DOI: 10.1175/JCLI-D-14-00496.1
Scopus记录号: 2-s2.0-84944088520
论文题名: Contraction of the northern hemisphere, lower-tropospheric, wintertime cold pool over the past 66 years
作者: Martin J.E.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2015
卷: 28, 期: 9 起始页码: 3764
结束页码: 3778
语种: 英语
Scopus关键词: Climatology
; Fighter aircraft
; Global warming
; Lakes
; Snow
; Storms
; Troposphere
; Cold pool
; Correlation analysis
; East Asian winter monsoon
; Geo-potential heights
; Interannual variability
; Northern Hemispheres
; Threshold temperatures
; Tropospheric temperature
; Climate change
; climate change
; climatology
; cold pool
; contraction
; El Nino-Southern Oscillation
; Northern Hemisphere
; troposphere
; winter
; Atlantic Ocean
; Eurasia
; North America
; Pacific Ocean
英文摘要: Employing reanalysis datasets, several threshold temperatures at 850 hPa are used to measure the wintertime [December-February (DJF)] areal extent of the lower-tropospheric, Northern Hemisphere, cold-air pool over the past 66 cold seasons. The analysis indicates a systematic contraction of the cold pool at each of the threshold temperatures. Special emphasis is placed on analysis of the trends in the extent of the -5°C air. Composite differences in lower-tropospheric temperature, midtropospheric geopotential height, and tropopause level jet anomalies between the five coldest and five warmest years are considered. Cold years are characterized by an equatorward expansion of the jet in the Pacific and Atlantic sectors of the hemisphere and by invigorated cold-air production in high-latitude Eurasia and North America. Systematic poleward encroachment of the -5°C isotherm in the exit regions of the storm tracks accounts for nearly 50% of the observed contraction of the hemispheric wintertime cold pool since 1948. It is suggested that this trend is linked to displacement of the storm tracks associated with global warming. Correlation analyses suggest that the interannual variability of the areal extent of the 850-hPa cold pool is unrelated to variations in hemispheric snow cover, the Arctic Oscillation, or the phase and intensity of ENSO. A modest statistical connection with the East Asian winter monsoon, however, does appear to exist. Importantly, there is no evidence that a resurgent trend in cold Northern Hemisphere winters is ongoing. In fact, the winter of 2013/14, though desperately cold in North America, was the warmest ever observed in the 66-yr time series. © 2015 American Meteorological Society. 资助项目: NSF, National Science Foundation
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/50432
Appears in Collections: 气候变化事实与影响
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作者单位: Department of Atmospheric and Oceanic Sciences, University of Wisconsin-Madison, Madison, WI, United States
Recommended Citation:
Martin J.E.. Contraction of the northern hemisphere, lower-tropospheric, wintertime cold pool over the past 66 years[J]. Journal of Climate,2015-01-01,28(9)