A,DKSAT,DWSAT, & DSOIL,DTOT,ETT,FRCSNO,FRCSOI,EPSCA,F1,FXEXP,FRZX,HS, & KDT,LVH2O,PRCP1,PSISAT,QUARTZ,R,RCH,REFKDT,RR,RGL, & RSMAX, & RSNOW,SNDENS,SNCOND,SBETA,SN_NEW,SLOPE,SNUP,SALP,SOILWM, & SOILWW,T1V,T24,T2V,TH2V,TOPT,TFREEZ,TSNOW,ZBOT,Z0,PRCPF, & ETNS,PTU,LSUBS ! ---------------------------------------------------------------------- ! DECLARATIONS - PARAMETERS ! ---------------------------------------------------------------------- PARAMETER (TFREEZ = 273.15) PARAMETER (LVH2O = 2.501E+6) PARAMETER (LSUBS = 2.83E+6) PARAMETER (R = 287.04) ! ---------------------------------------------------------------------- ! INITIALIZATION ! ---------------------------------------------------------------------- RUNOFF1 = 0.0 RUNOFF2 = 0.0 RUNOFF3 = 0.0 SNOMLT = 0.0 ! ---------------------------------------------------------------------- ! THE VARIABLE "ICE" IS A FLAG DENOTING SEA-ICE CASE ! ---------------------------------------------------------------------- ! SEA-ICE LAYERS ARE EQUAL THICKNESS AND SUM TO 3 METERS ! ---------------------------------------------------------------------- IF (ICE == 1) THEN DO KZ = 1,NSOIL ZSOIL (KZ) = -3.* FLOAT (KZ)/ FLOAT (NSOIL) END DO ! ---------------------------------------------------------------------- ! CALCULATE DEPTH (NEGATIVE) BELOW GROUND FROM TOP SKIN SFC TO BOTTOM OF ! EACH SOIL LAYER. NOTE: SIGN OF ZSOIL IS NEGATIVE (DENOTING BELOW ! GROUND) ! ---------------------------------------------------------------------- ELSE ZSOIL (1) = - SLDPTH (1) DO KZ = 2,NSOIL ZSOIL (KZ) = - SLDPTH (KZ) + ZSOIL (KZ -1) END DO ! ---------------------------------------------------------------------- ! NEXT IS CRUCIAL CALL TO SET THE LAND-SURFACE PARAMETERS, INCLUDING ! SOIL-TYPE AND VEG-TYPE DEPENDENT PARAMETERS. ! ---------------------------------------------------------------------- CALL REDPRM (VEGTYP,SOILTYP,SLOPETYP,CFACTR,CMCMAX,RSMAX,TOPT, & REFKDT,KDT,SBETA, SHDFAC,RSMIN,RGL,HS,ZBOT,FRZX, & PSISAT,SLOPE,SNUP,SALP,BEXP,DKSAT,DWSAT, & SMCMAX,SMCWLT,SMCREF,SMCDRY,F1,QUARTZ,FXEXP, & RTDIS,SLDPTH,ZSOIL,NROOT,NSOIL,Z0BRD,CZIL,XLAI, & CSOIL,ALB,PTU,LLANDUSE,LSOIL,LOCAL) END IF !urban IF(VEGTYP==1)THEN SHDFAC=0.05 RSMIN=400.0 SMCMAX = 0.45 SMCREF = 0.42 SMCWLT = 0.40 SMCDRY = 0.40 ENDIF ! ---------------------------------------------------------------------- ! INITIALIZE PRECIPITATION LOGICALS. ! ---------------------------------------------------------------------- SNOWNG = .FALSE. FRZGRA = .FALSE. ! ---------------------------------------------------------------------- ! IF SEA-ICE CASE, ASSIGN DEFAULT WATER-EQUIV SNOW ON TOP ! ---------------------------------------------------------------------- IF (ICE == 1) THEN SNEQV = 0.01 SNOWH = 0.05 ! ---------------------------------------------------------------------- ! IF INPUT SNOWPACK IS NONZERO, THEN COMPUTE SNOW DENSITY "SNDENS" AND ! SNOW THERMAL CONDUCTIVITY "SNCOND" (NOTE THAT CSNOW IS A FUNCTION ! SUBROUTINE) ! ---------------------------------------------------------------------- END IF IF (SNEQV == 0.0) THEN SNDENS = 0.0 SNOWH = 0.0 SNCOND = 1.0 ELSE SNDENS = SNEQV / SNOWH IF(SNDENS > 1.0) THEN CALL wrf_error_fatal ( 'Physical snow depth is less than snow water equiv.' ) ENDIF CALL CSNOW (SNCOND,SNDENS) END IF ! ---------------------------------------------------------------------- ! DETERMINE IF IT'S PRECIPITATING AND WHAT KIND OF PRECIP IT IS. ! IF IT'S PRCPING AND THE AIR TEMP IS COLDER THAN 0 C, IT'S SNOWING! ! IF IT'S PRCPING AND THE AIR TEMP IS WARMER THAN 0 C, BUT THE GRND ! TEMP IS COLDER THAN 0 C, FREEZING RAIN IS PRESUMED TO BE FALLING. ! ---------------------------------------------------------------------- IF (PRCP > 0.0) THEN ! snow defined when fraction of frozen precip (FFROZP) > 0.5, ! passed in from model microphysics. IF (FFROZP .GT. 0.5) THEN SNOWNG = .TRUE. ELSE IF (T1 <= TFREEZ) FRZGRA = .TRUE. END IF END IF ! ---------------------------------------------------------------------- ! IF EITHER PRCP FLAG IS SET, DETERMINE NEW SNOWFALL (CONVERTING PRCP ! RATE FROM KG M-2 S-1 TO A LIQUID EQUIV SNOW DEPTH IN METERS) AND ADD ! IT TO THE EXISTING SNOWPACK. ! NOTE THAT SINCE ALL PRECIP IS ADDED TO SNOWPACK, NO PRECIP INFILTRATES ! INTO THE SOIL SO THAT PRCP1 IS SET TO ZERO. ! ---------------------------------------------------------------------- IF ( (SNOWNG) .OR. (FRZGRA) ) THEN SN_NEW = PRCP * DT * 0.001 SNEQV = SNEQV + SN_NEW PRCPF = 0.0 ! ---------------------------------------------------------------------- ! UPDATE SNOW DENSITY BASED ON NEW SNOWFALL, USING OLD AND NEW SNOW. ! UPDATE SNOW THERMAL CONDUCTIVITY ! ---------------------------------------------------------------------- CALL SNOW_NEW (SFCTMP,SN_NEW,SNOWH,SNDENS) CALL CSNOW (SNCOND,SNDENS) ! ---------------------------------------------------------------------- ! PRECIP IS LIQUID (RAIN), HENCE SAVE IN THE PRECIP VARIABLE THAT ! LATER CAN WHOLELY OR PARTIALLY INFILTRATE THE SOIL (ALONG WITH ! ANY CANOPY "DRIP" ADDED TO THIS LATER) ! ---------------------------------------------------------------------- ELSE PRCPF = PRCP END IF ! ---------------------------------------------------------------------- ! DETERMINE SNOWCOVER AND ALBEDO OVER LAND. ! ---------------------------------------------------------------------- ! ---------------------------------------------------------------------- ! IF SNOW DEPTH=0, SET SNOW FRACTION=0, ALBEDO=SNOW FREE ALBEDO. ! ---------------------------------------------------------------------- IF (ICE == 0) THEN IF (SNEQV == 0.0) THEN SNCOVR = 0.0 ALBEDO = ALB EMISSI = EMBRD ELSE ! ---------------------------------------------------------------------- ! DETERMINE SNOW FRACTIONAL COVERAGE. ! DETERMINE SURFACE ALBEDO MODIFICATION DUE TO SNOWDEPTH STATE. ! ---------------------------------------------------------------------- CALL SNFRAC (SNEQV,SNUP,SALP,SNOWH,SNCOVR) ! limit snow cover fraction to maximum of 0.98 SNCOVR = MIN(SNCOVR,0.98) CALL ALCALC (ALB,SNOALB,EMBRD,SHDFAC,SHDMIN,SNCOVR,TSNOW,ALBEDO,EMISSI) END IF ! ---------------------------------------------------------------------- ! SNOW COVER, ALBEDO OVER SEA-ICE ! ---------------------------------------------------------------------- ELSE SNCOVR = 1.0 ALBEDO = 0.65 EMISSI = EMISSI_S END IF ! ---------------------------------------------------------------------- ! THERMAL CONDUCTIVITY FOR SEA-ICE CASE ! ---------------------------------------------------------------------- IF (ICE == 1) THEN DF1 = 2.2 ELSE ! ---------------------------------------------------------------------- ! NEXT CALCULATE THE SUBSURFACE HEAT FLUX, WHICH FIRST REQUIRES ! CALCULATION OF THE THERMAL DIFFUSIVITY. TREATMENT OF THE ! LATTER FOLLOWS THAT ON PAGES 148-149 FROM "HEAT TRANSFER IN ! COLD CLIMATES", BY V. J. LUNARDINI (PUBLISHED IN 1981 ! BY VAN NOSTRAND REINHOLD CO.) I.E. TREATMENT OF TWO CONTIGUOUS ! "PLANE PARALLEL" MEDIUMS (NAMELY HERE THE FIRST SOIL LAYER ! AND THE SNOWPACK LAYER, IF ANY). THIS DIFFUSIVITY TREATMENT ! BEHAVES WELL FOR BOTH ZERO AND NONZERO SNOWPACK, INCLUDING THE ! LIMIT OF VERY THIN SNOWPACK. THIS TREATMENT ALSO ELIMINATES ! THE NEED TO IMPOSE AN ARBITRARY UPPER BOUND ON SUBSURFACE ! HEAT FLUX WHEN THE SNOWPACK BECOMES EXTREMELY THIN. ! ---------------------------------------------------------------------- ! FIRST CALCULATE THERMAL DIFFUSIVITY OF TOP SOIL LAYER, USING ! BOTH THE FROZEN AND LIQUID SOIL MOISTURE, FOLLOWING THE ! SOIL THERMAL DIFFUSIVITY FUNCTION OF PETERS-LIDARD ET AL. ! (1998,JAS, VOL 55, 1209-1224), WHICH REQUIRES THE SPECIFYING ! THE QUARTZ CONTENT OF THE GIVEN SOIL CLASS (SEE ROUTINE REDPRM) ! ---------------------------------------------------------------------- ! ---------------------------------------------------------------------- ! NEXT ADD SUBSURFACE HEAT FLUX REDUCTION EFFECT FROM THE ! OVERLYING GREEN CANOPY, ADAPTED FROM SECTION 2.1.2 OF ! PETERS-LIDARD ET AL. (1997, JGR, VOL 102(D4)) ! ---------------------------------------------------------------------- CALL TDFCND (DF1,SMC (1),QUARTZ,SMCMAX,SH2O (1)) !urban IF (VEGTYP==1) DF1=3.24 DF1 = DF1 * EXP (SBETA * SHDFAC) ! ---------------------------------------------------------------------- ! FINALLY "PLANE PARALLEL" SNOWPACK EFFECT FOLLOWING ! V.J. LINARDINI REFERENCE CITED ABOVE. NOTE THAT DTOT IS ! COMBINED DEPTH OF SNOWDEPTH AND THICKNESS OF FIRST SOIL LAYER ! ---------------------------------------------------------------------- END IF DSOIL = - (0.5 * ZSOIL (1)) IF (SNEQV == 0.) THEN SSOIL = DF1 * (T1- STC (1) ) / DSOIL ELSE DTOT = SNOWH + DSOIL FRCSNO = SNOWH / DTOT ! 1. HARMONIC MEAN (SERIES FLOW) ! DF1 = (SNCOND*DF1)/(FRCSOI*SNCOND+FRCSNO*DF1) FRCSOI = DSOIL / DTOT ! 2. ARITHMETIC MEAN (PARALLEL FLOW) ! DF1 = FRCSNO*SNCOND + FRCSOI*DF1 DF1H = (SNCOND * DF1)/ (FRCSOI * SNCOND+ FRCSNO * DF1) ! 3. GEOMETRIC MEAN (INTERMEDIATE BETWEEN HARMONIC AND ARITHMETIC MEAN) ! DF1 = (SNCOND**FRCSNO)*(DF1**FRCSOI) ! weigh DF by snow fraction ! DF1 = DF1H*SNCOVR + DF1A*(1.0-SNCOVR) ! DF1 = DF1H*SNCOVR + DF1*(1.0-SNCOVR) DF1A = FRCSNO * SNCOND+ FRCSOI * DF1 ! ---------------------------------------------------------------------- ! CALCULATE SUBSURFACE HEAT FLUX, SSOIL, FROM FINAL THERMAL DIFFUSIVITY ! OF SURFACE MEDIUMS, DF1 ABOVE, AND SKIN TEMPERATURE AND TOP ! MID-LAYER SOIL TEMPERATURE ! ---------------------------------------------------------------------- DF1 = DF1A * SNCOVR + DF1* (1.0- SNCOVR) SSOIL = DF1 * (T1- STC (1) ) / DTOT END IF ! ---------------------------------------------------------------------- ! DETERMINE SURFACE ROUGHNESS OVER SNOWPACK USING SNOW CONDITION FROM ! THE PREVIOUS TIMESTEP. ! ---------------------------------------------------------------------- IF (SNCOVR > 0. ) THEN CALL SNOWZ0 (SNCOVR,Z0,Z0BRD) ELSE Z0=Z0BRD END IF ! ---------------------------------------------------------------------- ! NEXT CALL ROUTINE SFCDIF TO CALCULATE THE SFC EXCHANGE COEF (CH) FOR ! HEAT AND MOISTURE. ! NOTE !!! ! DO NOT CALL SFCDIF UNTIL AFTER ABOVE CALL TO REDPRM, IN CASE ! ALTERNATIVE VALUES OF ROUGHNESS LENGTH (Z0) AND ZILINTINKEVICH COEF ! (CZIL) ARE SET THERE VIA NAMELIST I/O. ! NOTE !!! ! ROUTINE SFCDIF RETURNS A CH THAT REPRESENTS THE WIND SPD TIMES THE ! "ORIGINAL" NONDIMENSIONAL "Ch" TYPICAL IN LITERATURE. HENCE THE CH ! RETURNED FROM SFCDIF HAS UNITS OF M/S. THE IMPORTANT COMPANION ! COEFFICIENT OF CH, CARRIED HERE AS "RCH", IS THE CH FROM SFCDIF TIMES ! AIR DENSITY AND PARAMETER "CP". "RCH" IS COMPUTED IN "CALL PENMAN". ! RCH RATHER THAN CH IS THE COEFF USUALLY INVOKED LATER IN EQNS. ! NOTE !!! ! ---------------------------------------------------------------------- ! SFCDIF ALSO RETURNS THE SURFACE EXCHANGE COEFFICIENT FOR MOMENTUM, CM, ! ALSO KNOWN AS THE SURFACE DRAGE COEFFICIENT. Needed as a state variable ! for iterative/implicit solution of CH in SFCDIF ! ---------------------------------------------------------------------- ! IF(.NOT.LCH) THEN ! T1V = T1 * (1.0+ 0.61 * Q2) ! TH2V = TH2 * (1.0+ 0.61 * Q2) ! CALL SFCDIF_off (ZLVL,Z0,T1V,TH2V,SFCSPD,CZIL,CM,CH) ! ENDIF ! ---------------------------------------------------------------------- ! CALL PENMAN SUBROUTINE TO CALCULATE POTENTIAL EVAPORATION (ETP), AND ! OTHER PARTIAL PRODUCTS AND SUMS SAVE IN COMMON/RITE FOR LATER ! CALCULATIONS. ! ---------------------------------------------------------------------- ! ---------------------------------------------------------------------- ! CALCULATE TOTAL DOWNWARD RADIATION (SOLAR PLUS LONGWAVE) NEEDED IN ! PENMAN EP SUBROUTINE THAT FOLLOWS ! ---------------------------------------------------------------------- ! FDOWN = SOLDN * (1.0- ALBEDO) + LWDN FDOWN = SOLNET + LWDN ! ---------------------------------------------------------------------- ! CALC VIRTUAL TEMPS AND VIRTUAL POTENTIAL TEMPS NEEDED BY SUBROUTINES ! PENMAN. T2V = SFCTMP * (1.0+ 0.61 * Q2 ) iout=0 if(iout.eq.1) then print*,'before penman' print*,' SFCTMP',SFCTMP,'SFCPRS',SFCPRS,'CH',CH,'T2V',T2V, & 'TH2',TH2,'PRCP',PRCP,'FDOWN',FDOWN,'T24',T24,'SSOIL',SSOIL, & 'Q2',Q2,'Q2SAT',Q2SAT,'ETP',ETP,'RCH',RCH, & 'EPSCA',EPSCA,'RR',RR ,'SNOWNG',SNOWNG,'FRZGRA',FRZGRA, & 'DQSDT2',DQSDT2,'FLX2',FLX2,'SNOWH',SNOWH,'SNEQV',SNEQV, & ' DSOIL',DSOIL,' FRCSNO',FRCSNO,' SNCOVR',SNCOVR,' DTOT',DTOT, & ' ZSOIL (1)',ZSOIL(1),' DF1',DF1,'T1',T1,' STC1',STC(1), & 'ALBEDO',ALBEDO,'SMC',SMC,'STC',STC,'SH2O',SH2O endif CALL PENMAN (SFCTMP,SFCPRS,CH,T2V,TH2,PRCP,FDOWN,T24,SSOIL, & Q2,Q2SAT,ETP,RCH,EPSCA,RR,SNOWNG,FRZGRA, & DQSDT2,FLX2,EMISSI,SNEQV) ! ---------------------------------------------------------------------- ! CALL CANRES TO CALCULATE THE CANOPY RESISTANCE AND CONVERT IT INTO PC ! IF NONZERO GREENNESS FRACTION ! ---------------------------------------------------------------------- ! ---------------------------------------------------------------------- ! FROZEN GROUND EXTENSION: TOTAL SOIL WATER "SMC" WAS REPLACED ! BY UNFROZEN SOIL WATER "SH2O" IN CALL TO CANRES BELOW ! ---------------------------------------------------------------------- IF (SHDFAC > 0.) THEN CALL CANRES (SOLDN,CH,SFCTMP,Q2,SFCPRS,SH2O,ZSOIL,NSOIL, & SMCWLT,SMCREF,RSMIN,RC,PC,NROOT,Q2SAT,DQSDT2, & TOPT,RSMAX,RGL,HS,XLAI, & RCS,RCT,RCQ,RCSOIL,EMISSI) END IF ! ---------------------------------------------------------------------- ! NOW DECIDE MAJOR PATHWAY BRANCH TO TAKE DEPENDING ON WHETHER SNOWPACK ! EXISTS OR NOT: ! ---------------------------------------------------------------------- ESNOW = 0.0 IF (SNEQV == 0.0) THEN CALL NOPAC (ETP,ETA,PRCP,SMC,SMCMAX,SMCWLT, & SMCREF,SMCDRY,CMC,CMCMAX,NSOIL,DT, & SHDFAC, & SBETA,Q2,T1,SFCTMP,T24,TH2,FDOWN,F1,EMISSI, & SSOIL, & STC,EPSCA,BEXP,PC,RCH,RR,CFACTR, & SH2O,SLOPE,KDT,FRZX,PSISAT,ZSOIL, & DKSAT,DWSAT,TBOT,ZBOT,RUNOFF1,RUNOFF2, & RUNOFF3,EDIR,EC,ET,ETT,NROOT,ICE,RTDIS, & QUARTZ,FXEXP,CSOIL, & BETA,DRIP,DEW,FLX1,FLX3,VEGTYP) ETA_KINEMATIC = ETA ELSE CALL SNOPAC (ETP,ETA,PRCP,PRCPF,SNOWNG,SMC,SMCMAX,SMCWLT, & SMCREF,SMCDRY,CMC,CMCMAX,NSOIL,DT, & SBETA,DF1, & Q2,T1,SFCTMP,T24,TH2,FDOWN,F1,SSOIL,STC,EPSCA, & SFCPRS,BEXP,PC,RCH,RR,CFACTR,SNCOVR,SNEQV,SNDENS,& SNOWH,SH2O,SLOPE,KDT,FRZX,PSISAT, & ZSOIL,DWSAT,DKSAT,TBOT,ZBOT,SHDFAC,RUNOFF1, & RUNOFF2,RUNOFF3,EDIR,EC,ET,ETT,NROOT,SNOMLT, & ICE,RTDIS,QUARTZ,FXEXP,CSOIL, & BETA,DRIP,DEW,FLX1,FLX2,FLX3,ESNOW,ETNS,EMISSI, & VEGTYP) ETA_KINEMATIC = ESNOW + ETNS END IF ! Calculate effective mixing ratio at grnd level (skin) ! ! Q1=Q2+ETA*CP/RCH Q1=Q2+ETA_KINEMATIC*CP/RCH ! ! ---------------------------------------------------------------------- ! DETERMINE SENSIBLE HEAT (H) IN ENERGY UNITS (W M-2) ! ---------------------------------------------------------------------- SHEAT = - (CH * CP * SFCPRS)/ (R * T2V) * ( TH2- T1 ) ! ---------------------------------------------------------------------- ! CONVERT EVAP TERMS FROM KINEMATIC (KG M-2 S-1) TO ENERGY UNITS (W M-2) ! ---------------------------------------------------------------------- EDIR = EDIR * LVH2O EC = EC * LVH2O DO K=1,4 ET(K) = ET(K) * LVH2O ENDDO ETT = ETT * LVH2O ESNOW = ESNOW * LSUBS ETP = ETP*((1.-SNCOVR)*LVH2O + SNCOVR*LSUBS) IF (ETP .GT. 0.) THEN ETA = EDIR + EC + ETT + ESNOW ELSE ETA = ETP ENDIF ! ---------------------------------------------------------------------- ! DETERMINE BETA (RATIO OF ACTUAL TO POTENTIAL EVAP) ! ---------------------------------------------------------------------- IF (ETP == 0.0) THEN BETA = 0.0 ELSE BETA = ETA/ETP ENDIF ! ---------------------------------------------------------------------- ! CONVERT THE SIGN OF SOIL HEAT FLUX SO THAT: ! SSOIL>0: WARM THE SURFACE (NIGHT TIME) ! SSOIL<0: COOL THE SURFACE (DAY TIME) ! ---------------------------------------------------------------------- SSOIL = -1.0* SSOIL ! ---------------------------------------------------------------------- ! CONVERT RUNOFF3 (INTERNAL LAYER RUNOFF FROM SUPERSAT) FROM M TO M S-1 ! AND ADD TO SUBSURFACE RUNOFF/DRAINAGE/BASEFLOW ! ---------------------------------------------------------------------- RUNOFF3 = RUNOFF3/ DT RUNOFF2 = RUNOFF2+ RUNOFF3 ! ---------------------------------------------------------------------- ! TOTAL COLUMN SOIL MOISTURE IN METERS (SOILM) AND ROOT-ZONE ! SOIL MOISTURE AVAILABILITY (FRACTION) RELATIVE TO POROSITY/SATURATION ! ---------------------------------------------------------------------- IF (ICE == 0) THEN SOILM = -1.0* SMC (1)* ZSOIL (1) DO K = 2,NSOIL SOILM = SOILM + SMC (K)* (ZSOIL (K -1) - ZSOIL (K)) END DO SOILWM = -1.0* (SMCMAX - SMCWLT)* ZSOIL (1) SOILWW = -1.0* (SMC (1) - SMCWLT)* ZSOIL (1) IF (NROOT >= 2) THEN DO K = 2,NROOT SOILWM = SOILWM + (SMCMAX - SMCWLT)* (ZSOIL (K -1) - ZSOIL (K)) SOILWW = SOILWW + (SMC(K) - SMCWLT)* (ZSOIL (K -1) - ZSOIL (K)) END DO END IF IF (SOILWM .LT. 1.E-6) THEN SOILWM = 0.0 SOILW = 0.0 SOILM = 0.0 ELSE SOILW = SOILWW / SOILWM END IF ELSE SOILWM = 0.0 SOILW = 0.0 SOILM = 0.0 END IF ! ---------------------------------------------------------------------- END SUBROUTINE SFLX ! ---------------------------------------------------------------------- SUBROUTINE ALCALC (ALB,SNOALB,EMBRD,SHDFAC,SHDMIN,SNCOVR,TSNOW,ALBEDO,EMISSI) ! ---------------------------------------------------------------------- ! CALCULATE ALBEDO INCLUDING SNOW EFFECT (0 -> 1) ! ALB SNOWFREE ALBEDO ! SNOALB MAXIMUM (DEEP) SNOW ALBEDO ! SHDFAC AREAL FRACTIONAL COVERAGE OF GREEN VEGETATION ! SHDMIN MINIMUM AREAL FRACTIONAL COVERAGE OF GREEN VEGETATION ! SNCOVR FRACTIONAL SNOW COVER ! ALBEDO SURFACE ALBEDO INCLUDING SNOW EFFECT ! TSNOW SNOW SURFACE TEMPERATURE (K) ! ---------------------------------------------------------------------- IMPLICIT NONE ! ---------------------------------------------------------------------- ! SNOALB IS ARGUMENT REPRESENTING MAXIMUM ALBEDO OVER DEEP SNOW, ! AS PASSED INTO SFLX, AND ADAPTED FROM THE SATELLITE-BASED MAXIMUM ! SNOW ALBEDO FIELDS PROVIDED BY D. ROBINSON AND G. KUKLA ! (1985, JCAM, VOL 24, 402-411) ! ---------------------------------------------------------------------- REAL, INTENT(IN) :: ALB, SNOALB, EMBRD, SHDFAC, SHDMIN, SNCOVR, TSNOW REAL, INTENT(OUT) :: ALBEDO, EMISSI ! turn of vegetation effect ! ALBEDO = ALB + (1.0- (SHDFAC - SHDMIN))* SNCOVR * (SNOALB - ALB) ! ALBEDO = (1.0-SNCOVR)*ALB + SNCOVR*SNOALB !this is equivalent to below ALBEDO = ALB + SNCOVR*(SNOALB-ALB) EMISSI = EMBRD + SNCOVR*(EMISSI_S - EMBRD) ! BASE FORMULATION (DICKINSON ET AL., 1986, COGLEY ET AL., 1990) ! IF (TSNOW.LE.263.16) THEN ! ALBEDO=SNOALB ! ELSE ! IF (TSNOW.LT.273.16) THEN ! TM=0.1*(TSNOW-263.16) ! ALBEDO=0.5*((0.9-0.2*(TM**3))+(0.8-0.16*(TM**3))) ! ELSE ! ALBEDO=0.67 ! ENDIF ! ENDIF ! ISBA FORMULATION (VERSEGHY, 1991; BAKER ET AL., 1990) ! IF (TSNOW.LT.273.16) THEN ! ALBEDO=SNOALB-0.008*DT/86400 ! ELSE ! ALBEDO=(SNOALB-0.5)*EXP(-0.24*DT/86400)+0.5 ! ENDIF IF (ALBEDO > SNOALB) ALBEDO = SNOALB ! ---------------------------------------------------------------------- END SUBROUTINE ALCALC ! ---------------------------------------------------------------------- SUBROUTINE CANRES (SOLAR,CH,SFCTMP,Q2,SFCPRS,SMC,ZSOIL,NSOIL, & SMCWLT,SMCREF,RSMIN,RC,PC,NROOT,Q2SAT,DQSDT2, & TOPT,RSMAX,RGL,HS,XLAI, & RCS,RCT,RCQ,RCSOIL,EMISSI) ! ---------------------------------------------------------------------- ! SUBROUTINE CANRES ! ---------------------------------------------------------------------- ! CALCULATE CANOPY RESISTANCE WHICH DEPENDS ON INCOMING SOLAR RADIATION, ! AIR TEMPERATURE, ATMOSPHERIC WATER VAPOR PRESSURE DEFICIT AT THE ! LOWEST MODEL LEVEL, AND SOIL MOISTURE (PREFERABLY UNFROZEN SOIL ! MOISTURE RATHER THAN TOTAL) ! ---------------------------------------------------------------------- ! SOURCE: JARVIS (1976), NOILHAN AND PLANTON (1989, MWR), JACQUEMIN AND ! NOILHAN (1990, BLM) ! SEE ALSO: CHEN ET AL (1996, JGR, VOL 101(D3), 7251-7268), EQNS 12-14 ! AND TABLE 2 OF SEC. 3.1.2 ! ---------------------------------------------------------------------- ! INPUT: ! SOLAR INCOMING SOLAR RADIATION ! CH SURFACE EXCHANGE COEFFICIENT FOR HEAT AND MOISTURE ! SFCTMP AIR TEMPERATURE AT 1ST LEVEL ABOVE GROUND ! Q2 AIR HUMIDITY AT 1ST LEVEL ABOVE GROUND ! Q2SAT SATURATION AIR HUMIDITY AT 1ST LEVEL ABOVE GROUND ! DQSDT2 SLOPE OF SATURATION HUMIDITY FUNCTION WRT TEMP ! SFCPRS SURFACE PRESSURE ! SMC VOLUMETRIC SOIL MOISTURE ! ZSOIL SOIL DEPTH (NEGATIVE SIGN, AS IT IS BELOW GROUND) ! NSOIL NO. OF SOIL LAYERS ! NROOT NO. OF SOIL LAYERS IN ROOT ZONE (1.LE.NROOT.LE.NSOIL) ! XLAI LEAF AREA INDEX ! SMCWLT WILTING POINT ! SMCREF REFERENCE SOIL MOISTURE (WHERE SOIL WATER DEFICIT STRESS ! SETS IN) ! RSMIN, RSMAX, TOPT, RGL, HS ARE CANOPY STRESS PARAMETERS SET IN ! SURBOUTINE REDPRM ! OUTPUT: ! PC PLANT COEFFICIENT ! RC CANOPY RESISTANCE ! ---------------------------------------------------------------------- IMPLICIT NONE INTEGER, INTENT(IN) :: NROOT,NSOIL INTEGER K REAL, INTENT(IN) :: CH,DQSDT2,HS,Q2,Q2SAT,RSMIN,RGL,RSMAX, & SFCPRS,SFCTMP,SMCREF,SMCWLT, SOLAR,TOPT,XLAI, & EMISSI REAL,DIMENSION(1:NSOIL), INTENT(IN) :: SMC,ZSOIL REAL, INTENT(OUT):: PC,RC,RCQ,RCS,RCSOIL,RCT REAL :: DELTA,FF,GX,P,RR REAL, DIMENSION(1:NSOIL) :: PART REAL, PARAMETER :: SLV = 2.501000E6 ! ---------------------------------------------------------------------- ! INITIALIZE CANOPY RESISTANCE MULTIPLIER TERMS. ! ---------------------------------------------------------------------- RCS = 0.0 RCT = 0.0 RCQ = 0.0 RCSOIL = 0.0 ! ---------------------------------------------------------------------- ! CONTRIBUTION DUE TO INCOMING SOLAR RADIATION ! ---------------------------------------------------------------------- RC = 0.0 FF = 0.55*2.0* SOLAR / (RGL * XLAI) RCS = (FF + RSMIN / RSMAX) / (1.0+ FF) ! ---------------------------------------------------------------------- ! CONTRIBUTION DUE TO AIR TEMPERATURE AT FIRST MODEL LEVEL ABOVE GROUND ! RCT EXPRESSION FROM NOILHAN AND PLANTON (1989, MWR). ! ---------------------------------------------------------------------- RCS = MAX (RCS,0.0001) RCT = 1.0- 0.0016* ( (TOPT - SFCTMP)**2.0) ! ---------------------------------------------------------------------- ! CONTRIBUTION DUE TO VAPOR PRESSURE DEFICIT AT FIRST MODEL LEVEL. ! RCQ EXPRESSION FROM SSIB ! ---------------------------------------------------------------------- RCT = MAX (RCT,0.0001) RCQ = 1.0/ (1.0+ HS * (Q2SAT - Q2)) ! ---------------------------------------------------------------------- ! CONTRIBUTION DUE TO SOIL MOISTURE AVAILABILITY. ! DETERMINE CONTRIBUTION FROM EACH SOIL LAYER, THEN ADD THEM UP. ! ---------------------------------------------------------------------- RCQ = MAX (RCQ,0.01) GX = (SMC (1) - SMCWLT) / (SMCREF - SMCWLT) IF (GX > 1.) GX = 1. IF (GX < 0.) GX = 0. ! ---------------------------------------------------------------------- ! USE SOIL DEPTH AS WEIGHTING FACTOR ! ---------------------------------------------------------------------- ! ---------------------------------------------------------------------- ! USE ROOT DISTRIBUTION AS WEIGHTING FACTOR ! PART(1) = RTDIS(1) * GX ! ---------------------------------------------------------------------- PART (1) = (ZSOIL (1)/ ZSOIL (NROOT)) * GX DO K = 2,NROOT GX = (SMC (K) - SMCWLT) / (SMCREF - SMCWLT) IF (GX > 1.) GX = 1. IF (GX < 0.) GX = 0. ! ---------------------------------------------------------------------- ! USE SOIL DEPTH AS WEIGHTING FACTOR ! ---------------------------------------------------------------------- ! ---------------------------------------------------------------------- ! USE ROOT DISTRIBUTION AS WEIGHTING FACTOR ! PART(K) = RTDIS(K) * GX ! ---------------------------------------------------------------------- PART (K) = ( (ZSOIL (K) - ZSOIL (K -1))/ ZSOIL (NROOT)) * GX END DO DO K = 1,NROOT RCSOIL = RCSOIL + PART (K) END DO ! ---------------------------------------------------------------------- ! DETERMINE CANOPY RESISTANCE DUE TO ALL FACTORS. CONVERT CANOPY ! RESISTANCE (RC) TO PLANT COEFFICIENT (PC) TO BE USED WITH POTENTIAL ! EVAP IN DETERMINING ACTUAL EVAP. PC IS DETERMINED BY: ! PC * LINERIZED PENMAN POTENTIAL EVAP = ! PENMAN-MONTEITH ACTUAL EVAPORATION (CONTAINING RC TERM). ! ---------------------------------------------------------------------- RCSOIL = MAX (RCSOIL,0.0001) RC = RSMIN / (XLAI * RCS * RCT * RCQ * RCSOIL) ! RR = (4.* SIGMA * RD / CP)* (SFCTMP **4.)/ (SFCPRS * CH) + 1.0 RR = (4.* EMISSI *SIGMA * RD / CP)* (SFCTMP **4.)/ (SFCPRS * CH) & + 1.0 DELTA = (SLV / CP)* DQSDT2 PC = (RR + DELTA)/ (RR * (1. + RC * CH) + DELTA) ! ---------------------------------------------------------------------- END SUBROUTINE CANRES ! ---------------------------------------------------------------------- SUBROUTINE CSNOW (SNCOND,DSNOW) ! ---------------------------------------------------------------------- ! SUBROUTINE CSNOW ! FUNCTION CSNOW ! ---------------------------------------------------------------------- ! CALCULATE SNOW TERMAL CONDUCTIVITY ! ---------------------------------------------------------------------- IMPLICIT NONE REAL, INTENT(IN) :: DSNOW REAL, INTENT(OUT):: SNCOND REAL :: C REAL, PARAMETER :: UNIT = 0.11631 ! ---------------------------------------------------------------------- ! SNCOND IN UNITS OF CAL/(CM*HR*C), RETURNED IN W/(M*C) ! CSNOW IN UNITS OF CAL/(CM*HR*C), RETURNED IN W/(M*C) ! BASIC VERSION IS DYACHKOVA EQUATION (1960), FOR RANGE 0.1-0.4 ! ---------------------------------------------------------------------- C = 0.328*10** (2.25* DSNOW) ! CSNOW=UNIT*C ! ---------------------------------------------------------------------- ! DE VAUX EQUATION (1933), IN RANGE 0.1-0.6 ! ---------------------------------------------------------------------- ! SNCOND=0.0293*(1.+100.*DSNOW**2) ! CSNOW=0.0293*(1.+100.*DSNOW**2) ! ---------------------------------------------------------------------- ! E. ANDERSEN FROM FLERCHINGER ! ---------------------------------------------------------------------- ! SNCOND=0.021+2.51*DSNOW**2 ! CSNOW=0.021+2.51*DSNOW**2 ! SNCOND = UNIT * C ! double snow thermal conductivity SNCOND = 2.0 * UNIT * C ! ---------------------------------------------------------------------- END SUBROUTINE CSNOW ! ---------------------------------------------------------------------- SUBROUTINE DEVAP (EDIR,ETP1,SMC,ZSOIL,SHDFAC,SMCMAX,BEXP, & DKSAT,DWSAT,SMCDRY,SMCREF,SMCWLT,FXEXP) ! ---------------------------------------------------------------------- ! SUBROUTINE DEVAP ! FUNCTION DEVAP ! ---------------------------------------------------------------------- ! CALCULATE DIRECT SOIL EVAPORATION ! ---------------------------------------------------------------------- IMPLICIT NONE REAL, INTENT(IN) :: ETP1,SMC,BEXP,DKSAT,DWSAT,FXEXP, & SHDFAC,SMCDRY,SMCMAX,ZSOIL,SMCREF,SMCWLT REAL, INTENT(OUT):: EDIR REAL :: FX, SRATIO ! ---------------------------------------------------------------------- ! DIRECT EVAP A FUNCTION OF RELATIVE SOIL MOISTURE AVAILABILITY, LINEAR ! WHEN FXEXP=1. ! ---------------------------------------------------------------------- ! ---------------------------------------------------------------------- ! FX > 1 REPRESENTS DEMAND CONTROL ! FX < 1 REPRESENTS FLUX CONTROL ! ---------------------------------------------------------------------- SRATIO = (SMC - SMCDRY) / (SMCMAX - SMCDRY) IF (SRATIO > 0.) THEN FX = SRATIO**FXEXP FX = MAX ( MIN ( FX, 1. ) ,0. ) ELSE FX = 0. ENDIF ! ---------------------------------------------------------------------- ! ALLOW FOR THE DIRECT-EVAP-REDUCING EFFECT OF SHADE ! ---------------------------------------------------------------------- EDIR = FX * ( 1.0- SHDFAC ) * ETP1 ! ---------------------------------------------------------------------- END SUBROUTINE DEVAP ! ---------------------------------------------------------------------- SUBROUTINE EVAPO (ETA1,SMC,NSOIL,CMC,ETP1,DT,ZSOIL, & SH2O, & SMCMAX,BEXP,PC,SMCWLT,DKSAT,DWSAT, & SMCREF,SHDFAC,CMCMAX, & SMCDRY,CFACTR, & EDIR,EC,ET,ETT,SFCTMP,Q2,NROOT,RTDIS,FXEXP) ! ---------------------------------------------------------------------- ! SUBROUTINE EVAPO ! ---------------------------------------------------------------------- ! CALCULATE SOIL MOISTURE FLUX. THE SOIL MOISTURE CONTENT (SMC - A PER ! UNIT VOLUME MEASUREMENT) IS A DEPENDENT VARIABLE THAT IS UPDATED WITH ! PROGNOSTIC EQNS. THE CANOPY MOISTURE CONTENT (CMC) IS ALSO UPDATED. ! FROZEN GROUND VERSION: NEW STATES ADDED: SH2O, AND FROZEN GROUND ! CORRECTION FACTOR, FRZFACT AND PARAMETER SLOPE. ! ---------------------------------------------------------------------- IMPLICIT NONE INTEGER, INTENT(IN) :: NSOIL, NROOT INTEGER :: I,K REAL, INTENT(IN) :: BEXP, CFACTR,CMC,CMCMAX,DKSAT, & DT,DWSAT,ETP1,FXEXP,PC,Q2,SFCTMP, & SHDFAC,SMCDRY,SMCMAX,SMCREF,SMCWLT REAL, INTENT(OUT) :: EC,EDIR,ETA1,ETT REAL :: CMC2MS REAL,DIMENSION(1:NSOIL), INTENT(IN) :: RTDIS, SMC, SH2O, ZSOIL REAL,DIMENSION(1:NSOIL), INTENT(OUT) :: ET ! ---------------------------------------------------------------------- ! EXECUTABLE CODE BEGINS HERE IF THE POTENTIAL EVAPOTRANSPIRATION IS ! GREATER THAN ZERO. ! ---------------------------------------------------------------------- EDIR = 0. EC = 0. ETT = 0. DO K = 1,NSOIL ET (K) = 0. END DO ! ---------------------------------------------------------------------- ! RETRIEVE DIRECT EVAPORATION FROM SOIL SURFACE. CALL THIS FUNCTION ! ONLY IF VEG COVER NOT COMPLETE. ! FROZEN GROUND VERSION: SH2O STATES REPLACE SMC STATES. ! ---------------------------------------------------------------------- IF (ETP1 > 0.0) THEN IF (SHDFAC < 1.) THEN CALL DEVAP (EDIR,ETP1,SMC (1),ZSOIL (1),SHDFAC,SMCMAX, & BEXP,DKSAT,DWSAT,SMCDRY,SMCREF,SMCWLT,FXEXP) END IF ! ---------------------------------------------------------------------- ! INITIALIZE PLANT TOTAL TRANSPIRATION, RETRIEVE PLANT TRANSPIRATION, ! AND ACCUMULATE IT FOR ALL SOIL LAYERS. ! ---------------------------------------------------------------------- IF (SHDFAC > 0.0) THEN CALL TRANSP (ET,NSOIL,ETP1,SH2O,CMC,ZSOIL,SHDFAC,SMCWLT, & CMCMAX,PC,CFACTR,SMCREF,SFCTMP,Q2,NROOT,RTDIS) DO K = 1,NSOIL ETT = ETT + ET ( K ) END DO ! ---------------------------------------------------------------------- ! CALCULATE CANOPY EVAPORATION. ! IF STATEMENTS TO AVOID TANGENT LINEAR PROBLEMS NEAR CMC=0.0. ! ---------------------------------------------------------------------- IF (CMC > 0.0) THEN EC = SHDFAC * ( ( CMC / CMCMAX ) ** CFACTR ) * ETP1 ELSE EC = 0.0 END IF ! ---------------------------------------------------------------------- ! EC SHOULD BE LIMITED BY THE TOTAL AMOUNT OF AVAILABLE WATER ON THE ! CANOPY. -F.CHEN, 18-OCT-1994 ! ---------------------------------------------------------------------- CMC2MS = CMC / DT EC = MIN ( CMC2MS, EC ) END IF END IF ! ---------------------------------------------------------------------- ! TOTAL UP EVAP AND TRANSP TYPES TO OBTAIN ACTUAL EVAPOTRANSP ! ---------------------------------------------------------------------- ETA1 = EDIR + ETT + EC ! ---------------------------------------------------------------------- END SUBROUTINE EVAPO ! ---------------------------------------------------------------------- SUBROUTINE FRH2O (FREE,TKELV,SMC,SH2O,SMCMAX,BEXP,PSIS) ! ---------------------------------------------------------------------- ! SUBROUTINE FRH2O ! ---------------------------------------------------------------------- ! CALCULATE AMOUNT OF SUPERCOOLED LIQUID SOIL WATER CONTENT IF ! TEMPERATURE IS BELOW 273.15K (T0). REQUIRES NEWTON-TYPE ITERATION TO ! SOLVE THE NONLINEAR IMPLICIT EQUATION GIVEN IN EQN 17 OF KOREN ET AL ! (1999, JGR, VOL 104(D16), 19569-19585). ! ---------------------------------------------------------------------- ! NEW VERSION (JUNE 2001): MUCH FASTER AND MORE ACCURATE NEWTON ! ITERATION ACHIEVED BY FIRST TAKING LOG OF EQN CITED ABOVE -- LESS THAN ! 4 (TYPICALLY 1 OR 2) ITERATIONS ACHIEVES CONVERGENCE. ALSO, EXPLICIT ! 1-STEP SOLUTION OPTION FOR SPECIAL CASE OF PARAMETER CK=0, WHICH ! REDUCES THE ORIGINAL IMPLICIT EQUATION TO A SIMPLER EXPLICIT FORM, ! KNOWN AS THE "FLERCHINGER EQN". IMPROVED HANDLING OF SOLUTION IN THE ! LIMIT OF FREEZING POINT TEMPERATURE T0. ! ---------------------------------------------------------------------- ! INPUT: ! TKELV.........TEMPERATURE (Kelvin) ! SMC...........TOTAL SOIL MOISTURE CONTENT (VOLUMETRIC) ! SH2O..........LIQUID SOIL MOISTURE CONTENT (VOLUMETRIC) ! SMCMAX........SATURATION SOIL MOISTURE CONTENT (FROM REDPRM) ! B.............SOIL TYPE "B" PARAMETER (FROM REDPRM) ! PSIS..........SATURATED SOIL MATRIC POTENTIAL (FROM REDPRM) ! OUTPUT: ! FRH2O.........SUPERCOOLED LIQUID WATER CONTENT ! FREE..........SUPERCOOLED LIQUID WATER CONTENT ! ---------------------------------------------------------------------- IMPLICIT NONE REAL, INTENT(IN) :: BEXP,PSIS,SH2O,SMC,SMCMAX,TKELV REAL, INTENT(OUT) :: FREE REAL :: BX,DENOM,DF,DSWL,FK,SWL,SWLK INTEGER :: NLOG,KCOUNT ! PARAMETER(CK = 0.0) REAL, PARAMETER :: CK = 8.0, BLIM = 5.5, ERROR = 0.005, & HLICE = 3.335E5, GS = 9.81,DICE = 920.0, & DH2O = 1000.0, T0 = 273.15 ! ---------------------------------------------------------------------- ! LIMITS ON PARAMETER B: B < 5.5 (use parameter BLIM) ! SIMULATIONS SHOWED IF B > 5.5 UNFROZEN WATER CONTENT IS ! NON-REALISTICALLY HIGH AT VERY LOW TEMPERATURES. ! ---------------------------------------------------------------------- BX = BEXP ! ---------------------------------------------------------------------- ! INITIALIZING ITERATIONS COUNTER AND ITERATIVE SOLUTION FLAG. ! ---------------------------------------------------------------------- IF (BEXP > BLIM) BX = BLIM NLOG = 0 ! ---------------------------------------------------------------------- ! IF TEMPERATURE NOT SIGNIFICANTLY BELOW FREEZING (T0), SH2O = SMC ! ---------------------------------------------------------------------- KCOUNT = 0 ! FRH2O = SMC IF (TKELV > (T0- 1.E-3)) THEN FREE = SMC ELSE ! ---------------------------------------------------------------------- ! OPTION 1: ITERATED SOLUTION FOR NONZERO CK ! IN KOREN ET AL, JGR, 1999, EQN 17 ! ---------------------------------------------------------------------- ! INITIAL GUESS FOR SWL (frozen content) ! ---------------------------------------------------------------------- IF (CK /= 0.0) THEN SWL = SMC - SH2O ! ---------------------------------------------------------------------- ! KEEP WITHIN BOUNDS. ! ---------------------------------------------------------------------- IF (SWL > (SMC -0.02)) SWL = SMC -0.02 ! ---------------------------------------------------------------------- ! START OF ITERATIONS ! ---------------------------------------------------------------------- IF (SWL < 0.) SWL = 0. 1001 Continue IF (.NOT.( (NLOG < 10) .AND. (KCOUNT == 0))) goto 1002 NLOG = NLOG +1 DF = ALOG ( ( PSIS * GS / HLICE ) * ( ( 1. + CK * SWL )**2.) * & ( SMCMAX / (SMC - SWL) )** BX) - ALOG ( - ( & TKELV - T0)/ TKELV) DENOM = 2. * CK / ( 1. + CK * SWL ) + BX / ( SMC - SWL ) SWLK = SWL - DF / DENOM ! ---------------------------------------------------------------------- ! BOUNDS USEFUL FOR MATHEMATICAL SOLUTION. ! ---------------------------------------------------------------------- IF (SWLK > (SMC -0.02)) SWLK = SMC - 0.02 IF (SWLK < 0.) SWLK = 0. ! ---------------------------------------------------------------------- ! MATHEMATICAL SOLUTION BOUNDS APPLIED. ! ---------------------------------------------------------------------- DSWL = ABS (SWLK - SWL) ! ---------------------------------------------------------------------- ! IF MORE THAN 10 ITERATIONS, USE EXPLICIT METHOD (CK=0 APPROX.) ! WHEN DSWL LESS OR EQ. ERROR, NO MORE ITERATIONS REQUIRED. ! ---------------------------------------------------------------------- SWL = SWLK IF ( DSWL <= ERROR ) THEN KCOUNT = KCOUNT +1 END IF ! ---------------------------------------------------------------------- ! END OF ITERATIONS ! ---------------------------------------------------------------------- ! BOUNDS APPLIED WITHIN DO-BLOCK ARE VALID FOR PHYSICAL SOLUTION. ! ---------------------------------------------------------------------- ! FRH2O = SMC - SWL goto 1001 1002 continue FREE = SMC - SWL END IF ! ---------------------------------------------------------------------- ! END OPTION 1 ! ---------------------------------------------------------------------- ! ---------------------------------------------------------------------- ! OPTION 2: EXPLICIT SOLUTION FOR FLERCHINGER EQ. i.e. CK=0 ! IN KOREN ET AL., JGR, 1999, EQN 17 ! APPLY PHYSICAL BOUNDS TO FLERCHINGER SOLUTION ! ---------------------------------------------------------------------- IF (KCOUNT == 0) THEN PRINT *,'Flerchinger USEd in NEW version. Iterations=',NLOG FK = ( ( (HLICE / (GS * ( - PSIS)))* & ( (TKELV - T0)/ TKELV))** ( -1/ BX))* SMCMAX ! FRH2O = MIN (FK, SMC) IF (FK < 0.02) FK = 0.02 FREE = MIN (FK, SMC) ! ---------------------------------------------------------------------- ! END OPTION 2 ! ---------------------------------------------------------------------- END IF END IF ! ---------------------------------------------------------------------- END SUBROUTINE FRH2O ! ---------------------------------------------------------------------- SUBROUTINE HRT (RHSTS,STC,SMC,SMCMAX,NSOIL,ZSOIL,YY,ZZ1, & TBOT,ZBOT,PSISAT,SH2O,DT,BEXP, & F1,DF1,QUARTZ,CSOIL,AI,BI,CI,VEGTYP) ! ---------------------------------------------------------------------- ! SUBROUTINE HRT ! ---------------------------------------------------------------------- ! CALCULATE THE RIGHT HAND SIDE OF THE TIME TENDENCY TERM OF THE SOIL ! THERMAL DIFFUSION EQUATION. ALSO TO COMPUTE ( PREPARE ) THE MATRIX ! COEFFICIENTS FOR THE TRI-DIAGONAL MATRIX OF THE IMPLICIT TIME SCHEME. ! ---------------------------------------------------------------------- IMPLICIT NONE LOGICAL :: ITAVG INTEGER, INTENT(IN) :: NSOIL, VEGTYP INTEGER :: I, K REAL, INTENT(IN) :: BEXP, CSOIL, DF1, DT,F1,PSISAT,QUARTZ, & SMCMAX ,TBOT,YY,ZZ1, ZBOT REAL, DIMENSION(1:NSOIL), INTENT(IN) :: SMC,STC,ZSOIL REAL, DIMENSION(1:NSOIL), INTENT(INOUT):: SH2O REAL, DIMENSION(1:NSOIL), INTENT(OUT) :: RHSTS REAL, DIMENSION(1:NSOIL), INTENT(OUT) :: AI, BI,CI REAL :: DDZ, DDZ2, DENOM, DF1N, DF1K, DTSDZ, & DTSDZ2,HCPCT,QTOT,SSOIL,SICE,TAVG,TBK, & TBK1,TSNSR,TSURF,CSOIL_LOC REAL, PARAMETER :: T0 = 273.15, CAIR = 1004.0, CICE = 2.106E6,& CH2O = 4.2E6 !urban IF(VEGTYP==1) then CSOIL_LOC=3.0E6 ELSE CSOIL_LOC=CSOIL ENDIF ! ---------------------------------------------------------------------- ! INITIALIZE LOGICAL FOR SOIL LAYER TEMPERATURE AVERAGING. ! ---------------------------------------------------------------------- ITAVG = .TRUE. ! ---------------------------------------------------------------------- ! BEGIN SECTION FOR TOP SOIL LAYER ! ---------------------------------------------------------------------- ! CALC THE HEAT CAPACITY OF THE TOP SOIL LAYER ! ---------------------------------------------------------------------- HCPCT = SH2O (1)* CH2O + (1.0- SMCMAX)* CSOIL_LOC + (SMCMAX - SMC (1))& * CAIR & + ( SMC (1) - SH2O (1) )* CICE ! ---------------------------------------------------------------------- ! CALC THE MATRIX COEFFICIENTS AI, BI, AND CI FOR THE TOP LAYER ! ---------------------------------------------------------------------- DDZ = 1.0 / ( -0.5 * ZSOIL (2) ) AI (1) = 0.0 CI (1) = (DF1 * DDZ) / (ZSOIL (1) * HCPCT) ! ---------------------------------------------------------------------- ! CALCULATE THE VERTICAL SOIL TEMP GRADIENT BTWN THE 1ST AND 2ND SOIL ! LAYERS. THEN CALCULATE THE SUBSURFACE HEAT FLUX. USE THE TEMP ! GRADIENT AND SUBSFC HEAT FLUX TO CALC "RIGHT-HAND SIDE TENDENCY ! TERMS", OR "RHSTS", FOR TOP SOIL LAYER. ! ---------------------------------------------------------------------- BI (1) = - CI (1) + DF1 / (0.5 * ZSOIL (1) * ZSOIL (1)* HCPCT * & ZZ1) DTSDZ = (STC (1) - STC (2)) / ( -0.5 * ZSOIL (2)) SSOIL = DF1 * (STC (1) - YY) / (0.5 * ZSOIL (1) * ZZ1) ! RHSTS(1) = (DF1 * DTSDZ - SSOIL) / (ZSOIL(1) * HCPCT) DENOM = (ZSOIL (1) * HCPCT) ! ---------------------------------------------------------------------- ! NEXT CAPTURE THE VERTICAL DIFFERENCE OF THE HEAT FLUX AT TOP AND ! BOTTOM OF FIRST SOIL LAYER FOR USE IN HEAT FLUX CONSTRAINT APPLIED TO ! POTENTIAL SOIL FREEZING/THAWING IN ROUTINE SNKSRC. ! ---------------------------------------------------------------------- ! QTOT = SSOIL - DF1*DTSDZ RHSTS (1) = (DF1 * DTSDZ - SSOIL) / DENOM ! ---------------------------------------------------------------------- ! CALCULATE FROZEN WATER CONTENT IN 1ST SOIL LAYER. ! ---------------------------------------------------------------------- QTOT = -1.0* RHSTS (1)* DENOM ! ---------------------------------------------------------------------- ! IF TEMPERATURE AVERAGING INVOKED (ITAVG=TRUE; ELSE SKIP): ! SET TEMP "TSURF" AT TOP OF SOIL COLUMN (FOR USE IN FREEZING SOIL ! PHYSICS LATER IN FUNCTION SUBROUTINE SNKSRC). IF SNOWPACK CONTENT IS ! ZERO, THEN TSURF EXPRESSION BELOW GIVES TSURF = SKIN TEMP. IF ! SNOWPACK IS NONZERO (HENCE ARGUMENT ZZ1=1), THEN TSURF EXPRESSION ! BELOW YIELDS SOIL COLUMN TOP TEMPERATURE UNDER SNOWPACK. THEN ! CALCULATE TEMPERATURE AT BOTTOM INTERFACE OF 1ST SOIL LAYER FOR USE ! LATER IN FUNCTION SUBROUTINE SNKSRC ! ---------------------------------------------------------------------- SICE = SMC (1) - SH2O (1) IF (ITAVG) THEN TSURF = (YY + (ZZ1-1) * STC (1)) / ZZ1 ! ---------------------------------------------------------------------- ! IF FROZEN WATER PRESENT OR ANY OF LAYER-1 MID-POINT OR BOUNDING ! INTERFACE TEMPERATURES BELOW FREEZING, THEN CALL SNKSRC TO ! COMPUTE HEAT SOURCE/SINK (AND CHANGE IN FROZEN WATER CONTENT) ! DUE TO POSSIBLE SOIL WATER PHASE CHANGE ! ---------------------------------------------------------------------- CALL TBND (STC (1),STC (2),ZSOIL,ZBOT,1,NSOIL,TBK) IF ( (SICE > 0.) .OR. (STC (1) < T0) .OR. & (TSURF < T0) .OR. (TBK < T0) ) THEN ! TSNSR = SNKSRC (TAVG,SMC(1),SH2O(1), CALL TMPAVG (TAVG,TSURF,STC (1),TBK,ZSOIL,NSOIL,1) CALL SNKSRC (TSNSR,TAVG,SMC (1),SH2O (1), & ZSOIL,NSOIL,SMCMAX,PSISAT,BEXP,DT,1,QTOT) ! RHSTS(1) = RHSTS(1) - TSNSR / ( ZSOIL(1) * HCPCT ) RHSTS (1) = RHSTS (1) - TSNSR / DENOM END IF ELSE ! TSNSR = SNKSRC (STC(1),SMC(1),SH2O(1), IF ( (SICE > 0.) .OR. (STC (1) < T0) ) THEN CALL SNKSRC (TSNSR,STC (1),SMC (1),SH2O (1), & ZSOIL,NSOIL,SMCMAX,PSISAT,BEXP,DT,1,QTOT) ! RHSTS(1) = RHSTS(1) - TSNSR / ( ZSOIL(1) * HCPCT ) RHSTS (1) = RHSTS (1) - TSNSR / DENOM END IF ! ---------------------------------------------------------------------- ! THIS ENDS SECTION FOR TOP SOIL LAYER. ! ---------------------------------------------------------------------- END IF ! INITIALIZE DDZ2 ! ---------------------------------------------------------------------- DDZ2 = 0.0 DF1K = DF1 ! ---------------------------------------------------------------------- ! LOOP THRU THE REMAINING SOIL LAYERS, REPEATING THE ABOVE PROCESS ! (EXCEPT SUBSFC OR "GROUND" HEAT FLUX NOT REPEATED IN LOWER LAYERS) ! ---------------------------------------------------------------------- ! CALCULATE HEAT CAPACITY FOR THIS SOIL LAYER. ! ---------------------------------------------------------------------- DO K = 2,NSOIL HCPCT = SH2O (K)* CH2O + (1.0- SMCMAX)* CSOIL_LOC + (SMCMAX - SMC ( & K))* CAIR + ( SMC (K) - SH2O (K) )* CICE ! ---------------------------------------------------------------------- ! THIS SECTION FOR LAYER 2 OR GREATER, BUT NOT LAST LAYER. ! ---------------------------------------------------------------------- ! CALCULATE THERMAL DIFFUSIVITY FOR THIS LAYER. ! ---------------------------------------------------------------------- IF (K /= NSOIL) THEN ! ---------------------------------------------------------------------- ! CALC THE VERTICAL SOIL TEMP GRADIENT THRU THIS LAYER ! ---------------------------------------------------------------------- CALL TDFCND (DF1N,SMC (K),QUARTZ,SMCMAX,SH2O (K)) !urban IF(VEGTYP==1) DF1N = 3.24 DENOM = 0.5 * ( ZSOIL (K -1) - ZSOIL (K +1) ) ! ---------------------------------------------------------------------- ! CALC THE MATRIX COEF, CI, AFTER CALC'NG ITS PARTIAL PRODUCT ! ---------------------------------------------------------------------- DTSDZ2 = ( STC (K) - STC (K +1) ) / DENOM DDZ2 = 2. / (ZSOIL (K -1) - ZSOIL (K +1)) ! ---------------------------------------------------------------------- ! IF TEMPERATURE AVERAGING INVOKED (ITAVG=TRUE; ELSE SKIP): CALCULATE ! TEMP AT BOTTOM OF LAYER. ! ---------------------------------------------------------------------- CI (K) = - DF1N * DDZ2 / ( (ZSOIL (K -1) - ZSOIL (K)) * & HCPCT) IF (ITAVG) THEN CALL TBND (STC (K),STC (K +1),ZSOIL,ZBOT,K,NSOIL,TBK1) END IF ELSE ! ---------------------------------------------------------------------- ! SPECIAL CASE OF BOTTOM SOIL LAYER: CALCULATE THERMAL DIFFUSIVITY FOR ! BOTTOM LAYER. ! ---------------------------------------------------------------------- ! ---------------------------------------------------------------------- ! CALC THE VERTICAL SOIL TEMP GRADIENT THRU BOTTOM LAYER. ! ---------------------------------------------------------------------- CALL TDFCND (DF1N,SMC (K),QUARTZ,SMCMAX,SH2O (K)) !urban IF(VEGTYP==1) DF1N = 3.24 DENOM = .5 * (ZSOIL (K -1) + ZSOIL (K)) - ZBOT ! ---------------------------------------------------------------------- ! SET MATRIX COEF, CI TO ZERO IF BOTTOM LAYER. ! ---------------------------------------------------------------------- DTSDZ2 = (STC (K) - TBOT) / DENOM ! ---------------------------------------------------------------------- ! IF TEMPERATURE AVERAGING INVOKED (ITAVG=TRUE; ELSE SKIP): CALCULATE ! TEMP AT BOTTOM OF LAST LAYER. ! ---------------------------------------------------------------------- CI (K) = 0. IF (ITAVG) THEN CALL TBND (STC (K),TBOT,ZSOIL,ZBOT,K,NSOIL,TBK1) END IF ! ---------------------------------------------------------------------- ! THIS ENDS SPECIAL LOOP FOR BOTTOM LAYER. END IF ! ---------------------------------------------------------------------- ! CALCULATE RHSTS FOR THIS LAYER AFTER CALC'NG A PARTIAL PRODUCT. ! ---------------------------------------------------------------------- DENOM = ( ZSOIL (K) - ZSOIL (K -1) ) * HCPCT RHSTS (K) = ( DF1N * DTSDZ2- DF1K * DTSDZ ) / DENOM QTOT = -1.0* DENOM * RHSTS (K) SICE = SMC (K) - SH2O (K) IF (ITAVG) THEN CALL TMPAVG (TAVG,TBK,STC (K),TBK1,ZSOIL,NSOIL,K) ! TSNSR = SNKSRC(TAVG,SMC(K),SH2O(K),ZSOIL,NSOIL, IF ( (SICE > 0.) .OR. (STC (K) < T0) .OR. & (TBK .lt. T0) .OR. (TBK1 .lt. T0) ) THEN CALL SNKSRC (TSNSR,TAVG,SMC (K),SH2O (K),ZSOIL,NSOIL, & SMCMAX,PSISAT,BEXP,DT,K,QTOT) RHSTS (K) = RHSTS (K) - TSNSR / DENOM END IF ELSE ! TSNSR = SNKSRC(STC(K),SMC(K),SH2O(K),ZSOIL,NSOIL, IF ( (SICE > 0.) .OR. (STC (K) < T0) ) THEN CALL SNKSRC (TSNSR,STC (K),SMC (K),SH2O (K),ZSOIL,NSOIL, & SMCMAX,PSISAT,BEXP,DT,K,QTOT) RHSTS (K) = RHSTS (K) - TSNSR / DENOM END IF END IF ! ---------------------------------------------------------------------- ! CALC MATRIX COEFS, AI, AND BI FOR THIS LAYER. ! ---------------------------------------------------------------------- AI (K) = - DF1K * DDZ / ( (ZSOIL (K -1) - ZSOIL (K)) * HCPCT) ! ---------------------------------------------------------------------- ! RESET VALUES OF DF1, DTSDZ, DDZ, AND TBK FOR LOOP TO NEXT SOIL LAYER. ! ---------------------------------------------------------------------- BI (K) = - (AI (K) + CI (K)) TBK = TBK1 DF1K = DF1N DTSDZ = DTSDZ2 DDZ = DDZ2 END DO ! ---------------------------------------------------------------------- END SUBROUTINE HRT ! ---------------------------------------------------------------------- SUBROUTINE HRTICE (RHSTS,STC,NSOIL,ZSOIL,YY,ZZ1,DF1,AI,BI,CI) ! ---------------------------------------------------------------------- ! SUBROUTINE HRTICE ! ---------------------------------------------------------------------- ! CALCULATE THE RIGHT HAND SIDE OF THE TIME TENDENCY TERM OF THE SOIL ! THERMAL DIFFUSION EQUATION IN THE CASE OF SEA-ICE PACK. ALSO TO ! COMPUTE (PREPARE) THE MATRIX COEFFICIENTS FOR THE TRI-DIAGONAL MATRIX ! OF THE IMPLICIT TIME SCHEME. ! ---------------------------------------------------------------------- IMPLICIT NONE INTEGER, INTENT(IN) :: NSOIL INTEGER :: K REAL, INTENT(IN) :: DF1,YY,ZZ1 REAL, DIMENSION(1:NSOIL), INTENT(OUT):: AI, BI,CI REAL, DIMENSION(1:NSOIL), INTENT(IN) :: STC, ZSOIL REAL, DIMENSION(1:NSOIL), INTENT(OUT):: RHSTS REAL :: DDZ,DDZ2,DENOM,DTSDZ,DTSDZ2,SSOIL, & ZBOT,TBOT REAL, PARAMETER :: HCPCT = 1.72396E+6 ! ---------------------------------------------------------------------- ! SET A NOMINAL UNIVERSAL VALUE OF THE SEA-ICE SPECIFIC HEAT CAPACITY, ! HCPCT = 1880.0*917.0. ! ---------------------------------------------------------------------- DATA TBOT /271.16/ ! ---------------------------------------------------------------------- ! THE INPUT ARGUMENT DF1 IS A UNIVERSALLY CONSTANT VALUE OF SEA-ICE ! THERMAL DIFFUSIVITY, SET IN ROUTINE SNOPAC AS DF1 = 2.2. ! ---------------------------------------------------------------------- ! SET ICE PACK DEPTH. USE TBOT AS ICE PACK LOWER BOUNDARY TEMPERATURE ! (THAT OF UNFROZEN SEA WATER AT BOTTOM OF SEA ICE PACK). ASSUME ICE ! PACK IS OF N=NSOIL LAYERS SPANNING A UNIFORM CONSTANT ICE PACK ! THICKNESS AS DEFINED BY ZSOIL(NSOIL) IN ROUTINE SFLX. ! ---------------------------------------------------------------------- ! ---------------------------------------------------------------------- ! CALC THE MATRIX COEFFICIENTS AI, BI, AND CI FOR THE TOP LAYER ! ---------------------------------------------------------------------- ZBOT = ZSOIL (NSOIL) DDZ = 1.0 / ( -0.5 * ZSOIL (2) ) AI (1) = 0.0 CI (1) = (DF1 * DDZ) / (ZSOIL (1) * HCPCT) ! ---------------------------------------------------------------------- ! CALC THE VERTICAL SOIL TEMP GRADIENT BTWN THE TOP AND 2ND SOIL LAYERS. ! RECALC/ADJUST THE SOIL HEAT FLUX. USE THE GRADIENT AND FLUX TO CALC ! RHSTS FOR THE TOP SOIL LAYER. ! ---------------------------------------------------------------------- BI (1) = - CI (1) + DF1/ (0.5 * ZSOIL (1) * ZSOIL (1) * HCPCT * & ZZ1) DTSDZ = ( STC (1) - STC (2) ) / ( -0.5 * ZSOIL (2) ) SSOIL = DF1 * ( STC (1) - YY ) / ( 0.5 * ZSOIL (1) * ZZ1 ) ! ---------------------------------------------------------------------- ! INITIALIZE DDZ2 ! ---------------------------------------------------------------------- RHSTS (1) = ( DF1 * DTSDZ - SSOIL ) / ( ZSOIL (1) * HCPCT ) ! ---------------------------------------------------------------------- ! LOOP THRU THE REMAINING SOIL LAYERS, REPEATING THE ABOVE PROCESS ! ---------------------------------------------------------------------- DDZ2 = 0.0 DO K = 2,NSOIL ! ---------------------------------------------------------------------- ! CALC THE VERTICAL SOIL TEMP GRADIENT THRU THIS LAYER. ! ---------------------------------------------------------------------- IF (K /= NSOIL) THEN DENOM = 0.5 * ( ZSOIL (K -1) - ZSOIL (K +1) ) ! ---------------------------------------------------------------------- ! CALC THE MATRIX COEF, CI, AFTER CALC'NG ITS PARTIAL PRODUCT. ! ---------------------------------------------------------------------- DTSDZ2 = ( STC (K) - STC (K +1) ) / DENOM DDZ2 = 2. / (ZSOIL (K -1) - ZSOIL (K +1)) CI (K) = - DF1 * DDZ2 / ( (ZSOIL (K -1) - ZSOIL (K))*HCPCT) ! ---------------------------------------------------------------------- ! CALC THE VERTICAL SOIL TEMP GRADIENT THRU THE LOWEST LAYER. ! ---------------------------------------------------------------------- ELSE ! ---------------------------------------------------------------------- ! SET MATRIX COEF, CI TO ZERO. ! ---------------------------------------------------------------------- DTSDZ2 = (STC (K) - TBOT)/ (.5 * (ZSOIL (K -1) + ZSOIL (K)) & - ZBOT) CI (K) = 0. ! ---------------------------------------------------------------------- ! CALC RHSTS FOR THIS LAYER AFTER CALC'NG A PARTIAL PRODUCT. ! ---------------------------------------------------------------------- END IF DENOM = ( ZSOIL (K) - ZSOIL (K -1) ) * HCPCT ! ---------------------------------------------------------------------- ! CALC MATRIX COEFS, AI, AND BI FOR THIS LAYER. ! ---------------------------------------------------------------------- RHSTS (K) = ( DF1 * DTSDZ2- DF1 * DTSDZ ) / DENOM AI (K) = - DF1 * DDZ / ( (ZSOIL (K -1) - ZSOIL (K)) * HCPCT) ! ---------------------------------------------------------------------- ! RESET VALUES OF DTSDZ AND DDZ FOR LOOP TO NEXT SOIL LYR. ! ---------------------------------------------------------------------- BI (K) = - (AI (K) + CI (K)) DTSDZ = DTSDZ2 DDZ = DDZ2 END DO ! ---------------------------------------------------------------------- END SUBROUTINE HRTICE ! ---------------------------------------------------------------------- SUBROUTINE HSTEP (STCOUT,STCIN,RHSTS,DT,NSOIL,AI,BI,CI) ! ---------------------------------------------------------------------- ! SUBROUTINE HSTEP ! ---------------------------------------------------------------------- ! CALCULATE/UPDATE THE SOIL TEMPERATURE FIELD. ! ---------------------------------------------------------------------- IMPLICIT NONE INTEGER, INTENT(IN) :: NSOIL INTEGER :: K REAL, DIMENSION(1:NSOIL), INTENT(IN):: STCIN REAL, DIMENSION(1:NSOIL), INTENT(OUT):: STCOUT REAL, DIMENSION(1:NSOIL), INTENT(INOUT):: RHSTS REAL, DIMENSION(1:NSOIL), INTENT(INOUT):: AI,BI,CI REAL, DIMENSION(1:NSOIL) :: RHSTSin REAL, DIMENSION(1:NSOIL) :: CIin REAL :: DT ! ---------------------------------------------------------------------- ! CREATE FINITE DIFFERENCE VALUES FOR USE IN ROSR12 ROUTINE ! ---------------------------------------------------------------------- DO K = 1,NSOIL RHSTS (K) = RHSTS (K) * DT AI (K) = AI (K) * DT BI (K) = 1. + BI (K) * DT CI (K) = CI (K) * DT END DO ! ---------------------------------------------------------------------- ! COPY VALUES FOR INPUT VARIABLES BEFORE CALL TO ROSR12 ! ---------------------------------------------------------------------- DO K = 1,NSOIL RHSTSin (K) = RHSTS (K) END DO DO K = 1,NSOIL CIin (K) = CI (K) END DO ! ---------------------------------------------------------------------- ! SOLVE THE TRI-DIAGONAL MATRIX EQUATION ! ---------------------------------------------------------------------- CALL ROSR12 (CI,AI,BI,CIin,RHSTSin,RHSTS,NSOIL) ! ---------------------------------------------------------------------- ! CALC/UPDATE THE SOIL TEMPS USING MATRIX SOLUTION ! ---------------------------------------------------------------------- DO K = 1,NSOIL STCOUT (K) = STCIN (K) + CI (K) END DO ! ---------------------------------------------------------------------- END SUBROUTINE HSTEP ! ---------------------------------------------------------------------- SUBROUTINE NOPAC (ETP,ETA,PRCP,SMC,SMCMAX,SMCWLT, & SMCREF,SMCDRY,CMC,CMCMAX,NSOIL,DT,SHDFAC, & SBETA,Q2,T1,SFCTMP,T24,TH2,FDOWN,F1,EMISSI, & SSOIL, & STC,EPSCA,BEXP,PC,RCH,RR,CFACTR, & SH2O,SLOPE,KDT,FRZFACT,PSISAT,ZSOIL, & DKSAT,DWSAT,TBOT,ZBOT,RUNOFF1,RUNOFF2, & RUNOFF3,EDIR,EC,ET,ETT,NROOT,ICE,RTDIS, & QUARTZ,FXEXP,CSOIL, & BETA,DRIP,DEW,FLX1,FLX3,VEGTYP) ! ---------------------------------------------------------------------- ! SUBROUTINE NOPAC ! ---------------------------------------------------------------------- ! CALCULATE SOIL MOISTURE AND HEAT FLUX VALUES AND UPDATE SOIL MOISTURE ! CONTENT AND SOIL HEAT CONTENT VALUES FOR THE CASE WHEN NO SNOW PACK IS ! PRESENT. ! ---------------------------------------------------------------------- IMPLICIT NONE INTEGER, INTENT(IN) :: ICE, NROOT,NSOIL,VEGTYP INTEGER :: K REAL, INTENT(IN) :: BEXP,CFACTR, CMCMAX,CSOIL,DKSAT,DT,DWSAT, & EPSCA,ETP,FDOWN,F1,FXEXP,FRZFACT,KDT,PC, & PRCP,PSISAT,Q2,QUARTZ,RCH,RR,SBETA,SFCTMP,& SHDFAC,SLOPE,SMCDRY,SMCMAX,SMCREF,SMCWLT, & T24,TBOT,TH2,ZBOT,EMISSI REAL, INTENT(INOUT) :: CMC,BETA,T1 REAL, INTENT(OUT) :: DEW,DRIP,EC,EDIR,ETA,ETT,FLX1,FLX3, & RUNOFF1,RUNOFF2,RUNOFF3,SSOIL REAL, DIMENSION(1:NSOIL),INTENT(IN) :: RTDIS,ZSOIL REAL, DIMENSION(1:NSOIL),INTENT(OUT) :: ET REAL, DIMENSION(1:NSOIL), INTENT(INOUT) :: SMC,SH2O,STC REAL, DIMENSION(1:NSOIL) :: ET1 REAL :: EC1,EDIR1,ETT1,DF1,ETA1,ETP1,PRCP1,YY, & YYNUM,ZZ1 ! ---------------------------------------------------------------------- ! EXECUTABLE CODE BEGINS HERE: ! CONVERT ETP Fnd PRCP FROM KG M-2 S-1 TO M S-1 AND INITIALIZE DEW. ! ---------------------------------------------------------------------- PRCP1 = PRCP * 0.001 ETP1 = ETP * 0.001 DEW = 0.0 ! ---------------------------------------------------------------------- ! INITIALIZE EVAP TERMS. ! ---------------------------------------------------------------------- EDIR = 0. EDIR1 = 0. EC1 = 0. EC = 0. DO K = 1,NSOIL ET(K) = 0. ET1(K) = 0. END DO ETT = 0. ETT1 = 0. IF (ETP > 0.0) THEN CALL EVAPO (ETA1,SMC,NSOIL,CMC,ETP1,DT,ZSOIL, & SH2O, & SMCMAX,BEXP,PC,SMCWLT,DKSAT,DWSAT, & SMCREF,SHDFAC,CMCMAX, & SMCDRY,CFACTR, & EDIR1,EC1,ET1,ETT1,SFCTMP,Q2,NROOT,RTDIS,FXEXP) CALL SMFLX (SMC,NSOIL,CMC,DT,PRCP1,ZSOIL, & SH2O,SLOPE,KDT,FRZFACT, & SMCMAX,BEXP,SMCWLT,DKSAT,DWSAT, & SHDFAC,CMCMAX, & RUNOFF1,RUNOFF2,RUNOFF3, & EDIR1,EC1,ET1, & DRIP) ! ---------------------------------------------------------------------- ! CONVERT MODELED EVAPOTRANSPIRATION FROM M S-1 TO KG M-2 S-1. ! ---------------------------------------------------------------------- ETA = ETA1 * 1000.0 ! ---------------------------------------------------------------------- ! IF ETP < 0, ASSUME DEW FORMS (TRANSFORM ETP1 INTO DEW AND REINITIALIZE ! ETP1 TO ZERO). ! ---------------------------------------------------------------------- ELSE DEW = - ETP1 ! ---------------------------------------------------------------------- ! CONVERT PRCP FROM 'KG M-2 S-1' TO 'M S-1' AND ADD DEW AMOUNT. ! ---------------------------------------------------------------------- PRCP1 = PRCP1+ DEW CALL SMFLX (SMC,NSOIL,CMC,DT,PRCP1,ZSOIL, & SH2O,SLOPE,KDT,FRZFACT, & SMCMAX,BEXP,SMCWLT,DKSAT,DWSAT, & SHDFAC,CMCMAX, & RUNOFF1,RUNOFF2,RUNOFF3, & EDIR1,EC1,ET1, & DRIP) ! ---------------------------------------------------------------------- ! CONVERT MODELED EVAPOTRANSPIRATION FROM 'M S-1' TO 'KG M-2 S-1'. ! ---------------------------------------------------------------------- ! ETA = ETA1 * 1000.0 END IF ! ---------------------------------------------------------------------- ! BASED ON ETP AND E VALUES, DETERMINE BETA ! ---------------------------------------------------------------------- IF ( ETP <= 0.0 ) THEN BETA = 0.0 ETA = ETP IF ( ETP < 0.0 ) THEN BETA = 1.0 END IF ELSE BETA = ETA / ETP END IF ! ---------------------------------------------------------------------- ! CONVERT MODELED EVAPOTRANSPIRATION COMPONENTS 'M S-1' TO 'KG M-2 S-1'. ! ---------------------------------------------------------------------- EDIR = EDIR1*1000. EC = EC1*1000. DO K = 1,NSOIL ET(K) = ET1(K)*1000. END DO ETT = ETT1*1000. ! ---------------------------------------------------------------------- ! GET SOIL THERMAL DIFFUXIVITY/CONDUCTIVITY FOR TOP SOIL LYR, ! CALC. ADJUSTED TOP LYR SOIL TEMP AND ADJUSTED SOIL FLUX, THEN ! CALL SHFLX TO COMPUTE/UPDATE SOIL HEAT FLUX AND SOIL TEMPS. ! ---------------------------------------------------------------------- CALL TDFCND (DF1,SMC (1),QUARTZ,SMCMAX,SH2O (1)) !urban IF (VEGTYP==1) DF1=3.24 ! ! ---------------------------------------------------------------------- ! VEGETATION GREENNESS FRACTION REDUCTION IN SUBSURFACE HEAT FLUX ! VIA REDUCTION FACTOR, WHICH IS CONVENIENT TO APPLY HERE TO THERMAL ! DIFFUSIVITY THAT IS LATER USED IN HRT TO COMPUTE SUB SFC HEAT FLUX ! (SEE ADDITIONAL COMMENTS ON VEG EFFECT SUB-SFC HEAT FLX IN ! ROUTINE SFLX) ! ---------------------------------------------------------------------- DF1 = DF1 * EXP (SBETA * SHDFAC) ! ---------------------------------------------------------------------- ! COMPUTE INTERMEDIATE TERMS PASSED TO ROUTINE HRT (VIA ROUTINE ! SHFLX BELOW) FOR USE IN COMPUTING SUBSURFACE HEAT FLUX IN HRT ! ---------------------------------------------------------------------- YYNUM = FDOWN - EMISSI*SIGMA * T24 YY = SFCTMP + (YYNUM / RCH + TH2- SFCTMP - BETA * EPSCA) / RR ZZ1 = DF1 / ( -0.5 * ZSOIL (1) * RCH * RR ) + 1.0 !urban CALL SHFLX (SSOIL,STC,SMC,SMCMAX,NSOIL,T1,DT,YY,ZZ1,ZSOIL, & TBOT,ZBOT,SMCWLT,PSISAT,SH2O,BEXP,F1,DF1,ICE, & QUARTZ,CSOIL,VEGTYP) ! ---------------------------------------------------------------------- ! SET FLX1 AND FLX3 (SNOPACK PHASE CHANGE HEAT FLUXES) TO ZERO SINCE ! THEY ARE NOT USED HERE IN SNOPAC. FLX2 (FREEZING RAIN HEAT FLUX) WAS ! SIMILARLY INITIALIZED IN THE PENMAN ROUTINE. ! ---------------------------------------------------------------------- FLX1 = 0.0 FLX3 = 0.0 ! ---------------------------------------------------------------------- END SUBROUTINE NOPAC ! ---------------------------------------------------------------------- SUBROUTINE PENMAN (SFCTMP,SFCPRS,CH,T2V,TH2,PRCP,FDOWN,T24,SSOIL, & & Q2,Q2SAT,ETP,RCH,EPSCA,RR,SNOWNG,FRZGRA, & & DQSDT2,FLX2,EMISSI_IN,SNEQV) ! ---------------------------------------------------------------------- ! SUBROUTINE PENMAN ! ---------------------------------------------------------------------- ! CALCULATE POTENTIAL EVAPORATION FOR THE CURRENT POINT. VARIOUS ! PARTIAL SUMS/PRODUCTS ARE ALSO CALCULATED AND PASSED BACK TO THE ! CALLING ROUTINE FOR LATER USE. ! ---------------------------------------------------------------------- IMPLICIT NONE LOGICAL, INTENT(IN) :: SNOWNG, FRZGRA REAL, INTENT(IN) :: CH, DQSDT2,FDOWN,PRCP, & Q2, Q2SAT,SSOIL, SFCPRS, SFCTMP, & T2V, TH2,EMISSI_IN,SNEQV REAL, INTENT(OUT) :: EPSCA,ETP,FLX2,RCH,RR,T24 REAL :: A, DELTA, FNET,RAD,RHO,EMISSI,ELCP1,LVS REAL, PARAMETER :: ELCP = 2.4888E+3, LSUBC = 2.501000E+6,CP = 1004.6 REAL, PARAMETER :: LSUBS = 2.83E+6 ! ---------------------------------------------------------------------- ! EXECUTABLE CODE BEGINS HERE: ! ---------------------------------------------------------------------- ! ---------------------------------------------------------------------- ! PREPARE PARTIAL QUANTITIES FOR PENMAN EQUATION. ! ---------------------------------------------------------------------- EMISSI=EMISSI_IN IF(SNEQV == 0.)THEN ELCP1=ELCP LVS=LSUBC ELSE ! EMISSI=EMISSI_S ! FOR SNOW ELCP1=ELCP*LSUBS/LSUBC LVS=LSUBS ENDIF FLX2 = 0.0 ! DELTA = ELCP * DQSDT2 DELTA = ELCP1 * DQSDT2 T24 = SFCTMP * SFCTMP * SFCTMP * SFCTMP ! RR = T24 * 6.48E-8 / (SFCPRS * CH) + 1.0 RR = EMISSI*T24 * 6.48E-8 / (SFCPRS * CH) + 1.0 RHO = SFCPRS / (RD * T2V) ! ---------------------------------------------------------------------- ! ADJUST THE PARTIAL SUMS / PRODUCTS WITH THE LATENT HEAT ! EFFECTS CAUSED BY FALLING PRECIPITATION. ! ---------------------------------------------------------------------- RCH = RHO * CP * CH IF (.NOT. SNOWNG) THEN IF (PRCP > 0.0) RR = RR + CPH2O * PRCP / RCH ELSE RR = RR + CPICE * PRCP / RCH END IF ! ---------------------------------------------------------------------- ! INCLUDE THE LATENT HEAT EFFECTS OF FRZNG RAIN CONVERTING TO ICE ON ! IMPACT IN THE CALCULATION OF FLX2 AND FNET. ! ---------------------------------------------------------------------- ! FNET = FDOWN - SIGMA * T24- SSOIL FNET = FDOWN - EMISSI*SIGMA * T24- SSOIL IF (FRZGRA) THEN FLX2 = - LSUBF * PRCP FNET = FNET - FLX2 ! ---------------------------------------------------------------------- ! FINISH PENMAN EQUATION CALCULATIONS. ! ---------------------------------------------------------------------- END IF RAD = FNET / RCH + TH2- SFCTMP ! A = ELCP * (Q2SAT - Q2) A = ELCP1 * (Q2SAT - Q2) EPSCA = (A * RR + RAD * DELTA) / (DELTA + RR) ! ETP = EPSCA * RCH / LSUBC ETP = EPSCA * RCH / LVS ! ---------------------------------------------------------------------- END SUBROUTINE PENMAN ! ---------------------------------------------------------------------- SUBROUTINE REDPRM (VEGTYP,SOILTYP,SLOPETYP,CFACTR,CMCMAX,RSMAX, & TOPT, & REFKDT,KDT,SBETA, SHDFAC,RSMIN,RGL,HS,ZBOT,FRZX, & PSISAT,SLOPE,SNUP,SALP,BEXP,DKSAT,DWSAT, & SMCMAX,SMCWLT,SMCREF,SMCDRY,F1,QUARTZ,FXEXP, & RTDIS,SLDPTH,ZSOIL, NROOT,NSOIL,Z0BRD,CZIL,LAI, & CSOIL,ALBBRD,PTU,LLANDUSE,LSOIL,LOCAL) IMPLICIT NONE ! ---------------------------------------------------------------------- ! Internally set (default valuess) ! all soil and vegetation parameters required for the execusion oF ! the Noah lsm are defined in VEGPARM.TBL, SOILPARM.TB, and GENPARM.TBL. ! ---------------------------------------------------------------------- ! Vegetation parameters: ! ALBBRD: SFC background snow-free albedo ! CMXTBL: MAX CNPY Capacity ! Z0BRD: Background roughness length ! SHDFAC: Green vegetation fraction ! NROOT: Rooting depth ! RSMIN: Mimimum stomatal resistance ! RSMAX: Max. stomatal resistance ! RGL: Parameters used in radiation stress function ! HS: Parameter used in vapor pressure deficit functio ! TOPT: Optimum transpiration air temperature. ! CMCMAX: Maximum canopy water capacity ! CFACTR: Parameter used in the canopy inteception calculation ! SNUP: Threshold snow depth (in water equivalent m) that ! implies 100 percent snow cover ! LAI: Leaf area index ! ! ---------------------------------------------------------------------- ! Soil parameters: ! SMCMAX: MAX soil moisture content (porosity) ! SMCREF: Reference soil moisture (field capacity) ! SMCWLT: Wilting point soil moisture ! SMCWLT: Air dry soil moist content limits ! SSATPSI: SAT (saturation) soil potential ! DKSAT: SAT soil conductivity ! BEXP: B parameter ! SSATDW: SAT soil diffusivity ! F1: Soil thermal diffusivity/conductivity coef. ! QUARTZ: Soil quartz content ! Modified by F. Chen (12/22/97) to use the STATSGO soil map ! Modified By F. Chen (01/22/00) to include PLaya, Lava, and White San ! Modified By F. Chen (08/05/02) to include additional parameters for the Noah ! NOTE: SATDW = BB*SATDK*(SATPSI/MAXSMC) ! F11 = ALOG10(SATPSI) + BB*ALOG10(MAXSMC) + 2.0 ! REFSMC1=MAXSMC*(5.79E-9/SATDK)**(1/(2*BB+3)) 5.79E-9 m/s= 0.5 mm ! REFSMC=REFSMC1+1./3.(MAXSMC-REFSMC1) ! WLTSMC1=MAXSMC*(200./SATPSI)**(-1./BB) (Wetzel and Chang, 198 ! WLTSMC=WLTSMC1-0.5*WLTSMC1 ! Note: the values for playa is set for it to have a thermal conductivit ! as sand and to have a hydrulic conductivity as clay ! ! ---------------------------------------------------------------------- ! Class parameter 'SLOPETYP' was included to estimate linear reservoir ! coefficient 'SLOPE' to the baseflow runoff out of the bottom layer. ! lowest class (slopetyp=0) means highest slope parameter = 1. ! definition of slopetyp from 'zobler' slope type: ! slope class percent slope ! 1 0-8 ! 2 8-30 ! 3 > 30 ! 4 0-30 ! 5 0-8 & > 30 ! 6 8-30 & > 30 ! 7 0-8, 8-30, > 30 ! 9 GLACIAL ICE ! BLANK OCEAN/SEA ! SLOPE_DATA: linear reservoir coefficient ! SBETA_DATA: parameter used to caluculate vegetation effect on soil heat ! FXEXP_DAT: soil evaporation exponent used in DEVAP ! CSOIL_DATA: soil heat capacity [J M-3 K-1] ! SALP_DATA: shape parameter of distribution function of snow cover ! REFDK_DATA and REFKDT_DATA: parameters in the surface runoff parameteriz ! FRZK_DATA: frozen ground parameter ! ZBOT_DATA: depth[M] of lower boundary soil temperature ! CZIL_DATA: calculate roughness length of heat ! SMLOW_DATA and MHIGH_DATA: two soil moisture wilt, soil moisture referen ! parameters ! Set maximum number of soil-, veg-, and slopetyp in data statement. ! ---------------------------------------------------------------------- INTEGER, PARAMETER :: MAX_SLOPETYP=30,MAX_SOILTYP=30,MAX_VEGTYP=30 LOGICAL :: LOCAL CHARACTER (LEN=4), INTENT(IN):: LLANDUSE, LSOIL ! Veg parameters INTEGER, INTENT(IN) :: VEGTYP INTEGER, INTENT(OUT) :: NROOT REAL, INTENT(OUT) :: HS,LAI,RSMIN,RGL,SHDFAC,SNUP,Z0BRD, & CMCMAX,RSMAX,TOPT,ALBBRD ! Soil parameters INTEGER, INTENT(IN) :: SOILTYP REAL, INTENT(OUT) :: BEXP,DKSAT,DWSAT,F1,QUARTZ,SMCDRY, & SMCMAX,SMCREF,SMCWLT,PSISAT ! General parameters INTEGER, INTENT(IN) :: SLOPETYP,NSOIL INTEGER :: I REAL, INTENT(OUT) :: SLOPE,CZIL,SBETA,FXEXP, & CSOIL,SALP,FRZX,KDT,CFACTR, & ZBOT,REFKDT,PTU REAL,DIMENSION(1:NSOIL),INTENT(IN) :: SLDPTH,ZSOIL REAL,DIMENSION(1:NSOIL),INTENT(OUT):: RTDIS REAL :: FRZFACT,FRZK,REFDK ! SAVE ! ---------------------------------------------------------------------- ! IF (SOILTYP .gt. SLCATS) THEN CALL wrf_error_fatal ( 'Warning: too many input soil types' ) END IF IF (VEGTYP .gt. LUCATS) THEN CALL wrf_error_fatal ( 'Warning: too many input landuse types' ) END IF IF (SLOPETYP .gt. SLPCATS) THEN CALL wrf_error_fatal ( 'Warning: too many input slope types' ) END IF ! ---------------------------------------------------------------------- ! SET-UP SOIL PARAMETERS ! ---------------------------------------------------------------------- CSOIL = CSOIL_DATA BEXP = BB (SOILTYP) DKSAT = SATDK (SOILTYP) DWSAT = SATDW (SOILTYP) F1 = F11 (SOILTYP) PSISAT = SATPSI (SOILTYP) QUARTZ = QTZ (SOILTYP) SMCDRY = DRYSMC (SOILTYP) SMCMAX = MAXSMC (SOILTYP) SMCREF = REFSMC (SOILTYP) SMCWLT = WLTSMC (SOILTYP) ! ---------------------------------------------------------------------- ! Set-up universal parameters (not dependent on SOILTYP, VEGTYP or ! SLOPETYP) ! ---------------------------------------------------------------------- ZBOT = ZBOT_DATA SALP = SALP_DATA SBETA = SBETA_DATA REFDK = REFDK_DATA FRZK = FRZK_DATA FXEXP = FXEXP_DATA REFKDT = REFKDT_DATA PTU = 0. ! (not used yet) to satisify intent(out) KDT = REFKDT * DKSAT / REFDK CZIL = CZIL_DATA SLOPE = SLOPE_DATA (SLOPETYP) ! ---------------------------------------------------------------------- ! TO ADJUST FRZK PARAMETER TO ACTUAL SOIL TYPE: FRZK * FRZFACT ! ---------------------------------------------------------------------- FRZFACT = (SMCMAX / SMCREF) * (0.412 / 0.468) FRZX = FRZK * FRZFACT ! ---------------------------------------------------------------------- ! SET-UP VEGETATION PARAMETERS ! ---------------------------------------------------------------------- TOPT = TOPT_DATA CMCMAX = CMCMAX_DATA CFACTR = CFACTR_DATA RSMAX = RSMAX_DATA NROOT = NROTBL (VEGTYP) SNUP = SNUPTBL (VEGTYP) RSMIN = RSTBL (VEGTYP) RGL = RGLTBL (VEGTYP) HS = HSTBL (VEGTYP) LAI = LAITBL (VEGTYP) IF(LOCAL) THEN ALBBRD = ALBTBL(VEGTYP) Z0BRD = Z0TBL(VEGTYP) SHDFAC = SHDTBL(VEGTYP) ENDIF IF (VEGTYP .eq. BARE) SHDFAC = 0.0 IF (NROOT .gt. NSOIL) THEN WRITE (err_message,*) 'Error: too many root layers ', & NSOIL,NROOT CALL wrf_error_fatal ( err_message ) ! ---------------------------------------------------------------------- ! CALCULATE ROOT DISTRIBUTION. PRESENT VERSION ASSUMES UNIFORM ! DISTRIBUTION BASED ON SOIL LAYER DEPTHS. ! ---------------------------------------------------------------------- END IF DO I = 1,NROOT RTDIS (I) = - SLDPTH (I)/ ZSOIL (NROOT) ! ---------------------------------------------------------------------- ! SET-UP SLOPE PARAMETER ! ---------------------------------------------------------------------- END DO ! print*,'end of PRMRED' ! print*,'VEGTYP',VEGTYP,'SOILTYP',SOILTYP,'SLOPETYP',SLOPETYP, & ! & 'CFACTR',CFACTR,'CMCMAX',CMCMAX,'RSMAX',RSMAX,'TOPT',TOPT, & ! & 'REFKDT',REFKDT,'KDT',KDT,'SBETA',SBETA, 'SHDFAC',SHDFAC, & ! & 'RSMIN',RSMIN,'RGL',RGL,'HS',HS,'ZBOT',ZBOT,'FRZX',FRZX, & ! & 'PSISAT',PSISAT,'SLOPE',SLOPE,'SNUP',SNUP,'SALP',SALP,'BEXP', & ! & BEXP, & ! & 'DKSAT',DKSAT,'DWSAT',DWSAT, & ! & 'SMCMAX',SMCMAX,'SMCWLT',SMCWLT,'SMCREF',SMCREF,'SMCDRY',SMCDRY, & ! & 'F1',F1,'QUARTZ',QUARTZ,'FXEXP',FXEXP, & ! & 'RTDIS',RTDIS,'SLDPTH',SLDPTH,'ZSOIL',ZSOIL, 'NROOT',NROOT, & ! & 'NSOIL',NSOIL,'Z0',Z0,'CZIL',CZIL,'LAI',LAI, & ! & 'CSOIL',CSOIL,'PTU',PTU, & ! & 'LOCAL', LOCAL END SUBROUTINE REDPRM SUBROUTINE ROSR12 (P,A,B,C,D,DELTA,NSOIL) ! ---------------------------------------------------------------------- ! SUBROUTINE ROSR12 ! ---------------------------------------------------------------------- ! INVERT (SOLVE) THE TRI-DIAGONAL MATRIX PROBLEM SHOWN BELOW: ! ### ### ### ### ### ### ! #B(1), C(1), 0 , 0 , 0 , . . . , 0 # # # # # ! #A(2), B(2), C(2), 0 , 0 , . . . , 0 # # # # # ! # 0 , A(3), B(3), C(3), 0 , . . . , 0 # # # # D(3) # ! # 0 , 0 , A(4), B(4), C(4), . . . , 0 # # P(4) # # D(4) # ! # 0 , 0 , 0 , A(5), B(5), . . . , 0 # # P(5) # # D(5) # ! # . . # # . # = # . # ! # . . # # . # # . # ! # . . # # . # # . # ! # 0 , . . . , 0 , A(M-2), B(M-2), C(M-2), 0 # #P(M-2)# #D(M-2)# ! # 0 , . . . , 0 , 0 , A(M-1), B(M-1), C(M-1)# #P(M-1)# #D(M-1)# ! # 0 , . . . , 0 , 0 , 0 , A(M) , B(M) # # P(M) # # D(M) # ! ### ### ### ### ### ### ! ---------------------------------------------------------------------- IMPLICIT NONE INTEGER, INTENT(IN) :: NSOIL INTEGER :: K, KK REAL, DIMENSION(1:NSOIL), INTENT(IN):: A, B, D REAL, DIMENSION(1:NSOIL),INTENT(INOUT):: C,P,DELTA ! ---------------------------------------------------------------------- ! INITIALIZE EQN COEF C FOR THE LOWEST SOIL LAYER ! ---------------------------------------------------------------------- C (NSOIL) = 0.0 P (1) = - C (1) / B (1) ! ---------------------------------------------------------------------- ! SOLVE THE COEFS FOR THE 1ST SOIL LAYER ! ---------------------------------------------------------------------- ! ---------------------------------------------------------------------- ! SOLVE THE COEFS FOR SOIL LAYERS 2 THRU NSOIL ! ---------------------------------------------------------------------- DELTA (1) = D (1) / B (1) DO K = 2,NSOIL P (K) = - C (K) * ( 1.0 / (B (K) + A (K) * P (K -1)) ) DELTA (K) = (D (K) - A (K)* DELTA (K -1))* (1.0/ (B (K) + A (K)& * P (K -1))) END DO ! ---------------------------------------------------------------------- ! SET P TO DELTA FOR LOWEST SOIL LAYER ! ---------------------------------------------------------------------- P (NSOIL) = DELTA (NSOIL) ! ---------------------------------------------------------------------- ! ADJUST P FOR SOIL LAYERS 2 THRU NSOIL ! ---------------------------------------------------------------------- DO K = 2,NSOIL KK = NSOIL - K + 1 P (KK) = P (KK) * P (KK +1) + DELTA (KK) END DO ! ---------------------------------------------------------------------- END SUBROUTINE ROSR12 ! ---------------------------------------------------------------------- SUBROUTINE SHFLX (SSOIL,STC,SMC,SMCMAX,NSOIL,T1,DT,YY,ZZ1,ZSOIL, & TBOT,ZBOT,SMCWLT,PSISAT,SH2O,BEXP,F1,DF1,ICE, & QUARTZ,CSOIL,VEGTYP) ! ---------------------------------------------------------------------- ! SUBROUTINE SHFLX ! ---------------------------------------------------------------------- ! UPDATE THE TEMPERATURE STATE OF THE SOIL COLUMN BASED ON THE THERMAL ! DIFFUSION EQUATION AND UPDATE THE FROZEN SOIL MOISTURE CONTENT BASED ! ON THE TEMPERATURE. ! ---------------------------------------------------------------------- IMPLICIT NONE INTEGER, INTENT(IN) :: ICE, NSOIL, VEGTYP INTEGER :: I REAL, INTENT(IN) :: BEXP,CSOIL,DF1,DT,F1,PSISAT,QUARTZ, & SMCMAX, SMCWLT, TBOT,YY, ZBOT,ZZ1 REAL, INTENT(INOUT) :: T1 REAL, INTENT(OUT) :: SSOIL REAL, DIMENSION(1:NSOIL), INTENT(IN) :: SMC,ZSOIL REAL, DIMENSION(1:NSOIL), INTENT(INOUT) :: SH2O REAL, DIMENSION(1:NSOIL), INTENT(INOUT) :: STC REAL, DIMENSION(1:NSOIL) :: AI, BI, CI, STCF,RHSTS REAL, PARAMETER :: T0 = 273.15 ! ---------------------------------------------------------------------- ! HRT ROUTINE CALCS THE RIGHT HAND SIDE OF THE SOIL TEMP DIF EQN ! ---------------------------------------------------------------------- ! ---------------------------------------------------------------------- ! SEA-ICE CASE ! ---------------------------------------------------------------------- IF (ICE == 1) THEN CALL HRTICE (RHSTS,STC,NSOIL,ZSOIL,YY,ZZ1,DF1,AI,BI,CI) CALL HSTEP (STCF,STC,RHSTS,DT,NSOIL,AI,BI,CI) ! ---------------------------------------------------------------------- ! LAND-MASS CASE ! ---------------------------------------------------------------------- ELSE CALL HRT (RHSTS,STC,SMC,SMCMAX,NSOIL,ZSOIL,YY,ZZ1,TBOT, & ZBOT,PSISAT,SH2O,DT, & BEXP,F1,DF1,QUARTZ,CSOIL,AI,BI,CI,VEGTYP) CALL HSTEP (STCF,STC,RHSTS,DT,NSOIL,AI,BI,CI) END IF DO I = 1,NSOIL STC (I) = STCF (I) END DO ! ---------------------------------------------------------------------- ! IN THE NO SNOWPACK CASE (VIA ROUTINE NOPAC BRANCH,) UPDATE THE GRND ! (SKIN) TEMPERATURE HERE IN RESPONSE TO THE UPDATED SOIL TEMPERATURE ! PROFILE ABOVE. (NOTE: INSPECTION OF ROUTINE SNOPAC SHOWS THAT T1 ! BELOW IS A DUMMY VARIABLE ONLY, AS SKIN TEMPERATURE IS UPDATED ! DIFFERENTLY IN ROUTINE SNOPAC) ! ---------------------------------------------------------------------- ! ---------------------------------------------------------------------- ! CALCULATE SURFACE SOIL HEAT FLUX ! ---------------------------------------------------------------------- T1 = (YY + (ZZ1- 1.0) * STC (1)) / ZZ1 SSOIL = DF1 * (STC (1) - T1) / (0.5 * ZSOIL (1)) ! ---------------------------------------------------------------------- END SUBROUTINE SHFLX ! ---------------------------------------------------------------------- SUBROUTINE SMFLX (SMC,NSOIL,CMC,DT,PRCP1,ZSOIL, & & SH2O,SLOPE,KDT,FRZFACT, & & SMCMAX,BEXP,SMCWLT,DKSAT,DWSAT, & & SHDFAC,CMCMAX, & & RUNOFF1,RUNOFF2,RUNOFF3, & & EDIR,EC,ET, & & DRIP) ! ---------------------------------------------------------------------- ! SUBROUTINE SMFLX ! ---------------------------------------------------------------------- ! CALCULATE SOIL MOISTURE FLUX. THE SOIL MOISTURE CONTENT (SMC - A PER ! UNIT VOLUME MEASUREMENT) IS A DEPENDENT VARIABLE THAT IS UPDATED WITH ! PROGNOSTIC EQNS. THE CANOPY MOISTURE CONTENT (CMC) IS ALSO UPDATED. ! FROZEN GROUND VERSION: NEW STATES ADDED: SH2O, AND FROZEN GROUND ! CORRECTION FACTOR, FRZFACT AND PARAMETER SLOPE. ! ---------------------------------------------------------------------- IMPLICIT NONE INTEGER, INTENT(IN) :: NSOIL INTEGER :: I,K REAL, INTENT(IN) :: BEXP, CMCMAX, DKSAT,DWSAT, DT, EC, EDIR, & KDT, PRCP1, SHDFAC, SLOPE, SMCMAX, SMCWLT REAL, INTENT(OUT) :: DRIP, RUNOFF1, RUNOFF2, RUNOFF3 REAL, INTENT(INOUT) :: CMC REAL, DIMENSION(1:NSOIL), INTENT(IN) :: ET,ZSOIL REAL, DIMENSION(1:NSOIL), INTENT(INOUT):: SMC, SH2O REAL, DIMENSION(1:NSOIL) :: AI, BI, CI, STCF,RHSTS, RHSTT, & SICE, SH2OA, SH2OFG REAL :: DUMMY, EXCESS,FRZFACT,PCPDRP,RHSCT,TRHSCT ! ---------------------------------------------------------------------- ! EXECUTABLE CODE BEGINS HERE. ! ---------------------------------------------------------------------- ! ---------------------------------------------------------------------- ! COMPUTE THE RIGHT HAND SIDE OF THE CANOPY EQN TERM ( RHSCT ) ! ---------------------------------------------------------------------- DUMMY = 0. ! ---------------------------------------------------------------------- ! CONVERT RHSCT (A RATE) TO TRHSCT (AN AMOUNT) AND ADD IT TO EXISTING ! CMC. IF RESULTING AMT EXCEEDS MAX CAPACITY, IT BECOMES DRIP AND WILL ! FALL TO THE GRND. ! ---------------------------------------------------------------------- RHSCT = SHDFAC * PRCP1- EC DRIP = 0. TRHSCT = DT * RHSCT EXCESS = CMC + TRHSCT ! ---------------------------------------------------------------------- ! PCPDRP IS THE COMBINED PRCP1 AND DRIP (FROM CMC) THAT GOES INTO THE ! SOIL ! ---------------------------------------------------------------------- IF (EXCESS > CMCMAX) DRIP = EXCESS - CMCMAX PCPDRP = (1. - SHDFAC) * PRCP1+ DRIP / DT ! ---------------------------------------------------------------------- ! STORE ICE CONTENT AT EACH SOIL LAYER BEFORE CALLING SRT and SSTEP ! DO I = 1,NSOIL SICE (I) = SMC (I) - SH2O (I) END DO ! ---------------------------------------------------------------------- ! CALL SUBROUTINES SRT AND SSTEP TO SOLVE THE SOIL MOISTURE ! TENDENCY EQUATIONS. ! IF THE INFILTRATING PRECIP RATE IS NONTRIVIAL, ! (WE CONSIDER NONTRIVIAL TO BE A PRECIP TOTAL OVER THE TIME STEP ! EXCEEDING ONE ONE-THOUSANDTH OF THE WATER HOLDING CAPACITY OF ! THE FIRST SOIL LAYER) ! THEN CALL THE SRT/SSTEP SUBROUTINE PAIR TWICE IN THE MANNER OF ! TIME SCHEME "F" (IMPLICIT STATE, AVERAGED COEFFICIENT) ! OF SECTION 2 OF KALNAY AND KANAMITSU (1988, MWR, VOL 116, ! PAGES 1945-1958)TO MINIMIZE 2-DELTA-T OSCILLATIONS IN THE ! SOIL MOISTURE VALUE OF THE TOP SOIL LAYER THAT CAN ARISE BECAUSE ! OF THE EXTREME NONLINEAR DEPENDENCE OF THE SOIL HYDRAULIC ! DIFFUSIVITY COEFFICIENT AND THE HYDRAULIC CONDUCTIVITY ON THE ! SOIL MOISTURE STATE ! OTHERWISE CALL THE SRT/SSTEP SUBROUTINE PAIR ONCE IN THE MANNER OF ! TIME SCHEME "D" (IMPLICIT STATE, EXPLICIT COEFFICIENT) ! OF SECTION 2 OF KALNAY AND KANAMITSU ! PCPDRP IS UNITS OF KG/M**2/S OR MM/S, ZSOIL IS NEGATIVE DEPTH IN M ! ---------------------------------------------------------------------- ! IF ( PCPDRP .GT. 0.0 ) THEN ! ---------------------------------------------------------------------- ! FROZEN GROUND VERSION: ! SMC STATES REPLACED BY SH2O STATES IN SRT SUBR. SH2O & SICE STATES ! INC&UDED IN SSTEP SUBR. FROZEN GROUND CORRECTION FACTOR, FRZFACT ! ADDED. ALL WATER BALANCE CALCULATIONS USING UNFROZEN WATER ! ---------------------------------------------------------------------- IF ( (PCPDRP * DT) > (0.001*1000.0* (- ZSOIL (1))* SMCMAX) ) THEN CALL SRT (RHSTT,EDIR,ET,SH2O,SH2O,NSOIL,PCPDRP,ZSOIL, & DWSAT,DKSAT,SMCMAX,BEXP,RUNOFF1, & RUNOFF2,DT,SMCWLT,SLOPE,KDT,FRZFACT,SICE,AI,BI,CI) CALL SSTEP (SH2OFG,SH2O,DUMMY,RHSTT,RHSCT,DT,NSOIL,SMCMAX, & CMCMAX,RUNOFF3,ZSOIL,SMC,SICE,AI,BI,CI) DO K = 1,NSOIL SH2OA (K) = (SH2O (K) + SH2OFG (K)) * 0.5 END DO CALL SRT (RHSTT,EDIR,ET,SH2O,SH2OA,NSOIL,PCPDRP,ZSOIL, & DWSAT,DKSAT,SMCMAX,BEXP,RUNOFF1, & RUNOFF2,DT,SMCWLT,SLOPE,KDT,FRZFACT,SICE,AI,BI,CI) CALL SSTEP (SH2O,SH2O,CMC,RHSTT,RHSCT,DT,NSOIL,SMCMAX, & CMCMAX,RUNOFF3,ZSOIL,SMC,SICE,AI,BI,CI) ELSE CALL SRT (RHSTT,EDIR,ET,SH2O,SH2O,NSOIL,PCPDRP,ZSOIL, & DWSAT,DKSAT,SMCMAX,BEXP,RUNOFF1, & RUNOFF2,DT,SMCWLT,SLOPE,KDT,FRZFACT,SICE,AI,BI,CI) CALL SSTEP (SH2O,SH2O,CMC,RHSTT,RHSCT,DT,NSOIL,SMCMAX, & CMCMAX,RUNOFF3,ZSOIL,SMC,SICE,AI,BI,CI) ! RUNOF = RUNOFF END IF ! ---------------------------------------------------------------------- END SUBROUTINE SMFLX ! ---------------------------------------------------------------------- SUBROUTINE SNFRAC (SNEQV,SNUP,SALP,SNOWH,SNCOVR) ! ---------------------------------------------------------------------- ! SUBROUTINE SNFRAC ! ---------------------------------------------------------------------- ! CALCULATE SNOW FRACTION (0 -> 1) ! SNEQV SNOW WATER EQUIVALENT (M) ! SNUP THRESHOLD SNEQV DEPTH ABOVE WHICH SNCOVR=1 ! SALP TUNING PARAMETER ! SNCOVR FRACTIONAL SNOW COVER ! ---------------------------------------------------------------------- IMPLICIT NONE REAL, INTENT(IN) :: SNEQV,SNUP,SALP,SNOWH REAL, INTENT(OUT) :: SNCOVR REAL :: RSNOW, Z0N ! ---------------------------------------------------------------------- ! SNUP IS VEG-CLASS DEPENDENT SNOWDEPTH THRESHHOLD (SET IN ROUTINE ! REDPRM) ABOVE WHICH SNOCVR=1. ! ---------------------------------------------------------------------- IF (SNEQV < SNUP) THEN RSNOW = SNEQV / SNUP SNCOVR = 1. - ( EXP ( - SALP * RSNOW) - RSNOW * EXP ( - SALP)) ELSE SNCOVR = 1.0 END IF ! FORMULATION OF DICKINSON ET AL. 1986 ! Z0N = 0.035 ! SNCOVR=SNOWH/(SNOWH + 5*Z0N) ! FORMULATION OF MARSHALL ET AL. 1994 ! SNCOVR=SNEQV/(SNEQV + 2*Z0N) ! ---------------------------------------------------------------------- END SUBROUTINE SNFRAC ! ---------------------------------------------------------------------- SUBROUTINE SNKSRC (TSNSR,TAVG,SMC,SH2O,ZSOIL,NSOIL, & & SMCMAX,PSISAT,BEXP,DT,K,QTOT) ! ---------------------------------------------------------------------- ! SUBROUTINE SNKSRC ! ---------------------------------------------------------------------- ! CALCULATE SINK/SOURCE TERM OF THE TERMAL DIFFUSION EQUATION. (SH2O) IS ! AVAILABLE LIQUED WATER. ! ---------------------------------------------------------------------- IMPLICIT NONE INTEGER, INTENT(IN) :: K,NSOIL REAL, INTENT(IN) :: BEXP, DT, PSISAT, QTOT, SMC, SMCMAX, & TAVG REAL, INTENT(INOUT) :: SH2O REAL, DIMENSION(1:NSOIL), INTENT(IN):: ZSOIL REAL :: DF, DZ, DZH, FREE, TSNSR, & TDN, TM, TUP, TZ, X0, XDN, XH2O, XUP REAL, PARAMETER :: DH2O = 1.0000E3, HLICE = 3.3350E5, & T0 = 2.7315E2 IF (K == 1) THEN DZ = - ZSOIL (1) ELSE DZ = ZSOIL (K -1) - ZSOIL (K) END IF ! ---------------------------------------------------------------------- ! VIA FUNCTION FRH2O, COMPUTE POTENTIAL OR 'EQUILIBRIUM' UNFROZEN ! SUPERCOOLED FREE WATER FOR GIVEN SOIL TYPE AND SOIL LAYER TEMPERATURE. ! FUNCTION FRH20 INVOKES EQN (17) FROM V. KOREN ET AL (1999, JGR, VOL. ! 104, PG 19573). (ASIDE: LATTER EQN IN JOURNAL IN CENTIGRADE UNITS. ! ROUTINE FRH2O USE FORM OF EQN IN KELVIN UNITS.) ! ---------------------------------------------------------------------- ! FREE = FRH2O(TAVG,SMC,SH2O,SMCMAX,BEXP,PSISAT) ! ---------------------------------------------------------------------- ! IN NEXT BLOCK OF CODE, INVOKE EQN 18 OF V. KOREN ET AL (1999, JGR, ! VOL. 104, PG 19573.) THAT IS, FIRST ESTIMATE THE NEW AMOUNTOF LIQUID ! WATER, 'XH2O', IMPLIED BY THE SUM OF (1) THE LIQUID WATER AT THE BEGIN ! OF CURRENT TIME STEP, AND (2) THE FREEZE OF THAW CHANGE IN LIQUID ! WATER IMPLIED BY THE HEAT FLUX 'QTOT' PASSED IN FROM ROUTINE HRT. ! SECOND, DETERMINE IF XH2O NEEDS TO BE BOUNDED BY 'FREE' (EQUIL AMT) OR ! IF 'FREE' NEEDS TO BE BOUNDED BY XH2O. ! ---------------------------------------------------------------------- CALL FRH2O (FREE,TAVG,SMC,SH2O,SMCMAX,BEXP,PSISAT) ! ---------------------------------------------------------------------- ! FIRST, IF FREEZING AND REMAINING LIQUID LESS THAN LOWER BOUND, THEN ! REDUCE EXTENT OF FREEZING, THEREBY LETTING SOME OR ALL OF HEAT FLUX ! QTOT COOL THE SOIL TEMP LATER IN ROUTINE HRT. ! ---------------------------------------------------------------------- XH2O = SH2O + QTOT * DT / (DH2O * HLICE * DZ) IF ( XH2O < SH2O .AND. XH2O < FREE) THEN IF ( FREE > SH2O ) THEN XH2O = SH2O ELSE XH2O = FREE END IF END IF ! ---------------------------------------------------------------------- ! SECOND, IF THAWING AND THE INCREASE IN LIQUID WATER GREATER THAN UPPER ! BOUND, THEN REDUCE EXTENT OF THAW, THEREBY LETTING SOME OR ALL OF HEAT ! FLUX QTOT WARM THE SOIL TEMP LATER IN ROUTINE HRT. ! ---------------------------------------------------------------------- IF ( XH2O > SH2O .AND. XH2O > FREE ) THEN IF ( FREE < SH2O ) THEN XH2O = SH2O ELSE XH2O = FREE END IF END IF ! ---------------------------------------------------------------------- ! CALCULATE PHASE-CHANGE HEAT SOURCE/SINK TERM FOR USE IN ROUTINE HRT ! AND UPDATE LIQUID WATER TO REFLCET FINAL FREEZE/THAW INCREMENT. ! ---------------------------------------------------------------------- ! SNKSRC = -DH2O*HLICE*DZ*(XH2O-SH2O)/DT IF (XH2O < 0.) XH2O = 0. IF (XH2O > SMC) XH2O = SMC TSNSR = - DH2O * HLICE * DZ * (XH2O - SH2O)/ DT SH2O = XH2O ! ---------------------------------------------------------------------- END SUBROUTINE SNKSRC ! ---------------------------------------------------------------------- SUBROUTINE SNOPAC (ETP,ETA,PRCP,PRCPF,SNOWNG,SMC,SMCMAX,SMCWLT, & SMCREF,SMCDRY,CMC,CMCMAX,NSOIL,DT, & SBETA,DF1, & Q2,T1,SFCTMP,T24,TH2,FDOWN,F1,SSOIL,STC,EPSCA,& SFCPRS,BEXP,PC,RCH,RR,CFACTR,SNCOVR,ESD,SNDENS,& SNOWH,SH2O,SLOPE,KDT,FRZFACT,PSISAT, & ZSOIL,DWSAT,DKSAT,TBOT,ZBOT,SHDFAC,RUNOFF1, & RUNOFF2,RUNOFF3,EDIR,EC,ET,ETT,NROOT,SNOMLT, & ICE,RTDIS,QUARTZ,FXEXP,CSOIL, & BETA,DRIP,DEW,FLX1,FLX2,FLX3,ESNOW,ETNS,EMISSI,& VEGTYP) ! ---------------------------------------------------------------------- ! SUBROUTINE SNOPAC ! ---------------------------------------------------------------------- ! CALCULATE SOIL MOISTURE AND HEAT FLUX VALUES & UPDATE SOIL MOISTURE ! CONTENT AND SOIL HEAT CONTENT VALUES FOR THE CASE WHEN A SNOW PACK IS ! PRESENT. ! ---------------------------------------------------------------------- IMPLICIT NONE INTEGER, INTENT(IN) :: ICE, NROOT, NSOIL,VEGTYP INTEGER :: K LOGICAL, INTENT(IN) :: SNOWNG REAL, INTENT(IN) :: BEXP,CFACTR, CMCMAX,CSOIL,DF1,DKSAT, & DT,DWSAT, EPSCA,ETP,FDOWN,F1,FXEXP, & FRZFACT,KDT,PC, PRCP,PSISAT,Q2,QUARTZ, & RCH,RR,SBETA,SFCPRS, SFCTMP, SHDFAC, & SLOPE,SMCDRY,SMCMAX,SMCREF,SMCWLT, T24, & TBOT,TH2,ZBOT,EMISSI REAL, INTENT(INOUT) :: CMC, BETA, ESD,FLX2,PRCPF,SNOWH,SNCOVR, & SNDENS, T1 REAL, INTENT(OUT) :: DEW,DRIP,EC,EDIR, ETNS, ESNOW,ETT, & FLX1,FLX3, RUNOFF1,RUNOFF2,RUNOFF3, & SSOIL,SNOMLT REAL, DIMENSION(1:NSOIL),INTENT(IN) :: RTDIS,ZSOIL REAL, DIMENSION(1:NSOIL),INTENT(OUT) :: ET REAL, DIMENSION(1:NSOIL), INTENT(INOUT) :: SMC,SH2O,STC REAL, DIMENSION(1:NSOIL) :: ET1 REAL :: DENOM,DSOIL,DTOT,EC1,EDIR1,ESDFLX,ETA, & ETT1, ESNOW1, ESNOW2, ETA1,ETP1,ETP2, & ETP3, ETNS1, ETANRG, ETAX, EX, FLX3X, & FRCSNO,FRCSOI, PRCP1, QSAT,RSNOW, SEH, & SNCOND,SSOIL1, T11,T12, T12A, T12AX, & T12B, T14, YY, ZZ1 ! T12B, T14, YY, ZZ1,EMISSI_S REAL, PARAMETER :: ESDMIN = 1.E-6, LSUBC = 2.501000E+6, & LSUBS = 2.83E+6, TFREEZ = 273.15, & SNOEXP = 2.0 ! ---------------------------------------------------------------------- ! EXECUTABLE CODE BEGINS HERE: ! INITIALIZE EVAP TERMS. ! ---------------------------------------------------------------------- ! conversions: ! ESNOW [KG M-2 S-1] ! ESDFLX [KG M-2 S-1] .le. ESNOW ! ESNOW1 [M S-1] ! ESNOW2 [M] ! ETP [KG M-2 S-1] ! ETP1 [M S-1] ! ETP2 [M] ! ---------------------------------------------------------------------- DEW = 0. EDIR = 0. EDIR1 = 0. EC1 = 0. EC = 0. ! EMISSI_S=0.95 ! For snow DO K = 1,NSOIL ET (K) = 0. ET1 (K) = 0. END DO ETT = 0. ETT1 = 0. ETNS = 0. ETNS1 = 0. ESNOW = 0. ESNOW1 = 0. ESNOW2 = 0. ! ---------------------------------------------------------------------- ! CONVERT POTENTIAL EVAP (ETP) FROM KG M-2 S-1 TO ETP1 IN M S-1 ! ---------------------------------------------------------------------- PRCP1 = PRCPF *0.001 ETP1 = ETP * 0.001 ! ---------------------------------------------------------------------- ! IF ETP<0 (DOWNWARD) THEN DEWFALL (=FROSTFALL IN THIS CASE). ! ---------------------------------------------------------------------- BETA = 1.0 IF (ETP <= 0.0) THEN IF(ETP == 0.) BETA = 0.0 DEW = -ETP1 ESNOW2 = ETP1*DT ETANRG = ETP*((1.-SNCOVR)*LSUBC + SNCOVR*LSUBS) ELSE IF (ICE /= 1) THEN IF (SNCOVR < 1.) THEN CALL EVAPO (ETNS1,SMC,NSOIL,CMC,ETP1,DT,ZSOIL, & SH2O, & SMCMAX,BEXP,PC,SMCWLT,DKSAT,DWSAT, & SMCREF,SHDFAC,CMCMAX, & SMCDRY,CFACTR, & EDIR1,EC1,ET1,ETT1,SFCTMP,Q2,NROOT,RTDIS, & FXEXP) ! ---------------------------------------------------------------------------- EDIR1 = EDIR1* (1. - SNCOVR) EC1 = EC1* (1. - SNCOVR) DO K = 1,NSOIL ET1 (K) = ET1 (K)* (1. - SNCOVR) END DO ETT1 = ETT1*(1.-SNCOVR) ! ETNS1 = EDIR1+ EC1+ ETT1 ETNS1 = ETNS1*(1.-SNCOVR) ! ---------------------------------------------------------------------------- EDIR = EDIR1*1000. EC = EC1*1000. DO K = 1,NSOIL ET (K) = ET1 (K)*1000. END DO ETT = ETT1*1000. ETNS = ETNS1*1000. ! ---------------------------------------------------------------------- ! end IF (SNCOVR .lt. 1.) END IF ! end IF (ICE .ne. 1) END IF ESNOW = ETP*SNCOVR ESNOW1 = ESNOW*0.001 ESNOW2 = ESNOW1*DT ETANRG = ESNOW*LSUBS + ETNS*LSUBC ! end IF (ETP .le. 0.0) END IF ! ---------------------------------------------------------------------- ! IF PRECIP IS FALLING, CALCULATE HEAT FLUX FROM SNOW SFC TO NEWLY ! ACCUMULATING PRECIP. NOTE THAT THIS REFLECTS THE FLUX APPROPRIATE FOR ! THE NOT-YET-UPDATED SKIN TEMPERATURE (T1). ASSUMES TEMPERATURE OF THE ! SNOWFALL STRIKING THE GROUND IS =SFCTMP (LOWEST MODEL LEVEL AIR TEMP). ! ---------------------------------------------------------------------- FLX1 = 0.0 IF (SNOWNG) THEN FLX1 = CPICE * PRCP * (T1- SFCTMP) ELSE IF (PRCP > 0.0) FLX1 = CPH2O * PRCP * (T1- SFCTMP) ! ---------------------------------------------------------------------- ! CALCULATE AN 'EFFECTIVE SNOW-GRND SFC TEMP' (T12) BASED ON HEAT FLUXES ! BETWEEN THE SNOW PACK AND THE SOIL AND ON NET RADIATION. ! INCLUDE FLX1 (PRECIP-SNOW SFC) AND FLX2 (FREEZING RAIN LATENT HEAT) ! FLUXES. FLX1 FROM ABOVE, FLX2 BROUGHT IN VIA COMMOM BLOCK RITE. ! FLX2 REFLECTS FREEZING RAIN LATENT HEAT FLUX USING T1 CALCULATED IN ! PENMAN. ! ---------------------------------------------------------------------- END IF DSOIL = - (0.5 * ZSOIL (1)) DTOT = SNOWH + DSOIL DENOM = 1.0+ DF1 / (DTOT * RR * RCH) ! surface emissivity weighted by snow cover fraction ! T12A = ( (FDOWN - FLX1 - FLX2 - & ! & ((SNCOVR*EMISSI_S)+EMISSI*(1.0-SNCOVR))*SIGMA *T24)/RCH & ! & + TH2 - SFCTMP - ETANRG/RCH ) / RR T12A = ( (FDOWN - FLX1- FLX2- EMISSI * SIGMA * T24)/ RCH & + TH2- SFCTMP - ETANRG / RCH ) / RR T12B = DF1 * STC (1) / (DTOT * RR * RCH) ! ---------------------------------------------------------------------- ! IF THE 'EFFECTIVE SNOW-GRND SFC TEMP' IS AT OR BELOW FREEZING, NO SNOW ! MELT WILL OCCUR. SET THE SKIN TEMP TO THIS EFFECTIVE TEMP. REDUCE ! (BY SUBLIMINATION ) OR INCREASE (BY FROST) THE DEPTH OF THE SNOWPACK, ! DEPENDING ON SIGN OF ETP. ! UPDATE SOIL HEAT FLUX (SSOIL) USING NEW SKIN TEMPERATURE (T1) ! SINCE NO SNOWMELT, SET ACCUMULATED SNOWMELT TO ZERO, SET 'EFFECTIVE' ! PRECIP FROM SNOWMELT TO ZERO, SET PHASE-CHANGE HEAT FLUX FROM SNOWMELT ! TO ZERO. ! ---------------------------------------------------------------------- ! SUB-FREEZING BLOCK ! ---------------------------------------------------------------------- T12 = (SFCTMP + T12A + T12B) / DENOM IF (T12 <= TFREEZ) THEN T1 = T12 SSOIL = DF1 * (T1- STC (1)) / DTOT ! ESD = MAX (0.0, ESD- ETP2) ESD = MAX(0.0, ESD-ESNOW2) FLX3 = 0.0 EX = 0.0 SNOMLT = 0.0 ! ---------------------------------------------------------------------- ! IF THE 'EFFECTIVE SNOW-GRND SFC TEMP' IS ABOVE FREEZING, SNOW MELT ! WILL OCCUR. CALL THE SNOW MELT RATE,EX AND AMT, SNOMLT. REVISE THE ! EFFECTIVE SNOW DEPTH. REVISE THE SKIN TEMP BECAUSE IT WOULD HAVE CHGD ! DUE TO THE LATENT HEAT RELEASED BY THE MELTING. CALC THE LATENT HEAT ! RELEASED, FLX3. SET THE EFFECTIVE PRECIP, PRCP1 TO THE SNOW MELT RATE, ! EX FOR USE IN SMFLX. ADJUSTMENT TO T1 TO ACCOUNT FOR SNOW PATCHES. ! CALCULATE QSAT VALID AT FREEZING POINT. NOTE THAT ESAT (SATURATION ! VAPOR PRESSURE) VALUE OF 6.11E+2 USED HERE IS THAT VALID AT FRZZING ! POINT. NOTE THAT ETP FROM CALL PENMAN IN SFLX IS IGNORED HERE IN ! FAVOR OF BULK ETP OVER 'OPEN WATER' AT FREEZING TEMP. ! UPDATE SOIL HEAT FLUX (S) USING NEW SKIN TEMPERATURE (T1) ! ---------------------------------------------------------------------- ! ABOVE FREEZING BLOCK ! ---------------------------------------------------------------------- ELSE T1 = TFREEZ * SNCOVR ** SNOEXP + T12 * (1.0- SNCOVR ** SNOEXP) BETA = 1.0 ! ---------------------------------------------------------------------- ! IF POTENTIAL EVAP (SUBLIMATION) GREATER THAN DEPTH OF SNOWPACK. ! BETA<1 ! SNOWPACK HAS SUBLIMATED AWAY, SET DEPTH TO ZERO. ! ---------------------------------------------------------------------- SSOIL = DF1 * (T1- STC (1)) / DTOT IF (ESD-ESNOW2 <= ESDMIN) THEN ESD = 0.0 EX = 0.0 SNOMLT = 0.0 ! ---------------------------------------------------------------------- ! SUBLIMATION LESS THAN DEPTH OF SNOWPACK ! SNOWPACK (ESD) REDUCED BY ESNOW2 (DEPTH OF SUBLIMATED SNOW) ! ---------------------------------------------------------------------- ELSE ESD = ESD-ESNOW2 ETP3 = ETP * LSUBC SEH = RCH * (T1- TH2) T14 = T1* T1 T14 = T14* T14 ! FLX3 = FDOWN - FLX1 - FLX2 - & ! ((SNCOVR*EMISSI_S)+EMISSI*(1-SNCOVR))*SIGMA*T14 - & ! SSOIL - SEH - ETANRG FLX3 = FDOWN - FLX1- FLX2- EMISSI*SIGMA * T14- SSOIL - SEH - ETANRG IF (FLX3 <= 0.0) FLX3 = 0.0 ! ---------------------------------------------------------------------- ! SNOWMELT REDUCTION DEPENDING ON SNOW COVER ! ---------------------------------------------------------------------- EX = FLX3*0.001/ LSUBF ! ---------------------------------------------------------------------- ! ESDMIN REPRESENTS A SNOWPACK DEPTH THRESHOLD VALUE BELOW WHICH WE ! CHOOSE NOT TO RETAIN ANY SNOWPACK, AND INSTEAD INCLUDE IT IN SNOWMELT. ! ---------------------------------------------------------------------- SNOMLT = EX * DT IF (ESD- SNOMLT >= ESDMIN) THEN ESD = ESD- SNOMLT ! ---------------------------------------------------------------------- ! SNOWMELT EXCEEDS SNOW DEPTH ! ---------------------------------------------------------------------- ELSE EX = ESD / DT FLX3 = EX *1000.0* LSUBF SNOMLT = ESD ESD = 0.0 ! ---------------------------------------------------------------------- ! END OF 'ESD .LE. ETP2' IF-BLOCK ! ---------------------------------------------------------------------- END IF END IF ! ---------------------------------------------------------------------- ! END OF 'T12 .LE. TFREEZ' IF-BLOCK ! ---------------------------------------------------------------------- PRCP1 = PRCP1+ EX ! ---------------------------------------------------------------------- ! SET THE EFFECTIVE POTNL EVAPOTRANSP (ETP1) TO ZERO SINCE THIS IS SNOW ! CASE, SO SURFACE EVAP NOT CALCULATED FROM EDIR, EC, OR ETT IN SMFLX ! (BELOW). ! IF SEAICE (ICE=1) SKIP CALL TO SMFLX. ! SMFLX RETURNS UPDATED SOIL MOISTURE VALUES. IN THIS, THE SNOW PACK ! CASE, ETA1 IS NOT USED IN CALCULATION OF EVAP. ! ---------------------------------------------------------------------- END IF IF (ICE /= 1) THEN CALL SMFLX (SMC,NSOIL,CMC,DT,PRCP1,ZSOIL, & SH2O,SLOPE,KDT,FRZFACT, & SMCMAX,BEXP,SMCWLT,DKSAT,DWSAT, & SHDFAC,CMCMAX, & RUNOFF1,RUNOFF2,RUNOFF3, & EDIR1,EC1,ET1, & DRIP) ! ---------------------------------------------------------------------- ! BEFORE CALL SHFLX IN THIS SNOWPACK CASE, SET ZZ1 AND YY ARGUMENTS TO ! SPECIAL VALUES THAT ENSURE THAT GROUND HEAT FLUX CALCULATED IN SHFLX ! MATCHES THAT ALREADY COMPUTER FOR BELOW THE SNOWPACK, THUS THE SFC ! HEAT FLUX TO BE COMPUTED IN SHFLX WILL EFFECTIVELY BE THE FLUX AT THE ! SNOW TOP SURFACE. T11 IS A DUMMY ARGUEMENT SO WE WILL NOT USE THE ! SKIN TEMP VALUE AS REVISED BY SHFLX. ! ---------------------------------------------------------------------- END IF ZZ1 = 1.0 YY = STC (1) -0.5* SSOIL * ZSOIL (1)* ZZ1/ DF1 ! ---------------------------------------------------------------------- ! SHFLX WILL CALC/UPDATE THE SOIL TEMPS. NOTE: THE SUB-SFC HEAT FLUX ! (SSOIL1) AND THE SKIN TEMP (T11) OUTPUT FROM THIS SHFLX CALL ARE NOT ! USED IN ANY SUBSEQUENT CALCULATIONS. RATHER, THEY ARE DUMMY VARIABLES ! HERE IN THE SNOPAC CASE, SINCE THE SKIN TEMP AND SUB-SFC HEAT FLUX ARE ! UPDATED INSTEAD NEAR THE BEGINNING OF THE CALL TO SNOPAC. ! ---------------------------------------------------------------------- T11 = T1 CALL SHFLX (SSOIL1,STC,SMC,SMCMAX,NSOIL,T11,DT,YY,ZZ1,ZSOIL, & TBOT,ZBOT,SMCWLT,PSISAT,SH2O,BEXP,F1,DF1,ICE, & QUARTZ,CSOIL,VEGTYP) ! ---------------------------------------------------------------------- ! SNOW DEPTH AND DENSITY ADJUSTMENT BASED ON SNOW COMPACTION. YY IS ! ASSUMED TO BE THE SOIL TEMPERTURE AT THE TOP OF THE SOIL COLUMN. ! ---------------------------------------------------------------------- IF (ESD > 0.) THEN CALL SNOWPACK (ESD,DT,SNOWH,SNDENS,T1,YY) ELSE ESD = 0. SNOWH = 0. SNDENS = 0. SNCOND = 1. SNCOVR = 0. END IF ! ---------------------------------------------------------------------- END SUBROUTINE SNOPAC ! ---------------------------------------------------------------------- SUBROUTINE SNOWPACK (ESD,DTSEC,SNOWH,SNDENS,TSNOW,TSOIL) ! ---------------------------------------------------------------------- ! SUBROUTINE SNOWPACK ! ---------------------------------------------------------------------- ! CALCULATE COMPACTION OF SNOWPACK UNDER CONDITIONS OF INCREASING SNOW ! DENSITY, AS OBTAINED FROM AN APPROXIMATE SOLUTION OF E. ANDERSON'S ! DIFFERENTIAL EQUATION (3.29), NOAA TECHNICAL REPORT NWS 19, BY VICTOR ! KOREN, 03/25/95. ! ---------------------------------------------------------------------- ! ESD WATER EQUIVALENT OF SNOW (M) ! DTSEC TIME STEP (SEC) ! SNOWH SNOW DEPTH (M) ! SNDENS SNOW DENSITY (G/CM3=DIMENSIONLESS FRACTION OF H2O DENSITY) ! TSNOW SNOW SURFACE TEMPERATURE (K) ! TSOIL SOIL SURFACE TEMPERATURE (K) ! SUBROUTINE WILL RETURN NEW VALUES OF SNOWH AND SNDENS ! ---------------------------------------------------------------------- IMPLICIT NONE INTEGER :: IPOL, J REAL, INTENT(IN) :: ESD, DTSEC,TSNOW,TSOIL REAL, INTENT(INOUT) :: SNOWH, SNDENS REAL :: BFAC,DSX,DTHR,DW,SNOWHC,PEXP, & TAVGC,TSNOWC,TSOILC,ESDC,ESDCX REAL, PARAMETER :: C1 = 0.01, C2 = 21.0, G = 9.81, & KN = 4000.0 ! ---------------------------------------------------------------------- ! CONVERSION INTO SIMULATION UNITS ! ---------------------------------------------------------------------- SNOWHC = SNOWH *100. ESDC = ESD *100. DTHR = DTSEC /3600. TSNOWC = TSNOW -273.15 TSOILC = TSOIL -273.15 ! ---------------------------------------------------------------------- ! CALCULATING OF AVERAGE TEMPERATURE OF SNOW PACK ! ---------------------------------------------------------------------- ! ---------------------------------------------------------------------- ! CALCULATING OF SNOW DEPTH AND DENSITY AS A RESULT OF COMPACTION ! SNDENS=DS0*(EXP(BFAC*ESD)-1.)/(BFAC*ESD) ! BFAC=DTHR*C1*EXP(0.08*TAVGC-C2*DS0) ! NOTE: BFAC*ESD IN SNDENS EQN ABOVE HAS TO BE CAREFULLY TREATED ! NUMERICALLY BELOW: ! C1 IS THE FRACTIONAL INCREASE IN DENSITY (1/(CM*HR)) ! C2 IS A CONSTANT (CM3/G) KOJIMA ESTIMATED AS 21 CMS/G ! ---------------------------------------------------------------------- TAVGC = 0.5* (TSNOWC + TSOILC) IF (ESDC > 1.E-2) THEN ESDCX = ESDC ELSE ESDCX = 1.E-2 END IF ! DSX = SNDENS*((DEXP(BFAC*ESDC)-1.)/(BFAC*ESDC)) ! ---------------------------------------------------------------------- ! THE FUNCTION OF THE FORM (e**x-1)/x IMBEDDED IN ABOVE EXPRESSION ! FOR DSX WAS CAUSING NUMERICAL DIFFICULTIES WHEN THE DENOMINATOR "x" ! (I.E. BFAC*ESDC) BECAME ZERO OR APPROACHED ZERO (DESPITE THE FACT THAT ! THE ANALYTICAL FUNCTION (e**x-1)/x HAS A WELL DEFINED LIMIT AS ! "x" APPROACHES ZERO), HENCE BELOW WE REPLACE THE (e**x-1)/x ! EXPRESSION WITH AN EQUIVALENT, NUMERICALLY WELL-BEHAVED ! POLYNOMIAL EXPANSION. ! NUMBER OF TERMS OF POLYNOMIAL EXPANSION, AND HENCE ITS ACCURACY, ! IS GOVERNED BY ITERATION LIMIT "IPOL". ! IPOL GREATER THAN 9 ONLY MAKES A DIFFERENCE ON DOUBLE ! PRECISION (RELATIVE ERRORS GIVEN IN PERCENT %). ! IPOL=9, FOR REL.ERROR <~ 1.6 E-6 % (8 SIGNIFICANT DIGITS) ! IPOL=8, FOR REL.ERROR <~ 1.8 E-5 % (7 SIGNIFICANT DIGITS) ! IPOL=7, FOR REL.ERROR <~ 1.8 E-4 % ... ! ---------------------------------------------------------------------- BFAC = DTHR * C1* EXP (0.08* TAVGC - C2* SNDENS) IPOL = 4 PEXP = 0. ! PEXP = (1. + PEXP)*BFAC*ESDC/REAL(J+1) DO J = IPOL,1, -1 PEXP = (1. + PEXP)* BFAC * ESDCX / REAL (J +1) END DO PEXP = PEXP + 1. ! ---------------------------------------------------------------------- ! ABOVE LINE ENDS POLYNOMIAL SUBSTITUTION ! ---------------------------------------------------------------------- ! END OF KOREAN FORMULATION ! BASE FORMULATION (COGLEY ET AL., 1990) ! CONVERT DENSITY FROM G/CM3 TO KG/M3 ! DSM=SNDENS*1000.0 ! DSX=DSM+DTSEC*0.5*DSM*G*ESD/ ! & (1E7*EXP(-0.02*DSM+KN/(TAVGC+273.16)-14.643)) ! & CONVERT DENSITY FROM KG/M3 TO G/CM3 ! DSX=DSX/1000.0 ! END OF COGLEY ET AL. FORMULATION ! ---------------------------------------------------------------------- ! SET UPPER/LOWER LIMIT ON SNOW DENSITY ! ---------------------------------------------------------------------- DSX = SNDENS * (PEXP) IF (DSX > 0.40) DSX = 0.40 IF (DSX < 0.05) DSX = 0.05 ! ---------------------------------------------------------------------- ! UPDATE OF SNOW DEPTH AND DENSITY DEPENDING ON LIQUID WATER DURING ! SNOWMELT. ASSUMED THAT 13% OF LIQUID WATER CAN BE STORED IN SNOW PER ! DAY DURING SNOWMELT TILL SNOW DENSITY 0.40. ! ---------------------------------------------------------------------- SNDENS = DSX IF (TSNOWC >= 0.) THEN DW = 0.13* DTHR /24. SNDENS = SNDENS * (1. - DW) + DW IF (SNDENS >= 0.40) SNDENS = 0.40 ! ---------------------------------------------------------------------- ! CALCULATE SNOW DEPTH (CM) FROM SNOW WATER EQUIVALENT AND SNOW DENSITY. ! CHANGE SNOW DEPTH UNITS TO METERS ! ---------------------------------------------------------------------- END IF SNOWHC = ESDC / SNDENS SNOWH = SNOWHC *0.01 ! ---------------------------------------------------------------------- END SUBROUTINE SNOWPACK ! ---------------------------------------------------------------------- SUBROUTINE SNOWZ0 (SNCOVR,Z0, Z0BRD) ! ---------------------------------------------------------------------- ! SUBROUTINE SNOWZ0 ! ---------------------------------------------------------------------- ! CALCULATE TOTAL ROUGHNESS LENGTH OVER SNOW ! SNCOVR FRACTIONAL SNOW COVER ! Z0 ROUGHNESS LENGTH (m) ! Z0S SNOW ROUGHNESS LENGTH:=0.001 (m) ! ---------------------------------------------------------------------- IMPLICIT NONE REAL, INTENT(IN) :: SNCOVR, Z0BRD REAL, INTENT(OUT) :: Z0 REAL, PARAMETER :: Z0S=0.001 !m Z0 = (1.- SNCOVR)* Z0BRD + SNCOVR * Z0S Z0 = Z0BRD ! ---------------------------------------------------------------------- END SUBROUTINE SNOWZ0 ! ---------------------------------------------------------------------- SUBROUTINE SNOW_NEW (TEMP,NEWSN,SNOWH,SNDENS) ! ---------------------------------------------------------------------- ! SUBROUTINE SNOW_NEW ! ---------------------------------------------------------------------- ! CALCULATE SNOW DEPTH AND DENSITITY TO ACCOUNT FOR THE NEW SNOWFALL. ! NEW VALUES OF SNOW DEPTH & DENSITY RETURNED. ! TEMP AIR TEMPERATURE (K) ! NEWSN NEW SNOWFALL (M) ! SNOWH SNOW DEPTH (M) ! SNDENS SNOW DENSITY (G/CM3=DIMENSIONLESS FRACTION OF H2O DENSITY) ! ---------------------------------------------------------------------- IMPLICIT NONE REAL, INTENT(IN) :: NEWSN, TEMP REAL, INTENT(INOUT) :: SNDENS, SNOWH REAL :: DSNEW, HNEWC, SNOWHC,NEWSNC,TEMPC ! ---------------------------------------------------------------------- ! CONVERSION INTO SIMULATION UNITS ! ---------------------------------------------------------------------- SNOWHC = SNOWH *100. NEWSNC = NEWSN *100. ! ---------------------------------------------------------------------- ! CALCULATING NEW SNOWFALL DENSITY DEPENDING ON TEMPERATURE ! EQUATION FROM GOTTLIB L. 'A GENERAL RUNOFF MODEL FOR SNOWCOVERED ! AND GLACIERIZED BASIN', 6TH NORDIC HYDROLOGICAL CONFERENCE, ! VEMADOLEN, SWEDEN, 1980, 172-177PP. !----------------------------------------------------------------------- TEMPC = TEMP -273.15 IF (TEMPC <= -15.) THEN DSNEW = 0.05 ELSE DSNEW = 0.05+0.0017* (TEMPC +15.)**1.5 END IF ! ---------------------------------------------------------------------- ! ADJUSTMENT OF SNOW DENSITY DEPENDING ON NEW SNOWFALL ! ---------------------------------------------------------------------- HNEWC = NEWSNC / DSNEW IF (SNOWHC + HNEWC .LT. 1.0E-3) THEN SNDENS = MAX(DSNEW,SNDENS) ELSE SNDENS = (SNOWHC * SNDENS + HNEWC * DSNEW)/ (SNOWHC + HNEWC) ENDIF SNOWHC = SNOWHC + HNEWC SNOWH = SNOWHC *0.01 ! ---------------------------------------------------------------------- END SUBROUTINE SNOW_NEW ! ---------------------------------------------------------------------- SUBROUTINE SRT (RHSTT,EDIR,ET,SH2O,SH2OA,NSOIL,PCPDRP, & ZSOIL,DWSAT,DKSAT,SMCMAX,BEXP,RUNOFF1, & RUNOFF2,DT,SMCWLT,SLOPE,KDT,FRZX,SICE,AI,BI,CI) ! ---------------------------------------------------------------------- ! SUBROUTINE SRT ! ---------------------------------------------------------------------- ! CALCULATE THE RIGHT HAND SIDE OF THE TIME TENDENCY TERM OF THE SOIL ! WATER DIFFUSION EQUATION. ALSO TO COMPUTE ( PREPARE ) THE MATRIX ! COEFFICIENTS FOR THE TRI-DIAGONAL MATRIX OF THE IMPLICIT TIME SCHEME. ! ---------------------------------------------------------------------- IMPLICIT NONE INTEGER, INTENT(IN) :: NSOIL INTEGER :: IALP1, IOHINF, J, JJ, K, KS REAL, INTENT(IN) :: BEXP, DKSAT, DT, DWSAT, EDIR, FRZX, & KDT, PCPDRP, SLOPE, SMCMAX, SMCWLT REAL, INTENT(OUT) :: RUNOFF1, RUNOFF2 REAL, DIMENSION(1:NSOIL), INTENT(IN) :: ET, SH2O, SH2OA, SICE, & ZSOIL REAL, DIMENSION(1:NSOIL), INTENT(OUT) :: RHSTT REAL, DIMENSION(1:NSOIL), INTENT(OUT) :: AI, BI, CI REAL, DIMENSION(1:NSOIL) :: DMAX REAL :: ACRT, DD, DDT, DDZ, DDZ2, DENOM, & DENOM2,DICE, DSMDZ, DSMDZ2, DT1, & FCR,INFMAX,MXSMC,MXSMC2,NUMER,PDDUM, & PX, SICEMAX,SLOPX, SMCAV, SSTT, & SUM, VAL, WCND, WCND2, WDF, WDF2 INTEGER, PARAMETER :: CVFRZ = 3 ! ---------------------------------------------------------------------- ! FROZEN GROUND VERSION: ! REFERENCE FROZEN GROUND PARAMETER, CVFRZ, IS A SHAPE PARAMETER OF ! AREAL DISTRIBUTION FUNCTION OF SOIL ICE CONTENT WHICH EQUALS 1/CV. ! CV IS A COEFFICIENT OF SPATIAL VARIATION OF SOIL ICE CONTENT. BASED ! ON FIELD DATA CV DEPENDS ON AREAL MEAN OF FROZEN DEPTH, AND IT CLOSE ! TO CONSTANT = 0.6 IF AREAL MEAN FROZEN DEPTH IS ABOVE 20 CM. THAT IS ! WHY PARAMETER CVFRZ = 3 (INT{1/0.6*0.6}). ! CURRENT LOGIC DOESN'T ALLOW CVFRZ BE BIGGER THAN 3 ! ---------------------------------------------------------------------- ! ---------------------------------------------------------------------- ! DETERMINE RAINFALL INFILTRATION RATE AND RUNOFF. INCLUDE THE ! INFILTRATION FORMULE FROM SCHAAKE AND KOREN MODEL. ! MODIFIED BY Q DUAN ! ---------------------------------------------------------------------- ! ---------------------------------------------------------------------- ! LET SICEMAX BE THE GREATEST, IF ANY, FROZEN WATER CONTENT WITHIN SOIL ! LAYERS. ! ---------------------------------------------------------------------- IOHINF = 1 SICEMAX = 0.0 DO KS = 1,NSOIL IF (SICE (KS) > SICEMAX) SICEMAX = SICE (KS) ! ---------------------------------------------------------------------- ! DETERMINE RAINFALL INFILTRATION RATE AND RUNOFF ! ---------------------------------------------------------------------- END DO PDDUM = PCPDRP RUNOFF1 = 0.0 ! ---------------------------------------------------------------------- ! MODIFIED BY Q. DUAN, 5/16/94 ! ---------------------------------------------------------------------- ! IF (IOHINF == 1) THEN IF (PCPDRP /= 0.0) THEN DT1 = DT /86400. SMCAV = SMCMAX - SMCWLT ! ---------------------------------------------------------------------- ! FROZEN GROUND VERSION: ! ---------------------------------------------------------------------- DMAX (1)= - ZSOIL (1)* SMCAV DICE = - ZSOIL (1) * SICE (1) DMAX (1)= DMAX (1)* (1.0- (SH2OA (1) + SICE (1) - SMCWLT)/ & SMCAV) DD = DMAX (1) ! ---------------------------------------------------------------------- ! FROZEN GROUND VERSION: ! ---------------------------------------------------------------------- DO KS = 2,NSOIL DICE = DICE+ ( ZSOIL (KS -1) - ZSOIL (KS) ) * SICE (KS) DMAX (KS) = (ZSOIL (KS -1) - ZSOIL (KS))* SMCAV DMAX (KS) = DMAX (KS)* (1.0- (SH2OA (KS) + SICE (KS) & - SMCWLT)/ SMCAV) DD = DD+ DMAX (KS) ! ---------------------------------------------------------------------- ! VAL = (1.-EXP(-KDT*SQRT(DT1))) ! IN BELOW, REMOVE THE SQRT IN ABOVE ! ---------------------------------------------------------------------- END DO VAL = (1. - EXP ( - KDT * DT1)) DDT = DD * VAL PX = PCPDRP * DT IF (PX < 0.0) PX = 0.0 ! ---------------------------------------------------------------------- ! FROZEN GROUND VERSION: ! REDUCTION OF INFILTRATION BASED ON FROZEN GROUND PARAMETERS ! ---------------------------------------------------------------------- INFMAX = (PX * (DDT / (PX + DDT)))/ DT FCR = 1. IF (DICE > 1.E-2) THEN ACRT = CVFRZ * FRZX / DICE SUM = 1. IALP1 = CVFRZ - 1 DO J = 1,IALP1 K = 1 DO JJ = J +1,IALP1 K = K * JJ END DO SUM = SUM + (ACRT ** ( CVFRZ - J)) / FLOAT (K) END DO FCR = 1. - EXP ( - ACRT) * SUM END IF ! ---------------------------------------------------------------------- ! CORRECTION OF INFILTRATION LIMITATION: ! IF INFMAX .LE. HYDROLIC CONDUCTIVITY ASSIGN INFMAX THE VALUE OF ! HYDROLIC CONDUCTIVITY ! ---------------------------------------------------------------------- ! MXSMC = MAX ( SH2OA(1), SH2OA(2) ) INFMAX = INFMAX * FCR MXSMC = SH2OA (1) CALL WDFCND (WDF,WCND,MXSMC,SMCMAX,BEXP,DKSAT,DWSAT, & SICEMAX) INFMAX = MAX (INFMAX,WCND) INFMAX = MIN (INFMAX,PX) IF (PCPDRP > INFMAX) THEN RUNOFF1 = PCPDRP - INFMAX PDDUM = INFMAX END IF ! ---------------------------------------------------------------------- ! TO AVOID SPURIOUS DRAINAGE BEHAVIOR, 'UPSTREAM DIFFERENCING' IN LINE ! BELOW REPLACED WITH NEW APPROACH IN 2ND LINE: ! 'MXSMC = MAX(SH2OA(1), SH2OA(2))' ! ---------------------------------------------------------------------- END IF MXSMC = SH2OA (1) CALL WDFCND (WDF,WCND,MXSMC,SMCMAX,BEXP,DKSAT,DWSAT, & SICEMAX) ! ---------------------------------------------------------------------- ! CALC THE MATRIX COEFFICIENTS AI, BI, AND CI FOR THE TOP LAYER ! ---------------------------------------------------------------------- DDZ = 1. / ( - .5 * ZSOIL (2) ) AI (1) = 0.0 BI (1) = WDF * DDZ / ( - ZSOIL (1) ) ! ---------------------------------------------------------------------- ! CALC RHSTT FOR THE TOP LAYER AFTER CALC'NG THE VERTICAL SOIL MOISTURE ! GRADIENT BTWN THE TOP AND NEXT TO TOP LAYERS. ! ---------------------------------------------------------------------- CI (1) = - BI (1) DSMDZ = ( SH2O (1) - SH2O (2) ) / ( - .5 * ZSOIL (2) ) RHSTT (1) = (WDF * DSMDZ + WCND- PDDUM + EDIR + ET (1))/ ZSOIL (1) ! ---------------------------------------------------------------------- ! INITIALIZE DDZ2 ! ---------------------------------------------------------------------- SSTT = WDF * DSMDZ + WCND+ EDIR + ET (1) ! ---------------------------------------------------------------------- ! LOOP THRU THE REMAINING SOIL LAYERS, REPEATING THE ABV PROCESS ! ---------------------------------------------------------------------- DDZ2 = 0.0 DO K = 2,NSOIL DENOM2 = (ZSOIL (K -1) - ZSOIL (K)) IF (K /= NSOIL) THEN ! ---------------------------------------------------------------------- ! AGAIN, TO AVOID SPURIOUS DRAINAGE BEHAVIOR, 'UPSTREAM DIFFERENCING' IN ! LINE BELOW REPLACED WITH NEW APPROACH IN 2ND LINE: ! 'MXSMC2 = MAX (SH2OA(K), SH2OA(K+1))' ! ---------------------------------------------------------------------- SLOPX = 1. MXSMC2 = SH2OA (K) CALL WDFCND (WDF2,WCND2,MXSMC2,SMCMAX,BEXP,DKSAT,DWSAT, & SICEMAX) ! ----------------------------------------------------------------------- ! CALC SOME PARTIAL PRODUCTS FOR LATER USE IN CALC'NG RHSTT ! ---------------------------------------------------------------------- DENOM = (ZSOIL (K -1) - ZSOIL (K +1)) ! ---------------------------------------------------------------------- ! CALC THE MATRIX COEF, CI, AFTER CALC'NG ITS PARTIAL PRODUCT ! ---------------------------------------------------------------------- DSMDZ2 = (SH2O (K) - SH2O (K +1)) / (DENOM * 0.5) DDZ2 = 2.0 / DENOM CI (K) = - WDF2 * DDZ2 / DENOM2 ELSE ! ---------------------------------------------------------------------- ! SLOPE OF BOTTOM LAYER IS INTRODUCED ! ---------------------------------------------------------------------- ! ---------------------------------------------------------------------- ! RETRIEVE THE SOIL WATER DIFFUSIVITY AND HYDRAULIC CONDUCTIVITY FOR ! THIS LAYER ! ---------------------------------------------------------------------- SLOPX = SLOPE CALL WDFCND (WDF2,WCND2,SH2OA (NSOIL),SMCMAX,BEXP,DKSAT,DWSAT, & SICEMAX) ! ---------------------------------------------------------------------- ! CALC A PARTIAL PRODUCT FOR LATER USE IN CALC'NG RHSTT ! ---------------------------------------------------------------------- ! ---------------------------------------------------------------------- ! SET MATRIX COEF CI TO ZERO ! ---------------------------------------------------------------------- DSMDZ2 = 0.0 CI (K) = 0.0 ! ---------------------------------------------------------------------- ! CALC RHSTT FOR THIS LAYER AFTER CALC'NG ITS NUMERATOR ! ---------------------------------------------------------------------- END IF NUMER = (WDF2 * DSMDZ2) + SLOPX * WCND2- (WDF * DSMDZ) & - WCND+ ET (K) ! ---------------------------------------------------------------------- ! CALC MATRIX COEFS, AI, AND BI FOR THIS LAYER ! ---------------------------------------------------------------------- RHSTT (K) = NUMER / ( - DENOM2) AI (K) = - WDF * DDZ / DENOM2 ! ---------------------------------------------------------------------- ! RESET VALUES OF WDF, WCND, DSMDZ, AND DDZ FOR LOOP TO NEXT LYR ! RUNOFF2: SUB-SURFACE OR BASEFLOW RUNOFF ! ---------------------------------------------------------------------- BI (K) = - ( AI (K) + CI (K) ) IF (K .eq. NSOIL) THEN RUNOFF2 = SLOPX * WCND2 END IF IF (K .ne. NSOIL) THEN WDF = WDF2 WCND = WCND2 DSMDZ = DSMDZ2 DDZ = DDZ2 END IF END DO ! ---------------------------------------------------------------------- END SUBROUTINE SRT ! ---------------------------------------------------------------------- SUBROUTINE SSTEP (SH2OOUT,SH2OIN,CMC,RHSTT,RHSCT,DT, & NSOIL,SMCMAX,CMCMAX,RUNOFF3,ZSOIL,SMC,SICE, & AI,BI,CI) ! ---------------------------------------------------------------------- ! SUBROUTINE SSTEP ! ---------------------------------------------------------------------- ! CALCULATE/UPDATE SOIL MOISTURE CONTENT VALUES AND CANOPY MOISTURE ! CONTENT VALUES. ! ---------------------------------------------------------------------- IMPLICIT NONE INTEGER, INTENT(IN) :: NSOIL INTEGER :: I, K, KK11 REAL, INTENT(IN) :: CMCMAX, DT, SMCMAX REAL, INTENT(OUT) :: RUNOFF3 REAL, INTENT(INOUT) :: CMC REAL, DIMENSION(1:NSOIL), INTENT(IN) :: SH2OIN, SICE, ZSOIL REAL, DIMENSION(1:NSOIL), INTENT(OUT) :: SH2OOUT REAL, DIMENSION(1:NSOIL), INTENT(INOUT) :: RHSTT, SMC REAL, DIMENSION(1:NSOIL), INTENT(INOUT) :: AI, BI, CI REAL, DIMENSION(1:NSOIL) :: RHSTTin REAL, DIMENSION(1:NSOIL) :: CIin REAL :: DDZ, RHSCT, STOT, WPLUS ! ---------------------------------------------------------------------- ! CREATE 'AMOUNT' VALUES OF VARIABLES TO BE INPUT TO THE ! TRI-DIAGONAL MATRIX ROUTINE. ! ---------------------------------------------------------------------- DO K = 1,NSOIL RHSTT (K) = RHSTT (K) * DT AI (K) = AI (K) * DT BI (K) = 1. + BI (K) * DT CI (K) = CI (K) * DT END DO ! ---------------------------------------------------------------------- ! COPY VALUES FOR INPUT VARIABLES BEFORE CALL TO ROSR12 ! ---------------------------------------------------------------------- DO K = 1,NSOIL RHSTTin (K) = RHSTT (K) END DO DO K = 1,NSOIL CIin (K) = CI (K) END DO ! ---------------------------------------------------------------------- ! CALL ROSR12 TO SOLVE THE TRI-DIAGONAL MATRIX ! ---------------------------------------------------------------------- CALL ROSR12 (CI,AI,BI,CIin,RHSTTin,RHSTT,NSOIL) ! ---------------------------------------------------------------------- ! SUM THE PREVIOUS SMC VALUE AND THE MATRIX SOLUTION TO GET A ! NEW VALUE. MIN ALLOWABLE VALUE OF SMC WILL BE 0.02. ! RUNOFF3: RUNOFF WITHIN SOIL LAYERS ! ---------------------------------------------------------------------- WPLUS = 0.0 RUNOFF3 = 0. DDZ = - ZSOIL (1) DO K = 1,NSOIL IF (K /= 1) DDZ = ZSOIL (K - 1) - ZSOIL (K) SH2OOUT (K) = SH2OIN (K) + CI (K) + WPLUS / DDZ STOT = SH2OOUT (K) + SICE (K) IF (STOT > SMCMAX) THEN IF (K .eq. 1) THEN DDZ = - ZSOIL (1) ELSE KK11 = K - 1 DDZ = - ZSOIL (K) + ZSOIL (KK11) END IF WPLUS = (STOT - SMCMAX) * DDZ ELSE WPLUS = 0. END IF SMC (K) = MAX ( MIN (STOT,SMCMAX),0.02 ) SH2OOUT (K) = MAX ( (SMC (K) - SICE (K)),0.0) END DO ! ---------------------------------------------------------------------- ! UPDATE CANOPY WATER CONTENT/INTERCEPTION (CMC). CONVERT RHSCT TO ! AN 'AMOUNT' VALUE AND ADD TO PREVIOUS CMC VALUE TO GET NEW CMC. ! ---------------------------------------------------------------------- RUNOFF3 = WPLUS CMC = CMC + DT * RHSCT IF (CMC < 1.E-20) CMC = 0.0 CMC = MIN (CMC,CMCMAX) ! ---------------------------------------------------------------------- END SUBROUTINE SSTEP ! ---------------------------------------------------------------------- SUBROUTINE TBND (TU,TB,ZSOIL,ZBOT,K,NSOIL,TBND1) ! ---------------------------------------------------------------------- ! SUBROUTINE TBND ! ---------------------------------------------------------------------- ! CALCULATE TEMPERATURE ON THE BOUNDARY OF THE LAYER BY INTERPOLATION OF ! THE MIDDLE LAYER TEMPERATURES ! ---------------------------------------------------------------------- IMPLICIT NONE INTEGER, INTENT(IN) :: NSOIL INTEGER :: K REAL, INTENT(IN) :: TB, TU, ZBOT REAL, INTENT(OUT) :: TBND1 REAL, DIMENSION(1:NSOIL), INTENT(IN) :: ZSOIL REAL :: ZB, ZUP REAL, PARAMETER :: T0 = 273.15 ! ---------------------------------------------------------------------- ! USE SURFACE TEMPERATURE ON THE TOP OF THE FIRST LAYER ! ---------------------------------------------------------------------- IF (K == 1) THEN ZUP = 0. ELSE ZUP = ZSOIL (K -1) END IF ! ---------------------------------------------------------------------- ! USE DEPTH OF THE CONSTANT BOTTOM TEMPERATURE WHEN INTERPOLATE ! TEMPERATURE INTO THE LAST LAYER BOUNDARY ! ---------------------------------------------------------------------- IF (K == NSOIL) THEN ZB = 2.* ZBOT - ZSOIL (K) ELSE ZB = ZSOIL (K +1) END IF ! ---------------------------------------------------------------------- ! LINEAR INTERPOLATION BETWEEN THE AVERAGE LAYER TEMPERATURES ! ---------------------------------------------------------------------- TBND1 = TU + (TB - TU)* (ZUP - ZSOIL (K))/ (ZUP - ZB) ! ---------------------------------------------------------------------- END SUBROUTINE TBND ! ---------------------------------------------------------------------- SUBROUTINE TDFCND ( DF, SMC, QZ, SMCMAX, SH2O) ! ---------------------------------------------------------------------- ! SUBROUTINE TDFCND ! ---------------------------------------------------------------------- ! CALCULATE THERMAL DIFFUSIVITY AND CONDUCTIVITY OF THE SOIL FOR A GIVEN ! POINT AND TIME. ! ---------------------------------------------------------------------- ! PETERS-LIDARD APPROACH (PETERS-LIDARD et al., 1998) ! June 2001 CHANGES: FROZEN SOIL CONDITION. ! ---------------------------------------------------------------------- IMPLICIT NONE REAL, INTENT(IN) :: QZ, SMC, SMCMAX, SH2O REAL, INTENT(OUT) :: DF REAL :: AKE, GAMMD, THKDRY, THKICE, THKO, & THKQTZ,THKSAT,THKS,THKW,SATRATIO,XU, & XUNFROZ ! ---------------------------------------------------------------------- ! WE NOW GET QUARTZ AS AN INPUT ARGUMENT (SET IN ROUTINE REDPRM): ! DATA QUARTZ /0.82, 0.10, 0.25, 0.60, 0.52, ! & 0.35, 0.60, 0.40, 0.82/ ! ---------------------------------------------------------------------- ! IF THE SOIL HAS ANY MOISTURE CONTENT COMPUTE A PARTIAL SUM/PRODUCT ! OTHERWISE USE A CONSTANT VALUE WHICH WORKS WELL WITH MOST SOILS ! ---------------------------------------------------------------------- ! THKW ......WATER THERMAL CONDUCTIVITY ! THKQTZ ....THERMAL CONDUCTIVITY FOR QUARTZ ! THKO ......THERMAL CONDUCTIVITY FOR OTHER SOIL COMPONENTS ! THKS ......THERMAL CONDUCTIVITY FOR THE SOLIDS COMBINED(QUARTZ+OTHER) ! THKICE ....ICE THERMAL CONDUCTIVITY ! SMCMAX ....POROSITY (= SMCMAX) ! QZ .........QUARTZ CONTENT (SOIL TYPE DEPENDENT) ! ---------------------------------------------------------------------- ! USE AS IN PETERS-LIDARD, 1998 (MODIF. FROM JOHANSEN, 1975). ! PABLO GRUNMANN, 08/17/98 ! REFS.: ! FAROUKI, O.T.,1986: THERMAL PROPERTIES OF SOILS. SERIES ON ROCK ! AND SOIL MECHANICS, VOL. 11, TRANS TECH, 136 PP. ! JOHANSEN, O., 1975: THERMAL CONDUCTIVITY OF SOILS. PH.D. THESIS, ! UNIVERSITY OF TRONDHEIM, ! PETERS-LIDARD, C. D., ET AL., 1998: THE EFFECT OF SOIL THERMAL ! CONDUCTIVITY PARAMETERIZATION ON SURFACE ENERGY FLUXES ! AND TEMPERATURES. JOURNAL OF THE ATMOSPHERIC SCIENCES, ! VOL. 55, PP. 1209-1224. ! ---------------------------------------------------------------------- ! NEEDS PARAMETERS ! POROSITY(SOIL TYPE): ! POROS = SMCMAX ! SATURATION RATIO: ! PARAMETERS W/(M.K) SATRATIO = SMC / SMCMAX ! ICE CONDUCTIVITY: THKICE = 2.2 ! WATER CONDUCTIVITY: THKW = 0.57 ! THERMAL CONDUCTIVITY OF "OTHER" SOIL COMPONENTS ! IF (QZ .LE. 0.2) THKO = 3.0 THKO = 2.0 ! QUARTZ' CONDUCTIVITY THKQTZ = 7.7 ! SOLIDS' CONDUCTIVITY THKS = (THKQTZ ** QZ)* (THKO ** (1. - QZ)) ! UNFROZEN FRACTION (FROM 1., i.e., 100%LIQUID, TO 0. (100% FROZEN)) XUNFROZ = SH2O / SMC ! UNFROZEN VOLUME FOR SATURATION (POROSITY*XUNFROZ) XU = XUNFROZ * SMCMAX ! SATURATED THERMAL CONDUCTIVITY THKSAT = THKS ** (1. - SMCMAX)* THKICE ** (SMCMAX - XU)* THKW ** & (XU) ! DRY DENSITY IN KG/M3 GAMMD = (1. - SMCMAX)*2700. ! DRY THERMAL CONDUCTIVITY IN W.M-1.K-1 THKDRY = (0.135* GAMMD+ 64.7)/ (2700. - 0.947* GAMMD) ! FROZEN IF ( (SH2O + 0.0005) < SMC ) THEN AKE = SATRATIO ! UNFROZEN ! RANGE OF VALIDITY FOR THE KERSTEN NUMBER (AKE) ELSE ! KERSTEN NUMBER (USING "FINE" FORMULA, VALID FOR SOILS CONTAINING AT ! LEAST 5% OF PARTICLES WITH DIAMETER LESS THAN 2.E-6 METERS.) ! (FOR "COARSE" FORMULA, SEE PETERS-LIDARD ET AL., 1998). IF ( SATRATIO > 0.1 ) THEN AKE = LOG10 (SATRATIO) + 1.0 ! USE K = KDRY ELSE AKE = 0.0 END IF ! THERMAL CONDUCTIVITY END IF DF = AKE * (THKSAT - THKDRY) + THKDRY ! ---------------------------------------------------------------------- END SUBROUTINE TDFCND ! ---------------------------------------------------------------------- SUBROUTINE TMPAVG (TAVG,TUP,TM,TDN,ZSOIL,NSOIL,K) ! ---------------------------------------------------------------------- ! SUBROUTINE TMPAVG ! ---------------------------------------------------------------------- ! CALCULATE SOIL LAYER AVERAGE TEMPERATURE (TAVG) IN FREEZING/THAWING ! LAYER USING UP, DOWN, AND MIDDLE LAYER TEMPERATURES (TUP, TDN, TM), ! WHERE TUP IS AT TOP BOUNDARY OF LAYER, TDN IS AT BOTTOM BOUNDARY OF ! LAYER. TM IS LAYER PROGNOSTIC STATE TEMPERATURE. ! ---------------------------------------------------------------------- IMPLICIT NONE INTEGER K INTEGER NSOIL REAL DZ REAL DZH REAL T0 REAL TAVG REAL TDN REAL TM REAL TUP REAL X0 REAL XDN REAL XUP REAL ZSOIL (NSOIL) ! ---------------------------------------------------------------------- PARAMETER (T0 = 2.7315E2) IF (K .eq. 1) THEN DZ = - ZSOIL (1) ELSE DZ = ZSOIL (K -1) - ZSOIL (K) END IF DZH = DZ *0.5 IF (TUP .lt. T0) THEN IF (TM .lt. T0) THEN ! ---------------------------------------------------------------------- ! TUP, TM, TDN < T0 ! ---------------------------------------------------------------------- IF (TDN .lt. T0) THEN TAVG = (TUP + 2.0* TM + TDN)/ 4.0 ! ---------------------------------------------------------------------- ! TUP & TM < T0, TDN .ge. T0 ! ---------------------------------------------------------------------- ELSE X0 = (T0- TM) * DZH / (TDN - TM) TAVG = 0.5 * (TUP * DZH + TM * (DZH + X0) + T0* ( & & 2.* DZH - X0)) / DZ END IF ELSE ! ---------------------------------------------------------------------- ! TUP < T0, TM .ge. T0, TDN < T0 ! ---------------------------------------------------------------------- IF (TDN .lt. T0) THEN XUP = (T0- TUP) * DZH / (TM - TUP) XDN = DZH - (T0- TM) * DZH / (TDN - TM) TAVG = 0.5 * (TUP * XUP + T0* (2.* DZ - XUP - XDN) & & + TDN * XDN) / DZ ! ---------------------------------------------------------------------- ! TUP < T0, TM .ge. T0, TDN .ge. T0 ! ---------------------------------------------------------------------- ELSE XUP = (T0- TUP) * DZH / (TM - TUP) TAVG = 0.5 * (TUP * XUP + T0* (2.* DZ - XUP)) / DZ END IF END IF ELSE IF (TM .lt. T0) THEN ! ---------------------------------------------------------------------- ! TUP .ge. T0, TM < T0, TDN < T0 ! ---------------------------------------------------------------------- IF (TDN .lt. T0) THEN XUP = DZH - (T0- TUP) * DZH / (TM - TUP) TAVG = 0.5 * (T0* (DZ - XUP) + TM * (DZH + XUP) & & + TDN * DZH) / DZ ! ---------------------------------------------------------------------- ! TUP .ge. T0, TM < T0, TDN .ge. T0 ! ---------------------------------------------------------------------- ELSE XUP = DZH - (T0- TUP) * DZH / (TM - TUP) XDN = (T0- TM) * DZH / (TDN - TM) TAVG = 0.5 * (T0* (2.* DZ - XUP - XDN) + TM * & & (XUP + XDN)) / DZ END IF ELSE ! ---------------------------------------------------------------------- ! TUP .ge. T0, TM .ge. T0, TDN < T0 ! ---------------------------------------------------------------------- IF (TDN .lt. T0) THEN XDN = DZH - (T0- TM) * DZH / (TDN - TM) TAVG = (T0* (DZ - XDN) +0.5* (T0+ TDN)* XDN) / DZ ! ---------------------------------------------------------------------- ! TUP .ge. T0, TM .ge. T0, TDN .ge. T0 ! ---------------------------------------------------------------------- ELSE TAVG = (TUP + 2.0* TM + TDN) / 4.0 END IF END IF END IF ! ---------------------------------------------------------------------- END SUBROUTINE TMPAVG ! ---------------------------------------------------------------------- SUBROUTINE TRANSP (ET,NSOIL,ETP1,SMC,CMC,ZSOIL,SHDFAC,SMCWLT, & & CMCMAX,PC,CFACTR,SMCREF,SFCTMP,Q2,NROOT, & & RTDIS) ! ---------------------------------------------------------------------- ! SUBROUTINE TRANSP ! ---------------------------------------------------------------------- ! CALCULATE TRANSPIRATION FOR THE VEG CLASS. ! ---------------------------------------------------------------------- IMPLICIT NONE INTEGER I INTEGER K INTEGER NSOIL INTEGER NROOT REAL CFACTR REAL CMC REAL CMCMAX REAL DENOM REAL ET (NSOIL) REAL ETP1 REAL ETP1A !.....REAL PART(NSOIL) REAL GX (NROOT) REAL PC REAL Q2 REAL RTDIS (NSOIL) REAL RTX REAL SFCTMP REAL SGX REAL SHDFAC REAL SMC (NSOIL) REAL SMCREF REAL SMCWLT ! ---------------------------------------------------------------------- ! INITIALIZE PLANT TRANSP TO ZERO FOR ALL SOIL LAYERS. ! ---------------------------------------------------------------------- REAL ZSOIL (NSOIL) DO K = 1,NSOIL ET (K) = 0. ! ---------------------------------------------------------------------- ! CALCULATE AN 'ADJUSTED' POTENTIAL TRANSPIRATION ! IF STATEMENT BELOW TO AVOID TANGENT LINEAR PROBLEMS NEAR ZERO ! NOTE: GX AND OTHER TERMS BELOW REDISTRIBUTE TRANSPIRATION BY LAYER, ! ET(K), AS A FUNCTION OF SOIL MOISTURE AVAILABILITY, WHILE PRESERVING ! TOTAL ETP1A. ! ---------------------------------------------------------------------- END DO IF (CMC .ne. 0.0) THEN ETP1A = SHDFAC * PC * ETP1 * (1.0- (CMC / CMCMAX) ** CFACTR) ELSE ETP1A = SHDFAC * PC * ETP1 END IF SGX = 0.0 DO I = 1,NROOT GX (I) = ( SMC (I) - SMCWLT ) / ( SMCREF - SMCWLT ) GX (I) = MAX ( MIN ( GX (I), 1. ), 0. ) SGX = SGX + GX (I) END DO SGX = SGX / NROOT DENOM = 0. DO I = 1,NROOT RTX = RTDIS (I) + GX (I) - SGX GX (I) = GX (I) * MAX ( RTX, 0. ) DENOM = DENOM + GX (I) END DO IF (DENOM .le. 0.0) DENOM = 1. DO I = 1,NROOT ET (I) = ETP1A * GX (I) / DENOM ! ---------------------------------------------------------------------- ! ABOVE CODE ASSUMES A VERTICALLY UNIFORM ROOT DISTRIBUTION ! CODE BELOW TESTS A VARIABLE ROOT DISTRIBUTION ! ---------------------------------------------------------------------- ! ET(1) = ( ZSOIL(1) / ZSOIL(NROOT) ) * GX * ETP1A ! ET(1) = ( ZSOIL(1) / ZSOIL(NROOT) ) * ETP1A ! ---------------------------------------------------------------------- ! USING ROOT DISTRIBUTION AS WEIGHTING FACTOR ! ---------------------------------------------------------------------- ! ET(1) = RTDIS(1) * ETP1A ! ET(1) = ETP1A * PART(1) ! ---------------------------------------------------------------------- ! LOOP DOWN THRU THE SOIL LAYERS REPEATING THE OPERATION ABOVE, ! BUT USING THE THICKNESS OF THE SOIL LAYER (RATHER THAN THE ! ABSOLUTE DEPTH OF EACH LAYER) IN THE FINAL CALCULATION. ! ---------------------------------------------------------------------- ! DO K = 2,NROOT ! GX = ( SMC(K) - SMCWLT ) / ( SMCREF - SMCWLT ) ! GX = MAX ( MIN ( GX, 1. ), 0. ) ! TEST CANOPY RESISTANCE ! GX = 1.0 ! ET(K) = ((ZSOIL(K)-ZSOIL(K-1))/ZSOIL(NROOT))*GX*ETP1A ! ET(K) = ((ZSOIL(K)-ZSOIL(K-1))/ZSOIL(NROOT))*ETP1A ! ---------------------------------------------------------------------- ! USING ROOT DISTRIBUTION AS WEIGHTING FACTOR ! ---------------------------------------------------------------------- ! ET(K) = RTDIS(K) * ETP1A ! ET(K) = ETP1A*PART(K) ! END DO END DO ! ---------------------------------------------------------------------- END SUBROUTINE TRANSP ! ---------------------------------------------------------------------- SUBROUTINE WDFCND (WDF,WCND,SMC,SMCMAX,BEXP,DKSAT,DWSAT, & & SICEMAX) ! ---------------------------------------------------------------------- ! SUBROUTINE WDFCND ! ---------------------------------------------------------------------- ! CALCULATE SOIL WATER DIFFUSIVITY AND SOIL HYDRAULIC CONDUCTIVITY. ! ---------------------------------------------------------------------- IMPLICIT NONE REAL BEXP REAL DKSAT REAL DWSAT REAL EXPON REAL FACTR1 REAL FACTR2 REAL SICEMAX REAL SMC REAL SMCMAX REAL VKwgt REAL WCND ! ---------------------------------------------------------------------- ! CALC THE RATIO OF THE ACTUAL TO THE MAX PSBL SOIL H2O CONTENT ! ---------------------------------------------------------------------- REAL WDF FACTR1 = 0.2 / SMCMAX ! ---------------------------------------------------------------------- ! PREP AN EXPNTL COEF AND CALC THE SOIL WATER DIFFUSIVITY ! ---------------------------------------------------------------------- FACTR2 = SMC / SMCMAX EXPON = BEXP + 2.0 ! ---------------------------------------------------------------------- ! FROZEN SOIL HYDRAULIC DIFFUSIVITY. VERY SENSITIVE TO THE VERTICAL ! GRADIENT OF UNFROZEN WATER. THE LATTER GRADIENT CAN BECOME VERY ! EXTREME IN FREEZING/THAWING SITUATIONS, AND GIVEN THE RELATIVELY ! FEW AND THICK SOIL LAYERS, THIS GRADIENT SUFFERES SERIOUS ! TRUNCTION ERRORS YIELDING ERRONEOUSLY HIGH VERTICAL TRANSPORTS OF ! UNFROZEN WATER IN BOTH DIRECTIONS FROM HUGE HYDRAULIC DIFFUSIVITY. ! THEREFORE, WE FOUND WE HAD TO ARBITRARILY CONSTRAIN WDF ! -- ! VERSION D_10CM: ........ FACTR1 = 0.2/SMCMAX ! WEIGHTED APPROACH...................... PABLO GRUNMANN, 28_SEP_1999. ! ---------------------------------------------------------------------- WDF = DWSAT * FACTR2 ** EXPON IF (SICEMAX .gt. 0.0) THEN VKWGT = 1./ (1. + (500.* SICEMAX)**3.) WDF = VKWGT * WDF + (1. - VKWGT)* DWSAT * FACTR1** EXPON ! ---------------------------------------------------------------------- ! RESET THE EXPNTL COEF AND CALC THE HYDRAULIC CONDUCTIVITY ! ---------------------------------------------------------------------- END IF EXPON = (2.0 * BEXP) + 3.0 WCND = DKSAT * FACTR2 ** EXPON ! ---------------------------------------------------------------------- END SUBROUTINE WDFCND ! ---------------------------------------------------------------------- SUBROUTINE SFCDIF_off (ZLM,Z0,THZ0,THLM,SFCSPD,CZIL,AKMS,AKHS) ! ---------------------------------------------------------------------- ! SUBROUTINE SFCDIF (renamed SFCDIF_off to avoid clash with Eta PBL) ! ---------------------------------------------------------------------- ! CALCULATE SURFACE LAYER EXCHANGE COEFFICIENTS VIA ITERATIVE PROCESS. ! SEE CHEN ET AL (1997, BLM) ! ---------------------------------------------------------------------- IMPLICIT NONE REAL WWST, WWST2, G, VKRM, EXCM, BETA, BTG, ELFC, WOLD, WNEW REAL PIHF, EPSU2, EPSUST, EPSIT, EPSA, ZTMIN, ZTMAX, HPBL, & & SQVISC REAL RIC, RRIC, FHNEU, RFC, RFAC, ZZ, PSLMU, PSLMS, PSLHU, & & PSLHS REAL XX, PSPMU, YY, PSPMS, PSPHU, PSPHS, ZLM, Z0, THZ0, THLM REAL SFCSPD, CZIL, AKMS, AKHS, ZILFC, ZU, ZT, RDZ, CXCH REAL DTHV, DU2, BTGH, WSTAR2, USTAR, ZSLU, ZSLT, RLOGU, RLOGT REAL RLMO, ZETALT, ZETALU, ZETAU, ZETAT, XLU4, XLT4, XU4, XT4 !CC ......REAL ZTFC REAL XLU, XLT, XU, XT, PSMZ, SIMM, PSHZ, SIMH, USTARK, RLMN, & & RLMA INTEGER ITRMX, ILECH, ITR PARAMETER & & (WWST = 1.2,WWST2 = WWST * WWST,G = 9.8,VKRM = 0.40, & & EXCM = 0.001 & & ,BETA = 1./270.,BTG = BETA * G,ELFC = VKRM * BTG & & ,WOLD =.15,WNEW = 1. - WOLD,ITRMX = 05, & & PIHF = 3.14159265/2.) PARAMETER & & (EPSU2 = 1.E-4,EPSUST = 0.07,EPSIT = 1.E-4,EPSA = 1.E-8 & & ,ZTMIN = -5.,ZTMAX = 1.,HPBL = 1000.0 & & ,SQVISC = 258.2) PARAMETER & & (RIC = 0.183,RRIC = 1.0/ RIC,FHNEU = 0.8,RFC = 0.191 & & ,RFAC = RIC / (FHNEU * RFC * RFC)) ! ---------------------------------------------------------------------- ! NOTE: THE TWO CODE BLOCKS BELOW DEFINE FUNCTIONS ! ---------------------------------------------------------------------- ! LECH'S SURFACE FUNCTIONS ! ---------------------------------------------------------------------- PSLMU (ZZ)= -0.96* log (1.0-4.5* ZZ) PSLMS (ZZ)= ZZ * RRIC -2.076* (1. -1./ (ZZ +1.)) PSLHU (ZZ)= -0.96* log (1.0-4.5* ZZ) ! ---------------------------------------------------------------------- ! PAULSON'S SURFACE FUNCTIONS ! ---------------------------------------------------------------------- PSLHS (ZZ)= ZZ * RFAC -2.076* (1. -1./ (ZZ +1.)) PSPMU (XX)= -2.* log ( (XX +1.)*0.5) - log ( (XX * XX +1.)*0.5) & & +2.* ATAN (XX) & &- PIHF PSPMS (YY)= 5.* YY PSPHU (XX)= -2.* log ( (XX * XX +1.)*0.5) ! ---------------------------------------------------------------------- ! THIS ROUTINE SFCDIF CAN HANDLE BOTH OVER OPEN WATER (SEA, OCEAN) AND ! OVER SOLID SURFACE (LAND, SEA-ICE). ! ---------------------------------------------------------------------- PSPHS (YY)= 5.* YY ! ---------------------------------------------------------------------- ! ZTFC: RATIO OF ZOH/ZOM LESS OR EQUAL THAN 1 ! C......ZTFC=0.1 ! CZIL: CONSTANT C IN Zilitinkevich, S. S.1995,:NOTE ABOUT ZT ! ---------------------------------------------------------------------- ILECH = 0 ! ---------------------------------------------------------------------- ZILFC = - CZIL * VKRM * SQVISC ! C.......ZT=Z0*ZTFC ZU = Z0 RDZ = 1./ ZLM CXCH = EXCM * RDZ DTHV = THLM - THZ0 ! ---------------------------------------------------------------------- ! BELJARS CORRECTION OF USTAR ! ---------------------------------------------------------------------- DU2 = MAX (SFCSPD * SFCSPD,EPSU2) !cc If statements to avoid TANGENT LINEAR problems near zero BTGH = BTG * HPBL IF (BTGH * AKHS * DTHV .ne. 0.0) THEN WSTAR2 = WWST2* ABS (BTGH * AKHS * DTHV)** (2./3.) ELSE WSTAR2 = 0.0 END IF ! ---------------------------------------------------------------------- ! ZILITINKEVITCH APPROACH FOR ZT ! ---------------------------------------------------------------------- USTAR = MAX (SQRT (AKMS * SQRT (DU2+ WSTAR2)),EPSUST) ! ---------------------------------------------------------------------- ZT = EXP (ZILFC * SQRT (USTAR * Z0))* Z0 ZSLU = ZLM + ZU ! PRINT*,'ZSLT=',ZSLT ! PRINT*,'ZLM=',ZLM ! PRINT*,'ZT=',ZT ZSLT = ZLM + ZT RLOGU = log (ZSLU / ZU) RLOGT = log (ZSLT / ZT) ! PRINT*,'RLMO=',RLMO ! PRINT*,'ELFC=',ELFC ! PRINT*,'AKHS=',AKHS ! PRINT*,'DTHV=',DTHV ! PRINT*,'USTAR=',USTAR RLMO = ELFC * AKHS * DTHV / USTAR **3 ! ---------------------------------------------------------------------- ! 1./MONIN-OBUKKHOV LENGTH-SCALE ! ---------------------------------------------------------------------- DO ITR = 1,ITRMX ZETALT = MAX (ZSLT * RLMO,ZTMIN) RLMO = ZETALT / ZSLT ZETALU = ZSLU * RLMO ZETAU = ZU * RLMO ZETAT = ZT * RLMO IF (ILECH .eq. 0) THEN IF (RLMO .lt. 0.)THEN XLU4 = 1. -16.* ZETALU XLT4 = 1. -16.* ZETALT XU4 = 1. -16.* ZETAU XT4 = 1. -16.* ZETAT XLU = SQRT (SQRT (XLU4)) XLT = SQRT (SQRT (XLT4)) XU = SQRT (SQRT (XU4)) XT = SQRT (SQRT (XT4)) ! PRINT*,'-----------1------------' ! PRINT*,'PSMZ=',PSMZ ! PRINT*,'PSPMU(ZETAU)=',PSPMU(ZETAU) ! PRINT*,'XU=',XU ! PRINT*,'------------------------' PSMZ = PSPMU (XU) SIMM = PSPMU (XLU) - PSMZ + RLOGU PSHZ = PSPHU (XT) SIMH = PSPHU (XLT) - PSHZ + RLOGT ELSE ZETALU = MIN (ZETALU,ZTMAX) ZETALT = MIN (ZETALT,ZTMAX) ! PRINT*,'-----------2------------' ! PRINT*,'PSMZ=',PSMZ ! PRINT*,'PSPMS(ZETAU)=',PSPMS(ZETAU) ! PRINT*,'ZETAU=',ZETAU ! PRINT*,'------------------------' PSMZ = PSPMS (ZETAU) SIMM = PSPMS (ZETALU) - PSMZ + RLOGU PSHZ = PSPHS (ZETAT) SIMH = PSPHS (ZETALT) - PSHZ + RLOGT END IF ! ---------------------------------------------------------------------- ! LECH'S FUNCTIONS ! ---------------------------------------------------------------------- ELSE IF (RLMO .lt. 0.)THEN ! PRINT*,'-----------3------------' ! PRINT*,'PSMZ=',PSMZ ! PRINT*,'PSLMU(ZETAU)=',PSLMU(ZETAU) ! PRINT*,'ZETAU=',ZETAU ! PRINT*,'------------------------' PSMZ = PSLMU (ZETAU) SIMM = PSLMU (ZETALU) - PSMZ + RLOGU PSHZ = PSLHU (ZETAT) SIMH = PSLHU (ZETALT) - PSHZ + RLOGT ELSE ZETALU = MIN (ZETALU,ZTMAX) ZETALT = MIN (ZETALT,ZTMAX) ! PRINT*,'-----------4------------' ! PRINT*,'PSMZ=',PSMZ ! PRINT*,'PSLMS(ZETAU)=',PSLMS(ZETAU) ! PRINT*,'ZETAU=',ZETAU ! PRINT*,'------------------------' PSMZ = PSLMS (ZETAU) SIMM = PSLMS (ZETALU) - PSMZ + RLOGU PSHZ = PSLHS (ZETAT) SIMH = PSLHS (ZETALT) - PSHZ + RLOGT END IF ! ---------------------------------------------------------------------- ! BELJAARS CORRECTION FOR USTAR ! ---------------------------------------------------------------------- END IF ! ---------------------------------------------------------------------- ! ZILITINKEVITCH FIX FOR ZT ! ---------------------------------------------------------------------- USTAR = MAX (SQRT (AKMS * SQRT (DU2+ WSTAR2)),EPSUST) ZT = EXP (ZILFC * SQRT (USTAR * Z0))* Z0 ZSLT = ZLM + ZT !----------------------------------------------------------------------- RLOGT = log (ZSLT / ZT) USTARK = USTAR * VKRM AKMS = MAX (USTARK / SIMM,CXCH) !----------------------------------------------------------------------- ! IF STATEMENTS TO AVOID TANGENT LINEAR PROBLEMS NEAR ZERO !----------------------------------------------------------------------- AKHS = MAX (USTARK / SIMH,CXCH) IF (BTGH * AKHS * DTHV .ne. 0.0) THEN WSTAR2 = WWST2* ABS (BTGH * AKHS * DTHV)** (2./3.) ELSE WSTAR2 = 0.0 END IF !----------------------------------------------------------------------- RLMN = ELFC * AKHS * DTHV / USTAR **3 !----------------------------------------------------------------------- ! IF(ABS((RLMN-RLMO)/RLMA).LT.EPSIT) GO TO 110 !----------------------------------------------------------------------- RLMA = RLMO * WOLD+ RLMN * WNEW !----------------------------------------------------------------------- RLMO = RLMA ! PRINT*,'----------------------------' ! PRINT*,'SFCDIF OUTPUT ! ! ! ! ! ! ! ! ! ! ! !' ! PRINT*,'ZLM=',ZLM ! PRINT*,'Z0=',Z0 ! PRINT*,'THZ0=',THZ0 ! PRINT*,'THLM=',THLM ! PRINT*,'SFCSPD=',SFCSPD ! PRINT*,'CZIL=',CZIL ! PRINT*,'AKMS=',AKMS ! PRINT*,'AKHS=',AKHS ! PRINT*,'----------------------------' END DO ! ---------------------------------------------------------------------- END SUBROUTINE SFCDIF_off ! ---------------------------------------------------------------------- END MODULE module_sf_noahlsm