气候变化领域集成服务门户(CCPortal): Characteristics; trend; and precursors of extreme cold events in northwestern North America

CCPortal

DOI	10.1016/j.atmosres.2020.105338
	Characteristics; trend; and precursors of extreme cold events in northwestern North America
	Shi J.; Wu K.; Qian W.; Huang F.; Li C.; Tang C.
发表日期	2021
ISSN	0169-8095
卷号	249
英文摘要	The cold extremes along with record snowfalls in North America (NA) have attracted great concern for decades. In this study, we select 23 wintertime cold extremes in northwestern NA (NWNA) from 1981 to 2018 and find a significant weakening trend of their integrated yearly intensities. Strong northerlies and cold advections over NWNA associated with the cold events are driven by the intensified and southward Beaufort anticyclone at lower troposphere and the enhanced blocking high at higher levels. A strong low-pressure anomaly over NWNA extends from lower troposphere to stratosphere centered at around 250–300hPa, where the jet stream becomes stronger and moves northwestwards. Meanwhile, the cold anomaly under the low system is deep and more prominent at the surface of NWNA. There is a significant meridional dipole structure of height and temperature anomaly in mid-high latitudes, indicative of the negative phase of Arctic Oscillation. Results further suggest that the La Niña-like sea surface temperature anomalies may serve as a precursor for the cold extremes in NWNA, triggering a Pacific North America-like wave train including an active negative height anomaly center over NWNA, which is linked with the cold anomalies extending downward to the surface. However, the sea ice concentration anomalies in Arctic region and the snow cover anomalies in NA continent during early autumn are likely to exert a minimal influence on the wintertime cold extremes in NWNA. © 2020 Elsevier B.V.
英文关键词	Extreme cold events; Large-scale meteorological pattern; Northwestern North America; Precursor; Trend
语种	英语
scopus关键词	Sea ice; Snow; Surface waters; Troposphere; Arctic Oscillation; Arctic regions; Lower troposphere; Meridional dipole; Pacific-north america; Sea ice concentration; Sea surface temperature anomalies; Temperature anomaly; Oceanography; advection; air-sea interaction; anticyclone; atmospheric blocking; extreme event; jet stream; low pressure; sea ice; sea surface temperature; snow cover; stratosphere; trend analysis; troposphere; Arctic Ocean; North America
来源期刊	Atmospheric Research
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/162221
作者单位	Key Laboratory of Physical Oceanography, Institute for Advanced Ocean Study, Ocean University of China and Qingdao National Laboratory for Marine Science and Technology, Qingdao, China; College of Oceanic and Atmospheric Sciences, Ocean University of China, Qingdao, China; Department of Aviation Meteorology, Civil Aviation University of China, Tianjin, China; Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing, China; Guangzhou Institute of Tropical and Marine Meteorology/Guangdong Provincial Key Laboratory of Regional Numerical Weather Prediction, CMA, Guangzhou, China
推荐引用方式 GB/T 7714	Shi J.,Wu K.,Qian W.,et al. Characteristics; trend; and precursors of extreme cold events in northwestern North America[J],2021,249.
APA	Shi J.,Wu K.,Qian W.,Huang F.,Li C.,&Tang C..(2021).Characteristics; trend; and precursors of extreme cold events in northwestern North America.Atmospheric Research,249.
MLA	Shi J.,et al."Characteristics; trend; and precursors of extreme cold events in northwestern North America".Atmospheric Research 249(2021).