|
|
|
|
|
Barker, Stephen; Knorr, Gregor. |
A numerical algorithm is applied to the Greenland Ice Sheet Project 2 (GISP2) dust record from Greenland to remove the abrupt changes in dust flux associated with the Dansgaard-Oeschger (D-O) oscillations of the last glacial period. The procedure is based on the assumption that the rapid changes in dust are associated with large-scale changes in atmospheric transport and implies that D-O oscillations (in terms of their atmospheric imprint) are more symmetric in form than can be inferred from Greenland temperature records. After removal of the abrupt shifts the residual, dejumped dust record is found to match Antarctic climate variability with a temporal lag of several hundred years. It is argued that such variability may reflect changes in the source... |
Tipo: Text |
Palavras-chave: Dansgaard-Oeschger events; Rapid climate change; GISP2 dust record. |
Ano: 2007 |
URL: https://archimer.ifremer.fr/doc/00235/34643/33010.pdf |
| |
|
|
Sadatzki, Henrik; Maffezzoli, Niccolò; Dokken, Trond M.; Simon, Margit H; Berben, Sarah M. P.; Fahl, Kirsten; Kjær, Helle A.; Spolaor, Andrea; Stein, Ruediger; Vallelonga, Paul; Vinther, Bo M.; Jansen, Eystein. |
Constraining the past sea ice variability in the Nordic Seas is critical for a comprehensive understanding of the abrupt Dansgaard-Oeschger (D-O) climate changes during the last glacial. Here we present unprecedentedly detailed sea ice proxy evidence from two Norwegian Sea sediment cores and an East Greenland ice core to resolve and constrain sea ice variations during four D-O events between 32 and 41 ka. Our independent sea ice records consistently reveal a millennial-scale variability and threshold response between an extensive seasonal sea ice cover in the Nordic Seas during cold stadials and reduced seasonal sea ice conditions during warmer interstadials. They document substantial and rapid sea ice reductions that may have happened within 250 y or... |
Tipo: Text |
Palavras-chave: Sea ice; Nordic Seas; Dansgaard-Oeschger events; Abrupt climate change. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00659/77066/78374.pdf |
| |
|
|
Zhang, Xiao; Prange, Matthias; Merkel, Ute; Schulz, Michael. |
Pronounced millennial-scale climate variability during marine isotope stage 3 (MIS3) is considered to be linked to changes in the state of the Atlantic meridional overturning circulation (AMOC), i.e., a warm interstadial/cold stadial state corresponds to a strong/weak AMOC. Based on a series of freshwater hosing/extraction experiments with the state-of-the-art Community Climate System Model version 3, we construct a global spatial fingerprint of oceanic temperature anomalies in response to AMOC changes under MIS3 boundary conditions. Highest sensitivity to AMOC changes, especially in summer, is found in northeastern North Atlantic sea surface temperature, but a characteristic temperature fingerprint is also found at subsurface levels. After testing... |
Tipo: Text |
Palavras-chave: Atlantic meridional overturning circulation; Dansgaard-Oeschger events; Global climate modeling. |
Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00351/46267/46052.pdf |
| |
|
|
|