A Distinct Change in Atmospheric Circulation on the Central Tibetan Plateau at 16,800 Years Ago

Wednesday, 17 December 2014
Liping Zhu1, Xinmiao Lü1, Junbo Wang1, Ping Peng1, Yong Wang1, Quan Li2, Thomas Kasper3, Gerhard Daut3, Torsten Haberzettl3, Peter Frenzel3, Antje Schwalb4 and Roland Maeusbacher3, (1)ITP Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China, (2)Institute of Geographical Sciences and Natural Resource Research, Chinese Academy of Sciences, Beijing, China, (3)Friedrich Schiller University of Jena, Jena, Germany, (4)Technical University of Braunschweig, Braunschweig, Germany
The Tibetan Plateau (TP) has experienced similar environmental and climatic events as the Realm of North Atlantic Ocean (NA) since the Last Glacial Maximum (LGM). However, previous studies have not discussed in detail whether the influence is transported through the westerly crossing the Eurasian continent or by the thermohaline circulation influencing the Indian Summer Monsoon (ISM). Using observations in the transition zone between the westerly and the ISM on the TP, pollen assemblage variations from a lacustrine sediment record indicate changes in circulations patterns. Before 16.8 ka BP, climate on the TP was controlled by the southward westerly and the dipole-shaped tropical Atlantic sea surface temperature (SST) and rainfall anomaly due to sub-polar ice sheet expanding in the NA areas. After 16.8 ka BP, the Atlantic meridional overturning circulation (AMOC) exerted more influence to the Indian Ocean currents and then to the ISM, which was the dominant atmospheric circulation on the TP areas during the whole period.