Files in grid are the MITgcm grid specification files.
In particular (XC,YC) are the longitude/latitude coordinates
of the grid cell centers and (XG,YG) are the coordiates
of the southwest corners of the grid cells.
They are Binary, IEEE-big-endian Real*4, 960x931
XC=readbin('grid/XC_960x931',[960 931]);

Files in Salt are sea surface salinity in g/kg
specified at the grid cell centers (XC,YC):

Files in Theta are sea surface temperature in deg C
specified at the grid cell centers (XC,YC):

Files U and V are the surface velocity fields at southwest
edges of the grid cells.