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| Titel |
Thermal evolution of the western South Atlantic and the adjacent continent during Termination 1 |
| VerfasserIn |
C. M. Chiessi, S. Mulitza, G. Mollenhauer, J. B. Silva, J. Groeneveld, M. Prange |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1814-9324
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| Digitales Dokument |
URL |
| Erschienen |
In: Climate of the Past ; 11, no. 6 ; Nr. 11, no. 6 (2015-06-22), S.915-929 |
| Datensatznummer |
250117321
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| Publikation (Nr.) |
 copernicus.org/cp-11-915-2015.pdf |
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| Zusammenfassung |
| During Termination 1, millennial-scale weakening events of the Atlantic
meridional overturning circulation (AMOC) supposedly produced major changes
in sea surface temperatures (SSTs) of the western South Atlantic, and in mean
air temperatures (MATs) over southeastern South America. It has been suggested, for
instance, that the Brazil Current (BC) would strengthen (weaken) and the
North Brazil Current (NBC) would weaken (strengthen) during slowdown
(speed-up) events of the AMOC. This anti-phase pattern was claimed to be a
necessary response to the decreased North Atlantic heat piracy during periods
of weak AMOC. However, the thermal evolution of the western South Atlantic
and the adjacent continent is so far largely unknown. Here we address this
issue, presenting high-temporal-resolution SST and MAT records from the BC
and southeastern South America, respectively. We identify a warming in the
western South Atlantic during Heinrich Stadial 1 (HS1), which is followed
first by a drop and then by increasing temperatures during the
Bølling–Allerød, in phase with an existing SST record from the NBC.
Additionally, a similar SST evolution is shown by a southernmost eastern
South Atlantic record, suggesting a South Atlantic-wide pattern in SST
evolution during most of Termination 1. Over southeastern South America, our
MAT record shows a two-step increase during Termination 1, synchronous with
atmospheric CO2 rise (i.e., during the second half of HS1 and during the
Younger Dryas), and lagging abrupt SST changes by several thousand years.
This delay corroborates the notion that the long duration of HS1 was
fundamental in driving the Earth out of the last glacial. |
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