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Titel |
Combining T/P altimetric data with hydrographic data to estimate the mean dynamic topography of the North Atlantic and improve the geoid |
VerfasserIn |
P. LeGrand, H. Mercier, T. Reynaud |
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 ; 16, no. 5 ; Nr. 16, no. 5, S.638-650 |
Datensatznummer |
250013284
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Publikation (Nr.) |
copernicus.org/angeo-16-638-1998.pdf |
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Zusammenfassung |
The mean dynamic topography of the surface of
the North Atlantic is estimated using an inverse model of the ocean circulation
constrained by hydrographic and altimetric observations. In the North Atlantic,
altimetric observations have no significant impact on the topography estimate
because of the limited precision of available geoid height models. They have a
significant impact, however, when uncertainties in the density field are
increased to simulate interpolation errors in regions where hydrographic data
are scarce. This result, which moderates the conclusion drawn by Ganachaud and
co-workers of no significant contribution of altimetric observations to the
determination of the large-scale steady circulation, reflects the simple idea
that altimetric data are most useful near the surface of the ocean and in areas
where the hydrography is poorly determined. One application of the present
inverse estimate of the mean dynamic topography is to compute a geoid height
correction over the North Atlantic which reduces the uncertainty in the geoid
height expanded to spherical harmonic 40 down to a level of about 5 cm.
Key words. Oceanography: general (climate and
interannual variability) · Oceanography: physical (general circulation; remote
sensing) |
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