气候变化领域集成服务门户(CCPortal): Characteristics of cold-air outbreak events and associated polar mesoscale cyclogenesis over the north Atlantic region

CCPortal

DOI	10.1175/JCLI-D-20-0595.1
	Characteristics of cold-air outbreak events and associated polar mesoscale cyclogenesis over the north Atlantic region
	Terpstra A.; Renfrew I.A.; Sergeev D.E.
发表日期	2021
ISSN	08948755
起始页码	4567
结束页码	4584
卷号	34 期号:11
英文摘要	Equatorward excursions of cold polar air masses into ice-free regions, so-called cold-air outbreak (CAO) events, are frequently accompanied by the development of severe mesoscale weather features. Focusing on two key regions, the Labrador Sea and the Greenland–Norwegian Seas, we apply objective detection for both CAO events and polar mesoscale cyclones to outline the temporal evolution of CAO events and quantify associated mesoscale cyclogenesis. We introduce a novel metric, the CAO depth, which incorporates both the static stability and the temperature of the air mass. The large-scale atmospheric conditions during the onset of CAO events comprise a very cold upper-level trough over the CAO region and a surface cyclone downstream. As the CAO matures, the cold air mass extends southeastward, accompanied by lower static stability and enhanced surface fluxes. Despite the nearly 208 difference in latitude, CAO events over both regions exhibit similar evolution and characteristics including surface fluxes and thermodynamic structure. About two-thirds of the identified CAO events are accompanied by polar mesoscale cyclogenesis, with the majority of mesoscale cyclones originating inside the cold air masses. Neither the duration nor the maturity of the CAO event seems relevant for mesoscale cyclogenesis. Mesoscale cyclogenesis conditions during CAO events over the Labrador Sea are warmer, moister and exhibit stronger surface latent heat fluxes than their Norwegian Sea counterparts. © 2021 American Meteorological Society.
英文关键词	Atmosphere-ocean interaction; Cold air surges; Cyclogenesis/cyclolysis; Extreme events; Mesocyclones; Polar lows
语种	英语
scopus关键词	Surface measurement; Atmospheric conditions; Cold air outbreak; Ice-free regions; Mesoscale cyclones; Surface latent heat fluxes; Temporal evolution; Thermodynamic structures; Upper-level trough; Storms
来源期刊	Journal of Climate
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/178553
作者单位	Geophysical Institute, University of Bergen, Norway; School of Environmental Sciences, University of East Anglia, Norwich, United Kingdom; College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, United Kingdom
推荐引用方式 GB/T 7714	Terpstra A.,Renfrew I.A.,Sergeev D.E.. Characteristics of cold-air outbreak events and associated polar mesoscale cyclogenesis over the north Atlantic region[J],2021,34(11).
APA	Terpstra A.,Renfrew I.A.,&Sergeev D.E..(2021).Characteristics of cold-air outbreak events and associated polar mesoscale cyclogenesis over the north Atlantic region.Journal of Climate,34(11).
MLA	Terpstra A.,et al."Characteristics of cold-air outbreak events and associated polar mesoscale cyclogenesis over the north Atlantic region".Journal of Climate 34.11(2021).