da_balance_geoterm_lin.inc

1 subroutine da_balance_geoterm_lin( cori, rho, u, v, term_x, term_y)
2 
3    !---------------------------------------------------------------------------
4    !  Purpose: calculates linearised geostrophic term in balance equation.
5    !
6    !  method:  term is k x rho f u on a single level.
7    !
8    !  assumptions: Various (see documentation).
9    !---------------------------------------------------------------------------
10 
11    implicit none
12    
13    real, intent(in)    :: cori(ims:ime,jms:jme)   ! Coriolis factor.
14    real, intent(in)    :: rho(ims:ime,jms:jme)    ! Density
15    real, intent(in)    :: u(ims:ime,jms:jme)      ! u wind increment
16    real, intent(in)    :: v(ims:ime,jms:jme)      ! v wind increment
17    real, intent(inout) :: term_x(ims:ime,jms:jme) ! x component of term.
18    real, intent(inout) :: term_y(ims:ime,jms:jme) ! y component of term.
19 
20    integer :: is, js              ! i,j lower loop limits
21    integer :: ie, je              ! i,j upper loop limits
22 
23    if (trace_use) call da_trace_entry("da_balance_geoterm_lin")
24 
25    ! Set loop limits
26 
27    is = its-1
28    ie = ite+1
29    js = jts-1
30    je = jte+1
31    if (its == ids ) is = ids
32    if (ite == ide ) ie = ide
33    if (jts == jds ) js = jds
34    if (jte == jde ) je = jde
35 
36    !---------------------------------------------------------------------------
37    ! [1.0] Calculate term_x = -f rho v~:
38    !---------------------------------------------------------------------------
39 
40    term_x(is:ie,js:je) = term_x(is:ie,js:je) - rho(is:ie,js:je) * cori(is:ie,js:je) * v(is:ie,js:je)
41 
42    !---------------------------------------------------------------------------
43    ! [2.0] Calculate term_y = f rho u~:
44    !---------------------------------------------------------------------------
45 
46    term_y(is:ie,js:je) = term_y(is:ie,js:je) + rho(is:ie,js:je) * cori(is:ie,js:je) * u(is:ie,js:je)
47 
48    if (trace_use) call da_trace_exit("da_balance_geoterm_lin")
49 
50 end subroutine da_balance_geoterm_lin
51 
52