Using interp_restarts.x and interp_restarts_bin.x

Overview

The FV3 GridComp repository contains two executables that are used to regrid GEOS restarts on the cubed-sphere to a different cubed-sphere resolution. The first, interp_restarts.x regrids GEOS NetCDF restarts, and the second, interp_restarts_bin.x regrids GEOS binary restarts. In addition in one, interp_restart_bin.x also supports regridding restarts on a lat-lon grid to the cubed-sphere.

These are specialized tools that's sole purpose is to regrid GEOS restarts. They are not meant to be a general purpose tool nor should any attempt be made to use them as such. They must must be used with a minimum set of restarts, namely an fvcore_interanal_rst and a moist_internal_rst which are treated specially. In addition because the binary restarts have no metadata there are additional restrictions, for example, any additional restarts supplied must only contain 3D variables and they must all be on center locations.

Both of these can regrid both horizontally as well as to a different number of atmospheric levels where these are defined by m_set_eta in GMAO_Shared. In addition they require the topography of the input and output grids. This is necessary as even if the number of levels does not change, they are still vertically remapped to take into account topography changes.

Using interp_restarts.x

The programs uses a combination of assumed file names and command line options. The program assumes the following files are in the directory you are executing this from or linked there:

• fvcore_internal_restart
• moist_internal_restart

Here are the command line options:

• -im integer output cubed-sphere size where this is the number of cells along the face
• -lm integer output number of vertical levels
• -do_hydro integer, if 0, make_nh = .true. else if 1 make_nh = .false.
• -input_files space separated list of extra restarts beyond fvcore and moist
• -input_files