Improving altimetry’s non-tidal high frequency ocean de-aliasing correction through the inclusion of daily GRACE updates
Event: 2020 Ocean Surface Topography Science Team Meeting (virtual)
Session: Salient results from the 2017-2020 OSTST PIs
Presentation type: Type Forum only
We use a high-frequency GRACE series to improve the non-IB portion of the Dynamic Atmospheric Correction (DAC) used for Jason de-aliasing. As imperfections in the DAC will result in longer-period aliased errors in the ultimate sea surface height estimates, it is crucial to make this model as accurate as possible. The bottom pressure estimates from a near-daily GRACE “swath-style” gravity solution prove able to improve upon the DAC model in the 10-20 day frequency band, especially in the southern ocean. We use an EOF reconstruction, based on the spatial characteristics of the non-IB DAC itself, but time-series fits from GRACE, to make a combined model which proves better in the southern ocean than either GRACE or the DAC alone.