RuntimeError: Failed to open a variable named "sea_ice_fraction" in netCDF file ... from NASA Earthdata GHRSST GAMSSA_28km-ABOM-L4-GLOB-v01 granules. Detailed error information: KeyError: 'sea_ice_fraction'.

[jjrob]

It appears that GHRSST L4 GAMSSA_28km-ABOM-L4-GLOB-v01 and RAMSSA_09km-ABOM-L4-AUS-v01 datasets no longer have a sea_ice_fraction variable. The GHRSSTLevel4Granules constructor should omit sea_ice_fraction for these datasets.