Time And Space Distribution Of Zhejiang Haze Andurban Aerosol Optical Characteristics Research

Using the annual statistical data of haze in Zhejiang Province from 1980 to 2007 and the meteorological data of 66 ground control stations from 2007 to 2015 to study the haze temporal and spatial distribution characteristics of 11 prefecture-level cities in Zhejiang Province based on the 14-day haze day discrimination method.Based on the above analysis,studied the aerosol optical characteristics of Hangzhou,which is typical of haze pollution in Zhejiang Province,including AOD and Angstrom index.Based on the Hysplit back trajectory model studied,the paper includes the following conclusions:(1)Haze days on the interannual variability of zhejiang province in 11 cities as haze days average almost have the same change trend.In 2000 the province around the city haze days increased significantly,in 2010 haze days reduced appeared in small increments.A significant rise in average haze in 2013,2014 annual haze days fell slightly,haze days rise sharply again in 2015.Each lcity of zhejiang province haze seasonal value changed obvious,in addition to the wenzhou,the most is winter and much higher than other seasons,followed by autumn and spring,summer times is least.Third part of the lowest average July 11 cities in zhejiang province haze,followed in August,the highest in January,February,followed in December,and haze days season average variation characteristics are basically identical.(2)The temporal characteristics of Aerosol Optical Depth(AOD)and Angstrom exponent were analyzed using the sun photometer(CE318)data from June 2014 to May 2015 in HangZhou.The results show that the annual mean AOD was 0.65±0.31,which was at a relatively high level compare with national annual mean.The AOD varied seasonally,with a summer maximum(0.84±0.42),spring and autumn next(0.64±0.28 and 0.65±0.26)and a winner minimum(0.56±0.26).The turbidity annual mean was 0.28 ± 0.13,indicating that the air in Hangzhou was turbid.The annual mean of The proportion of the wavelength was 1.16±0.24,That showed that the fine particles were the principle aerosol particles.From the frequency distribution,The proportion of the wavelength exponent between 0.5 and 1.5 was 97.49%,between 1.1 and 1.5 was 53.63%,indicating that aerosol types of Hangzhou were continental type aerosol and marine type aerosol.The diurnal variations of AOD???? were small,basically the similar trend,a peak at morning and evening hours.The study of AOD and Atmospheric Visibility shows a positive correlation.(3)The backtrajectory analysis indicates that HangZhou area was mainly influenced by eastward currents and Inland Cyclone System in Southwest Zhejiang Province in summer,influenced by northward currents in autumn and influenced by northwest in winner,influenced by northwest currents in spring.