Possible linkage between winter extreme low temperature over central-western China and autumn sea ice loss
- 1Department of Atmospheric and Oceanic Sciences, and Institute of Atmospheric Sciences, Fudan University, Shanghai, China
- 2State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China
- 3CMA-FDU Joint Laboratory of Marine Meteorology, Shanghai, China
- 4Department of Atmospheric Science, Yunnan University, Kunming 650500, China
- 5Centre for Atmospheric Science, University Cambridge, Cambridge, UK
- 6Hommel&Graf Environmental, Goettingen, Germany
- 7School of Atmospheric Sciences, Chengdu University of Information Technology, Chengdu
Based on reanalysis datasets and sea-ice sensitivity experiments, this study has pointed out that the autumn sea ice loss in East Siberian-Chukchi-Beaufort (EsCB) Seas significantly increases the frequency of winter extreme low temperature over western-central China. Autumn sea ice loss warms the troposphere and generates anticyclonic anomaly over the Arctic region one month later. Under the effects of synoptic eddy-mean flow interaction and anomalous upward propagated planetary wave 2, the Arctic anticyclonic anomaly strengthens and develops toward Greenland-Northern Europe, accompanied by a weakened stratospheric polar vortex. In winter, following intra-seasonal downward propagation of stratospheric anomalies, the Northern European positive geopotential anomalies enhance and expand downstream within 7 days, favoring Arctic cold air east of Novaya Zemlya southward (the hyperpolar path) accumulating in Siberia around Lake of Baikal. In the subsequent 2~3 days, these cold anomalies rapidly intrude western-central China and induce abrupt sharp cooling, thus more frequent extreme low temperature there.
How to cite: Ding, S., Wu, B., Chen, W., Graf, H.-F., and Zhang, X.: Possible linkage between winter extreme low temperature over central-western China and autumn sea ice loss, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-10688, https://doi.org/10.5194/egusphere-egu23-10688, 2023.