Error Estimates for GRACE Data Assimilation Into Ocean Models

Author: Katherine J. Quinn and Rui M. Ponte
November 27, 2007
American Geophysical Union, Fall Meeting 2007

Quinn, K. J. and R. M. Ponte, Error Estimates for GRACE Data Assimilation Into Ocean Models, AGU Fall Meeting, 2007.

Using GRACE data to constrain ocean general circulation models requires quantitative estimates of the errors in GRACE estimates of ocean bottom pressure. We attempt a spatial mapping of these errors by comparing several GRACE data products and bottom pressure simulations from an ocean model. Uncertainties in the spatial mean and in the regional mass anomalies about that mean are considered separately. The resultant error maps, when zonally-averaged, are comparable to the calibrated errors provided by the GRACE processing centers. Noticeable differences are the larger errors at high latitudes and near continental regions with high amplitude hydrological seasonal cycles. The error estimates also depend on which de-aliasing background model is used when processing the GRACE data. Implications for ocean modeling and data assimilation are discussed.