The land water content contained in this dataset were generated from The Global Land Data Assimilation System (GLDAS). GLDAS outputs land water content by using numerous land surface models and data assimilation. For more information on GLDAS please visit http://grace.jpl.nasa.gov/data/get-data/land-water-content/ . The data are available on monthly 1 degree grids in NetCDF format.
This total water content is directly comparable to what the Gravity Recovery and Climate Experiment (GRACE) measures over land. The Greenland values should NOT be used, the model is not valid there. The twin satellites GRACE, launched in March of 2002, are making detailed monthly measurements of Earth's gravity field changes. These observations can detect regional mass changes of Earth's water reservoirs over land, ice and oceans. GRACE measures gravity variations by relating it to the distance variations between the two satellites, which fly in the same orbit, separated by about 240 km at an altitude of ~450 km.