DOI: 10.1002/2016JD025945
论文题名: A 1-D variational retrieval of temperature, humidity, and liquid cloud properties: Performance under idealized and real conditions
作者: Ebell K. ; Löhnert U. ; Päschke E. ; Orlandi E. ; Schween J.H. ; Crewell S.
刊名: Journal of Geophysical Research: Atmospheres
ISSN: 2169897X
出版年: 2017
卷: 122, 期: 3 起始页码: 1746
结束页码: 1766
语种: 英语
英文关键词: clouds
; humidity
; remote sensing
; retrieval
; temperature
Scopus关键词: boundary layer
; cloud
; cloud droplet
; convergence
; humidity
; information technology
; liquid
; microwave radiometer
; performance assessment
; radar
; remote sensing
; temperature profile
; uncertainty analysis
; water content
; Germany
; Julich
; North Rhine-Westphalia
英文摘要: An extended version of the Integrated Profiling Technique (IPT) is presented. The IPT combines measurements from cloud radar and microwave radiometer (MWR) with prior information in a 1D-Var approach in order to retrieve physically consistent atmospheric profiles of temperature, absolute humidity, liquid water content (LWC), and recently also cloud droplet effective radius (REF). Physical consistency implies the reproducibility of the measurements within the uncertainties. Results based on synthetic observations revealed a good retrieval performance with a high convergence rate of 98%. Retrieval uncertainties are typically around 0.06 g m−3 for LWC and 0.6 μm for REF. For the application to real measurements, quality-controlled, bias-free observations are crucial. A newly developed MWR spectral consistency check, which was applied to the measurements at the Jülich Observatory for Cloud Evolution (JOYCE), revealed strongly bias-affected channels. The IPT itself can serve as a further quality check: particularly in clear-sky cases, nonconvergence or physically inconsistent solutions may hint at measurement offset errors. Based on sensitivity studies, the final set of MWR frequencies was identified and the retrieval applied to 1 year of data. Physically consistent solutions could be found in 62% of all processed cases. A focus was put on the analysis of nondrizzling single-layer water clouds which typically have small geometrical thicknesses (<300 m), low liquid water paths (<50 g m−2), and small REF (<5 μm). The retrieved data product contains a high potential for the analysis of warm cloud characteristics and, in combination with auxiliary information from the JOYCE instrumentation, of associated boundary layer processes. ©2017. American Geophysical Union. All Rights Reserved. 资助项目: 01LK1209B
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/62684
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: Institute for Geophysics and Meteorology, University of Cologne, Cologne, Germany; Deutscher Wetterdienst, Meteorologisches Observatorium Lindenberg–Richard-Aßmann-Observatorium, Lindenberg, Germany; RPG Radiometer Physics GmbH, Meckenheim, Germany
Recommended Citation:
Ebell K.,Löhnert U.,Päschke E.,et al. A 1-D variational retrieval of temperature, humidity, and liquid cloud properties: Performance under idealized and real conditions[J]. Journal of Geophysical Research: Atmospheres,2017-01-01,122(3)