The impact of the new gravity field models on the Mean Dynamic Ocean Topography and the derived geostrophic velocities
The absolute Mean Dynamic ocean Topography (MDT) can be determined from an accurate geoid model and a Mean Sea Surface (MSS). The MSS is derived using long-term time series of sea surface heights from multi-mission satellite altimetry. Recently, data from the Gravity field and steady-state Ocean Cir...
| Main Authors: | , , , |
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| Format: | Conference Object |
| Language: | unknown |
| Published: |
2011
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| Subjects: | |
| Online Access: | https://epic.awi.de/id/eprint/25544/ https://epic.awi.de/id/eprint/25544/1/Poster_AGU2011_GEOTOP.pdf https://hdl.handle.net/10013/epic.38591 https://hdl.handle.net/10013/epic.38591.d001 |
| Summary: | The absolute Mean Dynamic ocean Topography (MDT) can be determined from an accurate geoid model and a Mean Sea Surface (MSS). The MSS is derived using long-term time series of sea surface heights from multi-mission satellite altimetry. Recently, data from the Gravity field and steady-state Ocean Circulation Explorer (GOCE) satellite has become available. Now, GOCE and GRACE satellite data can be combined to obtain a geoid with higher accuracy and spatial resolution than before. The improvement in the geoid accuracy and resolution implies improvements in the resolution of MDT. From only 6 months of GOCE data, oceanographic fields like mean dynamic topography and geostrophic velocities are given in a fine spatial scale that has been poorly resolved previously. This is especially true in the areas of strong currents like Agulhas, Gulf, Kuroshio and Antarctic Circumpolar Current. Geostrophic velocities derived from only satellite data show very good agreement with geostrophic velocities measured by drifters. In addition the assimilation of this data set allows us to obtain all surface and subsurface ocean variables consistent with new MDT, giving promising results in comparison to the free model. |
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