Measuring water accumulation rates using GRACE data in areas experiencing glacial isostatic adjustment: The Nelson River basin

Adrien Lambert (1) , J. Huang (1) , G. van Derkamp , J. Henton (1) , Stephane Mazzotti (2) , T. S. James (1) , N. Courtier (1) , A. G. Barr

1 GSC - Geological Survey of Canada - Office
2 Géosciences Montpellier - Risques

Gravity Recovery and Climate Experiment (GRACE) satellite-derived total water storage can be obscured by glacial isostatic adjustment. In order to solve this problem for the Nelson River drainage basin in Canada, a gravity rate map from 110 months (June 2002 to October 2011) of GRACE gravity data was corrected for glacial isostatic adjustment using an independent gravity rate map derived from updated GPS vertical velocities. The GPS-based map was converted to equivalent gravity rate using a transfer function developed from GPS and absolute-g data at colocated sites. The corrected GRACE gravity rate map revealed a major positive anomaly within the drainage basin, which was independently shown by hydrological data to be due to changes in water storage. The anomaly represents a cumulative increase at its center of about 340 mm of water, reflecting a progression from extreme drought to extremely wet conditions.

Mots clés: water storage; glacial isostatic adjustment; GRACE; GPS vertical; absolute gravity

Domaines: Géophysique [physics.geo-ph]; Géophysique [physics.geo-ph]; Milieux et Changements globaux

Adrien Lambert, J. Huang, G. van Derkamp, J. Henton, Stephane Mazzotti, et al.. Measuring water accumulation rates using GRACE data in areas experiencing glacial isostatic adjustment: The Nelson River basin. Geophysical Research Letters, 2013, 40 (23), pp.6118-6122. ⟨10.1002/2013GL057973⟩. ⟨hal-00940965⟩