Regridding in GEOS-Chem
NOTE: Page under construction!
On this page, we shall describe how GEOS-Chem regrids data from one resolution to another.
The MAP_A2A algorithm
In GEOS-Chem v9-01-03, we have added the following updates to the MAP_A2A regridding scheme:
The driver routine DO_REGRID_A2A now reads the grid input information (i.e. longitude edges and sines of latitude edges) from netCDF files. This replaces the original implementation, which read from ASCII files.
Important DO loops in routines DO_REGRID_A2A, XMAP and YMAP (all in GeosUtil/regrid_a2a_mod.F90) have now been parallelized with OpenMP directives.
The QSUM and SUM variables in routines XMAP and YMAP have been changed from REAL*4 to REAL*8. This eliminates some minor numerical noise past the 6th decimal place.