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A study of departures from the inverse‐barometer response of sea level to air‐pressure forcing at a period of 5 days
Author(s) -
Mathers E. L.,
Woodworth P. L.
Publication year - 2004
Publication title -
quarterly journal of the royal meteorological society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.744
H-Index - 143
eISSN - 1477-870X
pISSN - 0035-9009
DOI - 10.1256/qj.03.46
Subject(s) - barometer , barotropic fluid , tide gauge , atmospheric pressure , climatology , forcing (mathematics) , environmental science , sea level , surface pressure , altimeter , kelvin wave , amplitude , wind stress , geology , atmospheric sciences , meteorology , geography , geodesy , oceanography , physics , quantum mechanics
The response of the sea level to atmospheric forcing is investigated through the cross‐spectral analysis of tide‐gauge data from around 100 island and deep‐ocean stations and atmospheric pressure records. The focus is at a period of 5 days, coinciding with an atmospheric pressure oscillation (Madden–Julian wave) of the same frequency. Outside the Tropics the energy in synoptic weather systems masks the small amplitude of the pressure wave, resulting in a response indistinguishable from that of an inverse barometer (IB). Within the Tropics, variability of air pressure is smaller in comparison with the amplitude of the pressure wave and departures from the IB model are found. Analysis of several sub‐surface pressure records in the tropical Atlantic also yields departures at this time‐scale, and indicates the barotropic nature of the response. Findings from a near‐global barotropic numerical model forced with realistic air pressure and wind‐stress fields show reasonable agreement with results at tide‐gauge locations, and provide a more complete view of the sea‐level response. These results indicate the possibility of providing an improved simulation of sea‐level response to atmospheric‐pressure forcing at this time‐scale than is currently provided by the IB model, for example in the field of satellite altimetry. Copyright © 2004 Royal Meteorological Society