About this datasetThese maps show how water stored on and in the land changes from month to month. The maps are blue where there is more water than average and red where there is less water. Water accumulates on land in rivers and lakes, as ground water and soil moisture, and as snow and ice. Scientists track water both to understand the water cycle and to monitor the availability of fresh water. The maps show that water levels change throughout the year with the seasons. Changes from year to year may reveal drought or an excess of water.
Swenson, S. C., and Wahr, J. (2006) Post-processing removal of correlated errors in GRACE data. Geophysical Research Letters, 33, L08402.
Wahr, J., Molenaar, M., and Bryan, F. (1998) Time-variability of the Earth's gravity field: Hydrological and oceanic effects and their possible detection using GRACE. Journal of Geophysical Research, 103, 30,205-30,229.
Imagery by Kevin Ward, NASA Earth Observatory based on GRACE land data processed by Sean Swenson, supported by the NASA MEASURES Program.
Federal Geographic Data Committee Geospatial Metadata
View the FGDC Metatdata for Water Equivalent Anomaly (1 month, 2002-17)