source: LMDZ5/branches/IPSLCM5A2.1/libf/phylmd/regr_pr_av_m.F90 @ 5360

Last change on this file since 5360 was 2440, checked in by lguez, 9 years ago

For read_climoz = 1 or 2, replaced first order conservative regridding
of ozone by second order conservative regridding, with Van Leer
slope-limiting. The replacement is done for both latitude and pressure
regridding. The replacement is beneficial if the resolution of the
input data is coarser than the resolution of LMDZ. If the resolution
of the input data is finer, then the replacement is neutral, it does
not change much.

  • Property copyright set to
    Name of program: LMDZ
    Creation date: 1984
    Version: LMDZ5
    License: CeCILL version 2
    Holder: Laboratoire de m\'et\'eorologie dynamique, CNRS, UMR 8539
    See the license file in the root directory
File size: 4.6 KB
Line 
1! $Id$
2module regr_pr_av_m
3
4  ! Author: Lionel GUEZ
5
6  implicit none
7
8contains
9
10  subroutine regr_pr_av(ncid, name, julien, press_in_edg, paprs, v3)
11
12    ! "regr_pr_av" stands for "regrid pressure averaging".
13    ! In this procedure:
14    ! -- the root process reads 2D latitude-pressure fields from a
15    !    NetCDF file, at a given day.
16    ! -- the fields are packed to the LMDZ horizontal "physics"
17    !    grid and scattered to all threads of all processes;
18    ! -- in all the threads of all the processes, the fields are regridded in
19    !    pressure to the LMDZ vertical grid.
20    ! We assume that, in the input file, the fields have 3 dimensions:
21    ! latitude, pressure, julian day.
22    ! We assume that the input fields are already on the "rlatu"
23    ! latitudes, except that latitudes are in ascending order in the input
24    ! file.
25    ! We assume that all the inputs fields have the same coordinates.
26
27    ! The target vertical LMDZ grid is the grid of layer boundaries.
28    ! Regridding in pressure is conservative, second order.
29
30    ! All the fields are regridded as a single multi-dimensional array
31    ! so it saves CPU time to call this procedure once for several NetCDF
32    ! variables rather than several times, each time for a single
33    ! NetCDF variable.
34
35    use dimphy, only: klon
36    use netcdf95, only: nf95_inq_varid, handle_err
37    use netcdf, only: nf90_get_var
38    use assert_m, only: assert
39    use assert_eq_m, only: assert_eq
40    use regr1_conserv_m, only: regr1_conserv
41    use slopes_m, only: slopes
42    use mod_phys_lmdz_mpi_data, only: is_mpi_root
43    use mod_grid_phy_lmdz, only: nbp_lon, nbp_lat, nbp_lev
44    use mod_phys_lmdz_transfert_para, only: scatter2d
45    ! (pack to the LMDZ horizontal "physics" grid and scatter)
46
47    integer, intent(in):: ncid ! NetCDF ID of the file
48    character(len=*), intent(in):: name(:) ! of the NetCDF variables
49    integer, intent(in):: julien ! jour julien, 1 <= julien <= 360
50
51    real, intent(in):: press_in_edg(:)
52    ! edges of pressure intervals for input data, in Pa, in strictly
53    ! ascending order
54
55    real, intent(in):: paprs(:, :) ! (klon, llm + 1)
56    ! (pression pour chaque inter-couche, en Pa)
57
58    real, intent(out):: v3(:, :, :) ! (klon, llm, size(name))
59    ! regridded fields on the partial "physics" grid
60    ! "v3(i, k, l)" is at longitude "xlon(i)", latitude
61    ! "xlat(i)", in pressure interval "[paprs(i, k+1), paprs(i, k)]",
62    ! for NetCDF variable "name(l)".
63
64    ! Variables local to the procedure:
65
66    integer varid, ncerr ! for NetCDF
67
68    real  v1(nbp_lon, nbp_lat, size(press_in_edg) - 1, size(name))
69    ! input fields at day "julien", on the global "dynamics" horizontal grid
70    ! First dimension is for longitude.
71    ! The values are the same for all longitudes.
72    ! "v1(:, j, k, l)" is at latitude "rlatu(j)", for
73    ! pressure interval "[press_in_edg(k), press_in_edg(k+1)]" and
74    ! NetCDF variable "name(l)".
75
76    real v2(klon, size(press_in_edg) - 1, size(name))
77    ! fields scattered to the partial "physics" horizontal grid
78    ! "v2(i, k, l)" is at longitude "xlon(i)", latitude "xlat(i)",
79    ! for pressure interval "[press_in_edg(k), press_in_edg(k+1)]" and
80    ! NetCDF variable "name(l)".
81
82    integer i, n_var
83
84    !--------------------------------------------
85
86    call assert(size(v3, 1) == klon, size(v3, 2) == nbp_lev, &
87         "regr_pr_av v3 klon")
88    n_var = assert_eq(size(name), size(v3, 3), "regr_pr_av v3 n_var")
89    call assert(shape(paprs) == (/klon, nbp_lev+1/), "regr_pr_av paprs")
90
91    !$omp master
92    if (is_mpi_root) then
93       do i = 1, n_var
94          call nf95_inq_varid(ncid, trim(name(i)), varid)
95         
96          ! Get data at the right day from the input file:
97          ncerr = nf90_get_var(ncid, varid, v1(1, :, :, i), &
98               start=(/1, 1, julien/))
99          call handle_err("regr_pr_av nf90_get_var " // trim(name(i)), ncerr, &
100               ncid)
101       end do
102       
103       ! Latitudes are in ascending order in the input file while
104       ! "rlatu" is in descending order so we need to invert order:
105       v1(1, :, :, :) = v1(1, nbp_lat:1:-1, :, :)
106
107       ! Duplicate on all longitudes:
108       v1(2:, :, :, :) = spread(v1(1, :, :, :), dim=1, ncopies=nbp_lon-1)
109    end if
110    !$omp end master
111
112    call scatter2d(v1, v2)
113
114    ! Regrid in pressure at each horizontal position:
115    do i = 1, klon
116       call regr1_conserv(v2(i, :, :), press_in_edg, &
117            paprs(i, nbp_lev + 1:1:-1), v3(i, nbp_lev:1:-1, :), &
118            slopes(v2(i, :, :), press_in_edg))
119       ! (invert order of indices because "paprs" is in descending order)
120    end do
121
122  end subroutine regr_pr_av
123
124end module regr_pr_av_m
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