da_get_q_error.inc

1 subroutine da_get_q_error( p, t, q, t_error, rh_error, q_error)
2 
3    !-----------------------------------------------------------------------
4    ! Purpose: TBD
5    !-----------------------------------------------------------------------
6 
7    implicit none
8 
9    real, intent(in)          :: p        ! Observed pressure.
10    real, intent(in)          :: t        ! Observed temperature.
11    real, intent(in)          :: q        ! Observed specific humidity.
12    real, intent(in)          :: t_error  ! Temperature observation error.
13    real, intent(in)          :: rh_error ! RH observation error.
14    real, intent(out)         :: q_error  ! q observation error.
15 
16    real                      :: es    ! Saturation vapor pressure.
17    real                      :: qs    ! Saturation specific humidity.
18    real                      :: rh    ! Relative humidity.
19 
20    real :: f_qv_from_rh
21    external f_qv_from_rh
22 
23    if (ABS(p - missing_r) > 1.0 .AND. ABS(t - missing_r) > 1.0 .AND. &
24         ABS(q - missing_r) > 1) then
25 
26       ! Calculate rh:
27 
28       call da_tp_to_qs( t, p, es, qs)
29 
30       rh = 100.0 * q / qs
31       if (rh > 100.0) rh = 100.0
32 
33       ! Get observation error for qv. Is this right?
34 
35       q_error = f_qv_from_rh( rh_error, t_error, rh, t, p)
36 
37    else
38       q_error = missing_r
39    end if
40 
41    if (q_error == 0.0) q_error = missing_r
42 
43 end subroutine da_get_q_error
44 
45