| 1 | #undef DEBUG |
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| 2 | #define WRF_PORT |
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| 3 | |
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| 4 | module cldwat |
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| 5 | !----------------------------------------------------------------------- |
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| 6 | ! |
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| 7 | ! Purpose: Prognostic cloud water data and methods. |
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| 8 | ! |
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| 9 | ! Public interfaces: |
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| 10 | ! |
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| 11 | ! inimc -- Initialize constants |
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| 12 | ! pcond -- Calculate prognostic condensate |
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| 13 | ! |
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| 14 | ! cldwat_fice -- calculate fraction of condensate in ice phase (radiation partitioning) |
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| 15 | ! |
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| 16 | ! Author: P. Rasch, with Modifications by Minghua Zhang |
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| 17 | ! January 2010, modified by J. Kay to add precip fluxes for COSP simulator |
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| 18 | ! Ported to WRF by William.Gustafson@pnl.gov, Nov. 2009 |
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| 19 | ! updated to CESM1_0_1, Nov. 2010 |
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| 20 | ! |
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| 21 | !----------------------------------------------------------------------- |
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| 22 | use shr_kind_mod, only: r8 => shr_kind_r8 |
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| 23 | use physconst, only: tmelt |
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| 24 | #ifndef WRF_PORT |
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| 25 | use spmd_utils, only: masterproc |
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| 26 | use ppgrid, only: pcols, pver, pverp |
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| 27 | use wv_saturation, only: estblf, hlatv, tmin, hlatf, rgasv, pcf, & |
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| 28 | cp, epsqs, ttrice |
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| 29 | use abortutils, only: endrun |
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| 30 | use cam_logfile, only: iulog |
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| 31 | #else |
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| 32 | use module_cam_support, only: masterproc, & |
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| 33 | pcols, pver, pverp, & |
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| 34 | endrun, & |
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| 35 | iulog |
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| 36 | #endif |
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| 37 | |
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| 38 | implicit none |
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| 39 | |
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| 40 | !----------------------------------------------------------------------- |
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| 41 | ! PUBLIC: Make default data and interfaces private |
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| 42 | !----------------------------------------------------------------------- |
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| 43 | private |
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| 44 | save |
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| 45 | #ifndef WRF_PORT |
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| 46 | public inimc, pcond ! Public interfaces |
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| 47 | #endif |
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| 48 | public cldwat_fice ! Public interfaces |
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| 49 | #ifndef WRF_PORT |
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| 50 | public cldwat_readnl |
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| 51 | #endif |
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| 52 | integer, public:: ktop ! Level above 10 hPa |
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| 53 | |
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| 54 | #ifndef WRF_PORT |
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| 55 | real(r8),public :: icritc ! threshold for autoconversion of cold ice |
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| 56 | real(r8),public :: icritw ! threshold for autoconversion of warm ice |
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| 57 | !!$ real(r8),public,parameter:: conke = 1.e-6 ! tunable constant for evaporation of precip |
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| 58 | !!$ real(r8),public,parameter:: conke = 2.e-6 ! tunable constant for evaporation of precip |
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| 59 | real(r8),public :: conke ! tunable constant for evaporation of precip |
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| 60 | #else |
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| 61 | ! Currently, the WRF_PORT bipasses the namelist initialization of these |
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| 62 | ! tunable parameters. We are hard-coding them to the default values for |
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| 63 | ! the fv 0.23x0.31 grid. One might choose to implement an option to set |
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| 64 | ! these via the WRF Registry in the future. |
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| 65 | real(r8),public :: icritw = 2.0e-4 |
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| 66 | real(r8),public :: icritc = 45.0e-6 |
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| 67 | real(r8),public :: conke = 5.0e-6 |
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| 68 | |
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| 69 | #endif |
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| 70 | |
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| 71 | !----------------------------------------------------------------------- |
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| 72 | ! PRIVATE: Everything else is private to this module |
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| 73 | !----------------------------------------------------------------------- |
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| 74 | real(r8), private, parameter :: tmax_fice = tmelt - 10._r8 ! max temperature for cloud ice formation |
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| 75 | !!$ real(r8), private, parameter :: tmax_fice = tmelt ! max temperature for cloud ice formation |
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| 76 | !!$ real(r8), private, parameter :: tmin_fice = tmax_fice - 20.! min temperature for cloud ice formation |
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| 77 | real(r8), private, parameter :: tmin_fice = tmax_fice - 30._r8 ! min temperature for cloud ice formation |
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| 78 | ! pjr |
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| 79 | real(r8), private, parameter :: tmax_fsnow = tmelt ! max temperature for transition to convective snow |
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| 80 | real(r8), private, parameter :: tmin_fsnow = tmelt-5._r8 ! min temperature for transition to convective snow |
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| 81 | real(r8), private:: rhonot ! air density at surface |
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| 82 | real(r8), private:: t0 ! Freezing temperature |
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| 83 | real(r8), private:: cldmin ! assumed minimum cloud amount |
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| 84 | real(r8), private:: small ! small number compared to unity |
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| 85 | real(r8), private:: c ! constant for graupel like snow cm**(1-d)/s |
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| 86 | real(r8), private:: d ! constant for graupel like snow |
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| 87 | real(r8), private:: esi ! collection efficient for ice by snow |
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| 88 | real(r8), private:: esw ! collection efficient for water by snow |
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| 89 | real(r8), private:: nos ! particles snow / cm**4 |
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| 90 | real(r8), private:: pi ! Mathematical constant |
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| 91 | real(r8), private:: gravit ! Gravitational acceleration at surface |
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| 92 | real(r8), private:: rh2o |
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| 93 | real(r8), private:: prhonos |
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| 94 | real(r8), private:: thrpd ! numerical three added to d |
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| 95 | real(r8), private:: gam3pd ! gamma function on (3+d) |
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| 96 | real(r8), private:: gam4pd ! gamma function on (4+d) |
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| 97 | real(r8), private:: rhoi ! ice density |
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| 98 | real(r8), private:: rhos ! snow density |
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| 99 | real(r8), private:: rhow ! water density |
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| 100 | real(r8), private:: mcon01 ! constants used in cloud microphysics |
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| 101 | real(r8), private:: mcon02 ! constants used in cloud microphysics |
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| 102 | real(r8), private:: mcon03 ! constants used in cloud microphysics |
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| 103 | real(r8), private:: mcon04 ! constants used in cloud microphysics |
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| 104 | real(r8), private:: mcon05 ! constants used in cloud microphysics |
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| 105 | real(r8), private:: mcon06 ! constants used in cloud microphysics |
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| 106 | real(r8), private:: mcon07 ! constants used in cloud microphysics |
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| 107 | real(r8), private:: mcon08 ! constants used in cloud microphysics |
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| 108 | |
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| 109 | integer, private :: k1mb ! index of the eta level near 1 mb |
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| 110 | |
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| 111 | ! Parameters used in findmcnew |
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| 112 | real(r8) :: r3lcrit ! critical radius at which autoconversion become efficient |
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| 113 | real(r8) :: capnsi ! sea ice cloud particles / cm3 |
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| 114 | real(r8) :: capnc ! cold and oceanic cloud particles / cm3 |
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| 115 | real(r8) :: capnw ! warm continental cloud particles / cm3 |
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| 116 | real(r8) :: kconst ! const for terminal velocity (stokes regime) |
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| 117 | real(r8) :: effc ! collection efficiency |
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| 118 | real(r8) :: alpha ! ratio of 3rd moment radius to 2nd |
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| 119 | real(r8) :: capc ! constant for autoconversion |
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| 120 | real(r8) :: convfw ! constant used for fall velocity calculation |
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| 121 | real(r8) :: cracw ! constant used for rain accreting water |
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| 122 | real(r8) :: critpr ! critical precip rate collection efficiency changes |
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| 123 | real(r8) :: ciautb ! coefficient of autoconversion of ice (1/s) |
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| 124 | |
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| 125 | #ifdef DEBUG |
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| 126 | integer, private,parameter :: nlook = 1 ! Number of points to examine |
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| 127 | integer, private :: ilook(nlook) ! Longitude index to examine |
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| 128 | integer, private :: latlook(nlook) ! Latitude index to examine |
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| 129 | integer, private :: lchnklook(nlook) ! Chunk index to examine |
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| 130 | integer, private :: icollook(nlook) ! Column index to examine |
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| 131 | #endif |
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| 132 | ! Private data |
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| 133 | real(r8), parameter :: unset_r8 = huge(1.0_r8) |
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| 134 | |
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| 135 | contains |
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| 136 | !=============================================================================== |
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| 137 | subroutine cldwat_readnl(nlfile) |
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| 138 | #ifndef WRF_PORT |
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| 139 | use namelist_utils, only: find_group_name |
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| 140 | use units, only: getunit, freeunit |
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| 141 | use mpishorthand |
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| 142 | #endif |
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| 143 | |
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| 144 | character(len=*), intent(in) :: nlfile ! filepath for file containing namelist input |
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| 145 | #ifndef WRF_PORT |
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| 146 | |
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| 147 | |
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| 148 | |
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| 149 | ! Namelist variables |
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| 150 | real(r8) :: cldwat_icritw = unset_r8 ! icritw = threshold for autoconversion of warm ice |
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| 151 | real(r8) :: cldwat_icritc = unset_r8 ! icritc = threshold for autoconversion of cold ice |
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| 152 | real(r8) :: cldwat_conke = unset_r8 ! conke = tunable constant for evaporation of precip |
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| 153 | |
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| 154 | ! Local variables |
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| 155 | integer :: unitn, ierr |
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| 156 | character(len=*), parameter :: subname = 'cldwat_readnl' |
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| 157 | |
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| 158 | namelist /cldwat_nl/ cldwat_icritw, cldwat_icritc, cldwat_conke |
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| 159 | |
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| 160 | !----------------------------------------------------------------------------- |
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| 161 | |
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| 162 | if (masterproc) then |
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| 163 | unitn = getunit() |
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| 164 | open( unitn, file=trim(nlfile), status='old' ) |
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| 165 | call find_group_name(unitn, 'cldwat_nl', status=ierr) |
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| 166 | if (ierr == 0) then |
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| 167 | read(unitn, cldwat_nl, iostat=ierr) |
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| 168 | if (ierr /= 0) then |
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| 169 | call endrun(subname // ':: ERROR reading namelist') |
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| 170 | end if |
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| 171 | end if |
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| 172 | close(unitn) |
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| 173 | call freeunit(unitn) |
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| 174 | |
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| 175 | ! set local variables |
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| 176 | icritw = cldwat_icritw |
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| 177 | icritc = cldwat_icritc |
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| 178 | conke = cldwat_conke |
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| 179 | |
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| 180 | end if |
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| 181 | |
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| 182 | |
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| 183 | |
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| 184 | #ifdef SPMD |
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| 185 | ! Broadcast namelist variables |
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| 186 | call mpibcast(icritw, 1, mpir8, 0, mpicom) |
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| 187 | call mpibcast(icritc, 1, mpir8, 0, mpicom) |
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| 188 | call mpibcast(conke, 1, mpir8, 0, mpicom) |
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| 189 | #endif |
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| 190 | |
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| 191 | !endif for WRF_PORT: |
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| 192 | #endif |
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| 193 | |
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| 194 | end subroutine cldwat_readnl |
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| 195 | |
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| 196 | !================================================================================================ |
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| 197 | subroutine cldwat_fice(ncol, t, fice, fsnow) |
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| 198 | ! |
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| 199 | ! Compute the fraction of the total cloud water which is in ice phase. |
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| 200 | ! The fraction depends on temperature only. |
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| 201 | ! This is the form that was used for radiation, the code came from cldefr originally |
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| 202 | ! |
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| 203 | ! Author: B. A. Boville Sept 10, 2002 |
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| 204 | ! modified: PJR 3/13/03 (added fsnow to ascribe snow production for convection ) |
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| 205 | !----------------------------------------------------------------------- |
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| 206 | implicit none |
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| 207 | |
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| 208 | ! Arguments |
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| 209 | integer, intent(in) :: ncol ! number of active columns |
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| 210 | real(r8), intent(in) :: t(pcols,pver) ! temperature |
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| 211 | |
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| 212 | real(r8), intent(out) :: fice(pcols,pver) ! Fractional ice content within cloud |
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| 213 | real(r8), intent(out) :: fsnow(pcols,pver) ! Fractional snow content for convection |
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| 214 | |
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| 215 | ! Local variables |
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| 216 | integer :: i,k ! loop indexes |
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| 217 | |
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| 218 | !----------------------------------------------------------------------- |
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| 219 | |
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| 220 | ! Define fractional amount of cloud that is ice |
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| 221 | do k=1,pver |
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| 222 | do i=1,ncol |
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| 223 | |
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| 224 | ! If warmer than tmax then water phase |
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| 225 | if (t(i,k) > tmax_fice) then |
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| 226 | fice(i,k) = 0.0_r8 |
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| 227 | |
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| 228 | ! If colder than tmin then ice phase |
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| 229 | else if (t(i,k) < tmin_fice) then |
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| 230 | fice(i,k) = 1.0_r8 |
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| 231 | |
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| 232 | ! Otherwise mixed phase, with ice fraction decreasing linearly from tmin to tmax |
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| 233 | else |
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| 234 | fice(i,k) =(tmax_fice - t(i,k)) / (tmax_fice - tmin_fice) |
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| 235 | end if |
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| 236 | |
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| 237 | ! snow fraction partitioning |
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| 238 | |
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| 239 | ! If warmer than tmax then water phase |
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| 240 | if (t(i,k) > tmax_fsnow) then |
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| 241 | fsnow(i,k) = 0.0_r8 |
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| 242 | |
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| 243 | ! If colder than tmin then ice phase |
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| 244 | else if (t(i,k) < tmin_fsnow) then |
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| 245 | fsnow(i,k) = 1.0_r8 |
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| 246 | |
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| 247 | ! Otherwise mixed phase, with ice fraction decreasing linearly from tmin to tmax |
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| 248 | else |
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| 249 | fsnow(i,k) =(tmax_fsnow - t(i,k)) / (tmax_fsnow - tmin_fsnow) |
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| 250 | end if |
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| 251 | |
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| 252 | end do |
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| 253 | end do |
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| 254 | |
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| 255 | return |
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| 256 | end subroutine cldwat_fice |
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| 257 | |
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| 258 | #ifndef WRF_PORT |
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| 259 | subroutine inimc( tmeltx, rhonotx, gravitx, rh2ox) |
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| 260 | !----------------------------------------------------------------------- |
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| 261 | ! |
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| 262 | ! Purpose: |
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| 263 | ! initialize constants for the prognostic condensate |
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| 264 | ! |
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| 265 | ! Author: P. Rasch, April 1997 |
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| 266 | ! |
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| 267 | !----------------------------------------------------------------------- |
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| 268 | use pmgrid, only: plev, plevp |
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| 269 | use dycore, only: dycore_is, get_resolution |
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| 270 | use hycoef, only: hypm |
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| 271 | |
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| 272 | integer k |
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| 273 | real(r8), intent(in) :: tmeltx |
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| 274 | real(r8), intent(in) :: rhonotx |
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| 275 | real(r8), intent(in) :: gravitx |
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| 276 | real(r8), intent(in) :: rh2ox |
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| 277 | |
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| 278 | #ifdef UNICOSMP |
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| 279 | real(r8) signgam ! variable required by cray gamma function |
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| 280 | external gamma |
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| 281 | #endif |
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| 282 | rhonot = rhonotx ! air density at surface (gm/cm3) |
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| 283 | gravit = gravitx |
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| 284 | rh2o = rh2ox |
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| 285 | rhos = .1_r8 ! assumed snow density (gm/cm3) |
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| 286 | rhow = 1._r8 ! water density |
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| 287 | rhoi = 1._r8 ! ice density |
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| 288 | esi = 1.0_r8 ! collection efficient for ice by snow |
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| 289 | esw = 0.1_r8 ! collection efficient for water by snow |
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| 290 | t0 = tmeltx ! approximate freezing temp |
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| 291 | cldmin = 0.02_r8 ! assumed minimum cloud amount |
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| 292 | small = 1.e-22_r8 ! a small number compared to unity |
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| 293 | c = 152.93_r8 ! constant for graupel like snow cm**(1-d)/s |
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| 294 | d = 0.25_r8 ! constant for graupel like snow |
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| 295 | nos = 3.e-2_r8 ! particles snow / cm**4 |
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| 296 | pi = 4._r8*atan(1.0_r8) |
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| 297 | prhonos = pi*rhos*nos |
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| 298 | thrpd = 3._r8 + d |
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| 299 | if (d==0.25_r8) then |
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| 300 | gam3pd = 2.549256966718531_r8 ! only right for d = 0.25 |
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| 301 | gam4pd = 8.285085141835282_r8 |
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| 302 | else |
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| 303 | #ifdef UNICOSMP |
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| 304 | call gamma(3._r8+d, signgam, gam3pd) |
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| 305 | gam3pd = sign(exp(gam3pd),signgam) |
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| 306 | call gamma(4._r8+d, signgam, gam4pd) |
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| 307 | gam4pd = sign(exp(gam4pd),signgam) |
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| 308 | write(iulog,*) ' d, gamma(3+d), gamma(4+d) =', gam3pd, gam4pd |
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| 309 | #else |
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| 310 | write(iulog,*) ' can only use d ne 0.25 on a cray ' |
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| 311 | stop |
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| 312 | #endif |
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| 313 | endif |
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| 314 | mcon01 = pi*nos*c*gam3pd/4._r8 |
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| 315 | mcon02 = 1._r8/(c*gam4pd*sqrt(rhonot)/(6*prhonos**(d/4._r8))) |
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| 316 | mcon03 = -(0.5_r8+d/4._r8) |
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| 317 | mcon04 = 4._r8/(4._r8+d) |
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| 318 | mcon05 = (3+d)/(4+d) |
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| 319 | mcon06 = (3+d)/4._r8 |
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| 320 | mcon07 = mcon01*sqrt(rhonot)*mcon02**mcon05/prhonos**mcon06 |
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| 321 | mcon08 = -0.5_r8/(4._r8+d) |
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| 322 | |
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| 323 | ! find the level about 1mb, we wont do the microphysics above this level |
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| 324 | k1mb = 1 |
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| 325 | do k=1,pver-1 |
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| 326 | if (hypm(k) < 1.e2_r8 .and. hypm(k+1) >= 1.e2_r8) then |
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| 327 | if (1.e2_r8-hypm(k) < hypm(k+1)-1.e2_r8) then |
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| 328 | k1mb = k |
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| 329 | else |
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| 330 | k1mb = k + 1 |
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| 331 | end if |
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| 332 | goto 20 |
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| 333 | end if |
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| 334 | end do |
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| 335 | if (masterproc) then |
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| 336 | write(iulog,*)'inimc: model levels bracketing 1 mb not found' |
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| 337 | end if |
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| 338 | ! call endrun |
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| 339 | k1mb = 1 |
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| 340 | 20 if( masterproc ) write(iulog,*)'inimc: model level nearest 1 mb is',k1mb,'which is',hypm(k1mb),'pascals' |
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| 341 | |
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| 342 | if( masterproc ) write(iulog,*) 'cloud water initialization by inimc complete ' |
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| 343 | |
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| 344 | ! Initialize parameters used by findmcnew |
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| 345 | capnw = 400._r8 ! warm continental cloud particles / cm3 |
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| 346 | capnc = 150._r8 ! cold and oceanic cloud particles / cm3 |
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| 347 | ! capnsi = 40._r8 ! sea ice cloud particles density / cm3 |
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| 348 | capnsi = 75._r8 ! sea ice cloud particles density / cm3 |
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| 349 | |
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| 350 | kconst = 1.18e6_r8 ! const for terminal velocity |
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| 351 | |
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| 352 | ! effc = 1._r8 ! autoconv collection efficiency following boucher 96 |
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| 353 | ! effc = .55*0.05_r8 ! autoconv collection efficiency following baker 93 |
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| 354 | effc = 0.55_r8 ! autoconv collection efficiency following tripoli and cotton |
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| 355 | ! effc = 0._r8 ! turn off warm-cloud autoconv |
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| 356 | alpha = 1.1_r8**4 |
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| 357 | capc = pi**(-.333_r8)*kconst*effc *(0.75_r8)**(1.333_r8)*alpha ! constant for autoconversion |
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| 358 | |
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| 359 | !r3lcrit: critical radius where liq conversion begins (10.0 micron) |
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| 360 | r3lcrit = 10.0e-6_r8 |
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| 361 | |
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| 362 | ! critical precip rate at which we assume the collector drops can change the |
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| 363 | ! drop size enough to enhance the auto-conversion process (mm/day) |
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| 364 | critpr = 0.5_r8 |
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| 365 | convfw = 1.94_r8*2.13_r8*sqrt(rhow*1000._r8*9.81_r8*2.7e-4_r8) |
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| 366 | |
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| 367 | ! liquid microphysics |
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| 368 | ! cracw = 6_r8 ! beheng |
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| 369 | cracw = .884_r8*sqrt(9.81_r8/(rhow*1000._r8*2.7e-4_r8)) ! tripoli and cotton |
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| 370 | |
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| 371 | ! ice microphysics |
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| 372 | ciautb = 5.e-4_r8 |
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| 373 | |
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| 374 | if ( masterproc ) then |
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| 375 | write(iulog,*)'tuning parameters cldwat: icritw',icritw,'icritc',icritc,'conke',conke |
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| 376 | write(iulog,*)'tuning parameters cldwat: capnw',capnw,'capnc',capnc,'capnsi',capnsi,'kconst',kconst |
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| 377 | write(iulog,*)'tuning parameters cldwat: effc',effc,'alpha',alpha,'capc',capc,'r3lcrit',r3lcrit |
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| 378 | write(iulog,*)'tuning parameters cldwat: critpr',critpr,'convfw',convfw,'cracw',cracw,'ciautb',ciautb |
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| 379 | endif |
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| 380 | |
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| 381 | return |
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| 382 | end subroutine inimc |
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| 383 | |
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| 384 | subroutine pcond (lchnk ,ncol , & |
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| 385 | tn ,ttend ,qn ,qtend ,omega , & |
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| 386 | cwat ,p ,pdel ,cldn ,fice , fsnow, & |
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| 387 | cme ,prodprec,prodsnow,evapprec,evapsnow,evapheat, prfzheat, & |
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| 388 | meltheat,precip ,snowab ,deltat ,fwaut , & |
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| 389 | fsaut ,fracw ,fsacw ,fsaci ,lctend , & |
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| 390 | rhdfda ,rhu00 ,seaicef, zi ,ice2pr, liq2pr, & |
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| 391 | liq2snow, snowh, rkflxprc, rkflxsnw) |
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| 392 | !----------------------------------------------------------------------- |
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| 393 | ! |
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| 394 | ! Purpose: |
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| 395 | ! The public interface to the cloud water parameterization |
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| 396 | ! returns tendencies to water vapor, temperature and cloud water variables |
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| 397 | ! |
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| 398 | ! For basic method |
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| 399 | ! See: Rasch, P. J, and J. E. Kristjansson, A Comparison of the CCM3 |
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| 400 | ! model climate using diagnosed and |
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| 401 | ! predicted condensate parameterizations, 1998, J. Clim., 11, |
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| 402 | ! pp1587---1614. |
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| 403 | ! |
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| 404 | ! For important modifications to improve the method of determining |
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| 405 | ! condensation/evaporation see Zhang et al (2001, in preparation) |
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| 406 | ! |
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| 407 | ! Authors: M. Zhang, W. Lin, P. Rasch and J.E. Kristjansson |
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| 408 | ! B. A. Boville (latent heat of fusion) |
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| 409 | !----------------------------------------------------------------------- |
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| 410 | use wv_saturation, only: vqsatd |
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| 411 | use cam_control_mod, only: nlvdry |
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| 412 | ! |
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| 413 | !--------------------------------------------------------------------- |
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| 414 | ! |
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| 415 | ! Input Arguments |
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| 416 | ! |
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| 417 | integer, intent(in) :: lchnk ! chunk identifier |
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| 418 | integer, intent(in) :: ncol ! number of atmospheric columns |
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| 419 | |
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| 420 | real(r8), intent(in) :: fice(pcols,pver) ! fraction of cwat that is ice |
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| 421 | real(r8), intent(in) :: fsnow(pcols,pver) ! fraction of rain that freezes to snow |
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| 422 | real(r8), intent(in) :: cldn(pcols,pver) ! new value of cloud fraction (fraction) |
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| 423 | real(r8), intent(in) :: cwat(pcols,pver) ! cloud water (kg/kg) |
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| 424 | real(r8), intent(in) :: omega(pcols,pver) ! vert pressure vel (Pa/s) |
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| 425 | real(r8), intent(in) :: p(pcols,pver) ! pressure (K) |
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| 426 | real(r8), intent(in) :: pdel(pcols,pver) ! pressure thickness (Pa) |
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| 427 | real(r8), intent(in) :: qn(pcols,pver) ! new water vapor (kg/kg) |
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| 428 | real(r8), intent(in) :: qtend(pcols,pver) ! mixing ratio tend (kg/kg/s) |
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| 429 | real(r8), intent(in) :: tn(pcols,pver) ! new temperature (K) |
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| 430 | real(r8), intent(in) :: ttend(pcols,pver) ! temp tendencies (K/s) |
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| 431 | real(r8), intent(in) :: deltat ! time step to advance solution over |
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| 432 | real(r8), intent(in) :: lctend(pcols,pver) ! cloud liquid water tendencies ====wlin |
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| 433 | real(r8), intent(in) :: rhdfda(pcols,pver) ! dG(a)/da, rh=G(a), when rh>u00 ====wlin |
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| 434 | real(r8), intent(in) :: rhu00 (pcols,pver) ! Rhlim for cloud ====wlin |
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| 435 | real(r8), intent(in) :: seaicef(pcols) ! sea ice fraction (fraction) |
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| 436 | real(r8), intent(in) :: zi(pcols,pverp) ! layer interfaces (m) |
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| 437 | real(r8), intent(in) :: snowh(pcols) ! Snow depth over land, water equivalent (m) |
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| 438 | ! |
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| 439 | ! Output Arguments |
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| 440 | ! |
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| 441 | real(r8), intent(out) :: cme (pcols,pver) ! rate of cond-evap of condensate (1/s) |
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| 442 | real(r8), intent(out) :: prodprec(pcols,pver) ! rate of conversion of condensate to precip (1/s) |
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| 443 | real(r8), intent(out) :: evapprec(pcols,pver) ! rate of evaporation of falling precip (1/s) |
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| 444 | real(r8), intent(out) :: evapsnow(pcols,pver) ! rate of evaporation of falling snow (1/s) |
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| 445 | real(r8), intent(out) :: evapheat(pcols,pver) ! heating rate due to evaporation of precip (W/kg) |
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| 446 | real(r8), intent(out) :: prfzheat(pcols,pver) ! heating rate due to freezing of precip (W/kg) |
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| 447 | real(r8), intent(out) :: meltheat(pcols,pver) ! heating rate due to snow melt (W/kg) |
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| 448 | real(r8), intent(out) :: precip(pcols) ! rate of precipitation (kg / (m**2 * s)) |
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| 449 | real(r8), intent(out) :: snowab(pcols) ! rate of snow (kg / (m**2 * s)) |
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| 450 | real(r8), intent(out) :: ice2pr(pcols,pver) ! rate of conversion of ice to precip |
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| 451 | real(r8), intent(out) :: liq2pr(pcols,pver) ! rate of conversion of liquid to precip |
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| 452 | real(r8), intent(out) :: liq2snow(pcols,pver) ! rate of conversion of liquid to snow |
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| 453 | real(r8), intent(out) :: rkflxprc(pcols,pverp) ! grid-box mean RK flux_large_scale_cloud_rain at interfaces (kg m^-2 s^-1) |
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| 454 | real(r8), intent(out) :: rkflxsnw(pcols,pverp) ! grid-box mean RK flux_large_scale_cloud_snow at interfaces (kg m^-2 s^-1) |
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| 455 | |
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| 456 | real(r8) nice2pr ! rate of conversion of ice to snow |
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| 457 | real(r8) nliq2pr ! rate of conversion of liquid to precip |
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| 458 | real(r8) nliq2snow ! rate of conversion of liquid to snow |
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| 459 | real(r8) prodsnow(pcols,pver) ! rate of production of snow |
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| 460 | |
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| 461 | ! |
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| 462 | ! Local workspace |
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| 463 | ! |
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| 464 | real(r8) :: precab(pcols) ! rate of precipitation (kg / (m**2 * s)) |
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| 465 | integer i ! work variable |
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| 466 | integer iter ! #iterations for precipitation calculation |
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| 467 | integer k ! work variable |
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| 468 | integer l ! work variable |
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| 469 | |
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| 470 | real(r8) cldm(pcols) ! mean cloud fraction over the time step |
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| 471 | real(r8) cldmax(pcols) ! max cloud fraction above |
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| 472 | real(r8) coef(pcols) ! conversion time scale for condensate to rain |
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| 473 | real(r8) cwm(pcols) ! cwat mixing ratio at midpoint of time step |
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| 474 | real(r8) cwn(pcols) ! cwat mixing ratio at end |
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| 475 | real(r8) denom ! work variable |
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| 476 | real(r8) dqsdt ! change in sat spec. hum. wrt temperature |
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| 477 | real(r8) es(pcols) ! sat. vapor pressure |
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| 478 | real(r8) fracw(pcols,pver) ! relative importance of collection of liquid by rain |
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| 479 | real(r8) fsaci(pcols,pver) ! relative importance of collection of ice by snow |
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| 480 | real(r8) fsacw(pcols,pver) ! relative importance of collection of liquid by snow |
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| 481 | real(r8) fsaut(pcols,pver) ! relative importance of ice auto conversion |
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| 482 | real(r8) fwaut(pcols,pver) ! relative importance of warm cloud autoconversion |
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| 483 | real(r8) gamma(pcols) ! d qs / dT |
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| 484 | real(r8) icwc(pcols) ! in-cloud water content (kg/kg) |
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| 485 | real(r8) mincld ! a small cloud fraction to avoid / zero |
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| 486 | real(r8) omeps ! 1 minus epsilon |
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| 487 | real(r8),parameter ::omsm=0.99999_r8 ! a number just less than unity (for rounding) |
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| 488 | real(r8) prprov(pcols) ! provisional value of precip at btm of layer |
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| 489 | real(r8) prtmp ! work variable |
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| 490 | real(r8) q(pcols,pver) ! mixing ratio before time step ignoring condensate |
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| 491 | real(r8) qs(pcols) ! spec. hum. of water vapor |
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| 492 | real(r8) qsn, esn ! work variable |
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| 493 | real(r8) qsp(pcols,pver) ! sat pt mixing ratio |
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| 494 | real(r8) qtl(pcols) ! tendency which would saturate the grid box in deltat |
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| 495 | real(r8) qtmp, ttmp ! work variable |
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| 496 | real(r8) relhum1(pcols) ! relative humidity |
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| 497 | real(r8) relhum(pcols) ! relative humidity |
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| 498 | !!$ real(r8) tc ! crit temp of transition to ice |
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| 499 | real(r8) t(pcols,pver) ! temp before time step ignoring condensate |
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| 500 | real(r8) tsp(pcols,pver) ! sat pt temperature |
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| 501 | real(r8) pol ! work variable |
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| 502 | real(r8) cdt ! work variable |
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| 503 | real(r8) wtthick ! work variable |
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| 504 | |
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| 505 | ! Extra local work space for cloud scheme modification |
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| 506 | |
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| 507 | real(r8) cpohl !Cp/Hlatv |
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| 508 | real(r8) hlocp !Hlatv/Cp |
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| 509 | real(r8) dto2 !0.5*deltat (delta=2.0*dt) |
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| 510 | real(r8) calpha(pcols) !alpha of new C - E scheme formulation |
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| 511 | real(r8) cbeta (pcols) !beta of new C - E scheme formulation |
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| 512 | real(r8) cbetah(pcols) !beta_hat at saturation portion |
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| 513 | real(r8) cgamma(pcols) !gamma of new C - E scheme formulation |
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| 514 | real(r8) cgamah(pcols) !gamma_hat at saturation portion |
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| 515 | real(r8) rcgama(pcols) !gamma/gamma_hat |
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| 516 | real(r8) csigma(pcols) !sigma of new C - E scheme formulation |
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| 517 | real(r8) cmec1 (pcols) !c1 of new C - E scheme formulation |
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| 518 | real(r8) cmec2 (pcols) !c2 of new C - E scheme formulation |
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| 519 | real(r8) cmec3 (pcols) !c3 of new C - E scheme formulation |
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| 520 | real(r8) cmec4 (pcols) !c4 of new C - E scheme formulation |
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| 521 | real(r8) cmeres(pcols) !residual cond of over-sat after cme and evapprec |
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| 522 | real(r8) ctmp !a scalar representation of cmeres |
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| 523 | real(r8) clrh2o ! Ratio of latvap to water vapor gas const |
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| 524 | real(r8) ice(pcols,pver) ! ice mixing ratio |
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| 525 | real(r8) liq(pcols,pver) ! liquid mixing ratio |
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| 526 | real(r8) rcwn(pcols,2,pver), rliq(pcols,2,pver), rice(pcols,2,pver) |
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| 527 | real(r8) cwnsave(pcols,2,pver), cmesave(pcols,2,pver) |
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| 528 | real(r8) prodprecsave(pcols,2,pver) |
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| 529 | logical error_found |
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| 530 | ! |
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| 531 | !------------------------------------------------------------ |
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| 532 | ! |
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| 533 | clrh2o = hlatv/rh2o ! Ratio of latvap to water vapor gas const |
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| 534 | omeps = 1.0_r8 - epsqs |
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| 535 | #ifdef PERGRO |
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| 536 | mincld = 1.e-4_r8 |
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| 537 | iter = 1 ! number of times to iterate the precipitation calculation |
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| 538 | #else |
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| 539 | mincld = 1.e-4_r8 |
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| 540 | iter = 2 |
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| 541 | #endif |
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| 542 | ! omsm = 0.99999 |
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| 543 | cpohl = cp/hlatv |
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| 544 | hlocp = hlatv/cp |
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| 545 | dto2=0.5_r8*deltat |
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| 546 | ! |
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| 547 | ! Constant for computing rate of evaporation of precipitation: |
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| 548 | ! |
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| 549 | !!$ conke = 1.e-5 |
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| 550 | !!$ conke = 1.e-6 |
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| 551 | ! |
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| 552 | ! initialize a few single level fields |
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| 553 | ! |
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| 554 | do i = 1,ncol |
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| 555 | precip(i) = 0.0_r8 |
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| 556 | precab(i) = 0.0_r8 |
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| 557 | snowab(i) = 0.0_r8 |
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| 558 | cldmax(i) = 0.0_r8 |
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| 559 | end do |
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| 560 | ! |
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| 561 | ! initialize multi-level fields |
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| 562 | ! |
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| 563 | do k = 1,pver |
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| 564 | do i = 1,ncol |
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| 565 | q(i,k) = qn(i,k) |
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| 566 | t(i,k) = tn(i,k) |
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| 567 | ! q(i,k)=qn(i,k)-qtend(i,k)*deltat |
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| 568 | ! t(i,k)=tn(i,k)-ttend(i,k)*deltat |
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| 569 | end do |
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| 570 | end do |
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| 571 | cme (:ncol,:) = 0._r8 |
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| 572 | evapprec(:ncol,:) = 0._r8 |
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| 573 | prodprec(:ncol,:) = 0._r8 |
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| 574 | evapsnow(:ncol,:) = 0._r8 |
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| 575 | prodsnow(:ncol,:) = 0._r8 |
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| 576 | evapheat(:ncol,:) = 0._r8 |
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| 577 | meltheat(:ncol,:) = 0._r8 |
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| 578 | prfzheat(:ncol,:) = 0._r8 |
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| 579 | ice2pr(:ncol,:) = 0._r8 |
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| 580 | liq2pr(:ncol,:) = 0._r8 |
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| 581 | liq2snow(:ncol,:) = 0._r8 |
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| 582 | fwaut(:ncol,:) = 0._r8 |
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| 583 | fsaut(:ncol,:) = 0._r8 |
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| 584 | fracw(:ncol,:) = 0._r8 |
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| 585 | fsacw(:ncol,:) = 0._r8 |
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| 586 | fsaci(:ncol,:) = 0._r8 |
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| 587 | rkflxprc(:ncol,:) = 0._r8 |
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| 588 | rkflxsnw(:ncol,:) = 0._r8 |
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| 589 | |
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| 590 | ! |
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| 591 | ! find the wet bulb temp and saturation value |
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| 592 | ! for the provisional t and q without condensation |
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| 593 | ! |
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| 594 | call findsp (lchnk, ncol, qn, tn, p, tsp, qsp) |
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| 595 | do 800 k = k1mb,pver |
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| 596 | call vqsatd (t(1,k), p(1,k), es, qs, gamma, ncol) |
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| 597 | do i = 1,ncol |
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| 598 | relhum(i) = q(i,k)/qs(i) |
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| 599 | ! |
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| 600 | cldm(i) = max(cldn(i,k),mincld) |
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| 601 | ! |
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| 602 | ! the max cloud fraction above this level |
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| 603 | ! |
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| 604 | cldmax(i) = max(cldmax(i), cldm(i)) |
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| 605 | |
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| 606 | ! define the coefficients for C - E calculation |
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| 607 | |
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| 608 | calpha(i) = 1.0_r8/qs(i) |
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| 609 | cbeta (i) = q(i,k)/qs(i)**2*gamma(i)*cpohl |
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| 610 | cbetah(i) = 1.0_r8/qs(i)*gamma(i)*cpohl |
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| 611 | cgamma(i) = calpha(i)+hlatv*cbeta(i)/cp |
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| 612 | cgamah(i) = calpha(i)+hlatv*cbetah(i)/cp |
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| 613 | rcgama(i) = cgamma(i)/cgamah(i) |
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| 614 | |
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| 615 | if(cldm(i) > mincld) then |
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| 616 | icwc(i) = max(0._r8,cwat(i,k)/cldm(i)) |
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| 617 | else |
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| 618 | icwc(i) = 0.0_r8 |
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| 619 | endif |
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| 620 | !PJR the above logic give zero icwc with nonzero cwat, dont like it! |
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| 621 | !PJR generates problems with csigma |
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| 622 | !PJR set the icwc to a very small number, so we can start from zero cloud cover and make some clouds |
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| 623 | ! icwc(i) = max(1.e-8_r8,cwat(i,k)/cldm(i)) |
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| 624 | |
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| 625 | ! |
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| 626 | ! initial guess of evaporation, will be updated within iteration |
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| 627 | ! |
|---|
| 628 | evapprec(i,k) = conke*(1._r8 - cldm(i))*sqrt(precab(i)) & |
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| 629 | *(1._r8 - min(relhum(i),1._r8)) |
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| 630 | |
|---|
| 631 | ! |
|---|
| 632 | ! zero cmeres before iteration for each level |
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| 633 | ! |
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| 634 | cmeres(i)=0.0_r8 |
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| 635 | |
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| 636 | end do |
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| 637 | do i = 1,ncol |
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| 638 | ! |
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| 639 | ! fractions of ice at this level |
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| 640 | ! |
|---|
| 641 | !!$ tc = t(i,k) - t0 |
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| 642 | !!$ fice(i,k) = max(0._r8,min(-tc*0.05,1.0_r8)) |
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| 643 | ! |
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| 644 | ! calculate the cooling due to a phase change of the rainwater |
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| 645 | ! from above |
|---|
| 646 | ! |
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| 647 | if (t(i,k) >= t0) then |
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| 648 | meltheat(i,k) = -hlatf * snowab(i) * gravit/pdel(i,k) |
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| 649 | snowab(i) = 0._r8 |
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| 650 | else |
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| 651 | meltheat(i,k) = 0._r8 |
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| 652 | endif |
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| 653 | end do |
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| 654 | |
|---|
| 655 | ! |
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| 656 | ! calculate cme and formation of precip. |
|---|
| 657 | ! |
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| 658 | ! The cloud microphysics is highly nonlinear and coupled with cme |
|---|
| 659 | ! Both rain processes and cme are calculated iteratively. |
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| 660 | ! |
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| 661 | do 100 l = 1,iter |
|---|
| 662 | |
|---|
| 663 | do i = 1,ncol |
|---|
| 664 | |
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| 665 | ! |
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| 666 | ! calculation of cme has 4 scenarios |
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| 667 | ! ================================== |
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| 668 | ! |
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| 669 | if(relhum(i) > rhu00(i,k)) then |
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| 670 | |
|---|
| 671 | ! 1. whole grid saturation |
|---|
| 672 | ! ======================== |
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| 673 | if(relhum(i) >= 0.999_r8 .or. cldm(i) >= 0.999_r8 ) then |
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| 674 | cme(i,k)=(calpha(i)*qtend(i,k)-cbetah(i)*ttend(i,k))/cgamah(i) |
|---|
| 675 | |
|---|
| 676 | ! 2. fractional saturation |
|---|
| 677 | ! ======================== |
|---|
| 678 | else |
|---|
| 679 | if (rhdfda(i,k) .eq. 0. .and. icwc(i).eq.0.) then |
|---|
| 680 | write (iulog,*) ' cldwat.F90: empty rh cloud ', i, k, lchnk |
|---|
| 681 | write (iulog,*) ' relhum, iter ', relhum(i), l, rhu00(i,k), cldm(i), cldn(i,k) |
|---|
| 682 | call endrun () |
|---|
| 683 | endif |
|---|
| 684 | csigma(i) = 1.0_r8/(rhdfda(i,k)+cgamma(i)*icwc(i)) |
|---|
| 685 | cmec1(i) = (1.0_r8-cldm(i))*csigma(i)*rhdfda(i,k) |
|---|
| 686 | cmec2(i) = cldm(i)*calpha(i)/cgamah(i)+(1.0_r8-rcgama(i)*cldm(i))* & |
|---|
| 687 | csigma(i)*calpha(i)*icwc(i) |
|---|
| 688 | cmec3(i) = cldm(i)*cbetah(i)/cgamah(i) + & |
|---|
| 689 | (cbeta(i)-rcgama(i)*cldm(i)*cbetah(i))*csigma(i)*icwc(i) |
|---|
| 690 | cmec4(i) = csigma(i)*cgamma(i)*icwc(i) |
|---|
| 691 | |
|---|
| 692 | ! Q=C-E=-C1*Al + C2*Aq - C3* At + C4*Er |
|---|
| 693 | |
|---|
| 694 | cme(i,k) = -cmec1(i)*lctend(i,k) + cmec2(i)*qtend(i,k) & |
|---|
| 695 | -cmec3(i)*ttend(i,k) + cmec4(i)*evapprec(i,k) |
|---|
| 696 | endif |
|---|
| 697 | |
|---|
| 698 | ! 3. when rh < rhu00, evaporate existing cloud water |
|---|
| 699 | ! ================================================== |
|---|
| 700 | else if(cwat(i,k) > 0.0_r8)then |
|---|
| 701 | ! liquid water should be evaporated but not to exceed |
|---|
| 702 | ! saturation point. if qn > qsp, not to evaporate cwat |
|---|
| 703 | cme(i,k)=-min(max(0._r8,qsp(i,k)-qn(i,k)),cwat(i,k))/deltat |
|---|
| 704 | |
|---|
| 705 | ! 4. no condensation nor evaporation |
|---|
| 706 | ! ================================== |
|---|
| 707 | else |
|---|
| 708 | cme(i,k)=0.0_r8 |
|---|
| 709 | endif |
|---|
| 710 | |
|---|
| 711 | |
|---|
| 712 | end do !end loop for cme update |
|---|
| 713 | |
|---|
| 714 | ! Because of the finite time step, |
|---|
| 715 | ! place a bound here not to exceed wet bulb point |
|---|
| 716 | ! and not to evaporate more than available water |
|---|
| 717 | ! |
|---|
| 718 | do i = 1, ncol |
|---|
| 719 | qtmp = qn(i,k) - cme(i,k)*deltat |
|---|
| 720 | |
|---|
| 721 | ! possibilities to have qtmp > qsp |
|---|
| 722 | ! |
|---|
| 723 | ! 1. if qn > qs(tn), it condenses; |
|---|
| 724 | ! if after applying cme, qtmp > qsp, more condensation is applied. |
|---|
| 725 | ! |
|---|
| 726 | ! 2. if qn < qs, evaporation should not exceed qsp, |
|---|
| 727 | |
|---|
| 728 | if(qtmp > qsp(i,k)) then |
|---|
| 729 | cme(i,k) = cme(i,k) + (qtmp-qsp(i,k))/deltat |
|---|
| 730 | endif |
|---|
| 731 | |
|---|
| 732 | ! |
|---|
| 733 | ! if net evaporation, it should not exceed available cwat |
|---|
| 734 | ! |
|---|
| 735 | if(cme(i,k) < -cwat(i,k)/deltat) & |
|---|
| 736 | cme(i,k) = -cwat(i,k)/deltat |
|---|
| 737 | ! |
|---|
| 738 | ! addition of residual condensation from previous step of iteration |
|---|
| 739 | ! |
|---|
| 740 | cme(i,k) = cme(i,k) + cmeres(i) |
|---|
| 741 | |
|---|
| 742 | end do |
|---|
| 743 | |
|---|
| 744 | ! limit cme for roundoff errors |
|---|
| 745 | do i = 1, ncol |
|---|
| 746 | cme(i,k) = cme(i,k)*omsm |
|---|
| 747 | end do |
|---|
| 748 | |
|---|
| 749 | do i = 1,ncol |
|---|
| 750 | ! |
|---|
| 751 | ! as a safe limit, condensation should not reduce grid mean rh below rhu00 |
|---|
| 752 | ! |
|---|
| 753 | if(cme(i,k) > 0.0_r8 .and. relhum(i) > rhu00(i,k) ) & |
|---|
| 754 | cme(i,k) = min(cme(i,k), (qn(i,k)-qs(i)*rhu00(i,k))/deltat) |
|---|
| 755 | ! |
|---|
| 756 | ! initial guess for cwm (mean cloud water over time step) if 1st iteration |
|---|
| 757 | ! |
|---|
| 758 | if(l < 2) then |
|---|
| 759 | cwm(i) = max(cwat(i,k)+cme(i,k)*dto2, 0._r8) |
|---|
| 760 | endif |
|---|
| 761 | |
|---|
| 762 | enddo |
|---|
| 763 | |
|---|
| 764 | ! provisional precipitation falling through model layer |
|---|
| 765 | do i = 1,ncol |
|---|
| 766 | !!$ prprov(i) = precab(i) + prodprec(i,k)*pdel(i,k)/gravit |
|---|
| 767 | ! rain produced in this layer not too effective in collection process |
|---|
| 768 | wtthick = max(0._r8,min(0.5_r8,((zi(i,k)-zi(i,k+1))/1000._r8)**2)) |
|---|
| 769 | prprov(i) = precab(i) + wtthick*prodprec(i,k)*pdel(i,k)/gravit |
|---|
| 770 | end do |
|---|
| 771 | |
|---|
| 772 | ! calculate conversion of condensate to precipitation by cloud microphysics |
|---|
| 773 | call findmcnew (lchnk ,ncol , & |
|---|
| 774 | k ,prprov ,snowab, t ,p , & |
|---|
| 775 | cwm ,cldm ,cldmax ,fice(1,k),coef , & |
|---|
| 776 | fwaut(1,k),fsaut(1,k),fracw(1,k),fsacw(1,k),fsaci(1,k), & |
|---|
| 777 | seaicef, snowh) |
|---|
| 778 | ! |
|---|
| 779 | ! calculate the precip rate |
|---|
| 780 | ! |
|---|
| 781 | error_found = .false. |
|---|
| 782 | do i = 1,ncol |
|---|
| 783 | if (cldm(i) > 0) then |
|---|
| 784 | ! |
|---|
| 785 | ! first predict the cloud water |
|---|
| 786 | ! |
|---|
| 787 | cdt = coef(i)*deltat |
|---|
| 788 | if (cdt > 0.01_r8) then |
|---|
| 789 | pol = cme(i,k)/coef(i) ! production over loss |
|---|
| 790 | cwn(i) = max(0._r8,(cwat(i,k)-pol)*exp(-cdt)+ pol) |
|---|
| 791 | else |
|---|
| 792 | cwn(i) = max(0._r8,(cwat(i,k) + cme(i,k)*deltat)/(1+cdt)) |
|---|
| 793 | endif |
|---|
| 794 | ! |
|---|
| 795 | ! now back out the tendency of net rain production |
|---|
| 796 | ! |
|---|
| 797 | prodprec(i,k) = max(0._r8,cme(i,k)-(cwn(i)-cwat(i,k))/deltat) |
|---|
| 798 | else |
|---|
| 799 | prodprec(i,k) = 0.0_r8 |
|---|
| 800 | cwn(i) = 0._r8 |
|---|
| 801 | endif |
|---|
| 802 | |
|---|
| 803 | ! provisional calculation of conversion terms |
|---|
| 804 | ice2pr(i,k) = prodprec(i,k)*(fsaut(i,k)+fsaci(i,k)) |
|---|
| 805 | liq2pr(i,k) = prodprec(i,k)*(fwaut(i,k)+fsacw(i,k)+fracw(i,k)) |
|---|
| 806 | !old liq2snow(i,k) = prodprec(i,k)*fsacw(i,k) |
|---|
| 807 | |
|---|
| 808 | ! revision suggested by Jim McCaa |
|---|
| 809 | ! it controls the amount of snow hitting the sfc |
|---|
| 810 | ! by forcing a lot of conversion of cloud liquid to snow phase |
|---|
| 811 | ! it might be better done later by an explicit representation of |
|---|
| 812 | ! rain accreting ice (and freezing), or by an explicit freezing of raindrops |
|---|
| 813 | liq2snow(i,k) = max(prodprec(i,k)*fsacw(i,k), fsnow(i,k)*liq2pr(i,k)) |
|---|
| 814 | |
|---|
| 815 | ! bounds |
|---|
| 816 | nice2pr = min(ice2pr(i,k),(cwat(i,k)+cme(i,k)*deltat)*fice(i,k)/deltat) |
|---|
| 817 | nliq2pr = min(liq2pr(i,k),(cwat(i,k)+cme(i,k)*deltat)*(1._r8-fice(i,k))/deltat) |
|---|
| 818 | ! write(iulog,*) ' prodprec ', i, k, prodprec(i,k) |
|---|
| 819 | ! write(iulog,*) ' nliq2pr, nice2pr ', nliq2pr, nice2pr |
|---|
| 820 | if (liq2pr(i,k).ne.0._r8) then |
|---|
| 821 | nliq2snow = liq2snow(i,k)*nliq2pr/liq2pr(i,k) ! correction |
|---|
| 822 | else |
|---|
| 823 | nliq2snow = liq2snow(i,k) |
|---|
| 824 | endif |
|---|
| 825 | |
|---|
| 826 | ! avoid roundoff problems generating negatives |
|---|
| 827 | nliq2snow = nliq2snow*omsm |
|---|
| 828 | nliq2pr = nliq2pr*omsm |
|---|
| 829 | nice2pr = nice2pr*omsm |
|---|
| 830 | |
|---|
| 831 | ! final estimates of conversion to precip and snow |
|---|
| 832 | prodprec(i,k) = (nliq2pr + nice2pr) |
|---|
| 833 | prodsnow(i,k) = (nice2pr + nliq2snow) |
|---|
| 834 | |
|---|
| 835 | rcwn(i,l,k) = cwat(i,k) + (cme(i,k)- prodprec(i,k))*deltat |
|---|
| 836 | rliq(i,l,k) = (cwat(i,k) + cme(i,k)*deltat)*(1._r8-fice(i,k)) - nliq2pr * deltat |
|---|
| 837 | rice(i,l,k) = (cwat(i,k) + cme(i,k)*deltat)* fice(i,k) - nice2pr *deltat |
|---|
| 838 | |
|---|
| 839 | ! Save for sanity check later... |
|---|
| 840 | ! Putting sanity checks inside loops 100 and 800 screws up the |
|---|
| 841 | ! IBM compiler for reasons as yet unknown. TBH |
|---|
| 842 | cwnsave(i,l,k) = cwn(i) |
|---|
| 843 | cmesave(i,l,k) = cme(i,k) |
|---|
| 844 | prodprecsave(i,l,k) = prodprec(i,k) |
|---|
| 845 | ! End of save for sanity check later... |
|---|
| 846 | |
|---|
| 847 | ! final version of condensate to precip terms |
|---|
| 848 | liq2pr(i,k) = nliq2pr |
|---|
| 849 | liq2snow(i,k) = nliq2snow |
|---|
| 850 | ice2pr(i,k) = nice2pr |
|---|
| 851 | |
|---|
| 852 | cwn(i) = rcwn(i,l,k) |
|---|
| 853 | ! |
|---|
| 854 | ! update any remaining provisional values |
|---|
| 855 | ! |
|---|
| 856 | cwm(i) = (cwn(i) + cwat(i,k))*0.5_r8 |
|---|
| 857 | ! |
|---|
| 858 | ! update in cloud water |
|---|
| 859 | ! |
|---|
| 860 | if(cldm(i) > mincld) then |
|---|
| 861 | icwc(i) = cwm(i)/cldm(i) |
|---|
| 862 | else |
|---|
| 863 | icwc(i) = 0.0_r8 |
|---|
| 864 | endif |
|---|
| 865 | !PJR the above logic give zero icwc with nonzero cwat, dont like it! |
|---|
| 866 | !PJR generates problems with csigma |
|---|
| 867 | !PJR set the icwc to a very small number, so we can start from zero cloud cover and make some clouds |
|---|
| 868 | ! icwc(i) = max(1.e-8_r8,cwm(i)/cldm(i)) |
|---|
| 869 | |
|---|
| 870 | end do ! end of do i = 1,ncol |
|---|
| 871 | |
|---|
| 872 | ! |
|---|
| 873 | ! calculate provisional value of cloud water for |
|---|
| 874 | ! evaporation of precipitate (evapprec) calculation |
|---|
| 875 | ! |
|---|
| 876 | do i = 1,ncol |
|---|
| 877 | qtmp = qn(i,k) - cme(i,k)*deltat |
|---|
| 878 | ttmp = tn(i,k) + deltat/cp * ( meltheat(i,k) & |
|---|
| 879 | + (hlatv + hlatf*fice(i,k)) * cme(i,k) ) |
|---|
| 880 | esn = estblf(ttmp) |
|---|
| 881 | qsn = min(epsqs*esn/(p(i,k) - omeps*esn),1._r8) |
|---|
| 882 | qtl(i) = max((qsn - qtmp)/deltat,0._r8) |
|---|
| 883 | relhum1(i) = qtmp/qsn |
|---|
| 884 | end do |
|---|
| 885 | ! |
|---|
| 886 | do i = 1,ncol |
|---|
| 887 | #ifdef PERGRO |
|---|
| 888 | evapprec(i,k) = conke*(1._r8 - max(cldm(i),mincld))* & |
|---|
| 889 | sqrt(precab(i))*(1._r8 - min(relhum1(i),1._r8)) |
|---|
| 890 | #else |
|---|
| 891 | evapprec(i,k) = conke*(1._r8 - cldm(i))*sqrt(precab(i)) & |
|---|
| 892 | *(1._r8 - min(relhum1(i),1._r8)) |
|---|
| 893 | #endif |
|---|
| 894 | ! |
|---|
| 895 | ! limit the evaporation to the amount which is entering the box |
|---|
| 896 | ! or saturates the box |
|---|
| 897 | ! |
|---|
| 898 | prtmp = precab(i)*gravit/pdel(i,k) |
|---|
| 899 | evapprec(i,k) = min(evapprec(i,k), prtmp, qtl(i))*omsm |
|---|
| 900 | #ifdef PERGRO |
|---|
| 901 | ! zeroing needed for pert growth |
|---|
| 902 | evapprec(i,k) = 0._r8 |
|---|
| 903 | #endif |
|---|
| 904 | ! |
|---|
| 905 | ! Partition evaporation of precipitate between rain and snow using |
|---|
| 906 | ! the fraction of snow falling into the box. Determine the heating |
|---|
| 907 | ! due to evaporation. Note that evaporation is positive (loss of precip, |
|---|
| 908 | ! gain of vapor) and that heating is negative. |
|---|
| 909 | if (evapprec(i,k) > 0._r8) then |
|---|
| 910 | evapsnow(i,k) = evapprec(i,k) * snowab(i) / precab(i) |
|---|
| 911 | evapheat(i,k) = -hlatv * evapprec(i,k) - hlatf * evapsnow(i,k) |
|---|
| 912 | else |
|---|
| 913 | evapsnow(i,k) = 0._r8 |
|---|
| 914 | evapheat(i,k) = 0._r8 |
|---|
| 915 | end if |
|---|
| 916 | ! Account for the latent heat of fusion for liquid drops collected by falling snow |
|---|
| 917 | prfzheat(i,k) = hlatf * liq2snow(i,k) |
|---|
| 918 | end do |
|---|
| 919 | |
|---|
| 920 | ! now remove the residual of any over-saturation. Normally, |
|---|
| 921 | ! the oversaturated water vapor should have been removed by |
|---|
| 922 | ! cme formulation plus constraints by wet bulb tsp/qsp |
|---|
| 923 | ! as computed above. However, because of non-linearity, |
|---|
| 924 | ! addition of (cme-evapprec) to update t and q may still cause |
|---|
| 925 | ! a very small amount of over saturation. It is called a |
|---|
| 926 | ! residual of over-saturation because theoretically, cme |
|---|
| 927 | ! should have taken care of all of large scale condensation. |
|---|
| 928 | ! |
|---|
| 929 | |
|---|
| 930 | do i = 1,ncol |
|---|
| 931 | qtmp = qn(i,k)-(cme(i,k)-evapprec(i,k))*deltat |
|---|
| 932 | ttmp = tn(i,k) + deltat/cp * ( meltheat(i,k) + evapheat(i,k) + prfzheat(i,k) & |
|---|
| 933 | + (hlatv + hlatf*fice(i,k)) * cme(i,k) ) |
|---|
| 934 | esn = estblf(ttmp) |
|---|
| 935 | qsn = min(epsqs*esn/(p(i,k) - omeps*esn),1._r8) |
|---|
| 936 | ! |
|---|
| 937 | !Upper stratosphere and mesosphere, qsn calculated |
|---|
| 938 | !above may be negative. Here just to skip it instead |
|---|
| 939 | !of resetting it to 1 as in aqsat |
|---|
| 940 | ! |
|---|
| 941 | if(qtmp > qsn .and. qsn > 0) then |
|---|
| 942 | !calculate dqsdt, a more precise calculation |
|---|
| 943 | !which taking into account different range of T |
|---|
| 944 | !can be found in aqsatd.F. Here follows |
|---|
| 945 | !cond.F to calculate it. |
|---|
| 946 | ! |
|---|
| 947 | denom = (p(i,k)-omeps*esn)*ttmp*ttmp |
|---|
| 948 | dqsdt = clrh2o*qsn*p(i,k)/denom |
|---|
| 949 | ! |
|---|
| 950 | !now extra condensation to bring air to just saturation |
|---|
| 951 | ! |
|---|
| 952 | ctmp = (qtmp-qsn)/(1._r8+hlocp*dqsdt)/deltat |
|---|
| 953 | cme(i,k) = cme(i,k)+ctmp |
|---|
| 954 | ! |
|---|
| 955 | ! save residual on cmeres to addtion to cme on entering next iteration |
|---|
| 956 | ! cme exit here contain the residual but overrided if back to iteration |
|---|
| 957 | ! |
|---|
| 958 | cmeres(i) = ctmp |
|---|
| 959 | else |
|---|
| 960 | cmeres(i) = 0.0_r8 |
|---|
| 961 | endif |
|---|
| 962 | end do |
|---|
| 963 | |
|---|
| 964 | 100 continue ! end of do l = 1,iter |
|---|
| 965 | |
|---|
| 966 | ! |
|---|
| 967 | ! precipitation |
|---|
| 968 | ! |
|---|
| 969 | do i = 1,ncol |
|---|
| 970 | precip(i) = precip(i) + pdel(i,k)/gravit * (prodprec(i,k) - evapprec(i,k)) |
|---|
| 971 | precab(i) = precab(i) + pdel(i,k)/gravit * (prodprec(i,k) - evapprec(i,k)) |
|---|
| 972 | if(precab(i).lt.0._r8) precab(i)=0._r8 |
|---|
| 973 | ! snowab(i) = snowab(i) + pdel(i,k)/gravit * (prodprec(i,k)*fice(i,k) - evapsnow(i,k)) |
|---|
| 974 | snowab(i) = snowab(i) + pdel(i,k)/gravit * (prodsnow(i,k) - evapsnow(i,k)) |
|---|
| 975 | |
|---|
| 976 | ! If temperature above freezing, all precip is rain flux. if temperature below freezing, all precip is snow flux. |
|---|
| 977 | rkflxprc(i,k+1) = precab(i) - snowab(i) |
|---|
| 978 | rkflxsnw(i,k+1) = snowab(i) |
|---|
| 979 | |
|---|
| 980 | !!$ if ((precab(i)) < 1.e-10) then |
|---|
| 981 | !!$ precab(i) = 0. |
|---|
| 982 | !!$ snowab(i) = 0. |
|---|
| 983 | !!$ endif |
|---|
| 984 | end do |
|---|
| 985 | 800 continue ! level loop (k=1,pver) |
|---|
| 986 | |
|---|
| 987 | ! begin sanity checks |
|---|
| 988 | error_found = .false. |
|---|
| 989 | do k = k1mb,pver |
|---|
| 990 | do l = 1,iter |
|---|
| 991 | do i = 1,ncol |
|---|
| 992 | if (abs(rcwn(i,l,k)).lt.1.e-300_r8) rcwn(i,l,k) = 0._r8 |
|---|
| 993 | if (abs(rliq(i,l,k)).lt.1.e-300_r8) rliq(i,l,k) = 0._r8 |
|---|
| 994 | if (abs(rice(i,l,k)).lt.1.e-300_r8) rice(i,l,k) = 0._r8 |
|---|
| 995 | if (rcwn(i,l,k).lt.0._r8) error_found = .true. |
|---|
| 996 | if (rliq(i,l,k).lt.0._r8) error_found = .true. |
|---|
| 997 | if (rice(i,l,k).lt.0._r8) error_found = .true. |
|---|
| 998 | enddo |
|---|
| 999 | enddo |
|---|
| 1000 | enddo |
|---|
| 1001 | if (error_found) then |
|---|
| 1002 | do k = k1mb,pver |
|---|
| 1003 | do l = 1,iter |
|---|
| 1004 | do i = 1,ncol |
|---|
| 1005 | if (rcwn(i,l,k).lt.0._r8) then |
|---|
| 1006 | write(iulog,*) ' prob with neg rcwn1 ', rcwn(i,l,k), & |
|---|
| 1007 | cwnsave(i,l,k) |
|---|
| 1008 | write(iulog,*) ' cwat, cme*deltat, prodprec*deltat ', & |
|---|
| 1009 | cwat(i,k), cmesave(i,l,k)*deltat, & |
|---|
| 1010 | prodprecsave(i,l,k)*deltat, & |
|---|
| 1011 | (cmesave(i,l,k)-prodprecsave(i,l,k))*deltat |
|---|
| 1012 | call endrun('PCOND') |
|---|
| 1013 | endif |
|---|
| 1014 | if (rliq(i,l,k).lt.0._r8) then |
|---|
| 1015 | write(iulog,*) ' prob with neg rliq1 ', rliq(i,l,k) |
|---|
| 1016 | call endrun('PCOND') |
|---|
| 1017 | endif |
|---|
| 1018 | if (rice(i,l,k).lt.0._r8) then |
|---|
| 1019 | write(iulog,*) ' prob with neg rice ', rice(i,l,k) |
|---|
| 1020 | call endrun('PCOND') |
|---|
| 1021 | endif |
|---|
| 1022 | enddo |
|---|
| 1023 | enddo |
|---|
| 1024 | enddo |
|---|
| 1025 | end if |
|---|
| 1026 | ! end sanity checks |
|---|
| 1027 | |
|---|
| 1028 | return |
|---|
| 1029 | end subroutine pcond |
|---|
| 1030 | |
|---|
| 1031 | !############################################################################## |
|---|
| 1032 | |
|---|
| 1033 | subroutine findmcnew (lchnk ,ncol , & |
|---|
| 1034 | k ,precab ,snowab, t ,p , & |
|---|
| 1035 | cwm ,cldm ,cldmax ,fice ,coef , & |
|---|
| 1036 | fwaut ,fsaut ,fracw ,fsacw ,fsaci , & |
|---|
| 1037 | seaicef ,snowh ) |
|---|
| 1038 | !----------------------------------------------------------------------- |
|---|
| 1039 | ! |
|---|
| 1040 | ! Purpose: |
|---|
| 1041 | ! calculate the conversion of condensate to precipitate |
|---|
| 1042 | ! |
|---|
| 1043 | ! Method: |
|---|
| 1044 | ! See: Rasch, P. J, and J. E. Kristjansson, A Comparison of the CCM3 |
|---|
| 1045 | ! model climate using diagnosed and |
|---|
| 1046 | ! predicted condensate parameterizations, 1998, J. Clim., 11, |
|---|
| 1047 | ! pp1587---1614. |
|---|
| 1048 | ! |
|---|
| 1049 | ! Author: P. Rasch |
|---|
| 1050 | ! |
|---|
| 1051 | !----------------------------------------------------------------------- |
|---|
| 1052 | use phys_grid, only: get_rlat_all_p |
|---|
| 1053 | use comsrf, only: landm |
|---|
| 1054 | ! |
|---|
| 1055 | ! input args |
|---|
| 1056 | ! |
|---|
| 1057 | integer, intent(in) :: lchnk ! chunk identifier |
|---|
| 1058 | integer, intent(in) :: ncol ! number of atmospheric columns |
|---|
| 1059 | integer, intent(in) :: k ! level index |
|---|
| 1060 | |
|---|
| 1061 | real(r8), intent(in) :: precab(pcols) ! rate of precipitation from above (kg / (m**2 * s)) |
|---|
| 1062 | real(r8), intent(in) :: t(pcols,pver) ! temperature (K) |
|---|
| 1063 | real(r8), intent(in) :: p(pcols,pver) ! pressure (Pa) |
|---|
| 1064 | real(r8), intent(in) :: cldm(pcols) ! cloud fraction |
|---|
| 1065 | real(r8), intent(in) :: cldmax(pcols) ! max cloud fraction above this level |
|---|
| 1066 | real(r8), intent(in) :: cwm(pcols) ! condensate mixing ratio (kg/kg) |
|---|
| 1067 | real(r8), intent(in) :: fice(pcols) ! fraction of cwat that is ice |
|---|
| 1068 | real(r8), intent(in) :: seaicef(pcols) ! sea ice fraction |
|---|
| 1069 | real(r8), intent(in) :: snowab(pcols) ! rate of snow from above (kg / (m**2 * s)) |
|---|
| 1070 | real(r8), intent(in) :: snowh(pcols) ! Snow depth over land, water equivalent (m) |
|---|
| 1071 | |
|---|
| 1072 | ! output arguments |
|---|
| 1073 | real(r8), intent(out) :: coef(pcols) ! conversion rate (1/s) |
|---|
| 1074 | real(r8), intent(out) :: fwaut(pcols) ! relative importance of liquid autoconversion (a diagnostic) |
|---|
| 1075 | real(r8), intent(out) :: fsaut(pcols) ! relative importance of ice autoconversion (a diagnostic) |
|---|
| 1076 | real(r8), intent(out) :: fracw(pcols) ! relative importance of rain accreting liquid (a diagnostic) |
|---|
| 1077 | real(r8), intent(out) :: fsacw(pcols) ! relative importance of snow accreting liquid (a diagnostic) |
|---|
| 1078 | real(r8), intent(out) :: fsaci(pcols) ! relative importance of snow accreting ice (a diagnostic) |
|---|
| 1079 | |
|---|
| 1080 | ! work variables |
|---|
| 1081 | |
|---|
| 1082 | integer i |
|---|
| 1083 | integer ii |
|---|
| 1084 | integer ind(pcols) |
|---|
| 1085 | integer ncols |
|---|
| 1086 | |
|---|
| 1087 | real(r8), parameter :: degrad = 57.296_r8 ! divide by this to convert degrees to radians |
|---|
| 1088 | real(r8) capn ! local cloud particles / cm3 |
|---|
| 1089 | real(r8) capnoice ! local cloud particles when not over sea ice / cm3 |
|---|
| 1090 | real(r8) ciaut ! coefficient of autoconversion of ice (1/s) |
|---|
| 1091 | real(r8) cldloc(pcols) ! non-zero amount of cloud |
|---|
| 1092 | real(r8) cldpr(pcols) ! assumed cloudy volume occupied by rain and cloud |
|---|
| 1093 | real(r8) con1 ! work constant |
|---|
| 1094 | real(r8) con2 ! work constant |
|---|
| 1095 | real(r8) csacx ! constant used for snow accreting liquid or ice |
|---|
| 1096 | !!$ real(r8) dtice ! interval for transition from liquid to ice |
|---|
| 1097 | real(r8) icemr(pcols) ! in-cloud ice mixing ratio |
|---|
| 1098 | real(r8) icrit ! threshold for autoconversion of ice |
|---|
| 1099 | real(r8) liqmr(pcols) ! in-cloud liquid water mixing ratio |
|---|
| 1100 | real(r8) pracw ! rate of rain accreting water |
|---|
| 1101 | real(r8) prlloc(pcols) ! local rain flux in mm/day |
|---|
| 1102 | real(r8) prscgs(pcols) ! local snow amount in cgs units |
|---|
| 1103 | real(r8) psaci ! rate of collection of ice by snow (lin et al 1983) |
|---|
| 1104 | real(r8) psacw ! rate of collection of liquid by snow (lin et al 1983) |
|---|
| 1105 | real(r8) psaut ! rate of autoconversion of ice condensate |
|---|
| 1106 | real(r8) ptot ! total rate of conversion |
|---|
| 1107 | real(r8) pwaut ! rate of autoconversion of liquid condensate |
|---|
| 1108 | real(r8) r3l ! volume radius |
|---|
| 1109 | real(r8) rainmr(pcols) ! in-cloud rain mixing ratio |
|---|
| 1110 | real(r8) rat1 ! work constant |
|---|
| 1111 | real(r8) rat2 ! work constant |
|---|
| 1112 | !!$ real(r8) rdtice ! recipricol of dtice |
|---|
| 1113 | real(r8) rho(pcols) ! density (mks units) |
|---|
| 1114 | real(r8) rhocgs ! density (cgs units) |
|---|
| 1115 | real(r8) rlat(pcols) ! latitude (radians) |
|---|
| 1116 | real(r8) snowfr ! fraction of precipate existing as snow |
|---|
| 1117 | real(r8) totmr(pcols) ! in-cloud total condensate mixing ratio |
|---|
| 1118 | real(r8) vfallw ! fall speed of precipitate as liquid |
|---|
| 1119 | real(r8) wp ! weight factor used in calculating pressure dep of autoconversion |
|---|
| 1120 | real(r8) wsi ! weight factor for sea ice |
|---|
| 1121 | real(r8) wt ! fraction of ice |
|---|
| 1122 | real(r8) wland ! fraction of land |
|---|
| 1123 | |
|---|
| 1124 | ! real(r8) csaci |
|---|
| 1125 | ! real(r8) csacw |
|---|
| 1126 | ! real(r8) cwaut |
|---|
| 1127 | ! real(r8) efact |
|---|
| 1128 | ! real(r8) lamdas |
|---|
| 1129 | ! real(r8) lcrit |
|---|
| 1130 | ! real(r8) rcwm |
|---|
| 1131 | ! real(r8) r3lc2 |
|---|
| 1132 | ! real(r8) snowmr(pcols) |
|---|
| 1133 | ! real(r8) vfalls |
|---|
| 1134 | |
|---|
| 1135 | real(8) ftot |
|---|
| 1136 | |
|---|
| 1137 | ! inline statement functions |
|---|
| 1138 | real(r8) heavy, heavym, a1, a2, heavyp, heavymp |
|---|
| 1139 | heavy(a1,a2) = max(0._r8,sign(1._r8,a1-a2)) ! heavyside function |
|---|
| 1140 | heavym(a1,a2) = max(0.01_r8,sign(1._r8,a1-a2)) ! modified heavyside function |
|---|
| 1141 | ! |
|---|
| 1142 | ! New heavyside functions to perhaps address error growth problems |
|---|
| 1143 | ! |
|---|
| 1144 | heavyp(a1,a2) = a1/(a2+a1+1.e-36_r8) |
|---|
| 1145 | heavymp(a1,a2) = (a1+0.01_r8*a2)/(a2+a1+1.e-36_r8) |
|---|
| 1146 | |
|---|
| 1147 | ! |
|---|
| 1148 | ! find all the points where we need to do the microphysics |
|---|
| 1149 | ! and set the output variables to zero |
|---|
| 1150 | ! |
|---|
| 1151 | ncols = 0 |
|---|
| 1152 | do i = 1,ncol |
|---|
| 1153 | coef(i) = 0._r8 |
|---|
| 1154 | fwaut(i) = 0._r8 |
|---|
| 1155 | fsaut(i) = 0._r8 |
|---|
| 1156 | fracw(i) = 0._r8 |
|---|
| 1157 | fsacw(i) = 0._r8 |
|---|
| 1158 | fsaci(i) = 0._r8 |
|---|
| 1159 | liqmr(i) = 0._r8 |
|---|
| 1160 | rainmr(i) = 0._r8 |
|---|
| 1161 | if (cwm(i) > 1.e-20_r8) then |
|---|
| 1162 | ncols = ncols + 1 |
|---|
| 1163 | ind(ncols) = i |
|---|
| 1164 | endif |
|---|
| 1165 | end do |
|---|
| 1166 | |
|---|
| 1167 | !cdir nodep |
|---|
| 1168 | !DIR$ CONCURRENT |
|---|
| 1169 | do ii = 1,ncols |
|---|
| 1170 | i = ind(ii) |
|---|
| 1171 | ! |
|---|
| 1172 | ! the local cloudiness at this level |
|---|
| 1173 | ! |
|---|
| 1174 | cldloc(i) = max(cldmin,cldm(i)) |
|---|
| 1175 | ! |
|---|
| 1176 | ! a weighted mean between max cloudiness above, and this layer |
|---|
| 1177 | ! |
|---|
| 1178 | cldpr(i) = max(cldmin,(cldmax(i)+cldm(i))*0.5_r8) |
|---|
| 1179 | ! |
|---|
| 1180 | ! decompose the suspended condensate into |
|---|
| 1181 | ! an incloud liquid and ice phase component |
|---|
| 1182 | ! |
|---|
| 1183 | totmr(i) = cwm(i)/cldloc(i) |
|---|
| 1184 | icemr(i) = totmr(i)*fice(i) |
|---|
| 1185 | liqmr(i) = totmr(i)*(1._r8-fice(i)) |
|---|
| 1186 | ! |
|---|
| 1187 | ! density |
|---|
| 1188 | ! |
|---|
| 1189 | rho(i) = p(i,k)/(287._r8*t(i,k)) |
|---|
| 1190 | rhocgs = rho(i)*1.e-3_r8 ! density in cgs units |
|---|
| 1191 | ! |
|---|
| 1192 | ! decompose the precipitate into a liquid and ice phase |
|---|
| 1193 | ! |
|---|
| 1194 | if (t(i,k) > t0) then |
|---|
| 1195 | vfallw = convfw/sqrt(rho(i)) |
|---|
| 1196 | rainmr(i) = precab(i)/(rho(i)*vfallw*cldpr(i)) |
|---|
| 1197 | snowfr = 0 |
|---|
| 1198 | ! snowmr(i) |
|---|
| 1199 | else |
|---|
| 1200 | snowfr = 1 |
|---|
| 1201 | rainmr(i) = 0._r8 |
|---|
| 1202 | endif |
|---|
| 1203 | ! rainmr(i) = (precab(i)-snowab(i))/(rho(i)*vfallw*cldpr(i)) |
|---|
| 1204 | ! |
|---|
| 1205 | ! local snow amount in cgs units |
|---|
| 1206 | ! |
|---|
| 1207 | prscgs(i) = precab(i)/cldpr(i)*0.1_r8*snowfr |
|---|
| 1208 | ! prscgs(i) = snowab(i)/cldpr(i)*0.1 |
|---|
| 1209 | ! |
|---|
| 1210 | ! local rain amount in mm/day |
|---|
| 1211 | ! |
|---|
| 1212 | prlloc(i) = precab(i)*86400._r8/cldpr(i) |
|---|
| 1213 | end do |
|---|
| 1214 | |
|---|
| 1215 | con1 = 1._r8/(1.333_r8*pi)**0.333_r8 * 0.01_r8 ! meters |
|---|
| 1216 | ! |
|---|
| 1217 | ! calculate the conversion terms |
|---|
| 1218 | ! |
|---|
| 1219 | call get_rlat_all_p(lchnk, ncol, rlat) |
|---|
| 1220 | |
|---|
| 1221 | !cdir nodep |
|---|
| 1222 | !DIR$ CONCURRENT |
|---|
| 1223 | do ii = 1,ncols |
|---|
| 1224 | i = ind(ii) |
|---|
| 1225 | rhocgs = rho(i)*1.e-3_r8 ! density in cgs units |
|---|
| 1226 | ! |
|---|
| 1227 | ! exponential temperature factor |
|---|
| 1228 | ! |
|---|
| 1229 | ! efact = exp(0.025*(t(i,k)-t0)) |
|---|
| 1230 | ! |
|---|
| 1231 | ! some temperature dependent constants |
|---|
| 1232 | ! |
|---|
| 1233 | !!$ wt = min(1._r8,max(0._r8,(t0-t(i,k))*rdtice)) |
|---|
| 1234 | wt = fice(i) |
|---|
| 1235 | icrit = icritc*wt + icritw*(1-wt) |
|---|
| 1236 | ! |
|---|
| 1237 | ! jrm Reworked droplet number concentration algorithm |
|---|
| 1238 | ! Start with pressure-dependent value appropriate for continental air |
|---|
| 1239 | ! Note: reltab has a temperature dependence here |
|---|
| 1240 | capn = capnw + (capnc-capnw) * min(1._r8,max(0._r8,1.0_r8-(p(i,k)-0.8_r8*p(i,pver))/(0.2_r8*p(i,pver)))) |
|---|
| 1241 | ! Modify for snow depth over land |
|---|
| 1242 | capn = capn + (capnc-capn) * min(1.0_r8,max(0.0_r8,snowh(i)*10._r8)) |
|---|
| 1243 | ! Ramp between polluted value over land to clean value over ocean. |
|---|
| 1244 | capn = capn + (capnc-capn) * min(1.0_r8,max(0.0_r8,1.0_r8-landm(i,lchnk))) |
|---|
| 1245 | ! Ramp between the resultant value and a sea ice value in the presence of ice. |
|---|
| 1246 | capn = capn + (capnsi-capn) * min(1.0_r8,max(0.0_r8,seaicef(i))) |
|---|
| 1247 | ! end jrm |
|---|
| 1248 | ! |
|---|
| 1249 | #ifdef DEBUG2 |
|---|
| 1250 | if ( (lat(i) == latlook(1)) .or. (lat(i) == latlook(2)) ) then |
|---|
| 1251 | if (i == ilook(1)) then |
|---|
| 1252 | write(iulog,*) ' findmcnew: lat, k, seaicef, landm, wp, capnoice, capn ', & |
|---|
| 1253 | lat(i), k, seaicef(i), landm(i,lat(i)), wp, capnoice, capn |
|---|
| 1254 | endif |
|---|
| 1255 | endif |
|---|
| 1256 | #endif |
|---|
| 1257 | |
|---|
| 1258 | ! |
|---|
| 1259 | ! useful terms in following calculations |
|---|
| 1260 | ! |
|---|
| 1261 | rat1 = rhocgs/rhow |
|---|
| 1262 | rat2 = liqmr(i)/capn |
|---|
| 1263 | con2 = (rat1*rat2)**0.333_r8 |
|---|
| 1264 | ! |
|---|
| 1265 | ! volume radius |
|---|
| 1266 | ! |
|---|
| 1267 | ! r3l = (rhocgs*liqmr(i)/(1.333*pi*capn*rhow))**0.333 * 0.01 ! meters |
|---|
| 1268 | r3l = con1*con2 |
|---|
| 1269 | ! |
|---|
| 1270 | ! critical threshold for autoconversion if modified for mixed phase |
|---|
| 1271 | ! clouds to mimic a bergeron findeisen process |
|---|
| 1272 | ! r3lc2 = r3lcrit*(1.-0.5*fice(i)*(1-fice(i))) |
|---|
| 1273 | ! |
|---|
| 1274 | ! autoconversion of liquid |
|---|
| 1275 | ! |
|---|
| 1276 | ! cwaut = 2.e-4 |
|---|
| 1277 | ! cwaut = 1.e-3 |
|---|
| 1278 | ! lcrit = 2.e-4 |
|---|
| 1279 | ! lcrit = 5.e-4 |
|---|
| 1280 | ! pwaut = max(0._r8,liqmr(i)-lcrit)*cwaut |
|---|
| 1281 | ! |
|---|
| 1282 | ! pwaut is following tripoli and cotton (and many others) |
|---|
| 1283 | ! we reduce the autoconversion below critpr, because these are regions where |
|---|
| 1284 | ! the drop size distribution is likely to imply much smaller collector drops than |
|---|
| 1285 | ! those relevant for a cloud distribution corresponding to the value of effc = 0.55 |
|---|
| 1286 | ! suggested by cotton (see austin 1995 JAS, baker 1993) |
|---|
| 1287 | |
|---|
| 1288 | ! easy to follow form |
|---|
| 1289 | ! pwaut = capc*liqmr(i)**2*rhocgs/rhow |
|---|
| 1290 | ! $ *(liqmr(i)*rhocgs/(rhow*capn))**(.333) |
|---|
| 1291 | ! $ *heavy(r3l,r3lcrit) |
|---|
| 1292 | ! $ *max(0.10_r8,min(1._r8,prlloc(i)/critpr)) |
|---|
| 1293 | ! somewhat faster form |
|---|
| 1294 | #define HEAVYNEW |
|---|
| 1295 | #ifdef HEAVYNEW |
|---|
| 1296 | !#ifdef PERGRO |
|---|
| 1297 | pwaut = capc*liqmr(i)**2*rat1*con2*heavymp(r3l,r3lcrit) * & |
|---|
| 1298 | max(0.10_r8,min(1._r8,prlloc(i)/critpr)) |
|---|
| 1299 | #else |
|---|
| 1300 | pwaut = capc*liqmr(i)**2*rat1*con2*heavym(r3l,r3lcrit)* & |
|---|
| 1301 | max(0.10_r8,min(1._r8,prlloc(i)/critpr)) |
|---|
| 1302 | #endif |
|---|
| 1303 | ! |
|---|
| 1304 | ! autoconversion of ice |
|---|
| 1305 | ! |
|---|
| 1306 | ! ciaut = ciautb*efact |
|---|
| 1307 | ciaut = ciautb |
|---|
| 1308 | ! psaut = capc*totmr(i)**2*rhocgs/rhoi |
|---|
| 1309 | ! $ *(totmr(i)*rhocgs/(rhoi*capn))**(.333) |
|---|
| 1310 | ! |
|---|
| 1311 | ! autoconversion of ice condensate |
|---|
| 1312 | ! |
|---|
| 1313 | #ifdef PERGRO |
|---|
| 1314 | psaut = heavyp(icemr(i),icrit)*icemr(i)*ciaut |
|---|
| 1315 | #else |
|---|
| 1316 | psaut = max(0._r8,icemr(i)-icrit)*ciaut |
|---|
| 1317 | #endif |
|---|
| 1318 | ! |
|---|
| 1319 | ! collection of liquid by rain |
|---|
| 1320 | ! |
|---|
| 1321 | ! pracw = cracw*rho(i)*liqmr(i)*rainmr(i) !(beheng 1994) |
|---|
| 1322 | pracw = cracw*rho(i)*sqrt(rho(i))*liqmr(i)*rainmr(i) !(tripoli and cotton) |
|---|
| 1323 | !! pracw = 0. |
|---|
| 1324 | ! |
|---|
| 1325 | ! the following lines calculate the slope parameter and snow mixing ratio |
|---|
| 1326 | ! from the precip rate using the equations found in lin et al 83 |
|---|
| 1327 | ! in the most natural form, but it is expensive, so after some tedious |
|---|
| 1328 | ! algebraic manipulation you can use the cheaper form found below |
|---|
| 1329 | ! vfalls = c*gam4pd/(6*lamdas**d)*sqrt(rhonot/rhocgs) |
|---|
| 1330 | ! $ *0.01 ! convert from cm/s to m/s |
|---|
| 1331 | ! snowmr(i) = snowfr*precab(i)/(rho(i)*vfalls*cldpr(i)) |
|---|
| 1332 | ! snowmr(i) = ( prscgs(i)*mcon02 * (rhocgs**mcon03) )**mcon04 |
|---|
| 1333 | ! lamdas = (prhonos/max(rhocgs*snowmr(i),small))**0.25 |
|---|
| 1334 | ! csacw = mcon01*sqrt(rhonot/rhocgs)/(lamdas**thrpd) |
|---|
| 1335 | ! |
|---|
| 1336 | ! coefficient for collection by snow independent of phase |
|---|
| 1337 | ! |
|---|
| 1338 | csacx = mcon07*rhocgs**mcon08*prscgs(i)**mcon05 |
|---|
| 1339 | |
|---|
| 1340 | ! |
|---|
| 1341 | ! collection of liquid by snow (lin et al 1983) |
|---|
| 1342 | ! |
|---|
| 1343 | psacw = csacx*liqmr(i)*esw |
|---|
| 1344 | #ifdef PERGRO |
|---|
| 1345 | ! this is necessary for pergro |
|---|
| 1346 | psacw = 0._r8 |
|---|
| 1347 | #endif |
|---|
| 1348 | ! |
|---|
| 1349 | ! collection of ice by snow (lin et al 1983) |
|---|
| 1350 | ! |
|---|
| 1351 | psaci = csacx*icemr(i)*esi |
|---|
| 1352 | ! |
|---|
| 1353 | ! total conversion of condensate to precipitate |
|---|
| 1354 | ! |
|---|
| 1355 | ptot = pwaut + psaut + pracw + psacw + psaci |
|---|
| 1356 | ! |
|---|
| 1357 | ! the recipricol of cloud water amnt (or zero if no cloud water) |
|---|
| 1358 | ! |
|---|
| 1359 | ! rcwm = totmr(i)/(max(totmr(i),small)**2) |
|---|
| 1360 | ! |
|---|
| 1361 | ! turn the tendency back into a loss rate (1/seconds) |
|---|
| 1362 | ! |
|---|
| 1363 | if (totmr(i) > 0._r8) then |
|---|
| 1364 | coef(i) = ptot/totmr(i) |
|---|
| 1365 | else |
|---|
| 1366 | coef(i) = 0._r8 |
|---|
| 1367 | endif |
|---|
| 1368 | |
|---|
| 1369 | if (ptot.gt.0._r8) then |
|---|
| 1370 | fwaut(i) = pwaut/ptot |
|---|
| 1371 | fsaut(i) = psaut/ptot |
|---|
| 1372 | fracw(i) = pracw/ptot |
|---|
| 1373 | fsacw(i) = psacw/ptot |
|---|
| 1374 | fsaci(i) = psaci/ptot |
|---|
| 1375 | else |
|---|
| 1376 | fwaut(i) = 0._r8 |
|---|
| 1377 | fsaut(i) = 0._r8 |
|---|
| 1378 | fracw(i) = 0._r8 |
|---|
| 1379 | fsacw(i) = 0._r8 |
|---|
| 1380 | fsaci(i) = 0._r8 |
|---|
| 1381 | endif |
|---|
| 1382 | |
|---|
| 1383 | ftot = fwaut(i)+fsaut(i)+fracw(i)+fsacw(i)+fsaci(i) |
|---|
| 1384 | ! if (abs(ftot-1._r8).gt.1.e-14_r8.and.ftot.ne.0._r8) then |
|---|
| 1385 | ! write(iulog,*) ' something is wrong in findmcnew ', ftot, & |
|---|
| 1386 | ! fwaut(i),fsaut(i),fracw(i),fsacw(i),fsaci(i) |
|---|
| 1387 | ! write(iulog,*) ' unscaled ', ptot, & |
|---|
| 1388 | ! pwaut,psaut,pracw,psacw,psaci |
|---|
| 1389 | ! write(iulog,*) ' totmr, liqmr, icemr ', totmr(i), liqmr(i), icemr(i) |
|---|
| 1390 | ! call endrun() |
|---|
| 1391 | ! endif |
|---|
| 1392 | end do |
|---|
| 1393 | #ifdef DEBUG |
|---|
| 1394 | i = icollook(nlook) |
|---|
| 1395 | if (lchnk == lchnklook(nlook) ) then |
|---|
| 1396 | write(iulog,*) |
|---|
| 1397 | write(iulog,*) '------', k, i, lchnk |
|---|
| 1398 | write(iulog,*) ' liqmr, rainmr,precab ', liqmr(i), rainmr(i), precab(i)*8.64e4_r8 |
|---|
| 1399 | write(iulog,*) ' frac: waut,saut,racw,sacw,saci ', & |
|---|
| 1400 | fwaut(i), fsaut(i), fracw(i), fsacw(i), fsaci(i) |
|---|
| 1401 | endif |
|---|
| 1402 | #endif |
|---|
| 1403 | |
|---|
| 1404 | return |
|---|
| 1405 | end subroutine findmcnew |
|---|
| 1406 | |
|---|
| 1407 | !############################################################################## |
|---|
| 1408 | |
|---|
| 1409 | subroutine findsp (lchnk, ncol, q, t, p, tsp, qsp) |
|---|
| 1410 | !----------------------------------------------------------------------- |
|---|
| 1411 | ! |
|---|
| 1412 | ! Purpose: |
|---|
| 1413 | ! find the wet bulb temperature for a given t and q |
|---|
| 1414 | ! in a longitude height section |
|---|
| 1415 | ! wet bulb temp is the temperature and spec humidity that is |
|---|
| 1416 | ! just saturated and has the same enthalpy |
|---|
| 1417 | ! if q > qs(t) then tsp > t and qsp = qs(tsp) < q |
|---|
| 1418 | ! if q < qs(t) then tsp < t and qsp = qs(tsp) > q |
|---|
| 1419 | ! |
|---|
| 1420 | ! Method: |
|---|
| 1421 | ! a Newton method is used |
|---|
| 1422 | ! first guess uses an algorithm provided by John Petch from the UKMO |
|---|
| 1423 | ! we exclude points where the physical situation is unrealistic |
|---|
| 1424 | ! e.g. where the temperature is outside the range of validity for the |
|---|
| 1425 | ! saturation vapor pressure, or where the water vapor pressure |
|---|
| 1426 | ! exceeds the ambient pressure, or the saturation specific humidity is |
|---|
| 1427 | ! unrealistic |
|---|
| 1428 | ! |
|---|
| 1429 | ! Author: P. Rasch |
|---|
| 1430 | ! |
|---|
| 1431 | !----------------------------------------------------------------------- |
|---|
| 1432 | ! |
|---|
| 1433 | ! input arguments |
|---|
| 1434 | ! |
|---|
| 1435 | integer, intent(in) :: lchnk ! chunk identifier |
|---|
| 1436 | integer, intent(in) :: ncol ! number of atmospheric columns |
|---|
| 1437 | |
|---|
| 1438 | real(r8), intent(in) :: q(pcols,pver) ! water vapor (kg/kg) |
|---|
| 1439 | real(r8), intent(in) :: t(pcols,pver) ! temperature (K) |
|---|
| 1440 | real(r8), intent(in) :: p(pcols,pver) ! pressure (Pa) |
|---|
| 1441 | ! |
|---|
| 1442 | ! output arguments |
|---|
| 1443 | ! |
|---|
| 1444 | real(r8), intent(out) :: tsp(pcols,pver) ! saturation temp (K) |
|---|
| 1445 | real(r8), intent(out) :: qsp(pcols,pver) ! saturation mixing ratio (kg/kg) |
|---|
| 1446 | ! |
|---|
| 1447 | ! local variables |
|---|
| 1448 | ! |
|---|
| 1449 | integer i ! work variable |
|---|
| 1450 | integer k ! work variable |
|---|
| 1451 | logical lflg ! work variable |
|---|
| 1452 | integer iter ! work variable |
|---|
| 1453 | integer l ! work variable |
|---|
| 1454 | logical :: error_found |
|---|
| 1455 | |
|---|
| 1456 | real(r8) omeps ! 1 minus epsilon |
|---|
| 1457 | real(r8) trinv ! work variable |
|---|
| 1458 | real(r8) es ! sat. vapor pressure |
|---|
| 1459 | real(r8) desdt ! change in sat vap pressure wrt temperature |
|---|
| 1460 | ! real(r8) desdp ! change in sat vap pressure wrt pressure |
|---|
| 1461 | real(r8) dqsdt ! change in sat spec. hum. wrt temperature |
|---|
| 1462 | real(r8) dgdt ! work variable |
|---|
| 1463 | real(r8) g ! work variable |
|---|
| 1464 | real(r8) weight(pcols) ! work variable |
|---|
| 1465 | real(r8) hlatsb ! (sublimation) |
|---|
| 1466 | real(r8) hlatvp ! (vaporization) |
|---|
| 1467 | real(r8) hltalt(pcols,pver) ! lat. heat. of vap. |
|---|
| 1468 | real(r8) tterm ! work var. |
|---|
| 1469 | real(r8) qs ! spec. hum. of water vapor |
|---|
| 1470 | real(r8) tc ! crit temp of transition to ice |
|---|
| 1471 | |
|---|
| 1472 | ! work variables |
|---|
| 1473 | real(r8) t1, q1, dt, dq |
|---|
| 1474 | real(r8) dtm, dqm |
|---|
| 1475 | real(r8) qvd, a1, tmp |
|---|
| 1476 | real(r8) rair |
|---|
| 1477 | real(r8) r1b, c1, c2, c3 |
|---|
| 1478 | real(r8) denom |
|---|
| 1479 | real(r8) dttol |
|---|
| 1480 | real(r8) dqtol |
|---|
| 1481 | integer doit(pcols) |
|---|
| 1482 | real(r8) enin(pcols), enout(pcols) |
|---|
| 1483 | real(r8) tlim(pcols) |
|---|
| 1484 | |
|---|
| 1485 | omeps = 1.0_r8 - epsqs |
|---|
| 1486 | trinv = 1.0_r8/ttrice |
|---|
| 1487 | a1 = 7.5_r8*log(10._r8) |
|---|
| 1488 | rair = 287.04_r8 |
|---|
| 1489 | c3 = rair*a1/cp |
|---|
| 1490 | dtm = 0._r8 ! needed for iter=0 blowup with f90 -ei |
|---|
| 1491 | dqm = 0._r8 ! needed for iter=0 blowup with f90 -ei |
|---|
| 1492 | dttol = 1.e-4_r8 ! the relative temp error tolerance required to quit the iteration |
|---|
| 1493 | dqtol = 1.e-4_r8 ! the relative moisture error tolerance required to quit the iteration |
|---|
| 1494 | ! tmin = 173.16 ! the coldest temperature we can deal with |
|---|
| 1495 | ! |
|---|
| 1496 | ! max number of times to iterate the calculation |
|---|
| 1497 | iter = 8 |
|---|
| 1498 | ! |
|---|
| 1499 | do k = k1mb,pver |
|---|
| 1500 | |
|---|
| 1501 | ! |
|---|
| 1502 | ! first guess on the wet bulb temperature |
|---|
| 1503 | ! |
|---|
| 1504 | do i = 1,ncol |
|---|
| 1505 | |
|---|
| 1506 | #ifdef DEBUG |
|---|
| 1507 | if ( (lchnk == lchnklook(nlook) ) .and. (i == icollook(nlook) ) ) then |
|---|
| 1508 | write(iulog,*) ' ' |
|---|
| 1509 | write(iulog,*) ' level, t, q, p', k, t(i,k), q(i,k), p(i,k) |
|---|
| 1510 | endif |
|---|
| 1511 | #endif |
|---|
| 1512 | ! limit the temperature range to that relevant to the sat vap pres tables |
|---|
| 1513 | #if ( ! defined WACCM_PHYS ) |
|---|
| 1514 | tlim(i) = min(max(t(i,k),173._r8),373._r8) |
|---|
| 1515 | #else |
|---|
| 1516 | tlim(i) = min(max(t(i,k),128._r8),373._r8) |
|---|
| 1517 | #endif |
|---|
| 1518 | es = estblf(tlim(i)) |
|---|
| 1519 | denom = p(i,k) - omeps*es |
|---|
| 1520 | qs = epsqs*es/denom |
|---|
| 1521 | doit(i) = 0 |
|---|
| 1522 | enout(i) = 1._r8 |
|---|
| 1523 | ! make sure a meaningful calculation is possible |
|---|
| 1524 | if (p(i,k) > 5._r8*es .and. qs > 0._r8 .and. qs < 0.5_r8) then |
|---|
| 1525 | ! |
|---|
| 1526 | ! Saturation specific humidity |
|---|
| 1527 | ! |
|---|
| 1528 | qs = min(epsqs*es/denom,1._r8) |
|---|
| 1529 | ! |
|---|
| 1530 | ! "generalized" analytic expression for t derivative of es |
|---|
| 1531 | ! accurate to within 1 percent for 173.16 < t < 373.16 |
|---|
| 1532 | ! |
|---|
| 1533 | ! Weighting of hlat accounts for transition from water to ice |
|---|
| 1534 | ! polynomial expression approximates difference between es over |
|---|
| 1535 | ! water and es over ice from 0 to -ttrice (C) (min of ttrice is |
|---|
| 1536 | ! -40): required for accurate estimate of es derivative in transition |
|---|
| 1537 | ! range from ice to water also accounting for change of hlatv with t |
|---|
| 1538 | ! above freezing where const slope is given by -2369 j/(kg c) = cpv - cw |
|---|
| 1539 | ! |
|---|
| 1540 | tc = tlim(i) - t0 |
|---|
| 1541 | lflg = (tc >= -ttrice .and. tc < 0.0_r8) |
|---|
| 1542 | weight(i) = min(-tc*trinv,1.0_r8) |
|---|
| 1543 | hlatsb = hlatv + weight(i)*hlatf |
|---|
| 1544 | hlatvp = hlatv - 2369.0_r8*tc |
|---|
| 1545 | if (tlim(i) < t0) then |
|---|
| 1546 | hltalt(i,k) = hlatsb |
|---|
| 1547 | else |
|---|
| 1548 | hltalt(i,k) = hlatvp |
|---|
| 1549 | end if |
|---|
| 1550 | enin(i) = cp*tlim(i) + hltalt(i,k)*q(i,k) |
|---|
| 1551 | |
|---|
| 1552 | ! make a guess at the wet bulb temp using a UKMO algorithm (from J. Petch) |
|---|
| 1553 | tmp = q(i,k) - qs |
|---|
| 1554 | c1 = hltalt(i,k)*c3 |
|---|
| 1555 | c2 = (tlim(i) + 36._r8)**2 |
|---|
| 1556 | r1b = c2/(c2 + c1*qs) |
|---|
| 1557 | qvd = r1b*tmp |
|---|
| 1558 | tsp(i,k) = tlim(i) + ((hltalt(i,k)/cp)*qvd) |
|---|
| 1559 | #ifdef DEBUG |
|---|
| 1560 | if ( (lchnk == lchnklook(nlook) ) .and. (i == icollook(nlook) ) ) then |
|---|
| 1561 | write(iulog,*) ' relative humidity ', q(i,k)/qs |
|---|
| 1562 | write(iulog,*) ' first guess ', tsp(i,k) |
|---|
| 1563 | endif |
|---|
| 1564 | #endif |
|---|
| 1565 | es = estblf(tsp(i,k)) |
|---|
| 1566 | qsp(i,k) = min(epsqs*es/(p(i,k) - omeps*es),1._r8) |
|---|
| 1567 | else |
|---|
| 1568 | doit(i) = 1 |
|---|
| 1569 | tsp(i,k) = tlim(i) |
|---|
| 1570 | qsp(i,k) = q(i,k) |
|---|
| 1571 | enin(i) = 1._r8 |
|---|
| 1572 | endif |
|---|
| 1573 | end do ! end do i |
|---|
| 1574 | ! |
|---|
| 1575 | ! now iterate on first guess |
|---|
| 1576 | ! |
|---|
| 1577 | do l = 1, iter |
|---|
| 1578 | dtm = 0 |
|---|
| 1579 | dqm = 0 |
|---|
| 1580 | do i = 1,ncol |
|---|
| 1581 | if (doit(i) == 0) then |
|---|
| 1582 | es = estblf(tsp(i,k)) |
|---|
| 1583 | ! |
|---|
| 1584 | ! Saturation specific humidity |
|---|
| 1585 | ! |
|---|
| 1586 | qs = min(epsqs*es/(p(i,k) - omeps*es),1._r8) |
|---|
| 1587 | ! |
|---|
| 1588 | ! "generalized" analytic expression for t derivative of es |
|---|
| 1589 | ! accurate to within 1 percent for 173.16 < t < 373.16 |
|---|
| 1590 | ! |
|---|
| 1591 | ! Weighting of hlat accounts for transition from water to ice |
|---|
| 1592 | ! polynomial expression approximates difference between es over |
|---|
| 1593 | ! water and es over ice from 0 to -ttrice (C) (min of ttrice is |
|---|
| 1594 | ! -40): required for accurate estimate of es derivative in transition |
|---|
| 1595 | ! range from ice to water also accounting for change of hlatv with t |
|---|
| 1596 | ! above freezing where const slope is given by -2369 j/(kg c) = cpv - cw |
|---|
| 1597 | ! |
|---|
| 1598 | tc = tsp(i,k) - t0 |
|---|
| 1599 | lflg = (tc >= -ttrice .and. tc < 0.0_r8) |
|---|
| 1600 | weight(i) = min(-tc*trinv,1.0_r8) |
|---|
| 1601 | hlatsb = hlatv + weight(i)*hlatf |
|---|
| 1602 | hlatvp = hlatv - 2369.0_r8*tc |
|---|
| 1603 | if (tsp(i,k) < t0) then |
|---|
| 1604 | hltalt(i,k) = hlatsb |
|---|
| 1605 | else |
|---|
| 1606 | hltalt(i,k) = hlatvp |
|---|
| 1607 | end if |
|---|
| 1608 | if (lflg) then |
|---|
| 1609 | tterm = pcf(1) + tc*(pcf(2) + tc*(pcf(3)+tc*(pcf(4) + tc*pcf(5)))) |
|---|
| 1610 | else |
|---|
| 1611 | tterm = 0.0_r8 |
|---|
| 1612 | end if |
|---|
| 1613 | desdt = hltalt(i,k)*es/(rgasv*tsp(i,k)*tsp(i,k)) + tterm*trinv |
|---|
| 1614 | dqsdt = (epsqs + omeps*qs)/(p(i,k) - omeps*es)*desdt |
|---|
| 1615 | ! g = cp*(tlim(i)-tsp(i,k)) + hltalt(i,k)*q(i,k)- hltalt(i,k)*qsp(i,k) |
|---|
| 1616 | g = enin(i) - (cp*tsp(i,k) + hltalt(i,k)*qsp(i,k)) |
|---|
| 1617 | dgdt = -(cp + hltalt(i,k)*dqsdt) |
|---|
| 1618 | t1 = tsp(i,k) - g/dgdt |
|---|
| 1619 | dt = abs(t1 - tsp(i,k))/t1 |
|---|
| 1620 | tsp(i,k) = max(t1,tmin) |
|---|
| 1621 | es = estblf(tsp(i,k)) |
|---|
| 1622 | q1 = min(epsqs*es/(p(i,k) - omeps*es),1._r8) |
|---|
| 1623 | dq = abs(q1 - qsp(i,k))/max(q1,1.e-12_r8) |
|---|
| 1624 | qsp(i,k) = q1 |
|---|
| 1625 | #ifdef DEBUG |
|---|
| 1626 | if ( (lchnk == lchnklook(nlook) ) .and. (i == icollook(nlook) ) ) then |
|---|
| 1627 | write(iulog,*) ' rel chg lev, iter, t, q ', k, l, dt, dq, g |
|---|
| 1628 | endif |
|---|
| 1629 | #endif |
|---|
| 1630 | dtm = max(dtm,dt) |
|---|
| 1631 | dqm = max(dqm,dq) |
|---|
| 1632 | ! if converged at this point, exclude it from more iterations |
|---|
| 1633 | if (dt < dttol .and. dq < dqtol) then |
|---|
| 1634 | doit(i) = 2 |
|---|
| 1635 | endif |
|---|
| 1636 | enout(i) = cp*tsp(i,k) + hltalt(i,k)*qsp(i,k) |
|---|
| 1637 | ! bail out if we are too near the end of temp range |
|---|
| 1638 | #if ( ! defined WACCM_PHYS ) |
|---|
| 1639 | if (tsp(i,k) < 174.16_r8) then |
|---|
| 1640 | #else |
|---|
| 1641 | if (tsp(i,k) < 130.16_r8) then |
|---|
| 1642 | #endif |
|---|
| 1643 | doit(i) = 4 |
|---|
| 1644 | endif |
|---|
| 1645 | else |
|---|
| 1646 | endif |
|---|
| 1647 | end do ! do i = 1,ncol |
|---|
| 1648 | |
|---|
| 1649 | if (dtm < dttol .and. dqm < dqtol) then |
|---|
| 1650 | go to 10 |
|---|
| 1651 | endif |
|---|
| 1652 | |
|---|
| 1653 | end do ! do l = 1,iter |
|---|
| 1654 | 10 continue |
|---|
| 1655 | |
|---|
| 1656 | error_found = .false. |
|---|
| 1657 | if (dtm > dttol .or. dqm > dqtol) then |
|---|
| 1658 | do i = 1,ncol |
|---|
| 1659 | if (doit(i) == 0) error_found = .true. |
|---|
| 1660 | end do |
|---|
| 1661 | if (error_found) then |
|---|
| 1662 | do i = 1,ncol |
|---|
| 1663 | if (doit(i) == 0) then |
|---|
| 1664 | write(iulog,*) ' findsp not converging at point i, k ', i, k |
|---|
| 1665 | write(iulog,*) ' t, q, p, enin ', t(i,k), q(i,k), p(i,k), enin(i) |
|---|
| 1666 | write(iulog,*) ' tsp, qsp, enout ', tsp(i,k), qsp(i,k), enout(i) |
|---|
| 1667 | call endrun ('FINDSP') |
|---|
| 1668 | endif |
|---|
| 1669 | end do |
|---|
| 1670 | endif |
|---|
| 1671 | endif |
|---|
| 1672 | do i = 1,ncol |
|---|
| 1673 | if (doit(i) == 2 .and. abs((enin(i)-enout(i))/(enin(i)+enout(i))) > 1.e-4_r8) then |
|---|
| 1674 | error_found = .true. |
|---|
| 1675 | endif |
|---|
| 1676 | end do |
|---|
| 1677 | if (error_found) then |
|---|
| 1678 | do i = 1,ncol |
|---|
| 1679 | if (doit(i) == 2 .and. abs((enin(i)-enout(i))/(enin(i)+enout(i))) > 1.e-4_r8) then |
|---|
| 1680 | write(iulog,*) ' the enthalpy is not conserved for point ', & |
|---|
| 1681 | i, k, enin(i), enout(i) |
|---|
| 1682 | write(iulog,*) ' t, q, p, enin ', t(i,k), q(i,k), p(i,k), enin(i) |
|---|
| 1683 | write(iulog,*) ' tsp, qsp, enout ', tsp(i,k), qsp(i,k), enout(i) |
|---|
| 1684 | call endrun ('FINDSP') |
|---|
| 1685 | endif |
|---|
| 1686 | end do |
|---|
| 1687 | endif |
|---|
| 1688 | |
|---|
| 1689 | end do ! level loop (k=1,pver) |
|---|
| 1690 | |
|---|
| 1691 | return |
|---|
| 1692 | end subroutine findsp |
|---|
| 1693 | |
|---|
| 1694 | #endif |
|---|
| 1695 | |
|---|
| 1696 | end module cldwat |
|---|
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