Estimating Rapid Large-Scale Variability in Sea Level, With Application to Dealiasing of Satellite Missions

Type: Presentation

Venue: American Geophysical Union, Fall Meeting 2008


Ponte, R.M., S. V. Vinogradov, R. N. Hoffman, L. Carrère, 2008, Estimating rapid large-scale variability in sea level, with application to dealiasing of satellite missions. Ocean Surface Topography Science Team Meeting 2008, Nice, France, November 10-15 2008.

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Considerable nontidal sea level variability is found over the deep ocean at monthly and shorter timescales and at spatial scales greater than a few hundred kilometers. Such variability is mostly atmospherically-driven, can be barotropic or baroclinic and thus with a complex relation to bottom pressure, and is not fully resolved by satellite altimetry or gravity measurements. Model simulations of the rapid, large-scale signals can be affected by errors in forcing fields, bottom topography and other uncertain factors. Here we examine estimates of these signals obtained from the ECCO-GODAE solutions, which are constrained to most available oceanic data in a least-squares optimization procedure. Results indicate a considerable impact of the data on the estimated rapid, large-scale variability. Comparisons with independent hourly data from tide gauges reveal improvements in the constrained estimates and initial tests suggest that such estimates should be useful in procedures to dealias current satellite altimetry and gravity measurements.