source: LMDZ6/branches/Ocean_skin/libf/dyn3d/friction.F @ 3605

Last change on this file since 3605 was 2597, checked in by Ehouarn Millour, 8 years ago

Cleanup in the dynamics: get rid of comconst.h, make it a module comconst_mod.
EM

  • Property copyright set to
    Name of program: LMDZ
    Creation date: 1984
    Version: LMDZ5
    License: CeCILL version 2
    Holder: Laboratoire de m\'et\'eorologie dynamique, CNRS, UMR 8539
    See the license file in the root directory
  • Property svn:eol-style set to native
  • Property svn:keywords set to Author Date Id Revision
File size: 3.8 KB
Line 
1!
2! $Id: friction.F 2597 2016-07-22 06:44:47Z lguez $
3!
4c=======================================================================
5      SUBROUTINE friction(ucov,vcov,pdt)
6
7      USE control_mod
8#ifdef CPP_IOIPSL
9      USE IOIPSL
10#else
11! if not using IOIPSL, we still need to use (a local version of) getin
12      USE ioipsl_getincom
13#endif
14      USE comconst_mod, ONLY: pi
15      IMPLICIT NONE
16
17!=======================================================================
18!
19!   Friction for the Newtonian case:
20!   --------------------------------
21!    2 possibilities (depending on flag 'friction_type'
22!     friction_type=0 : A friction that is only applied to the lowermost
23!                       atmospheric layer
24!     friction_type=1 : Friction applied on all atmospheric layer (but
25!       (default)       with stronger magnitude near the surface; see
26!                       iniacademic.F)
27!=======================================================================
28
29      include "dimensions.h"
30      include "paramet.h"
31      include "comgeom2.h"
32      include "iniprint.h"
33      include "academic.h"
34
35! arguments:
36      REAL,INTENT(out) :: ucov( iip1,jjp1,llm )
37      REAL,INTENT(out) :: vcov( iip1,jjm,llm )
38      REAL,INTENT(in) :: pdt ! time step
39
40! local variables:
41
42      REAL modv(iip1,jjp1),zco,zsi
43      REAL vpn,vps,upoln,upols,vpols,vpoln
44      REAL u2(iip1,jjp1),v2(iip1,jjm)
45      INTEGER  i,j,l
46      REAL,PARAMETER :: cfric=1.e-5
47      LOGICAL,SAVE :: firstcall=.true.
48      INTEGER,SAVE :: friction_type=1
49      CHARACTER(len=20) :: modname="friction"
50      CHARACTER(len=80) :: abort_message
51     
52      IF (firstcall) THEN
53        ! set friction type
54        call getin("friction_type",friction_type)
55        if ((friction_type.lt.0).or.(friction_type.gt.1)) then
56          abort_message="wrong friction type"
57          write(lunout,*)'Friction: wrong friction type',friction_type
58          call abort_gcm(modname,abort_message,42)
59        endif
60        firstcall=.false.
61      ENDIF
62
63      if (friction_type.eq.0) then
64c   calcul des composantes au carre du vent naturel
65      do j=1,jjp1
66         do i=1,iip1
67            u2(i,j)=ucov(i,j,1)*ucov(i,j,1)*unscu2(i,j)
68         enddo
69      enddo
70      do j=1,jjm
71         do i=1,iip1
72            v2(i,j)=vcov(i,j,1)*vcov(i,j,1)*unscv2(i,j)
73         enddo
74      enddo
75
76c   calcul du module de V en dehors des poles
77      do j=2,jjm
78         do i=2,iip1
79            modv(i,j)=sqrt(0.5*(u2(i-1,j)+u2(i,j)+v2(i,j-1)+v2(i,j)))
80         enddo
81         modv(1,j)=modv(iip1,j)
82      enddo
83
84c   les deux composantes du vent au pole sont obtenues comme
85c   premiers modes de fourier de v pres du pole
86      upoln=0.
87      vpoln=0.
88      upols=0.
89      vpols=0.
90      do i=2,iip1
91         zco=cos(rlonv(i))*(rlonu(i)-rlonu(i-1))
92         zsi=sin(rlonv(i))*(rlonu(i)-rlonu(i-1))
93         vpn=vcov(i,1,1)/cv(i,1)
94         vps=vcov(i,jjm,1)/cv(i,jjm)
95         upoln=upoln+zco*vpn
96         vpoln=vpoln+zsi*vpn
97         upols=upols+zco*vps
98         vpols=vpols+zsi*vps
99      enddo
100      vpn=sqrt(upoln*upoln+vpoln*vpoln)/pi
101      vps=sqrt(upols*upols+vpols*vpols)/pi
102      do i=1,iip1
103c        modv(i,1)=vpn
104c        modv(i,jjp1)=vps
105         modv(i,1)=modv(i,2)
106         modv(i,jjp1)=modv(i,jjm)
107      enddo
108
109c   calcul du frottement au sol.
110      do j=2,jjm
111         do i=1,iim
112            ucov(i,j,1)=ucov(i,j,1)
113     s      -cfric*pdt*0.5*(modv(i+1,j)+modv(i,j))*ucov(i,j,1)
114         enddo
115         ucov(iip1,j,1)=ucov(1,j,1)
116      enddo
117      do j=1,jjm
118         do i=1,iip1
119            vcov(i,j,1)=vcov(i,j,1)
120     s      -cfric*pdt*0.5*(modv(i,j+1)+modv(i,j))*vcov(i,j,1)
121         enddo
122         vcov(iip1,j,1)=vcov(1,j,1)
123      enddo
124      endif ! of if (friction_type.eq.0)
125
126      if (friction_type.eq.1) then
127        do l=1,llm
128          ucov(:,:,l)=ucov(:,:,l)*(1.-pdt*kfrict(l))
129          vcov(:,:,l)=vcov(:,:,l)*(1.-pdt*kfrict(l))
130        enddo
131      endif
132     
133      RETURN
134      END
135
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