气候变化领域集成服务门户(CCPortal): Links between atmospheric blocking and North American winter cold spells in two generations of Canadian Earth System Model large ensembles

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DOI	10.1007/s00382-021-05801-0
	Links between atmospheric blocking and North American winter cold spells in two generations of Canadian Earth System Model large ensembles
	Jeong D.I.; Yu B.; Cannon A.J.
发表日期	2021
ISSN	0930-7575
起始页码	1243
结束页码	1271
英文摘要	Due to the significant negative consequences of winter cold extremes, there is need to better understand and simulate the mechanisms driving their occurrence. The impact of atmospheric blocking on winter cold spells over North America is investigated using ERA-Interim and NCEP-DOE-R2 reanalyses for 1981–2010. Initial-condition large-ensembles of two generations of Canadian Earth System Models (CanESM5 and its predecessor, CanESM2) are evaluated in terms of their ability to represent the blocking-cold spell linkage and the associated internal-variability. The reanalysis datasets show that 72 and 58% of cold spells in southern and northern North America coincide with blocking occurring in the high-latitude Pacific-North America. Compared to the two reanalyses, CanESM2 and CanESM5 ensembles underestimate by 19.9 and 14.3% cold spell events coincident with blocking, due to significant under-representation of blocking frequency over the North Pacific (− 47.1 and − 29.0%), whereas biases in cold spell frequency are relatively small (6.6 and − 4.7%). In the reanalyses, regions with statistically significant above-normal cold spell frequency relative to climatology lie on the east and/or south flanks of blocking events, whereas those with below-normal frequency lie along the core or surrounding the blocking. The two ensembles reproduce the observed blocking-cold spell linkage over North America, despite underestimating the magnitude of blocking frequency. The two ensembles also reproduce the physical drivers that underpin the blocking-cold spell linkage. Spatial agreement with the reanalyses is found in the simulated patterns of temperature advection and surface heat flux forcing anomalies during blocking events. While CanESM5 shows an improved representation of the blocking climatology relative to CanESM2, both yield similar results in terms of the blocking-cold spell linkage and associated internal-variability. © 2021, Crown.
英文关键词	Atmospheric blocking; Cold spell; GCM; Surface heat flux forcing; Temperature advection
来源期刊	Climate Dynamics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/183465
作者单位	Climate Research Division, Environment and Climate Change Canada, 4905 Dufferin Street, Toronto, ON M3H 5T4, Canada; Climate Research Division, Environment and Climate Change Canada, Victoria, BC V8W 2Y2, Canada
推荐引用方式 GB/T 7714	Jeong D.I.,Yu B.,Cannon A.J.. Links between atmospheric blocking and North American winter cold spells in two generations of Canadian Earth System Model large ensembles[J],2021.
APA	Jeong D.I.,Yu B.,&Cannon A.J..(2021).Links between atmospheric blocking and North American winter cold spells in two generations of Canadian Earth System Model large ensembles.Climate Dynamics.
MLA	Jeong D.I.,et al."Links between atmospheric blocking and North American winter cold spells in two generations of Canadian Earth System Model large ensembles".Climate Dynamics (2021).