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Evaluation of retrieval methods of daytime convective boundary layer height based on lidar data
Author(s) -
Li Hong,
Yang Yi,
Hu XiaoMing,
Huang Zhongwei,
Wang Guoyin,
Zhang Beidou,
Zhang Tiejun
Publication year - 2017
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
eISSN - 2169-8996
pISSN - 2169-897X
DOI - 10.1002/2016jd025620
Subject(s) - lidar , wavelet , daytime , remote sensing , planetary boundary layer , covariance , backscatter (email) , amplitude , sensitivity (control systems) , boundary layer , noise (video) , convective boundary layer , mathematics , geology , meteorology , optics , computer science , physics , statistics , artificial intelligence , atmospheric sciences , telecommunications , image (mathematics) , engineering , electronic engineering , wireless , thermodynamics
Abstract The atmospheric boundary layer height is a basic parameter in describing the structure of the lower atmosphere. Because of their high temporal resolution, ground‐based lidar data are widely used to determine the daytime convective boundary layer height (CBLH), but the currently available retrieval methods have their advantages and drawbacks. In this paper, four methods of retrieving the CBLH (i.e., the gradient method, the idealized backscatter method, and two forms of the wavelet covariance transform method) from lidar normalized relative backscatter are evaluated, using two artificial cases (an idealized profile and a case similar to real profile), to test their stability and accuracy. The results show that the gradient method is suitable for high signal‐to‐noise ratio conditions. The idealized backscatter method is less sensitive to the first estimate of the CBLH; however, it is computationally expensive. The results obtained from the two forms of the wavelet covariance transform method are influenced by the selection of the initial input value of the wavelet amplitude. Further sensitivity analysis using real profiles under different orders of magnitude of background counts show that when different initial input values are set, the idealized backscatter method always obtains consistent CBLH. For two wavelet methods, the different CBLH are always obtained with the increase in the wavelet amplitude when noise is significant. Finally, the CBLHs as measured by three lidar‐based methods are evaluated by as measured from L‐band soundings. The boundary layer heights from two instruments coincide with ±200 m in most situations.