Researchers report a record of sea ice in the Norwegian sea during the last glacial period. Greenland ice cores document repeated abrupt warming events, called Dansgaard-Oeschger (D-O) events, during the last glacial period. These events are believed to have been associated with rapid sea ice retreat in the Nordic Seas, but records of sea ice in this area during the last glacial period are limited. Henrik Sadatzki and colleagues reconstructed sea ice variability 32,000-41,000 years ago, during a period spanning four D-O events, at high temporal resolution. The authors inferred sea ice extents from molecular biomarkers found in two sediment cores from the Central and Southern Norwegian Sea. The authors observed large variations in these biomarkers over the period examined, consistent with extensive seasonal sea ice in the Norwegian Sea during cold stadial phases and reduced seasonal sea ice during warm interstadials. Rapid declines in sea ice appeared to coincide with the onset of D-O events. Bromine levels in an East Greenland ice core supported these findings. The results suggest that rapid loss of sea ice may have led to rapid release of heat and moisture from the ocean to the atmosphere, amplifying the warming of D-O events; the results could enrich understanding of the impact of present-day warming on Arctic sea ice, according to the authors.
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Article #20-05849:
"Rapid reductions and millennial-scale variability in Nordic Seas sea ice cover during abrupt glacial climate changes," by Henrik Sadatzki et al.
MEDIA CONTACT:
Henrik Sadatzki
Alfred Wegener Institute for Polar and Marine Research
Bremerhaven, GERMANY
tel: +49-471-4831-1099
+49-15774046036
e-mail: <henrik.sadatzki@awi.de>