source: LMDZ5/trunk/libf/phylmd/icefrac_lsc_mod.F90 @ 2518

Last change on this file since 2518 was 2507, checked in by jbmadeleine, 9 years ago

Added the iflag_t_glace = 2 option that turns off the convertion of cloud
water to ice close to the surface when T< t_glace_max (273.15K). This option
is now obsolete because the liquid precipitation is now converted to ice when the
temperature is negative using the iflag_bergeron option.

  • Property svn:executable set to *
File size: 1.5 KB
Line 
1!
2! $Header$
3!
4MODULE icefrac_lsc_mod
5
6IMPLICIT NONE
7
8CONTAINS
9!*******************************************************************
10
11SUBROUTINE icefrac_lsc(np,temp, sig, icefrac)
12  !
13  ! Compute the ice fraction 1-xliq (see e.g.
14  ! Doutriaux-Boucher & Quaas 2004, section 2.2.)
15  !
16  ! (JBM 3/14 8/14 5/16)
17 
18  USE print_control_mod, ONLY: lunout, prt_level
19  INCLUDE "nuage.h"
20
21  ! nuage.h contains:
22  ! t_glace_min: if T < Tmin, the cloud is only made of water ice
23  ! t_glace_max: if T > Tmax, the cloud is only made of liquid water
24  ! exposant_glace: controls the sharpness of the transition
25  INTEGER :: np
26  REAL, DIMENSION(np), INTENT(IN) :: temp ! temperature
27  REAL, DIMENSION(np), INTENT(IN) :: sig
28  REAL, DIMENSION(np), INTENT(OUT) :: icefrac
29
30  REAL :: sig0,www,tmin_tmp,icefrac_tmp
31  INTEGER :: ip
32
33  sig0=0.8
34
35  DO ip=1,np
36     IF (iflag_t_glace.EQ.1) THEN
37       ! Transition to ice close to surface for T<Tmax
38       ! w=1 at the surface and 0 for sig < sig0
39       www=(max(sig(ip)-sig0,0.))/(1.-sig0)
40     ELSEIF (iflag_t_glace.GE.2) THEN
41       ! No convertion to ice close to surface
42       www = 0.
43     ENDIF
44     tmin_tmp=www*t_glace_max+(1.-www)*t_glace_min
45     icefrac_tmp= 1.0 - (temp(ip)-tmin_tmp) / (t_glace_max-tmin_tmp)
46     icefrac_tmp = MIN(MAX(icefrac_tmp,0.0),1.0)
47     icefrac(ip) = icefrac_tmp**exposant_glace
48  ENDDO
49
50  RETURN
51END SUBROUTINE icefrac_lsc
52
53!*******************************************************************
54!
55END MODULE icefrac_lsc_mod
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