Is dust the egg or the hen of the past millennial climate variability?
Abstract
The last 130,000 years have been marked by the millennial scale climate variability. Although mainly described in northern hemisphere records, identifying the trigger of these variations between the ocean and the atmosphere still remains a key question. The increased resolution of the available records from the main domains yields new characteristics although their precise relationship remains still unknown. Here we show that the analysis of d18O and dust in Greenland ice-cores, and a critical study of their source variations, reconciles these high-resolution records with continental series over Eurasia. Furthermore we demonstrate the link between European loess sequences, Chinese ones, dust records in Greenland and the variations of the North Atlantic sea ice extent. We anticipate our study to be at the origin of more sophisticated investigations of the millennial and sub-millennial climate variability in Northern Hemisphere. For example loess deposits are covering a wide area over Eurasia that provides elements for model data comparisons in different climatic contexts. Furthermore, the origin and source of the emitted and transported material is variable and relates to different environment corresponding to present desert areas but also hidden regions related to low sea levels, dry rivers or zones close to the frontal moraines of the main ice-sheets.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2012
- Bibcode:
- 2012AGUFMPP22A..07R
- Keywords:
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- 4901 PALEOCEANOGRAPHY / Abrupt/rapid climate change;
- 4914 PALEOCEANOGRAPHY / Continental climate records;
- 4932 PALEOCEANOGRAPHY / Ice cores;
- 4960 PALEOCEANOGRAPHY / Stadial