DOI: 10.1002/jgrd.50610
论文题名: Seasonal to multidecadal variability of the width of the tropical belt
作者: Davis N.A. ; Birner T.
刊名: Journal of Geophysical Research Atmospheres
ISSN: 21698996
出版年: 2013
卷: 118, 期: 14 起始页码: 7773
结束页码: 7787
语种: 英语
英文关键词: climate change
; general circulation
; GPS radio occultation
; Hadley circulation
; reanalyses
; tropical belt
Scopus关键词: Climate change
; Clouds
; Uncertainty analysis
; General circulation
; GPS radio occultations
; Hadley circulation
; reanalyses
; Tropical belt
; Tropics
; assessment method
; belt
; climate change
; climate modeling
; decadal variation
; general circulation model
; GPS
; Northern Hemisphere
; seasonal variation
; seasonality
; timescale
; tropical environment
英文摘要: An expansion of the tropical belt has been extensively reported in observations, reanalyses, and climate model simulations, but there is a great deal of uncertainty in estimates of the rate of widening as different diagnostics give a wide range of results. This study critically examines robust diagnostics for the width of the tropical belt to explore their seasonality, interannual variability, and multidecadal trends. The width based on the latitudes of the maximum tropospheric dry bulk static stability, measuring the difference in potential temperature between the tropopause and the surface, is found to be closely coupled to the width based on the subtropical jet cores on all time scales. In contrast, the tropical belt width and Northern Hemisphere edge latitudes based on the latitudes at which the vertically averaged stream function vanishes, a measure of the Hadley circulation's poleward edges, lag those of the other diagnostics by approximately 1month. The tropical belt width varies by up to 10°latitude among the diagnostics, with trends in the tropical belt width ranging from -0.5 to 2.0°per decade over the 1979-2012 period. Nevertheless, in agreement with previous studies, nearly all diagnostics exhibit a widening trend, although the stream function diagnostic exhibits a significantly stronger widening than either the jet or dry bulk stability diagnostics. Finally, GPS radio occultation observations are used to assess the ability of the reanalyses to reproduce the tropical belt width, finding that they better situate the latitudes of maximum bulk stability versus those of the subtropical jets. Key Points Objective diagnostics exhibit a bi-annual seasonal cycle, significant expansion Hadley cell diagnostic lags other objective diagnostics by one month Reanalyses reproduce tropical belt widths observed from GPS-RO observations ©2013. American Geophysical Union. All Rights Reserved. 资助项目: NNX12AQ18G
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/63512
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
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作者单位: Department of Atmospheric Science, Colorado State University, 1371 Campus Delivery, Fort Collins, CO 80523, United States
Recommended Citation:
Davis N.A.,Birner T.. Seasonal to multidecadal variability of the width of the tropical belt[J]. Journal of Geophysical Research Atmospheres,2013-01-01,118(14)