da_pt_to_rho_lin.inc

1 subroutine da_pt_to_rho_lin(grid)
2 
3    !---------------------------------------------------------------------------
4    ! Purpose: Calculates density increments from pressure/temperature increments
5    !
6    ! Method:  Linearised ideal gas law: rho~/rho = p'/p - T'/T
7    !
8    ! Assumptions: 1) Model level stored top down.
9    !---------------------------------------------------------------------------
10 
11    implicit none
12 
13    type (domain), intent(inout) :: grid
14 
15    if (trace_use) call da_trace_entry("da_pt_to_rho_lin")
16    
17    grid%xa % rho(its:ite,jts:jte,kts:kte) = grid%xb % rho(its:ite,jts:jte,kts:kte) * ( &
18       grid%xa % p(its:ite,jts:jte,kts:kte) / grid%xb % p(its:ite,jts:jte,kts:kte) - &
19       grid%xa % t(its:ite,jts:jte,kts:kte) / grid%xb % t(its:ite,jts:jte,kts:kte))                       
20 
21 
22    if (trace_use) call da_trace_exit("da_pt_to_rho_lin")
23 
24 end subroutine da_pt_to_rho_lin
25 
26