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DOI	10.1016/j.atmosres.2018.11.007
	Impacts of distribution patterns of cloud optical depth on the calculation of radiative forcing
	Chen Y.; Chong K.; Fu Y.
发表日期	2019
ISSN	0169-8095
起始页码	70
结束页码	77
卷号	218
英文摘要	The gridding process applied to satellite-retrieved cloud properties results in the loss of certain information. In this study, we analyzed the error associated with using gridded cloud optical depth (τ) in calculating radiative forcing from the perspective of the distribution pattern of τ. Utilizing the simulated results from SBDART (Santa Babara DISORT Atmospheric Radiative Transfer), we calculated this error in ideal probability distribution functions (PDFs) of τ while keeping the average τ constant, and then used the τ retrieved from MODIS (Moderate Resolution Imaging Spectroradiometer) pixel-level observations to simulate real case studies. The results from both the ideal experiments and real case studies indicate that there is a large dependence of the error caused by gridding process on the PDF of τ. The greatest relative error occurs in the cases when τ fits a two-point or uniform distribution, reaching 10–20%, while this error is below 5% when τ follows a binomial distribution. From the analysis of MODIS pixel-level data from June 2016, we found that the PDFs of τ within one grid point (1° × 1°) could not be simply described by a normal distribution. Although using the logarithmic mean of τ controls the error effectively, the error can still be up to 4%. Our study suggests that using gridded data (especially the arithmetic mean) to calculate radiative forcing may result in uncertainty to a certain extent, which depends strongly on the distribution pattern of cloud properties within the grid point. The PDF of cloud properties should be comprehensively considered in the gridding process in the future. © 2018 Elsevier B.V.
英文关键词	Cloud optical depth; Distribution pattern; Grid; MODIS; Radiative forcing
语种	英语
scopus关键词	Atmospheric radiation; Errors; Normal distribution; Optical properties; Pixels; Radiometers; Cloud optical depth; Distribution patterns; Grid; MODIS; Radiative forcings; Distribution functions; cloud; MODIS; optical depth; radiative forcing; satellite data; statistical distribution
来源期刊	Atmospheric Research
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/162031
作者单位	School of Earth and Space Sciences, University of Science and Technology of China, Hefei, 230026, China
推荐引用方式 GB/T 7714	Chen Y.,Chong K.,Fu Y.. Impacts of distribution patterns of cloud optical depth on the calculation of radiative forcing[J],2019,218.
APA	Chen Y.,Chong K.,&Fu Y..(2019).Impacts of distribution patterns of cloud optical depth on the calculation of radiative forcing.Atmospheric Research,218.
MLA	Chen Y.,et al."Impacts of distribution patterns of cloud optical depth on the calculation of radiative forcing".Atmospheric Research 218(2019).