Searching for Atmospheric Pressure Errors over Antarctica with GRACE Accelerations

Wednesday, 17 December 2014
Ryan A Hardy1, David N Wiese2, Michael M Watkins2 and R Steven Nerem1, (1)University of Colorado at Boulder, Boulder, CO, United States, (2)Jet Propulsion Laboratory, Pasadena, CA, United States
The Gravity Recovery and Climate Experiment (GRACE) is sensitive to atmospheric pressure variations over Earth's surface, which are normally modeled out during initial processing of GRACE data. However, meteorological data over Antarctica and the Southern Ocean are poorly sampled and there are notable disagreements between models in that region. This means that GRACE solutions may be improved with the substitution of atmospheric models over Antarctica and that GRACE data may potentially offer improvements to these models. We use the GRACE K-band range acceleration residuals to explore variations in the gravity field over Antarctica at sub-monthly timescales during 2010, comparing these to surface mass balance and differences in surface pressure between models. We find correlations between pressure differences and accelerations residuals over certain regions in Antarctica and the Southern Ocean.