Publications

Wu, Jian; Luo, Jianguo; Zhang, Liya; Xia, Lan; Zhao, Deming; Tang, Jianping (2014). Improvement of aerosol optical depth retrieval using visibility data in China during the past 50years. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 119(23), 13370-13387.

Abstract
Horizontal visibility and water vapor pressure data from 483 stations in China from 1960 to 2009 were used to inverse aerosol optical depth (AOD) using a new series of parameters, which were revised for each station using the polybasic nonlinear regression method based on monthly Multiangle Imaging Spectroradiometer (MISR) AOD data during 2001-2005. Monthly AOD retrievals from 2006 to 2009 using the new parameters were compared with MISR AOD in the same period. AOD retrieved with the new parameters can capture the extreme values better than the inversion result with the original parameters, and the root-mean-square error between retrieval and MISR AOD reached the minimum of 0.047 in northwest China and the maximum of 0.102 in the Huang-Huai River Basin, respectively. The spatial distribution and seasonal features of monthly AOD from 1960 to 2009 in China were also analyzed. The monthly AOD in China for past 50 years, from 1960 to 2009, exhibited an increasing trend, especially during 1960-1985, with a linear rate of increase of 0.004/year. No distinct trend can be found for AOD from 1985 to 1995; then it increased obviously from 1996 to 2009 with an annual rate of 0.002. Seasonal change in AOD showed that it reached a maximum value in summer with the average value between 0.34 and 0.36 for the whole China, while a minimum value was reached in winter with a mean value between 0.2 and 0.22. It is noted that the aerosol vertical profile was a sensitive factor to the inversion result. The root-mean-square error using Goddard Chemistry Aerosol Radiation and Transport aerosol profiles was increased 1.9 to 5.7 times than using the traditional three-segment profile in northwest, southwest, northeast, and northern China, which meant that the retrieval AOD was sensitive to aerosol vertical profile in these regions; at the same time, the root-mean-square error was decreased 1.13 to 1.37 times in other regions.

DOI:
10.1002/2014JD021550

ISSN:
2169-897X