This page illustrates the topographical datasets used in GLDAS.
The GLDAS elevation field is based on the GTOPO30 Global 30 Arc Second (~1km) Elevation Dataset. The GTOPO elevation was averaged up to the GLDAS resolutions at 0.25 degree and 1 degree. The meteorological forcing fields (i.e. temperature, pressure, humidity and longwave radiation) are adjusted for differences in the GLDAS elevation and respective model terrain height, following Cosgrove et al. (2003).
Elevation Binary Datafiles: 1/4 degree, 1 degree
Fortran code to read data: 1/4 degree, 1 degree
GrADS Control Files: 1/4 degree, 1 degree
Python code to read data (contributed by Daniel McEvoy): 1/4degree
The same GTOPO30 elevation data is used in GLDAS-1 products. The difference from above GLDAS-2 elevation data is simply the land mask applied (i.e. UMD land cover based land mask in GLDAS-1 vs. MOD44W based in GLDAS-2).