Analysis of the Temporal and Spatial Distribution of Haze and its Influencing Factors in Shanghai.

The aim of this paper is to assess the influence of meteorological conditions on the variability of haze in Shanghai during 1981-2013. Based on the observational data of haze and air quality in Shanghai during this period and on the National Centers for Environmental Prediction final analysis data, the long-term variability and the spatial distribution of the haze was analyzed as well as with relationship between haze and atmospheric variables, including visibility, relative humidity, and air quality. Temporal evolution showed that the annual number of haze days in Shanghai represented a rapid decline in the last decade, which was caused by the direct effects of relative humidity and visibility. Global warming-induced changes, such as a warmer temperature, lower relative humidity, and wind speed in winter, were other important factors in the decline. Spatial distribution showed that the annual number of haze days in mid-western Shanghai was higher than those in the southeastern suburbs. [ABSTRACT FROM AUTHOR]