DOI: 10.1175/JCLI-D-16-0287.1
Scopus记录号: 2-s2.0-84997018121
论文题名: Detection, attribution, and projection of regional rainfall changes on (multi-) decadal time scales: A focus on southeastern South America
作者: Zhang H. ; Delworth T.L. ; Zeng F. ; Vecchi G. ; Paffendorf K. ; Jia L.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2016
卷: 29, 期: 23 起始页码: 8515
结束页码: 8534
语种: 英语
Scopus关键词: Atmospheric radiation
; Climate change
; Commerce
; Greenhouse gases
; Rain
; Atmospheric circulation
; Decadal variability
; Hydrologic cycles
; Multidecadal variability
; South America
; Climate models
英文摘要: Observed austral summertime (November through April) rainfall in southeastern South America (SESA)-including northern Argentina, Uruguay, southern Brazil, and Paraguay-has exhibited substantial low-frequency variations with a multidecadal moistening trend during the twentieth century and a subsequent decadal drying trend during the current century. Understanding the mechanisms responsible for these variations is essential for predicting long-term rainfall changes. Here with a suite of attribution experiments using a pair of high-resolution global climate models, GFDL CM2.5 and FLOR-FA, the authors investigate the causes of these regional rainfall variations. Both models reproduce the twentieth-century moistening trend, albeit with a weaker magnitude than observed, in response to the radiative forcing associated with increasing greenhouse gases. The increasing greenhouse gases drive tropical expansion; consequently, the subtropical dry branch of Hadley cell moves away from SESA, leading to the rainfall increase. The amplitude discrepancy between the observed and simulated rainfall changes suggests a possible underestimation by the models of the atmospheric response to the radiative forcing, as well as an important role for low-frequency internal variability in the observed moistening trend. Over the current century, increasing greenhouse gases drive a continuous SESA rainfall increase in the models. However, the observed decadal rainfall decline is largely (~60%) reproduced in response to the observed Pacific trade wind strengthening, which is likely associated with natural Pacific decadal variability. These results suggest that the recent summertime rainfall decline in SESA is temporary and that the positive trend will resume in response to both increasing greenhouse gases and a return of Pacific trade winds to normal conditions. © 2016 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/50136
Appears in Collections: 气候变化事实与影响
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作者单位: Program in Atmospheric and Oceanic Sciences, Princeton University, Princeton, NJ, United States; NOAA/Geophysical Fluid Dynamics Laboratory, Princeton, NJ, United States
Recommended Citation:
Zhang H.,Delworth T.L.,Zeng F.,et al. Detection, attribution, and projection of regional rainfall changes on (multi-) decadal time scales: A focus on southeastern South America[J]. Journal of Climate,2016-01-01,29(23)