DOI: 10.1175/2011JCLI4080.1
Scopus记录号: 2-s2.0-84856967954
论文题名: Modeling the summertime climate of Southwest Asia: The role of land surface processes in shaping the climate of semiarid regions
作者: Marcella M.P. ; Eltahir E.A.B.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2012
卷: 25, 期: 2 起始页码: 704
结束页码: 719
语种: 英语
Scopus关键词: Albedo
; Asia
; Climate
; Land surface
; Summer/warm season
; Arid regions
; Dust
; Hydrostatic pressure
; Irrigation
; NASA
; Surface measurement
; Solar radiation
; air temperature
; albedo
; climate modeling
; land surface
; radiation budget
; regional climate
; relative humidity
; seasonal variation
; semiarid region
; shortwave radiation
; summer
; surface temperature
; vapor pressure
; Asia
英文摘要: Presented is a study on the role of land surface processes in determining the summertime climate over the semiarid region of southwest Asia. In this region, a warm surface air temperature bias of 3.5°C is simulated in the summer by using the standard configuration of Regional Climate Model version 3 (RegCM3). Biases are also simulated in surface albedo (underestimation), shortwave incident radiation (overestimation), and vapor pressure (underestimation). Based on satellite measurements documented in NASA's surface radiation budget (SRB) dataset, a correction in surface albedo by 4% is introduced in RegCM3 to match the observed SRB data. Increasing albedo values results in a nearly 1°C cooling over the region. In addition, by incorporating RegCM3's dust module and including subgrid variability for surface wind, shortwave incident radiation bias originally of about 45 W m -2 is reduced by 30 W m -2. As a result, the reduction of shortwave incident radiation cools the surface by 0.6°C. Finally, including a representation for the irrigation and marshlands of Mesopotamia produces surface relative humidity values closer to observations, thus eliminating a nearly 5-mb vapor pressure dry bias over some of the region. Consequently, the representation of irrigation and marshlands results in cooling of nearly 1°C in areas downwind of the actual land-cover change. Along with identified biases in observational datasets, these combined processes explain the 3.5°C warm bias in RegCM3 simulations. Therefore, it is found that accurate representations of surface albedo, dust emissions, and irrigation are important in correctly modeling summertime climates of semiarid regions. © 2012 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/52625
Appears in Collections: 气候变化事实与影响
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作者单位: Massachusetts Institute of Technology, Cambridge, MA, United States
Recommended Citation:
Marcella M.P.,Eltahir E.A.B.. Modeling the summertime climate of Southwest Asia: The role of land surface processes in shaping the climate of semiarid regions[J]. Journal of Climate,2012-01-01,25(2)