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| Titel |
Evidence of different ocean responses to atmospheric pressurevariations in the Atlantic, Indian and Pacific Basins as deduced fromERS-2 altimetric data |
| VerfasserIn |
J. Gómez-Enri, P. Villares, M. Bruno, M. Catalán |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
0992-7689
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| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 22, no. 2 ; Nr. 22, no. 2 (2004-01-01), S.331-345 |
| Datensatznummer |
250014767
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| Publikation (Nr.) |
 copernicus.org/angeo-22-331-2004.pdf |
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| Zusammenfassung |
The exponential increase in the use of altimeter data in oceanographic studies in the past
two decades has improved the knowledge of the processes that govern the interaction
between the ocean and the atmosphere. One of these processes is the response of the
ocean to atmospheric pressure variations, which has been deeply analysed in the past.
That response is based on the isostatic assumption used to establish a standard
correction for altimetric purposes, the Inverse Barometer Correction (IBC). As a general
rule, the ocean goes up/down 1cm when the atmospheric pressure goes down/up
1mbar. However, in light of recent works in some oceanic regions, discrepancies arise
when the real response is compared to the hypothetical one. It is important to quantify
this discrepancy, in order to improve the accuracy of the correction, which is one of the
most significant geophysical corrections applied to altimeter records. Some aspects of
this response remain unclear, such as the real space-temporal scales where IBC can be
applied, the influence of wind, non-isostatic atmospheric pressure-driven signals, and
the effect of aliasing from high frequency signals. This paper is an attempt to gain
insight into this phenomenon. The data used are the residuals obtained between sea
surface heights from the ERS-2 altimeter and the outputs of a global barotropic ocean
model. Significant departures from the hypothetical isostatic response in all data series
(spatial and temporal domain) have been found, especially in the case of altimeter
records. By applying the collinear track method, we observe that the estimated Atlantic Ocean
response is quite similar to the one deduced from the isostatic assumption at
all latitudinal bands. Nonetheless, the Indian and Pacific Oceans show important
departures from the hypothetical value at low latitudes. Results obtained with the
crossover track method show important deviations at low latitudes in the three basins. In
order to understand why the Atlantic Ocean response is different from the one obtained
in the other two, we can infer some explanations based on the interaction of seasonal
and intraseasonal signals with the isostatic one.
Key words. Meteorology and atmospheric dynamics
(ocean-atmosphere interactions). Oceanography: physical
(sea level variations; remote sensing, instruments and
techniques) |
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