da_tprh_to_q_lin1.inc

1 subroutine da_tprh_to_q_lin1( t, p, es, q, rh, &
2                               t_prime, p_prime, rh_prime, q_prime )
3 
4    !---------------------------------------------------------------------------
5    !  Purpose: Convert T/pressure/rh to specific humidity increments.
6    !
7    !  Method: q~ = q (rh~/rh + qs~/qs)
8    !---------------------------------------------------------------------------
9 
10    implicit none
11 
12    real, intent(in)              :: t        ! Temperature.
13    real, intent(in)              :: p        ! Pressure.
14    real, intent(in)              :: es       ! Saturation vapour pressure.
15    real, intent(in)              :: q        ! Specific humidity.
16    real, intent(in)              :: rh       ! Relative Humidity.
17    real, intent(in)              :: t_prime  ! Temperature increment.
18    real, intent(in)              :: p_prime  ! Pressure increment.
19    real, intent(in)              :: rh_prime ! Pressure increment.
20    real, intent(out)             :: q_prime  ! Pressure increment.
21    
22    real                          :: qs_prime_over_qs ! qs~/qs.
23 
24    !---------------------------------------------------------------------------
25    ! [1.0] Calculate saturation specific humidity ratio qs~/qs:
26    !---------------------------------------------------------------------------
27 
28    call da_tp_to_qs_lin1( t, p, es, t_prime, p_prime, qs_prime_over_qs )
29    
30    !---------------------------------------------------------------------------
31    ! [2.0] Calculate specific humidity increment:
32    !---------------------------------------------------------------------------
33 
34    q_prime = q * ( rh_prime / rh + qs_prime_over_qs )
35 
36 end subroutine da_tprh_to_q_lin1
37 
38