TSINGHUA UNIVERSITY. Li Liu, Guangwen Yang, Bin Wang Center for Earth System Science, Tsinghua University

Transcription

1 CoR: a MliDi Multi-Dimensional i l Common Remapping Software for Earth System Model Li Liu, Guangwen Yang, Bin Wang Center for Earth System Science, Tsinghua University liuli-cess@tsinghua.edu.cn i

2 Outline Background Main design of CoR Scripts of CoR CoR V1.0 Future plan 2

3 Remapping is fundamental to ESM Widely used In pre-processing Initial data from observation data and reanalysis data In model execution Model coupling and model nesting Time-varying forcing data In post-processing Data analysis and usage 3

4 Necessity of common remapping software Four different dimensions on space and time Horizontal grid Longitude (lon) and latitude (lat) Vertical levels (lev) Time frames (time) Various data with different dimensions 4

5 Necessity of common remapping software Various horizontal grids Lat-lon grid Reduced d grid Cube spherical grid Tri-polar grid Icosahedral grid Horizontal ontal grid with/without itho t mask 5

6 Necessity of common remapping software Various vertical grids Z grid Sigma grid Hybrid grid 6

7 Necessity of common remapping software Various remapping algorithms Different number of dimensions 1D: linear, spline 2D: bilinear, inverse distance weight, bicubic, conservative 3D: conservative Different precision i Different usage: conservative or non-conservative Cascading of remapping algorithms 7

8 Outline Background Main design of CoR Scripts of CoR CoR V1.0 Future plan 8

9 Target functions of CoR Uniform grid representation Uniformly manages all kinds of grids with different structures and dimension numbers Reflects the relation between grids Supports whole grid and partial grid Multi-dimensional remapping Various common remapping algorithms with different dimension number and precision Cascading of remapping algorithms for multi-dimensional remapping Multiple usage In pre-processing, model execution and post-processing 9

10 Usage modes of CoR Write scripts CoR script Input data Fortran API New algorithm New CoR version Error report Check script and input data CoR computation Progress report Fortran code Output data 10

11 Outline Background Main design of CoR Scripts of CoR CoR V1.0 Future plan 11

12 Grid definition Definition of grid dimensions lt lat_src = new_1d_grid( lat, degrees, 196 ) lon_src = new_1d_grid( lon, degrees, cyclic, 360 ) lev_src = new_1d_grid( grid( lev lev, m, 30 ) lonlat_src = combine_grids(lon_src, lat_src, file%gsize) grid_src = combine_grids(lonlat_src, src lev_src) 12

13 Grid definition Setting of grid center/vertex values Case 1 lonlat_src%center%lat=read_field(src_grid_file, center_lat") lonlat_src%vertex%lat=read_field(src_grid_file, vertex_lat, 4 ) lonlat_src%center%lon=read_field(src_grid_file, center_lon") lonlat_src%vertex%lon=read_field(src_grid_file, vertex_lon, 4 ) grid_src%center%lev=read_field(src_grid_file, file, center_lev lev") Case 2 lat_src%center%lat=read_field(src_grid_file, g _ center_lat") lat_src%vertex%lat=read_field(src_grid_file, vertex_lat, 2 ) lon_src%center%lon=read_field(src_grid_file, center_lon") lon_src%vertex%lon=read_field(src_grid_file, t %l d ld( id fil vertex_lon, 2 ) lev_src%center%lev=read_field(src_grid_file, center_lev") 13

14 Grid definition Setting of grid center/vertex values Case 3 lat_src%center%lat=fspan( ) lon_src%center%lon=fspan( ) lev_src%center%lev=fspan( ) Case 4 grid_src%center%lev=lev_coord_from_sigma( ) coord sigma( 14

15 Grid definition Setting of mask values case1 lonlat_src%mask=read_field(src_grid_file, 2D_mask ) grid_src%mask=read_field(src_grid_file, 3D_mask ) case2 lonlat_src%mask=extract_mask( ) grid_src%mask=extract_mask ( ) case3 lonlat_src%mask=calc_ocn_mask( ) grid_src%mask=calc_ocn_mask( ) 15

16 Definition for remapping Definition of remapping operator lonlat_conserv=new_operator("conserv_2d", lonlat_src, lonlat_dst) lev_linear=new_operator("linear", lev_src, lev_dst) Definition of remapping scheme lonlat_ remap=combine _ operators(lonlat ( _ conserv) lonlatlev_remap=combine_operators(lonlat_conserv, lev_linear) 16

17 Remapping calculation Remapping field data remap(lonlat_remap, field_src, field_dst) remap(remap_wgts1, field_src, field_dst) Calculation of remapping weights remap_wgts1=calc_remap_wgts(lonlat_remap, grid_src1, grid_dst2) remap_wgts2=calc_remap_wgts(lonlatlev_remap, grid_src3, grid_dst4) Writing/reading remapping weights write_remap_wgts(io_file, remap_wgts, format_str) remap_wgts=read_remap_wgts(remap_strategy, field_grid_src, field_grid_dst, io_file, format_str) 17

18 Outline Background Main design of CoR Scripts of CoR CoR V1.0 Future plan 18

19 CoR V1.0 Uniform grid representation Lat-lon, tri-polar, cube spherical, Icosahedral, etc Multiple common remapping algorithms Inverse distance weight Bilinear First-order conservative on great arc edge of grid cells Linear Multi-dimensional remapping Remapping weights for CPL6/7, OASIS, S C-Coupler, C NCL, CDO, etc Hundreds d of checking points in the code Hundreds of test cases 19

20 Download CoR URL: username: , password: liuli-cess Source code User reference manual Examples for scripts 20

21 Examples Directly graph with NCL Flaws at pole region Remap with CDO then graph with NCL Flaws still exist Remap with CoR then graph with NCL No flaws 21

22 Outline Background Main design of CoR Scripts of CoR CoR V1.0 Future plan 22

23 Future plan More horizontal grids to support Rd Reduced dgrid, unstructured grid idfor observation data More remapping algorithms with higher precision Spline, bicubic, second order conservative, 3D conservative, etc Fortran interfaces Higher speed More users 23

24 Thank you! 24