DOI: 10.1002/jgrd.50614
论文题名: 3D cloud reconstructions: Evaluation of scanning radar scan strategy with a view to surface shortwave radiation closure
作者: Fielding M.D. ; Chiu J.C. ; Hogan R.J. ; Feingold G.
刊名: Journal of Geophysical Research Atmospheres
ISSN: 21698996
出版年: 2013
卷: 118, 期: 16 起始页码: 9153
结束页码: 9167
语种: 英语
Scopus关键词: Drops
; Large eddy simulation
; Cloud radiative effects
; Liquid water content
; Liquid water paths
; Radar reflectivities
; Radar sensitivity
; Short-wave radiation
; Solar radiative transfer
; Surface irradiance
; Radar
; cumulus
; droplet
; eddy
; radar
; radiation balance
; reconstruction
; shortwave radiation
; three-dimensional modeling
英文摘要: The ability of six scanning cloud radar scan strategies to reconstruct cumulus cloud fields for radiation study is assessed. Utilizing snapshots of clean and polluted cloud fields from large eddy simulations, an analysis is undertaken of error in both the liquid water path and monochromatic downwelling surface irradiance at 870 nm of the reconstructed cloud fields. Error introduced by radar sensitivity, choice of radar scan strategy, retrieval of liquid water content (LWC), and reconstruction scheme is explored. Given an infinitely sensitive radar and perfect LWC retrieval, domain average surface irradiance biases are typically less than 3Wm-2 μm-1, corresponding to 5-10% of the cloud radiative effect (CRE). However, when using a realistic radar sensitivity of -37.5 dBZ at 1 km, optically thin areas and edges of clouds are difficult to detect due to their low radar reflectivity; in clean conditions, overestimates are of order 10Wm-2 μm -1 (~20% of the CRE), but in polluted conditions, where the droplets are smaller, this increases to 10-26Wm-2 μm-1 (~40-100% of the CRE). Drizzle drops are also problematic; if treated as cloud droplets, reconstructions are poor, leading to large underestimates of 20-46Wm -2 μm-1 in domain average surface irradiance (~40-80% of the CRE). Nevertheless, a synergistic retrieval approach combining the detailed cloud structure obtained from scanning radar with the droplet-size information and location of cloud base gained from other instruments would potentially make accurate solar radiative transfer calculations in broken cloud possible for the first time. © 2013. Her Majesty the Queen in Right of Canada. American Geophysical Union. 资助项目: DESC0007233
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/63391
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 Meteorology, University of Reading, Earley Gate, PO Box 243, Reading RG6 6BB, United Kingdom; NOAA Earth System Research Laboratory, Boulder, CO, United States
Recommended Citation:
Fielding M.D.,Chiu J.C.,Hogan R.J.,et al. 3D cloud reconstructions: Evaluation of scanning radar scan strategy with a view to surface shortwave radiation closure[J]. Journal of Geophysical Research Atmospheres,2013-01-01,118(16)