G31A-1099
The Influence of Atmospheric Modeling Errors on GRACE Estimates of Mass Loss in Greenland and Antarctica
Wednesday, 16 December 2015
Poster Hall (Moscone South)
Ryan A Hardy, University of Colorado at Boulder, Boulder, CO, United States, R Steven Nerem, Univ of CO-Aerospace Egrg Sci, Boulder, CO, United States and David N Wiese, NASA Jet Propulsion Laboratory, Pasadena, CA, United States
Abstract:
The Gravity Recovery and Climate Experiment (GRACE) has produced robust estimates of the contributions of the Greenland and Antarctic ice sheets to sea level rise. A limiting factor in these estimates is the background model (AOD1B) used to remove the atmospheric contribution to the gravity signal. We test the accuracy of this background model against in situ pressure measurements in Greenland and Antarctica and find significant evidence of drift in the model relative to the instruments. Furthermore, we find that the ECMWF Reanalysis (ERA) Interim product better agrees with the in situ data over Greenland and Antarctica. Relative to ERA, biases in atmospheric pressure mask additional trends over both ice sheets and a significant acceleration in mass loss over Antarctica. Agreement with in situ measurements affirms the viability of ERA-Interim for correcting Level 2 GRACE products over these regions.
