DOI: 10.1002/2016JD026038
论文题名: Effects of topographic smoothing on the simulation of winter precipitation in High Mountain Asia
作者: Cannon F. ; Carvalho L.M.V. ; Jones C. ; Norris J. ; Bookhagen B. ; Kiladis G.N.
刊名: Journal of Geophysical Research: Atmospheres
ISSN: 2169897X
出版年: 2017
卷: 122, 期: 3 起始页码: 1456
结束页码: 1474
语种: 英语
英文关键词: extratropical cyclones
; High Mountain Asia
; orographic precipitation
; WRF
Scopus关键词: atmospheric circulation
; extratropical cyclone
; extreme event
; orography
; precipitation assessment
; simulation
; smoothing
; snowpack
; topographic effect
; weather forecasting
; winter
; Asia
英文摘要: Numerous studies have projected future changes in High Mountain Asia water resources based on temperature and precipitation from global circulation models (GCMs) under future climate scenarios. Although the potential benefit of such studies is immense, coarse grid-scale GCMs are unable to resolve High Mountain Asia's complex topography and thus have a biased representation of regional weather and climate. This study investigates biases in the simulation of physical mechanisms that generate snowfall and contribute to snowpack in High Mountain Asia in coarse topography experiments using the Weather Research and Forecasting model. Regional snowpack is event driven, thus 33 extreme winter orographic precipitation events are simulated at fine atmospheric resolution with 6.67 km resolution topography and smoothed 1.85° × 1.25° GCM topography. As with many modified topography experiments performed in other regions, the distribution of precipitation is highly dependent on first-order orographic effects, which dominate regional meteorology. However, we demonstrate that topographic smoothing enhances circulation in simulated extratropical cyclones, with significant impacts on orographic precipitation. Despite precipitation reductions of 28% over the highest ranges, due to reduced ascent on windward slopes, total precipitation over the study domain increased by an average of 9% in smoothed topography experiments on account of intensified extratropical cyclone dynamics and cross-barrier moisture flux. These findings identify an important source of bias in coarse-resolution simulated precipitation in High Mountain Asia, with important implications for the application of GCMs toward projecting future hydroclimate in the region. ©2017. 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/62697
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 Geography, University of California, Santa Barbara, CA, United States; Earth Research Institute, University of California, Santa Barbara, CA, United States; Institute of Earth and Environmental Science, University of Potsdam, Potsdam, Germany; Physical Sciences Division, NOAA Earth System Research Laboratory, Boulder, CO, United States
Recommended Citation:
Cannon F.,Carvalho L.M.V.,Jones C.,et al. Effects of topographic smoothing on the simulation of winter precipitation in High Mountain Asia[J]. Journal of Geophysical Research: Atmospheres,2017-01-01,122(3)