DOI: 10.1002/jgrd.50580
论文题名: Tibetan Plateau westerly forcing on the cloud amount over Sichuan Basin and the early Asian summer monsoon
作者: Wu C.-H. ; Chou M.-D.
刊名: Journal of Geophysical Research Atmospheres
ISSN: 21698996
出版年: 2013
卷: 118, 期: 14 起始页码: 7558
结束页码: 7568
语种: 英语
英文关键词: Asian Summer Monsoon
; Tibetan Plateau mechanical effect
Scopus关键词: E region
; Troposphere
; Anticyclonic circulation
; Asian summer monsoons
; Interannual variability
; Lower troposphere
; Mechanical effects
; Stationary wave patterns
; Tibetan Plateau
; Upper-tropospheric jet stream
; Atmospheric thermodynamics
; annual variation
; anticyclone
; atmospheric forcing
; cloud
; global warming
; monsoon
; summer
; troposphere
; China
; Qinghai-Xizang Plateau
; Sichuan Basin
; Citrus maxima
英文摘要: Data show that a sizeable mechanical effect of the Tibetan Plateau (TP) on the westerly, referred to as TP westerly forcing, is related to a sizeable midlevel cloud amount over Sichuan Basin (SB; centered near 30°N and 105°E) to the east of the TP. An investigation of the interannual variability of clouds over SB demonstrated that the TP westerly forcing closely correlates to the early Asian summer monsoon (ASM). When the monsoon commences in mid-May, the East Asian upper tropospheric jet stream moves northward with a southwest-northeast tilt; the tilt of the jet considerably influences the TP westerly forcing. Because of the stationary wave pattern superimposed on the westerly jet, the early ASM is substantially distinct by year. In the years the midlevel cloud amount in SB is sizeable (which corresponds to a strong TP westerly forcing), the tilt of the upper level jet increases, and the ascending southerly east of SB in 110°E-125°E strengthens. The warming of the troposphere in 110°E-125°E centered near 35°N corresponds to the westerly and southerly changes. Farther downstream in the 125°E-140°E region, the ascending southerly weakens. Correspondingly, an anomalous anticyclonic circulation occurs between SB and Japan, leading to a westward extension of the North Pacific high pressure in the lower troposphere and a reduction in precipitation of the early Mei-Yu season. Coincidentally, the midtropospheric monsoon trough south of the TP weakens, implying a weak monsoon in both East Asia and South Asia. Furthermore, the weak monsoon continues through the early summer. Key Points Midclouds of Sichuan Basin serve as a reliable index for the TP westerly forcing A larger TP westerly forcing in mid-May can be related to a weaker monsoon Impact of late-spring TP westerly forcing continues through early summer ©2013. American Geophysical Union. All Rights Reserved. 资助项目: NSC 100-2119-M-001-029-MY5
; NSC 100-2811-M-008-078
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/63515
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
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作者单位: Research Center for Environmental Changes, Academia Sinica, 128 Academia Rd., Section 2, Nankang, Taipei 115, Taiwan; Department of Atmospheric Sciences, National Central University, Chung-Li, Taiwan
Recommended Citation:
Wu C.-H.,Chou M.-D.. Tibetan Plateau westerly forcing on the cloud amount over Sichuan Basin and the early Asian summer monsoon[J]. Journal of Geophysical Research Atmospheres,2013-01-01,118(14)