The current version of the QTCM provides coverage from S to N in latitude and coverage over all longitudes. The grid has dimensions equal to 64 33. The east/west boundaries are periodic, and the north/south boundaries are solid walls, with sponge layers from S to S, and N to N. Thus, the grid spacing is 5.625 [i.e. 360/NX] degrees longitude and 3.75 [i.e. 120/(NY-1)] degrees latitude.
Following FORTRAN convention, the first index increments in the zonal (x) direction with increasing longitude in the eastward direction, beginning at 0 degrees E longitude. The second index increments in the meridional (y) direction with increasing latitude northward, beginning at S latitude (i.e. latitude). Thus:
grid box (1,1) is centered at E longitude,
latitude
grid box (2,1) is centered at E longitude,
latitude
grid box (2,2) is centered at E longitude,
latitude
grid box (NX,NY) is centered at E longitude,
latitude
The spatial array sizes NX and NY are set in the header file hgrid.h.
Higher resolution can be easily achieved by modifying hgrid.h and
subroutine parinit
. However, revised boundary data
sets will then need to be supplied.
Section 3.2.2 has a more complete description of the
model grid.