dx7 stream description file for gx1v4 SSMI iFrac data uses gx1v3 data -- this is OK because v4 is a subset of v3 in polar regions SSMI ifrac ifrac domain.ocn.gx1v4.060403.nc time xc yc area mask ssmi.ifrac.gx1v3.2000.nc ssmi.ifrac.gx1v3.2001.nc ssmi.ifrac.gx1v3.2002.nc ssmi.ifrac.gx1v3.2003.nc ssmi.ifrac.gx1v3.2004.nc null:/CCSM/data/cseg/csm/inputdata/ice/dice7/SSMI