Correction of TOPEX/POSEIDON altimeter data for nonisostatic sea level response to atmospheric pressure in the Japan/East Sea

Document Type

Article

Date of Original Version

1-28-2004

Abstract

High frequency (2-20 days) sea level fluctuations, driven by atmospheric pressure changes, must be eliminated from TOPEX/POSEIDON altimeter data, else these data sampled at 10-day interval will suffer aliasing when interpreted as lower frequency variability of the subsurface pressure and circulation. A simple analytic Helmholtz-like model [Lyu et al., 2002], which explains successfully the nonisostatic sea level response in the Japan/East Sea (JES), is applied to correct the high-frequency sea level fluctuation effects on the T/P data. The model removes these pressure-driven fluctuations better than the standard inverse barometer (IB) method, leaving residuals smaller by about 10% in the corrected mean sea level (MSL) data used in this study. Because the maximum difference between the model correction and the IB correction can reach 10 cm, the impact of the correction choice is substantial. Moreover, uncorrected or IB corrected T/P along-track data contain substantial high frequency variability which can lead to 'trackiness' errors between crossing and neighboring tracks, contaminating their use for synoptic mapping. The model correction reduced the trackiness significantly better than the usual IB correction. Copyright 2004 by the American Geophysical Union.

Publication Title, e.g., Journal

Geophysical Research Letters

Volume

31

Issue

2

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