DOI: 10.1175/2011JCLI4167.1
Scopus记录号: 2-s2.0-84856948197
论文题名: Changes in the interaction between tropical convection, radiation, and the large-scale circulation in a warming environment
作者: Posselt D.J. ; Van Den Heever S. ; Stephens G. ; Igel M.R.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2012
卷: 25, 期: 2 起始页码: 557
结束页码: 571
语种: 英语
Scopus关键词: Clear air
; Complex interaction
; Convective intensity
; Critical value
; Deep convection
; Hydrologic cycles
; Large-scale circulation
; Model experiments
; Monotonic dependence
; Non-monotonic function
; Overturning circulation
; Precipitation rates
; Radiative-convective equilibrium
; Sea surface temperatures
; Sea surfaces
; Stable layer
; Static stability
; Stratiform clouds
; Stratiform precipitation
; Surface warming
; Through the lens
; Tropical climates
; Tropical convection
; Upper troposphere
; Atmospheric humidity
; Experiments
; Feedback
; Heat convection
; Meteorological radar
; Natural convection
; Precipitation (meteorology)
; Tropics
; Troposphere
; Atmospherics
; atmospheric circulation
; atmospheric convection
; computer simulation
; hydrological cycle
; precipitation (climatology)
; relative humidity
; sea surface temperature
; stratiform cloud
; troposphere
; warming
英文摘要: This paper explores the response of the tropical hydrologic cycle to surface warming through the lens of large-domain cloud-system-resolving model experiments run in a radiative-convective equilibrium framework. Simulations are run for 55 days and are driven with fixed insolation and constant sea surface temparatures (SSTs) of 298 K, 300 K, and 302 K. In each experiment, convection organizes into coherent regions of large-scale ascent separated by areas with relatively clear air and troposphere-deep descent. Aspects of the simulations correspond to observed features of the tropical climate system, including the transition to large precipitation rates above a critical value of total column water vapor, and an increase in convective intensity with SST amidst weakening of the large-scale overturning circulation. However, the authors also find notable changes to the interaction between convection and the environment as the surface warms. In particular, organized convection in simulations with SSTs of 298 and 300 K is inhibited by the presence of a strong midtropospheric stable layer and dry upper troposphere. As a result, there is a decrease in the vigor of deep convection and an increase in stratiform precipitation fraction with an increase in SST from 298 to 300 K. With an increase in SST to 302 K, moistening of the middletroposphere and increase in lower-tropospheric buoyancy serve to overcome these limitations, leading to an overall increase in convective intensity and larger increase in upper-tropospheric relative humidity. The authors conclude that, while convective intensity increases with SST, the aggregate nature of deep convection is strongly affected by the details of the thermodynamic environment in which it develops. In particular, the positive feedback between increasing SST and a moistening upper troposphere found in the simulations, operates as a nonmonotonic function of SST and is modulated by a complex interaction between deep convection and the environmental relative humidity and static stability profile. The results suggest that projected changes in convection that assume a monotonic dependence on SST may constitute an oversimplification. © 2012 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/52591
Appears in Collections: 气候变化事实与影响
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作者单位: University of Michigan, Ann Arbor, MI, United States; Colorado State University, Fort Collins, CO, United States
Recommended Citation:
Posselt D.J.,Van Den Heever S.,Stephens G.,et al. Changes in the interaction between tropical convection, radiation, and the large-scale circulation in a warming environment[J]. Journal of Climate,2012-01-01,25(2)