| 1 |
jmc |
1.2 |
C $Header: /u/gcmpack/MITgcm/pkg/thsice/thsice_albedo.F,v 1.1 2003/12/31 17:44:32 jmc Exp $ |
| 2 |
jmc |
1.1 |
C $Name: $ |
| 3 |
|
|
|
| 4 |
|
|
#include "THSICE_OPTIONS.h" |
| 5 |
|
|
|
| 6 |
jmc |
1.2 |
CBOP |
| 7 |
|
|
C !ROUTINE: THSICE_READPARMS |
| 8 |
|
|
C !INTERFACE: |
| 9 |
|
|
SUBROUTINE THSICE_ALBEDO( |
| 10 |
|
|
I hi, hs, Tsf, age, |
| 11 |
|
|
O albedo, |
| 12 |
|
|
I myThid ) |
| 13 |
|
|
|
| 14 |
|
|
C !DESCRIPTION: \bv |
| 15 |
jmc |
1.1 |
C *==========================================================* |
| 16 |
|
|
C | S/R THSICE_ALBEDO |
| 17 |
|
|
C *==========================================================* |
| 18 |
|
|
C | Compute surface albedo |
| 19 |
|
|
C *==========================================================* |
| 20 |
jmc |
1.2 |
C \ev |
| 21 |
|
|
|
| 22 |
|
|
C !USES: |
| 23 |
jmc |
1.1 |
IMPLICIT NONE |
| 24 |
|
|
|
| 25 |
|
|
C == Global data == |
| 26 |
|
|
#include "THSICE_PARAMS.h" |
| 27 |
|
|
|
| 28 |
jmc |
1.2 |
C !INPUT/OUTPUT PARAMETERS: |
| 29 |
jmc |
1.1 |
C == Routine Arguments == |
| 30 |
|
|
_RL hi ! ice height |
| 31 |
|
|
_RL hs ! snow height |
| 32 |
|
|
_RL Tsf ! surface temperature |
| 33 |
|
|
_RL age ! snow age |
| 34 |
|
|
_RL albedo ! surface albedo |
| 35 |
jmc |
1.2 |
INTEGER myThid |
| 36 |
|
|
CEOP |
| 37 |
jmc |
1.1 |
|
| 38 |
|
|
#ifdef ALLOW_THSICE |
| 39 |
|
|
C == Local variables == |
| 40 |
|
|
C frsnow :: fractional snow cover |
| 41 |
|
|
C albsno :: albedo of snow |
| 42 |
|
|
C albice :: albedo of ice |
| 43 |
|
|
C albNewSnow :: albedo of new (fresh) snow |
| 44 |
jmc |
1.2 |
c _RL frsnow |
| 45 |
jmc |
1.1 |
_RL albsno, albice |
| 46 |
|
|
_RL albNewSnow |
| 47 |
|
|
|
| 48 |
|
|
C-- Albedo of Bare Sea-Ice |
| 49 |
|
|
albice = albIceMax + (albIceMin-albIceMax)*exp(-hi/hAlbIce) |
| 50 |
|
|
|
| 51 |
|
|
C-- LANL albedo calculation |
| 52 |
|
|
c frsnow = 0. |
| 53 |
|
|
c if (hs .gt. 0.) frsnow = 1. |
| 54 |
|
|
c if (Tsf .lt. 0.) then |
| 55 |
|
|
c albedo = frsnow*albColdSnow + (1.-frsnow)*albice |
| 56 |
|
|
c else |
| 57 |
|
|
c albedo = frsnow*albWarmSnow + (1.-frsnow)*albice |
| 58 |
|
|
c endif |
| 59 |
|
|
C-end LANL albedo calculation |
| 60 |
|
|
|
| 61 |
|
|
C-- GISS model albedo calculation |
| 62 |
|
|
c albice = 0.7 _d 0 |
| 63 |
|
|
|
| 64 |
|
|
C- New snow: (linear) transition between -10.oC and 0.oC |
| 65 |
|
|
C from cold/dry snow albedo to warm/wet snow albedo |
| 66 |
|
|
albNewSnow = albColdSnow |
| 67 |
|
|
& + (albWarmSnow - albColdSnow) |
| 68 |
|
|
& *MAX( 0. _d 0, 1. _d 0 + MIN(Tsf/10. _d 0, 0. _d 0) ) |
| 69 |
|
|
C- albedo of snow is function of snow-age (make age units into days): |
| 70 |
|
|
albsno = albOldSnow |
| 71 |
|
|
& +(albNewSnow-albOldSnow)*exp(-0.2 _d 0*age/86400. _d 0) |
| 72 |
|
|
C- layer of snow over the ice: |
| 73 |
|
|
albedo = albsno + (albice-albsno)*exp(-hs/hAlbSnow) |
| 74 |
|
|
|
| 75 |
|
|
if (albedo.gt.1. _d 0 .or. albedo.lt. .2 _d 0) then |
| 76 |
|
|
print*,'QQ - albedo problem', albedo, age, hs, albsno |
| 77 |
|
|
stop |
| 78 |
|
|
endif |
| 79 |
|
|
|
| 80 |
|
|
#endif /* ALLOW_THSICE */ |
| 81 |
|
|
|
| 82 |
|
|
C---+----1----+----2----+----3----+----4----+----5----+----6----+----7-|--+----| |
| 83 |
|
|
|
| 84 |
|
|
RETURN |
| 85 |
|
|
END |
Parent Directory
| 
Revision Log
| 
Revision Graph