[6331] | 1 | SUBROUTINE gradient_conserv(NX1, NY1, ibeg, jbeg, iloc, jloc, & |
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| 2 | cl_grd_src, id_per, cd_per, w_unit, & |
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| 3 | local_grad_lon, local_grad_lat, file_debug) |
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| 4 | |
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| 5 | ! |
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| 6 | !**** *gradient_conserv* - calculate gradients for conservative remapping |
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| 7 | ! |
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| 8 | ! Purpose: |
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| 9 | ! ------- |
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| 10 | ! Calculation of gradients in latitudinal and longitudinal direction. |
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| 11 | ! In a first step the gradients in direction of source-grid rows |
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| 12 | ! and lines are calculated. Then they are rotated to longitudinal |
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| 13 | ! and latitudinal direction, using the scalar product. |
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| 14 | ! This routine works for logically rectangular grids, only. |
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| 15 | ! |
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| 16 | !** Interface: |
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| 17 | ! --------- |
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| 18 | ! *CALL* *gradient_conserv*(NX1, NY1, jbeg, iloc, jloc, |
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| 19 | ! cl_grd_src, id_per, cd_per, w_unit, |
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| 20 | ! local_grad_lat, local_grad_lon, file_debug) |
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| 21 | ! |
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| 22 | ! Input: |
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| 23 | ! ----- |
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| 24 | ! NX1 : grid global dimension in x-direction (integer) |
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| 25 | ! NY1 : grid global dimension in y-direction (integer) |
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| 26 | ! ibeg : start of local domain in global domain in x-direction |
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| 27 | ! jbeg : start of local domain in global domain in y-direction |
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| 28 | ! iloc : grid local dimension in x-direction (integer) |
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| 29 | ! jloc : grid local dimension in y-direction (integer) |
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| 30 | ! cl_grd_src : grid acronym |
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| 31 | ! id_per : number of overlapping points for source grid |
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| 32 | ! cd_per : grip periodicity type |
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| 33 | ! w_unit : log file unit |
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| 34 | ! file_debug : logical for activating debug outputs |
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| 35 | ! |
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| 36 | ! Output: |
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| 37 | ! ------ |
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| 38 | ! local_grad_lon : gradient in longitudinal direction (real 2D) |
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| 39 | ! local_grad_lat : gradient in latitudinal direction (real 2D) |
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| 40 | ! |
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| 41 | ! %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% |
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| 42 | ! |
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| 43 | USE read_all_data |
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| 44 | USE function_ana |
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| 45 | ! |
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| 46 | IMPLICIT NONE |
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| 47 | |
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| 48 | INTEGER, PARAMETER :: wp = SELECTED_REAL_KIND(12,307) ! double |
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| 49 | !----------------------------------------------------------------------- |
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| 50 | ! INTENT(IN) |
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| 51 | !----------------------------------------------------------------------- |
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| 52 | INTEGER, INTENT(IN) :: & |
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| 53 | NX1, NY1, & ! source grid dimensions |
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| 54 | ibeg, jbeg, & ! source grid local start |
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| 55 | iloc, jloc ! source grid local dimensions |
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| 56 | |
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| 57 | CHARACTER(len=4), INTENT(IN) :: & |
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| 58 | cl_grd_src ! grid acronym |
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| 59 | |
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| 60 | INTEGER, INTENT(IN) :: & |
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| 61 | id_per, & ! nbr of overlapping grid points |
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| 62 | w_unit ! log file |
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| 63 | |
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| 64 | CHARACTER*8, INTENT(IN) :: & |
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| 65 | cd_per ! grip periodicity type |
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| 66 | |
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| 67 | LOGICAL, INTENT(IN) :: file_debug |
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| 68 | |
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| 69 | !----------------------------------------------------------------------- |
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| 70 | ! INTENT(OUT) |
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| 71 | !----------------------------------------------------------------------- |
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| 72 | REAL (kind=wp), DIMENSION(iloc,jloc), INTENT(OUT) :: & |
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| 73 | local_grad_lon, & ! gradient in longitudinal direction |
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| 74 | local_grad_lat ! gradient in latitudinal direction |
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| 75 | |
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| 76 | !----------------------------------------------------------------------- |
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| 77 | ! LOCAL VARIABLES |
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| 78 | !----------------------------------------------------------------------- |
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| 79 | INTEGER :: & |
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| 80 | i, j, & ! looping indicees |
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| 81 | ip1, jp1, im1, jm1, iend, jend |
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| 82 | |
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| 83 | REAL (kind=wp) :: & |
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| 84 | distance_rad ! distance in rad |
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| 85 | |
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| 86 | REAL (kind=wp) :: & |
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| 87 | dVar_i, dVar_j, & ! difference of Var in i / j direction |
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| 88 | dlat_i, dlat_j, & ! difference in lat in i / j direction |
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| 89 | dlon_i, dlon_j, & ! difference in lon in i / j direction |
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| 90 | dist_i, dist_j, & ! distance in i / j direction |
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| 91 | grad_i, grad_j, & ! gradient in i / j direction |
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| 92 | ABSold, ABSnew, lat_factor |
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| 93 | |
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| 94 | REAL (kind=wp), DIMENSION(:,:), POINTER :: & |
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| 95 | src_lon, & ! source grid longitudes [radiants] |
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| 96 | src_lat, & ! source grid latitudes [radiants] |
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| 97 | src_array, & ! analytical field |
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| 98 | grad_lon, & ! global gradient in latitudinal direction |
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| 99 | grad_lat ! global gradient in longitudinal direction |
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| 100 | |
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| 101 | INTEGER, DIMENSION(:,:), POINTER :: & |
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| 102 | sou_mask ! source grid mask |
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| 103 | |
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| 104 | REAL (kind=wp), PARAMETER :: & |
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| 105 | pi = 3.14159265358979323846, & ! PI |
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| 106 | pi2 = 2.0d0*pi, & ! 2PI |
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| 107 | pi180 = 1.74532925199432957692e-2 ! =PI/180 |
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| 108 | |
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| 109 | INTEGER, PARAMETER :: il_maskval= 1 ! in our grids sea_value = 0 and land_value = 1 |
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| 110 | |
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| 111 | !----------------------------------------------------------------------- |
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| 112 | ! |
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| 113 | ! Read global grid and global mask |
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| 114 | ! -------------------------------- |
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| 115 | ALLOCATE(src_lon(NX1, NY1)) |
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| 116 | ALLOCATE(src_lat(NX1, NY1)) |
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| 117 | CALL read_grid(NX1, NY1, 1, 1, NX1, NY1, cl_grd_src, w_unit, src_lon, src_lat, file_debug) |
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| 118 | ! |
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| 119 | ALLOCATE(sou_mask(NX1, NY1)) |
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| 120 | CALL read_mask(NX1, NY1, 1, 1, NX1, NY1, cl_grd_src, w_unit, sou_mask, file_debug) |
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| 121 | |
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| 122 | ! Global field from analytical function |
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| 123 | ! ------------------------------------- |
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| 124 | ALLOCATE(src_array(NX1, NY1)) |
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| 125 | #ifdef FANA1 |
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| 126 | CALL function_ana1(NX1, NY1, src_lon, src_lat, src_array) |
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| 127 | #elif defined FANA2 |
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| 128 | CALL function_ana2(NX1, NY1, src_lon, src_lat, src_array) |
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| 129 | #elif defined FANA3 |
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| 130 | CALL function_ana3(NX1, NY1, src_lon, src_lat, src_array) |
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| 131 | #endif |
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| 132 | |
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| 133 | ! Global gradient allocation |
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| 134 | ! -------------------------- |
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| 135 | ALLOCATE(grad_lon(NX1, NY1)) |
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| 136 | ALLOCATE(grad_lat(NX1, NY1)) |
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| 137 | |
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| 138 | ! Initialization |
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| 139 | ! -------------- |
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| 140 | grad_lon = 0. |
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| 141 | grad_lat = 0. |
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| 142 | |
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| 143 | ! transformation in radiants for gradient calculation |
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| 144 | ! --------------------------------------------------- |
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| 145 | src_lon = src_lon * pi180 |
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| 146 | src_lat = src_lat * pi180 |
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| 147 | |
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| 148 | ! calculate gradients |
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| 149 | ! ------------------- |
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| 150 | DO i = 1, NX1 |
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| 151 | DO j = 1, NY1 |
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| 152 | |
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| 153 | IF (sou_mask(i,j) /= il_maskval) THEN |
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| 154 | |
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| 155 | ip1 = i + 1 |
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| 156 | im1 = i - 1 |
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| 157 | IF (i == NX1) THEN |
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| 158 | IF (cd_per == 'P') ip1 = 1 + id_per ! the 0-meridian |
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| 159 | IF (cd_per == 'R') ip1 = NX1 |
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| 160 | ENDIF |
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| 161 | IF (i == 1 ) THEN |
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| 162 | IF (cd_per == 'P') im1 = NX1 - id_per |
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| 163 | IF (cd_per == 'R') im1 = 1 |
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| 164 | ENDIF |
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| 165 | jp1 = j + 1 |
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| 166 | jm1 = j - 1 |
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| 167 | IF (j == NY1) jp1 = NY1 ! treatment of the last.. |
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| 168 | IF (j == 1 ) jm1 = 1 ! .. and the first grid-row |
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| 169 | |
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| 170 | IF (sou_mask(ip1,j) == il_maskval) ip1 = i |
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| 171 | IF (sou_mask(im1,j) == il_maskval) im1 = i |
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| 172 | IF (sou_mask(i,jp1) == il_maskval) jp1 = j |
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| 173 | IF (sou_mask(i,jm1) == il_maskval) jm1 = j |
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| 174 | |
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| 175 | ! difference between neighbouring datapoints |
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| 176 | dVar_i = src_array(ip1,j) - src_array(im1,j) |
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| 177 | dVar_j = src_array(i,jp1) - src_array(i,jm1) |
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| 178 | |
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| 179 | ! difference in latitudes |
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| 180 | dlat_i = src_lat(ip1,j) - src_lat(im1,j) |
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| 181 | dlat_j = src_lat(i,jp1) - src_lat(i,jm1) |
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| 182 | |
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| 183 | ! difference in longitudes |
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| 184 | dlon_i = src_lon(ip1,j) - src_lon(im1,j) |
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| 185 | IF (dlon_i > pi) dlon_i = dlon_i - pi2 |
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| 186 | IF (dlon_i < (-pi)) dlon_i = dlon_i + pi2 |
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| 187 | dlon_j = src_lon(i,jp1) - src_lon(i,jm1) |
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| 188 | IF (dlon_j > pi) dlon_j = dlon_j - pi2 |
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| 189 | IF (dlon_j < (-pi)) dlon_j = dlon_j + pi2 |
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| 190 | lat_factor = COS(src_lat(i,j)) |
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| 191 | dlon_i = dlon_i * lat_factor |
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| 192 | dlon_j = dlon_j * lat_factor |
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| 193 | |
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| 194 | ! distance |
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| 195 | dist_i = distance_rad(src_lon(ip1,j), src_lat(ip1,j), & |
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| 196 | src_lon(im1,j), src_lat(im1,j)) |
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| 197 | dist_j = distance_rad(src_lon(i,jp1), src_lat(i,jp1), & |
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| 198 | src_lon(i,jm1), src_lat(i,jm1)) |
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| 199 | |
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| 200 | ! gradients: dVar / distance (= vector lenght) |
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| 201 | IF (dist_i /= 0.) THEN |
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| 202 | grad_i = dVar_i / dist_i |
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| 203 | ELSE |
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| 204 | grad_i = 0 |
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| 205 | ENDIF |
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| 206 | IF (dist_j /= 0.) THEN |
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| 207 | grad_j = dVar_j / dist_j |
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| 208 | ELSE |
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| 209 | grad_j = 0 |
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| 210 | ENDIF |
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| 211 | |
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| 212 | ! projection by scalar product |
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| 213 | ! ---------------------------- |
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| 214 | grad_lon(i,j) = grad_i * dlon_i + grad_j * dlat_i |
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| 215 | grad_lat(i,j) = grad_i * dlon_j + grad_j * dlat_j |
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| 216 | |
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| 217 | IF (dist_i /= 0) then |
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| 218 | grad_lon(i,j) = grad_lon(i,j) / dist_i |
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| 219 | ELSE |
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| 220 | grad_lon(i,j) = 0 |
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| 221 | ENDIF |
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| 222 | IF (dist_j /= 0) then |
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| 223 | grad_lat(i,j) = grad_lat(i,j) / dist_j |
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| 224 | ELSE |
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| 225 | grad_lat(i,j) = 0. |
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| 226 | ENDIF |
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| 227 | |
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| 228 | ! correct skale |
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| 229 | ! ------------- |
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| 230 | ABSold = SQRT(grad_i**2 + grad_j**2) |
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| 231 | ABSnew = SQRT(grad_lon(i,j)**2 + grad_lat(i,j)**2) |
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| 232 | IF (ABSnew > 1.E-10) THEN |
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| 233 | ! grad_lon(i,j) = grad_lon(i,j)*ABSold/ABSnew |
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| 234 | grad_lon(i,j) = grad_lon(i,j) |
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| 235 | ELSE |
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| 236 | grad_lon(i,j) = 0.0 |
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| 237 | ENDIF |
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| 238 | |
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| 239 | ! test orthogonality |
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| 240 | ! ------------------ |
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| 241 | IF ((dlon_i*dlon_j+dlat_j*dlat_i) > 0.1) THEN |
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| 242 | print*, 'ORTHOGONAL? ', i, j, (dlon_i*dlon_j+dlat_j*dlat_i) |
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| 243 | ENDIF |
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| 244 | |
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| 245 | ELSE |
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| 246 | |
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| 247 | grad_lat(i,j) = 0. |
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| 248 | grad_lon(i,j) = 0. |
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| 249 | |
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| 250 | ENDIF |
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| 251 | |
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| 252 | ENDDO |
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| 253 | ENDDO |
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| 254 | ! |
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| 255 | iend = ibeg+iloc-1 |
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| 256 | jend = jbeg+jloc-1 |
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| 257 | local_grad_lat = grad_lat(ibeg:iend, jbeg:jend) |
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| 258 | local_grad_lon = grad_lon(ibeg:iend, jbeg:jend) |
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| 259 | |
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| 260 | END SUBROUTINE gradient_conserv |
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