DOI: 10.1175/JCLI-D-15-0826.1
Scopus记录号: 2-s2.0-84995387927
论文题名: A mechanism for the response of the zonally asymmetric subtropical hydrologic cycle to global warming
作者: Levine X.J. ; Boos W.R.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2016
卷: 29, 期: 21 起始页码: 7851
结束页码: 7867
语种: 英语
Scopus关键词: Arid regions
; Atmospheric humidity
; Atmospheric temperature
; Climate change
; Earth (planet)
; Global warming
; Heat convection
; Hydrology
; Oceanography
; Tropics
; Troposphere
; General circulation model
; Global mean surface temperature
; Global-mean temperature
; Hydrologic cycles
; Non-monotonic dependence
; Stationary waves
; Subtropics
; Tropospheric moisture
; Climate models
英文摘要: Time-mean, zonally asymmetric circulations (hereafter referred to as stationary circulations) maintain intense hydrologic contrasts in Earth's subtropics in the present climate, especially between monsoon regions and deserts during local summer. Such zonal contrasts in hydrology generally increase in comprehensive GCM simulations of a warming climate, yet a full understanding of stationary circulations and their contribution to the hydrologic cycle in present and future climates is lacking. This study uses an idealized moist GCM to investigate the response of subtropical stationary circulations to global warming. Stationary circulations are forced by a prescribed subtropical surface heat source, and atmospheric infrared opacity is varied to produce a wide range of climates with global-mean surface temperatures between 267 and 319 K. The strength of stationary circulations varies nonmonotonically with global mean temperature in these simulations. Zonal asymmetries in precipitation increase with temperature in climates colder than or comparable to that of Earth but remain steady or weaken in warmer climates. A novel mechanism is proposed in which this behavior is caused by the changes in tropopause height and zonal SST gradients expected to occur with global warming. Casting this mechanism in terms of the first-baroclinic mode of the tropical troposphere produces a theory that quantitatively captures the nonmonotonic dependence of stationary circulation strength on global mean temperature. Zonally asymmetric changes in precipitation minus surface evaporation (P - E) are predicted by combining this dynamical theory with the tropospheric moisture changes expected if relative humidity remains constant. © 2016 American Meteorological Society. 资助项目: AGS, Division of Atmospheric and Geospace Sciences
; AGS, Division of Atmospheric and Geospace Sciences
; 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/50203
Appears in Collections: 气候变化事实与影响
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作者单位: Department of Geology and Geophysics, Yale University, New Haven, CT, United States
Recommended Citation:
Levine X.J.,Boos W.R.. A mechanism for the response of the zonally asymmetric subtropical hydrologic cycle to global warming[J]. Journal of Climate,2016-01-01,29(21)