DOI: 10.1029/2012JD018805
论文题名: Impact of land surface conditions on 2004 north american monsoon in gcm experiments
作者: Feng X. ; Bosilovich M. ; Houser P. ; Chern J.-D.
刊名: Journal of Geophysical Research Atmospheres
ISSN: 21698996
出版年: 2013
卷: 118, 期: 2 起始页码: 293
结束页码: 305
语种: 英语
Scopus关键词: Atmospheric temperature
; Atmospheric thermodynamics
; Experiments
; Feedback
; Heat flux
; Rain
; Soil moisture
; Atmospheric circulation
; Boundary layer instability
; Finite volume general circulation models
; Land data assimilation systems
; Land surface conditions
; Land surface modeling
; Moisture flux convergences
; North american monsoon systems
; Surface measurement
; atmospheric circulation
; boundary layer
; convection
; data assimilation
; experimental study
; finite volume method
; general circulation model
; land surface
; monsoon
; numerical model
; precipitation (climatology)
; pressure effect
; rainfall
; sensitivity analysis
; soil moisture
; Mexico [North America]
英文摘要: In this study, two sets of six-member ensemble simulations were performed for the boreal summer of 2004 using the Finite Volume General Circulation model to investigate the sensitivity of the North American monsoon (NAM) system to land surface conditions and further to identify the mechanisms by which land surface processes control the NAM precipitation. The control simulation uses a fully interactive land surface model, whereas the sensitivity experiment uses prescribed land surface fields from the Global Land Data Assimilation System. [2] The response of the monsoon precipitation to land surface changes varies over different regions modulated by two different soil moisture-precipitation feedbacks. The vast northern NAM region, including most of Arizona and New Mexico, as well as the northwestern Mexico shows that soil moisture has a positive feedback with precipitation primarily due to local recycling mechanisms. The reduction of soil moisture decreases latent heat flux and increases sensible heat flux and consequently increases the Bowen ratio and surface temperature, leading to a deep (warm and dry) boundary layer, which suppresses convection and hence reduces precipitation. Over the west coast of Mexico near Sinaloa, a negative soil moisture-precipitation relationship is noted to be associated with a large-scale mechanism. The reduced soil moisture changes surface fluxes and hence boundary layer instability and ultimately low-level circulation. As a result, the changes in surface pressure and large scale wind field increase moisture flux convergence and consequently moisture content, leading to increased atmospheric instability and in turn enhancing convection and accordingly precipitation. These results further reinforce the important role of land surface conditions on surface process, boundary structure, atmospheric circulation, and rainfall during the NAM development. © 2012. American Geophysical Union. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/63996
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: George Mason University, Fairfax, VA 22030, United States; Goddard Space Flight Center, NASA, Greenbelt, MD, United States; Morgan State University, Baltimore, MD, United States
Recommended Citation:
Feng X.,Bosilovich M.,Houser P.,et al. Impact of land surface conditions on 2004 north american monsoon in gcm experiments[J]. Journal of Geophysical Research Atmospheres,2013-01-01,118(2)