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| Titel |
Modelling global-scale climate impacts of the late Miocene Messinian Salinity Crisis |
| VerfasserIn |
R. F. Ivanovic, P. J. Valdes, R. Flecker, M. Gutjahr |
| 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 ; 10, no. 2 ; Nr. 10, no. 2 (2014-03-25), S.607-622 |
| Datensatznummer |
250116941
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| Publikation (Nr.) |
 copernicus.org/cp-10-607-2014.pdf |
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| Zusammenfassung |
Late Miocene tectonic changes in Mediterranean–Atlantic connectivity and
climatic changes caused Mediterranean salinity to fluctuate dramatically,
including a ten-fold increase and near-freshening. Recent proxy- and
model-based evidence suggests that at times during this Messinian
Salinity Crisis (MSC, 5.96–5.33 Ma), highly saline and highly fresh
Mediterranean water flowed into the North Atlantic Ocean, whilst at others,
no Mediterranean Outflow Water (MOW) reached the Atlantic. By running
extreme, sensitivity-type experiments with a fully coupled ocean–atmosphere
general circulation model, we investigate the potential of these various MSC
MOW scenarios to impact global-scale climate.
The simulations suggest that although the effect remains relatively small,
MOW had a greater influence on North Atlantic Ocean circulation and climate
than it does today. We also find that depending on the presence, strength and
salinity of MOW, the MSC could have been capable of cooling mid–high
northern latitudes by a few degrees, with the greatest cooling taking place
in the Labrador, Greenland–Iceland–Norwegian and Barents seas. With
hypersaline MOW, a component of North Atlantic Deep
Water formation shifts to the Mediterranean, strengthening the Atlantic
Meridional Overturning Circulation (AMOC) south of 35° N by
1.5–6 Sv. With hyposaline MOW, AMOC completely shuts down,
inducing a bipolar climate anomaly with strong cooling in the north (mainly
−1 to −3 °C, but up to −8 °C) and weaker warming in the
south (up to +0.5 to +2.7 °C).
These simulations identify key target regions and climate variables for
future proxy reconstructions to provide the best and most robust test cases
for (a) assessing Messinian model performance, (b) evaluating
Mediterranean–Atlantic connectivity during the MSC and (c) establishing
whether or not the MSC could ever have affected global-scale climate. |
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