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| Titel |
Circulation of the thermocline salinity maximum waters off the Northern Brazil as inferred from in situ measurements and numerical results |
| VerfasserIn |
A. C. Silva, B. Bourles, M. Araujo |
| 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 ; 27, no. 5 ; Nr. 27, no. 5 (2009-05-04), S.1861-1873 |
| Datensatznummer |
250016505
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| Publikation (Nr.) |
 copernicus.org/angeo-27-1861-2009.pdf |
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| Zusammenfassung |
| High resolution hydrographic observations of temperature and salinity are
used to analyse the subsurface circulation along the coast of North Brazil,
off the Amazon mouth, between 2° S and 6° N. Observations are
presented from four cruises carried out in different periods of the year
(March–May 1995, May–June 1999, July–August 2001 and October–November
1997). Numerical model outputs complement the results of the shipboard
measurements, and are used to complete the descriptions of mesoscale
circulation. The Salinity Maximum Waters are here analyzed, principally in
order to describe the penetration of waters originating in the Southern
Hemisphere toward the Northern Hemisphere through the North Brazil Current
(NBC)/North Brazil Undercurrent (NBUC). Our results show that, if the
Equatorial Undercurrent (EUC) is fed by Northern Atlantic Waters, this
contribution may only occur in the ocean interior, east of the western
boundary around 100 m depth. Modeling results indicate a southward
penetration of the Western Boundary Undercurrent (WBUC) below the
thermocline, along the North Brazilian coast into the EUC or the North
Equatorial Undercurrent (NEUC) (around 48° W–3° N). The WBUC in the
region does not flow more south than 3° N. The northern waters are
diverted eastward either by the NBC retroflection or by the northern edge of
the associated clockwise rings. The existence of subsurface mesoscale rings
associated to the NBC retroflection is evidenced, without any signature in
the surface layer, so confirming earlier numerical model outputs. These
subsurface anticyclones, linked to the NBC/NBUC retroflection into the North
Equatorial Undercurrent and the EUC, contribute to the transport of South
Atlantic high salinity water into the Northern Hemisphere. |
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