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| Titel |
A new record of Atlantic sea surface salinity since 1896 reveals the influence of climate variability and global warming |
| VerfasserIn |
Andrew Friedman, Gilles Reverdin, Myriam Khodri, Guillaume Gastineau |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250150518
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| Publikation (Nr.) |
 EGU/EGU2017-14989.pdf |
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| Zusammenfassung |
| Sea surface salinity (SSS) is a major ocean circulation component and
indicator of the hydrological cycle. Here, we investigate an
unprecedented Atlantic SSS compilation from 1896–2013 and analyze the
main modes of SSS decadal variability. The data are compiled from
independently-validated and bias-corrected in situ datasets, including
oceanographic research sections, weather ships, and ships-of-opportunity
transects, and measurements from the World Ocean Database. The data are
binned into 32 boxes of length scale 100–1000km, covering most of the
Atlantic between 20°S–70°N with annual (1-2-1 filtered) resolution.
Using principal component analysis, we find that the low-latitude
(tropical and subtropical) Atlantic and the subpolar Atlantic have
distinct variability. Subpolar and low-latitude SSS are negatively
correlated, with subpolar SSS anomalies leading low-latitude anomalies
by about a decade. Subpolar SSS varies in phase with the Atlantic
Multidecadal Oscillation (AMO), whereas low-latitude SSS varies in phase
with the North Atlantic Oscillation (NAO). Additionally, northern
tropical SSS is anticorrelated with Sahel rainfall, suggesting that it
reflects the position of the Atlantic Intertropical Convergence Zone.
The long-term SSS trend shows amplification of the mean SSS field, with
subpolar freshening and low-latitude salinification. Regressing out the
AMO and NAO reconciles the trend since 1970 with the long-term trend.
This pattern may reflect an intensification of the hydrological cycle
due to global warming, as well as Arctic cryosphere melting and Agulhas
inflow. |
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