dyn3d/Guide/tau2alpha.f

module tau2alpha_m

  IMPLICIT NONE

contains

  SUBROUTINE tau2alpha(lat_min_guide, lat_max_guide, factt, dxdy, rlat, &
       taumin, taumax, alpha)

    use init_tau2alpha_m, only: dxdy_min, dxdy_max, gamma
    USE nr_util, ONLY: assert_eq

    ! Dans le cas où on n'a les analyses que sur une bande de latitudes :
    REAL, intent(in):: lat_min_guide ! minimum latitude for nudging, in rad
    real, intent(in):: lat_max_guide ! maximum latitude for nudging, in rad

    REAL, intent(in):: factt
    ! pas de temps entre deux appels au guidage, en jours
    
    REAL, intent(in):: dxdy(:, :) ! (n_lon, n_lat)
    REAL, intent(in):: rlat(:) ! (n_lat)
    REAL, intent(in):: taumin, taumax
    real, intent(out):: alpha(:, :) ! (n_lon, n_lat)

    ! Local:
    REAL a_min, a_max, xi
    INTEGER i, j, n_lon, n_lat

    !------------------------------------------------------------

    PRINT *, 'Call sequence information: tau2alpha'

    n_lon = assert_eq(size(alpha, 1), size(dxdy, 1), "tau2alpha n_lon")
    n_lat = assert_eq(size(alpha, 2), size(dxdy, 2), size(rlat), &
         "tau2alpha n_lat")

    a_min = factt / taumax
    a_max = factt / taumin

    DO j = 1, n_lat
       IF (lat_min_guide <= rlat(j) .AND. rlat(j) <= lat_max_guide) THEN
          DO i = 1, n_lon
             xi = min(((dxdy_max - dxdy(i, j)) &
                  / (dxdy_max - dxdy_min))**gamma, 1.)
             alpha(i, j) = 1. - exp(- xi * a_min - (1. - xi) * a_max)
          END DO
       ELSE
          alpha(:, j) = 0.
       END IF
    END DO

  END SUBROUTINE tau2alpha

end module tau2alpha_m
1	guez	37	module tau2alpha_m
2
3	guez	103	IMPLICIT NONE
4	guez	37
5			contains
6
7	guez	211	SUBROUTINE tau2alpha(lat_min_guide, lat_max_guide, factt, dxdy, rlat, &
8			taumin, taumax, alpha)
9	guez	37
10	guez	115	use init_tau2alpha_m, only: dxdy_min, dxdy_max, gamma
11	guez	178	USE nr_util, ONLY: assert_eq
12	guez	37
13	guez	211	! Dans le cas où on n'a les analyses que sur une bande de latitudes :
14			REAL, intent(in):: lat_min_guide ! minimum latitude for nudging, in rad
15			real, intent(in):: lat_max_guide ! maximum latitude for nudging, in rad
16
17			REAL, intent(in):: factt
18			! pas de temps entre deux appels au guidage, en jours
19
20	guez	115	REAL, intent(in):: dxdy(:, :) ! (n_lon, n_lat)
21			REAL, intent(in):: rlat(:) ! (n_lat)
22			REAL, intent(in):: taumin, taumax
23			real, intent(out):: alpha(:, :) ! (n_lon, n_lat)
24	guez	103
25			! Local:
26	guez	210	REAL a_min, a_max, xi
27	guez	115	INTEGER i, j, n_lon, n_lat
28	guez	37
29	guez	44	!------------------------------------------------------------
30
31	guez	115	PRINT *, 'Call sequence information: tau2alpha'
32	guez	109
33	guez	115	n_lon = assert_eq(size(alpha, 1), size(dxdy, 1), "tau2alpha n_lon")
34			n_lat = assert_eq(size(alpha, 2), size(dxdy, 2), size(rlat), &
35			"tau2alpha n_lat")
36	guez	109
37	guez	210	a_min = factt / taumax
38			a_max = factt / taumin
39	guez	113
40	guez	115	DO j = 1, n_lat
41	guez	140	IF (lat_min_guide <= rlat(j) .AND. rlat(j) <= lat_max_guide) THEN
42	guez	115	DO i = 1, n_lon
43			xi = min(((dxdy_max - dxdy(i, j)) &
44			/ (dxdy_max - dxdy_min))**gamma, 1.)
45	guez	210	alpha(i, j) = 1. - exp(- xi * a_min - (1. - xi) * a_max)
46	guez	37	END DO
47			ELSE
48	guez	115	alpha(:, j) = 0.
49	guez	37	END IF
50			END DO
51
52			END SUBROUTINE tau2alpha
53
54			end module tau2alpha_m