SUBROUTINE inifrict(timestep)
      USE comgeomfi, ONLY : ngridmax,nlayermx
      USE constlim
      IMPLICIT NONE
c=======================================================================
c
c   Calcul des coefficients de ls diffusion verticale
c
c=======================================================================
c-----------------------------------------------------------------------
c   Declarations:
c   -------------

#include "comcstfi.h"
! include "comvert.h"

c   local:
c   ------

      REAL dgrad,cpr,rl2,rrr,timestep
      INTEGER l,ij

c-----------------------------------------------------------------------

      call initconstlim

      dtradia=timestep
      PRINT*,'DTPHYS',dtradia
      lmixmin=100.
      ais1    = 1.
      ais2    = ais1 - 1.
      print*,'ais1',ais1,'ais2',ais2
      cdzmin  = 1.e-6
      OPEN(99,file='cdzmin',status='old',err=9999)
      READ(99,*) cdzmin
9999  CLOSE(99)
      PRINT*,'cdzmin=',cdzmin

      cpr     = cpp/ r
      ccdzh   = 2.5*g
c!!!  cpgam   = 5.e-3*cpp
      cpgam=0.

c-----------------------------------------------------------------------
c   coefficient de diffusion dans l'atmosphere:
c   -------------------------------------------

      rl2=lmixmin**2
      cdzconst(1)= 0.
      DO 15 l=1,nlayermx - 1
         cdzconst(l+1)= dtradia*g*g*cpr*rl2
         print*,'cdzconst(',l+1,')  =  ',cdzconst(l+1)
  15  CONTINUE

c-----------------------------------------------------------------------
c   couche limite de surface:
c   -------------------------

      cdrat   = 2.e-3
      dgrad   = dtradia*g*cpp/r
      DO 16 ij = 1, ngridmax
         dgcdrag( ij ) = cdrat * dgrad
  16  CONTINUE

      RETURN
      END