气候变化领域集成服务门户(CCPortal): A midlatitude climatology and interannual variability of 200- And 500-hPa cut-off lows

CCPortal

DOI	10.1175/JCLI-D-19-0497.1
	A midlatitude climatology and interannual variability of 200- And 500-hPa cut-off lows
	Muñoz C.; Schultz D.; Vaughan G.
发表日期	2020
ISSN	0894-8755
起始页码	2201
结束页码	2222
卷号	33 期号:6
英文摘要	A climatology of midlatitude 200- and 500-hPa cut-off low systems in the Northern and Southern Hemispheres is constructed from the NCEP–NCAR reanalysis by detecting and tracking, under one consistent method, all of the systems that persisted for more than 36 h for the 58 years of 1960–2017. This method identifies a cut-off low as a cold-core geopotential height minimum that is isolated from the main westerlies and with a strong temperature gradient on its eastern flank. The obtained spatial and seasonal distributions show preferred regions of occurrence and that within these regions there is a level-dependent seasonality of cut-off lows. Whereas 200-hPa systems are more frequent in summer and autumn, 500-hPa systems are more evenly distributed throughout the seasons. Within each region and at each level, the annual number of cut-off lows has been increasing over time, trends that are consistent with documented signals of climate change such as a weakening and poleward shift of the subtropical jets and an increase in blocking frequency. These trends explain as much as 64% of the variance in the annual number of cut-off lows. The contribution of the annular modes and El Niño–Southern Oscillation to the interannual variability of the number of cut-off lows per season in each hemisphere is also investigated. Only the Northern Hemisphere annular mode has a statistically significant negative correlation throughout all seasons that explains 18%–45% of the variance in the yearly number of Northern Hemisphere 500-hPa cut-off lows. © 2020 American Meteorological Society. All rights reserved.
英文关键词	Atmospheric pressure; Geo-potential heights; Interannual variability; Negative correlation; Northern hemisphere annular modes; Northern Hemispheres; Seasonal distributions; Southern Hemisphere; Southern oscillation; Climate change; annual variation; climatology; El Nino-Southern Oscillation; midlatitude environment; Northern Hemisphere; seasonal variation; Southern Hemisphere; temperature gradient; westerly
语种	英语
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/171398
作者单位	Centre for Atmospheric Science, School of Earth and Environmental Sciences, University of Manchester, Manchester, United Kingdom; Centre for Atmospheric Science, School of Earth and Environmental Sciences, Centre for Crisis Studies and Mitigation, University of Manchester, Manchester, United Kingdom
推荐引用方式 GB/T 7714	Muñoz C.,Schultz D.,Vaughan G.. A midlatitude climatology and interannual variability of 200- And 500-hPa cut-off lows[J],2020,33(6).
APA	Muñoz C.,Schultz D.,&Vaughan G..(2020).A midlatitude climatology and interannual variability of 200- And 500-hPa cut-off lows.Journal of Climate,33(6).
MLA	Muñoz C.,et al."A midlatitude climatology and interannual variability of 200- And 500-hPa cut-off lows".Journal of Climate 33.6(2020).