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GEOPHYSICAL RESEARCH LETTERS, VOL. 31, L02304, doi:10.1029/2003GL018487, 2004

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

Sung Hyun Nam

School of Earth and Environmental Sciences, Seoul National University, Seoul, Korea


Sang Jin Lyu

School of Earth and Environmental Sciences, Seoul National University, Seoul, Korea


Young Ho Kim

School of Earth and Environmental Sciences, Seoul National University, Seoul, Korea


Kuh Kim

School of Earth and Environmental Sciences, Seoul National University, Seoul, Korea


Jae-Hun Park

Graduate School of Oceanography, University of Rhode Island, Rhode Island, USA


D. Randolph Watts

Graduate School of Oceanography, University of Rhode Island, Rhode Island, USA


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.

Received 25 August 2003; accepted 31 December 2003; published 28 January 2004.

Index Terms: 4243 Oceanography: General: Marginal and semienclosed seas; 4556 Oceanography: Physical: Sea level variations; 4275 Oceanography: General: Remote sensing and electromagnetic processes (0689); 4594 Oceanography: Physical: Instruments and techniques; 4504 Oceanography: Physical: Air/sea interactions (0312).

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Citation: Nam, S. H., S. J. Lyu, Y. H. Kim, K. Kim, J.-H. Park, and D. R. Watts (2004), Correction of TOPEX/POSEIDON altimeter data for nonisostatic sea level response to atmospheric pressure in the Japan/East Sea, Geophys. Res. Lett., 31, L02304, doi:10.1029/2003GL018487.