DOI: 10.1007/s00382-014-2083-y
Scopus记录号: 2-s2.0-84894469099
论文题名: La Niña diversity and Northwest Indian Ocean Rim teleconnections
作者: Hoell A. ; Funk C. ; Barlow M.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2014
卷: 43, 期: 2017-09-10 起始页码: 2707
结束页码: 2724
语种: 英语
英文关键词: Central-Southwest Asia
; Drought
; East Africa
; ENSO diversity
; La Niña
; Tropical warm pool
英文摘要: The differences in tropical Pacific sea surface temperature (SST) expressions of El Niño-Southern Oscillation (ENSO) events of the same phase have been linked with different global atmospheric circulation patterns. This study examines the dynamical forcing of precipitation during October–December (OND) and March–May (MAM) over East Africa and during December–March (DJFM) over Central-Southwest Asia for 1950–2010 associated with four tropical Pacific SST patterns characteristic of La Niña events, the cold phase of ENSO. The self-organizing map method along with a statistical distinguishability test was used to isolate La Niña events, and seasonal precipitation forcing was investigated in terms of the tropical overturning circulation and thermodynamic and moisture budgets. Recent La Niña events with strong opposing SST anomalies between the central and western Pacific Ocean (phases 3 and 4), force the strongest global circulation modifications and drought over the Northwest Indian Ocean Rim. Over East Africa during MAM and OND, subsidence is forced by an enhanced tropical overturning circulation and precipitation reductions are exacerbated by increases in moisture flux divergence. Over Central-Southwest Asia during DJFM, the thermodynamic forcing of subsidence is primarily responsible for precipitation reductions, with moisture flux divergence acting as a secondary mechanism to reduce precipitation. Eastern Pacific La Niña events in the absence of west Pacific SST anomalies (phases 1 and 2), are associated with weaker global teleconnections, particularly over the Indian Ocean Rim. The weak regional teleconnections result in statistically insignificant precipitation modifications over East Africa and Central-Southwest Asia. © 2014, Springer-Verlag (outside the USA). 资助项目: USAID, United States Agency for International Development
; USGS, U.S. Geological Survey
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/54565
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Geography, University of California Santa Barbara, Santa Barbara, CA, United States; Earth Resources Observation and Science Center, U.S. Geological Survey, Sioux Falls, SD, United States; Department of Environmental, Earth and Atmospheric Sciences, University of Massachusetts Lowell, Lowell, MA, United States
Recommended Citation:
Hoell A.,Funk C.,Barlow M.. La Niña diversity and Northwest Indian Ocean Rim teleconnections[J]. Climate Dynamics,2014-01-01,43(2017-09-10)