da_balance_geoterm.inc

1 subroutine da_balance_geoterm_nl (domain, k, u, v, term_x, term_y)
2  
3    !---------------------------------------------------------------------------
4    ! Purpose: calculates nonlinear geostrophic term in balance equation.
5    !
6    ! method:  term is k x rho f u on a single level.
7    !---------------------------------------------------------------------------
8 
9    implicit none
10 
11    type(domain), intent(in)  :: grid
12    integer,      intent(in)  :: k            ! Model level.
13    real,         intent(in)  :: u(:,:)       ! u wind comp. (dot pts)
14    real,         intent(in)  :: v(:,:)       ! v wind comp. (dot pts)
15    real,         intent(out) :: term_x(:,:)  ! x component of term.
16    real,         intent(out) :: term_y(:,:)  ! y component of term.
17 
18    if (trace_use) call da_trace_entry("da_balance_geoterm_nl")
19 
20    !---------------------------------------------------------------------------
21    !  [1.0] Initialise:
22    !---------------------------------------------------------------------------
23 
24    term_x(:,:) = 0.0
25    term_y(:,:) = 0.0
26 
27    !---------------------------------------------------------------------------
28    !  [2.0] Calculate term_x = -f rho v~:
29    !---------------------------------------------------------------------------
30 
31    term_x(its:ite, jts:jte) = -grid%xb%rho(its:ite, jts:jte, k) &
32       * grid%xb%  v(its:ite, jts:jte, k) * grid%xb%cori(its:ite, jts:jte)
33 
34    !---------------------------------------------------------------------------
35    !  [3.0] Calculate term_y = f rho u~:
36    !---------------------------------------------------------------------------
37 
38    term_y(its:ite, jts:jte) = grid%xb%rho(its:ite, jts:jte, k) &
39       * grid%xb%  u(its:ite, jts:jte, k) * grid%xb%cori(its:ite, jts:jte)
40 
41    if (trace_use) call da_trace_exit("da_balance_geoterm_nl")
42 
43 end subroutine da_balance_geoterm_nl
44 
45