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| Titel |
Multidecadal to interannual fluctuations in first year sea ice cover and river discharge on the Mackenzie Shelf (southern Beaufort Sea) during the last century |
| VerfasserIn |
Jérôme Kaiser, David Ledu, Guillaume Massé, Sabine Schmidt, Germain Bayon, Ioanna Bouloubassi, Marcel Babin |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250052703
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| Zusammenfassung |
| Arctic climate change affects global-scale climate and is as well affected by it through feedback mechanisms. Substantial changes in the Arctic have been observed in the last several decades, such as receding glaciers, thinning and dwindling sea ice, melting of the Greenland ice sheet, rising surface air temperatures, increasing atmospheric precipitations and a global freshening of the Arctic Ocean. Recent studies have shown a weakening in the global thermohaline circulation, with increasing freshwater transport to the North Atlantic Ocean, due to changes in melt and ice export from the Arctic Ocean through the Canadian Archipelago and Fram Strait.
Here, we present paleorecords based on the uppermost 30 cm of a 6 meter-long sediment core (MA680) retrieved during the Malina oceanographic expedition (August 2009) on the western Mackenzie Shelf in the southernmost part of the Beaufort Gyre. Applying a newly developed proxy for sea ice cover (SIC) fluctuations (IP25), as well as other organic and inorganic proxies, we can reconstruct fluctuations in first year sea ice and in the discharge of the Mackenzie River, ultimately linked to precipitation changes, at high resolution (≤ 2 years) over the last century. When compared to observational and instrumental data sets, the proxy-based records show strong relationships with Arctic air temperature variability and with shifts in the Arctic atmospheric circulation regime. Therefore, core MA680 may represent a unique opportunity to reconstruct variability in SIC, atmospheric circulation and precipitation in the southern Beaufort Sea over the last millennia at high resolution. |
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