Changeset 1988 for trunk/LMDZ.GENERIC/libf/phystd/gfluxv.F

Timestamp:

Aug 28, 2018, 4:22:24 PM (6 years ago)

Author:

jleconte

Message:

28/08/2018 == JL

We now shift the radiative model top from p=0 to the middle of the last physical layer. This is done by changing pmid and plevrad in callcorrk and some corrections need to be done in gfluxv.
This seems to get rid of the aratic temperature behavior in the last two layers of the model (especially on the night side on synchronous planets).
Additional speedup corrections have been made in gfluxi that change nothing to the result.
Finally, if aerosols are present in the last layer we must account for them. Provides better upper boundary condition in the IR. They must however be put to zero in the sw (see optcv and changes in last commit.)
This has been done for water ice in aeropacity, but same correction should probably be done for other aerosol types.

File:

• trunk/LMDZ.GENERIC/libf/phystd/gfluxv.F (modified) (3 diffs)

trunk/LMDZ.GENERIC/libf/phystd/gfluxv.F

@@ -240 +240 @@
 C     FLUX AT THE Ptop layer
 
-      EP    = 1.0
-      EM    = 1.0
+!      EP    = 1.0
+!      EM    = 1.0
+C JL18 correction to account for the fact that the radiative top is not at zero optical depth.
+      EXPTRM(L) = MIN(TAUMAX,LAMDA(L)*(TAUCUM(2)))
+      EP = EXP(EXPTRM(L))
+      EM    = 1.0/EP
       G4    = 1.0-G3(1)
       DENOM = LAMDA(1)**2 - 1./UBAR0**2
@@ -260 +264 @@
 C     AT THE MIDDLE OF THE LAYER.
 
-      CPMID  = AP
-      CMMID  = AM
+C      CPMID  = AP
+C      CMMID  = AM
+C JL18 correction to account for the fact that the radiative top is not at zero optical depth.
+      TAUMID   = TAUCUM(2)
+      CPMID = AP*EXP(-TAUMID/UBAR0)
+      CMMID = AM*EXP(-TAUMID/UBAR0)
 
       FLUXUP = XK1(1)*EP + GAMA(1)*XK2(1)*EM + CPMID
@@ -268 +276 @@
 C     ADD THE DIRECT FLUX TO THE DOWNWELLING TERM
 
-      fluxdn = fluxdn+UBAR0*F0PI*EXP(-MIN(TAUCUM(1),TAUMAX)/UBAR0)
+!      fluxdn = fluxdn+UBAR0*F0PI*EXP(-MIN(TAUCUM(1),TAUMAX)/UBAR0)
+!JL18 the line above assumed that the top of the radiative model was P=0
+!   it seems to be better for the IR to use the middle of the last physical layer as the radiative top. 
+!   so we correct the downwelling flux below for the calculation of the heating rate
+      fluxdn = fluxdn+UBAR0*F0PI*EXP(-TAUCUM(2)/UBAR0)
 
 C     This is for the "special" bottom layer, where we take