Improving the geoid: Combining altimetry and mean dynamic topography in the California Coastal Ocean

Sarah Gille (Scripps Institution of Oceanography, UC San Diego, United States)


Matthew Mazloff (Scripps Institution of Oceanography, UC San Diego, United States); Bruce Cornuelle (Scripps Institution of Oceanography, UC San Diego, United States)

Event: 2014 Ocean Surface Topography Science Team Meeting

Session: The Geoid, Mean Sea Surfaces and Mean Dynamic Topography

Presentation type: Type Poster

Satellite gravimeters and altimeters together allow the Earth's geoid to be mapped with an accuracy of order 1 m. To achieve greater accuracy than this requires knowledge of the dynamic ocean topography. In this study two dynamic ocean topographies are considered for the region of the California Current System: one is derived from an assimilating model (a regional version of ECCO) and the second is from AVISO. Both dynamic ocean topographies have accuracies of order 10 cm. They are used to solve for a geoid correction, in order to improve the overall consistency between the assimilated ocean model and along-track altimetric observations in the region. The correction is as large as the dynamic ocean topography, with a magnitude of 15 cm and significant structure, especially near the coast. While the improvement in the consistency is modest, it offers evidence that high-resolution dynamic ocean topography products can be used to correct estimates of the geoid.
Sarah Gille
Scripps Institution of Oceanography, UC San Diego
United States