| According to the World Resources Institute and the China Environmental Monitoring Center,China accounts for 20 of the world's 30 most polluted cities;China is home to six of the world's ten most polluted cities.With the rapid development of China's economy and society,nitrogen oxide?NOx?and volatile organic compounds?VOCs?discharged into the atmosphere have been increasing continuously,photochemical smog,or atmospheric ozone pollution,has become a common and difficult to deal with air pollution in China.Ozone is a secondary pollutant in the atmosphere,which can corrode aging building materials under certain conditions and cause possible economic loss;It continues to worsen the ecological environment by forcing crop cuts and curbing tree growth and,most importantly,is very harmful to human health.Although Lanzhou is one of the earliest cities with photochemical smog pollution in China,there are early warning signs in the mid-1970 s,but Gansu province is located in the northwest of China,There are few studies on the spatial and temporal distribution of atmospheric ozone in this region.In recent years,under the national emergency policy,the industrial and economic development in Gansu Province has been rapid,the anthropogenic emission sources of ozone precursors nitrogen oxides and volatile organic compounds have increased rapidly,and the atmospheric ozone concentration has also increased day by day.Therefore,to master the current situation of atmospheric ozone in Gansu province,to study its occurrence and change rules,to understand that the location of pollution source is the main task of environmental Atmospheric research and urban air pollution warning and control.This article uses OMIO3 data translated by OMI,a NASA satellite sensor,The extraction,filtering,input and output of O3 column values,the establishment of ozone database in Gansu province,the mapping of space-time distribution and the analysis of pollution sources were completed by processing OMIO3 level 2 Zonal storage format data using VISAN software and HDFView software.For the first time,the spatial and temporal distribution of atmospheric O3column concentration in Gansu Province and Prefectural?Prefectural?city was studied,and the spatial distribution and temporal trend of atmospheric O3 column concentration over the decade from 2006 to 2015 were mapped.?1?Based on the spatial distribution map of the 10 year mean column concentration of the atmospheric O3 column concentration in Gansu Province,the spatial distribution of the atmospheric O3 column concentration in Gansu province is "high in the middle and low in the surrounding area",and there are significant differences in the high and low levels of atmospheric ozone in various prefectures.Jinchang City-Zhangye City Wuwei city–Baiyin city are four high value centers in Gansu Province,and the edge is obvious.From the latitude and longitude,during 20062015,the spatial distribution of atmospheric O3 in Gansu province in general,there is a positive ratio with the increase of latitude,the concentration of the atmospheric O3 column increases.The high value area and sub high value area in Gansu province are mainly distributed in the high latitude area,about 35 degrees north latitude.The 10 year average column concentration of the atmospheric O3 in different regions from large to small is ranked as Jinchang>Wuwei>Baiyin>Zhangye>Lanzhou City>Jiuquan>Qingyang City>Linxia Hui Autonomous Prefecture>Pingliang City>Jiayuguan>Dingxi City>Tianshui.The spatial distribution of the seasonal variation of atmospheric O3column concentration in Gansu province is characterized by the "middle high two sides" in spring and summer in Gansu Province,and "36 degrees north latitude as the boundary of high and low values" in the autumn,and the atmospheric O3 column concentration in the four seasons in the winter of "96 degrees of east longitude" as the boundary of high and low values.There are obvious seasonal differences in the spatial distribution of O3 column concentration in the four seasons in Gansu province.Although the four seasons column concentration value range is different,on the whole,the high value area in spring and autumn is the most widely distributed,followed by summer and winter.?2?Based on the annual mean value of atmospheric O3 column concentration in Gansu in 2006 and seasonal mean value distribution map,the chart shows that:the annual average value of the atmospheric O3 column in Gansu province shows a trend from increasing to the maximum value,which shaped inverted?V?.From the seasonal variation,the atmospheric O3 column concentration in the 10 year seasons shows that the atmospheric O3 column concentration in Gansu province in spring and summer is obviously higher than that in autumn and winter,and the concentration of atmospheric O3 column from large to small is in summer>spring>winter>autumn.The concentration of O3 column in Gansu has significant difference over the past 10 years in the past 20062015 years.The magnitude of variation is ranked as summer>spring>winter>autumn.?3?Based on the correlation analysis of atmospheric O3 column concentration and air mass index?AQI?,the air quality grade indicated by the concentration of O3 column in the atmosphere of Gansu province was divided.In the 10 year of 20062015,the mean concentration of O3 column in the atmosphere was mild pollution and good two kinds of air quality grades,and the pollution degree was low in general,and no moderate pollution existed.The phenomenon of dyeing and severe pollution.The area with good air quality accounts for more than 88.7%of the total area of Gansu Province,which is widely distributed.During the period of 20062015,there were only mild pollution in Gansu's ozone pollution.In addition to 2011,most areas of air quality were good,and there were two kinds of good and mild pollution,and the overall pollution level was light.The air quality of the province in 2006 and 2007 was good,and there was a slight pollution in the small area in 2008 and 2009.In 2011,the light pollution range of Gansu province was greatly expanded to reach the maximum value of 10 years.Since 2011,the area of mild ozone pollution has been decreasing year by year,and the pollution area is also moving northward.?4?The 10 year mean values of atmospheric O3 column concentration in every city?state?in Gansu Province,according to the order from high to low,are respectively Gannan Tibetan Autonomous Prefecture<Longnan<Pingliang City<Pingliang City<Linxia Hui Autonomous Prefecture>Lanzhou City<Zhangye City<Zhangye City<Jinchang.The 5 regions of Lanzhou,Gannan Tibetan Autonomous Prefecture,Tianshui,Jinchang city and Jiuquan city are typical representative regions.The annual average values of atmospheric O3 column concentration in five types of cities all present the process of increasing and then decreasing.The general rule is consistent with the annual mean of the concentration of atmospheric O3 column in Gansu Province,which shaped inverted?V?distribution.The concentrations of O3column in the high value area of Jiuquan,Lanzhou and Lanzhou did not change significantly.The changes in the Tibetan Autonomous Prefecture of Tianshui,Gannan and other provinces fluctuated greatly.?5?The overall altitude of Gansu is the topographic feature of "the East is low and the west is high".It can be seen that the higher the altitude is,the lower the concentration of O3 column is.There is a negative correlation between DEM map and O3concentration distribution in Gansu province.The area of air temperature,air pressure,sunshine duration and moisture content line range is recoincide with most of the high value area of atmospheric O3 concentration,then some cities have special conditions because of special industrial activities and terrain factors.The main reason is that the industrial waste gas of the second industry is dominated by the industrial waste gas,and the emission of ozone precursor dioxide and formaldehyde,which is closely related to the concentration of the atmospheric O3 column,is the main cause of the situation of ozone pollution. |
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