DOI: 10.1002/jgrd.50565
论文题名: The relative roles of upper and lower tropospheric thermal contrasts and tropical influences in driving Asian summer monsoons
作者: Dai A. ; Li H. ; Sun Y. ; Hong L.-C. ; Ho L. ; Chou C. ; Zhou T.
刊名: Journal of Geophysical Research Atmospheres
ISSN: 21698996
出版年: 2013
卷: 118, 期: 13 起始页码: 7024
结束页码: 7045
语种: 英语
英文关键词: Asia
; land-sea contrast
; Monsoon
Scopus关键词: Atmospheric pressure
; Atmospheric temperature
; Computer simulation
; Global warming
; Oceanography
; Tropics
; Troposphere
; Asia
; Asian summer monsoons
; East Asian summer monsoon
; Land-ocean thermal gradients
; land-sea contrast
; Monsoon
; Sea surface temperature anomalies
; Tropospheric warming
; Atmospheric thermodynamics
; decadal variation
; El Nino-Southern Oscillation
; global warming
; sea surface temperature
; seasonal variation
; tropical region
; troposphere
; Asia
英文摘要: Summer thermal structure and winds over Asia show a larger land-ocean thermal gradient in the upper than in the lower troposphere, implying a bigger role of the upper troposphere in driving the Asian summer monsoon circulation. Using data from atmospheric re-analyses and model simulations, we show that the land-ocean thermal contrast in the mid-upper (200-500 hPa) troposphere (TCupper) contributes about three times as much as the thermal contrast in the mid-lower (500-850 hPa) troposphere (TClower) in determining both the strength and variations of Asian summer monsoon circulations. Tropical sea surface temperature anomalies associated with the annual cycle, El Niño-Southern Oscillation, decadal changes, and global warming all are accompanied with much larger variations and changes in TCupper than in TClower, partly due to enhanced latent heating aloft from convection. The variations and changes in TCupper and TClower are highly correlated with the strength of the South Asian Summer Monsoon (SASM) and the East Asian Summer Monsoon (EASM) in their respective sectors during the past 50-60 years. In particular, the weakening of the EASM since the 1950s is caused by the weakening mainly in TCupper and secondarily in TClower induced mainly by recent tropical surface warming, although spurious cooling over East Asia seen in reanalysis data may have enhanced this weakening. However, the strength of the SASM and EASM monsoons follows TCupper but decouples with TClower in the global warming case in the 21st century. The results suggest that the TCupper plays a dominant role and provides an efficient mechanism through which tropical oceans can influence extratropical monsoons. Key Points The land-sea T gradient is more important in the upper than in lower troposphere Tropical oceans influence extra-tropical monsoons through the upper troposphere Monsoon response to global warming depends on tropospheric warming patterns ©2013. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/63581
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: Department of Atmospheric and Environmental Sciences, State University of New York at Albany, 1400 Washington Ave., Albany, NY 12222, United States; National Center for Atmospheric Research, Boulder, CO, United States; Max Planck Institute of Meteorology, Hamburg, Germany; National Climate Center, China Meterological Administration, Beijing, China; Department of Atmospheric Sciences, National Taiwan University, Taipei, Taiwan; Research Center for Environmental Changes, Academia Sinica, Taipei, Taiwan; LASG, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China
Recommended Citation:
Dai A.,Li H.,Sun Y.,et al. The relative roles of upper and lower tropospheric thermal contrasts and tropical influences in driving Asian summer monsoons[J]. Journal of Geophysical Research Atmospheres,2013-01-01,118(13)