anchor.diff:      call calc_eta_star(ub,vb,eta,etastar,freesurfFac,nx,ny,dx,dy,dt)
   !print *, maxval(abs(etastar))
   
  +    ! prevent barotropic signals from bouncing around outside the wet region of the model.
  +    etastar = etastar*wetmask
  +
       call SOR_solver(a,etanew,etastar,freesurfFac,nx,ny, &
           dt,rjac,eps,maxits,n)
   !print *, maxval(abs(etanew))
  
positive.code:     return
      end subroutine
  
  kjlkj
  ! --------------------------------------------------------------
  
  !> Calculate the barotropic v velocity
  
negative.code: !> number of x and y grid points
      integer nx,ny !< number of x and y grid points
      integer layers !< number of active layers in the model
      parameter(nx=300,ny=300)
  
  !   number of active layers
      parameter(layers = 2)
  