Neoglacial transition of atmospheric circulation patterns over Fennoscandia recorded in Holocene Lake Tornetrask sediments

• Main Authors: Thienemann, Matthias, Kusch, Stephanie, Vogel, Hendrik, Ritter, Benedikt, Schefuss, Enno, Rethemeyer, Janet
• Format: Article in Journal/Newspaper
• Language: English
• Published: WILEY 2019
• Subjects: ddc:no; Arctic; Arctic Ocean; Fennoscandia; Fennoscandian; North Atlantic; Subarctic
• Online Access: https://kups.ub.uni-koeln.de/15211/

Atmospheric circulation over the North Atlantic has undergone significant fluctuations during the Holocene. To better constrain these changes and their impacts on the Fennoscandian subarctic, we investigated molecular and inorganic proxies as well as plant wax D/H isotopes (D-C28) in a Holocene sedimentary record from Lake Tornetrask (Sweden). These data indicate a thermal maximum c. 8100 to 6300cal. a BP with reduced soil organic matter input, followed by a long-term cooling trend with increasing soil erosion. D data suggest a stable atmospheric circulation with predominance of westerly flow and North Atlantic moisture sourcing during the Early and Middle Holocene. Asubstantial depletion in D followed by increased flood frequency starting at c. 5300cal. a BP and intensifying c. 1500cal. a BP suggests a reorganization of the atmospheric circulation from zonal towards meridional flow with predominantly Arctic Ocean and Baltic Sea moisture sourcing.