DOI: 10.1175/JCLI-D-18-0244.1
Scopus记录号: 2-s2.0-85059651622
论文题名: Investigating the causes of increased twentieth-century fall precipitation over the southeastern United States
作者: Bishop D.A. ; Williams A.P. ; Seager R. ; Fiore A.M. ; Cook B.I. ; Mankin J.S. ; Singh D. ; Smerdon J.E. ; Rao M.P.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2019
卷: 32, 期: 2 起始页码: 575
结束页码: 590
语种: 英语
英文关键词: Atmospheric circulation
; Climate variability
; Forcing
; Mass fluxes/transport
; North America
; Precipitation
Scopus关键词: Climatology
; Precipitation (chemical)
; Risk assessment
; Atmospheric circulation
; Climate variability
; Forcing
; Mass fluxes/transport
; North America
; Atmospheric humidity
; atmospheric circulation
; atmospheric forcing
; climate variation
; dry season
; mass transport
; moisture transfer
; precipitation (climatology)
; sea surface temperature
; twentieth century
; Atlantic Ocean
; Atlantic Ocean (North)
; Gulf of Mexico
; United States
英文摘要: Much of the eastern United States experienced increased precipitation over the twentieth century. Characterizing these trends and their causes is critical for assessing future hydroclimate risks. Here, U.S. precipitation trends are analyzed for 1895-2016, revealing that fall precipitation in the southeastern region north of the Gulf of Mexico (SE-Gulf) increased by nearly 40%, primarily increasing after the mid-1900s. Because fall is the climatological dry season in the SE-Gulf and precipitation in other seasons changed insignificantly, the seasonal precipitation cycle diminished substantially. The increase in SE-Gulf fall precipitation was caused by increased southerly moisture transport from the Gulf of Mexico, which was almost entirely driven by stronger winds associated with enhanced anticyclonic circulation west of the North Atlantic subtropical high (NASH) and not by increases in specific humidity. Atmospheric models forced by observed SSTs and fully coupled models forced by historical anthropogenic forcing do not robustly simulate twentieth-century fall wetting in the SE-Gulf. SST-forced atmospheric models do simulate an intensified anticyclonic low-level circulation around the NASH, but the modeled intensification occurred farther west than observed. CMIP5 analyses suggest an increased likelihood of positive SE-Gulf fall precipitation trends given historical and future GHG forcing. Nevertheless, individual model simulations (both SST forced and fully coupled) only very rarely produce the observed magnitude of the SE-Gulf fall precipitation trend. Further research into model representation of the western ridge of the fall NASH is needed, which will help us to better predict whether twentieth-century increases in SE-Gulf fall precipitation will persist into the future. © 2018 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/117242
Appears in Collections: 气候变化与战略
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Recommended Citation:
Bishop D.A.,Williams A.P.,Seager R.,et al. Investigating the causes of increased twentieth-century fall precipitation over the southeastern United States[J]. Journal of Climate,2019-01-01,32(2)