DOI: 10.1002/2017JD027916
Scopus记录号: 2-s2.0-85047447451
论文题名: Quantifying the Impacts of Subpixel Reflectance Variability on Cloud Optical Thickness and Effective Radius Retrievals Based On High-Resolution ASTER Observations
作者: Werner F. ; Zhang Z. ; Wind G. ; Miller D.J. ; Platnick S.
刊名: Journal of Geophysical Research: Atmospheres
ISSN: 2169897X
出版年: 2018
卷: 123, 期: 8 起始页码: 4239
结束页码: 4258
语种: 英语
英文关键词: ASTER
; clouds
; plane-parallel bias
; remote sensing
; retrieval
; satellite
Scopus关键词: ASTER
; boundary layer
; cloud
; cloud droplet
; numerical method
; optical property
; pixel
; quantitative analysis
; reflectance
; remote sensing
; satellite data
; satellite mission
; spatial resolution
英文摘要: Recently, Zhang et al. (2016, https://doi.org/10.1002/2016JD024837) presented a mathematical framework based on a second-order Taylor series expansion in order to quantify the plane-parallel homogeneous bias (PPHB) in cloud optical thickness (τ) and effective droplet radius (reff) retrieved from the bispectral solar reflective method. This study provides observational validation of the aforementioned framework, using high-resolution reflectance observations from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) over 48 marine boundary layer cloud scenes. ASTER reflectances at a horizontal resolution of 30 m are aggregated up to a scale of 1,920 m, providing retrievals of τ and reff at different spatial resolutions. A comparison between the PPHB derived from these retrievals and the predicted PPHB from the mathematical framework reveals a good agreement with correlation coefficients of r0.97 (for Δτ) and r 0.79 (for Δreff). To test the feasibility of PPHB predictions for present and future satellite missions, a scale analysis with varying horizontal resolutions of the subpixel and pixel-level observations is performed, followed by tests of corrections with only limited observational high-resolution data. It is shown that for reasonably thick clouds with a mean subpixel τ larger than 5, correlations between observed and predicted PPHB remain high, even if the number of available subpixels decreases or just a single band provides the information about subpixel reflectance variability. Only for thin clouds the predicted Δreff become less reliable, which can be attributed primarily to an increased retrieval uncertainty for reff. ©2018. 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/114049
Appears in Collections: 气候减缓与适应
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作者单位: Joint Center for Earth Systems Technology, Baltimore, MD, United States; Physics Department, University of Maryland, Baltimore, MD, United States; NASA Goddard Space Flight Center, Greenbelt, MD, United States
Recommended Citation:
Werner F.,Zhang Z.,Wind G.,et al. Quantifying the Impacts of Subpixel Reflectance Variability on Cloud Optical Thickness and Effective Radius Retrievals Based On High-Resolution ASTER Observations[J]. Journal of Geophysical Research: Atmospheres,2018-01-01,123(8)