Lagged atmospheric circulation response in the Black Sea region to Greenland Interstadial 10

• Published in: Proceedings of the National Academy of Sciences
• Main Authors: Czymzik, Markus, Nowaczyk, Norbert R., Dellwig, Olaf, Wegwerth, Antje, Muscheler, Raimund, Christl, Marcus, Arz, Helge W.
• Format: Text
• Language: English
• Published: National Academy of Sciences 2020
• Subjects: Physical Sciences; Greenland; Greenland ice cores
• Online Access: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7682583/; http://www.ncbi.nlm.nih.gov/pubmed/33139546; https://doi.org/10.1073/pnas.2005520117

Northern Hemispheric high-latitude climate variations during the last glacial are expected to propagate globally in a complex way. Investigating the evolution of these variations requires a precise synchronization of the considered environmental archives. Aligning the globally common production rate variations of the cosmogenic radionuclide (10)Be in different archives provides a tool for such synchronizations. Here, we present a (10)Be record at <40-y resolution along with subdecadal proxy records from one Black Sea sediment core around Greenland Interstadial 10 (GI-10) ∼41 ka BP and the Laschamp geomagnetic excursion. We synchronized our (10)Be record to that from Greenland ice cores based on its globally common production rate variations. The synchronized environmental proxy records reveal a bipartite climate response in the Black Sea region at the onset of GI-10. First, in phase with Greenland warming, reduced sedimentary coastal ice rafted detritus contents indicate less severe winters. Second, and with a lag of 190 (± 44) y, an increase in the detrital K/Ti ratio and authigenic Ca precipitation point to enhanced regional precipitation and warmer lake surface temperatures. We explain the lagged climatic response by a shift in the dominant mode of atmospheric circulation, likely connected with a time-transgressive adjustment of the regional thermal ocean interior to interstadial conditions.