Xiaomo Wang et a1Study on the Characteristics of Atmospheric Environmental Pollution in Jining City 9 ation of wind speedchange ln atmospheric inversion Iayer and human activities in winterIn Jiningwind speed was the mini- mum fr0m 07：00 t0 08：0o and then increased to the maximum fr0m 13：00 t0 17：00Wind speed decreased after 17：0oand wind was calm at nightGentle or calm wind was not conducive to diffusion of atmospheric pollutants。so that atmospheric pol- Iution became more seriousWhen wind was gentle。air current became Iess turbulent due to atmospheric inversion laver caused by radiation，and atmospheric pollution became most serious at night，In the morningatmospheric inversJon Iayer was damaged and raised gradually after sunrise。and turbulent mixing layer was formed at the Iower layerso that verticaI dif- fusion was inhibitedand the concentrations of atmospheric pol- Iutants increased to the maximum values。From April to Sep- tember，compared with the heating period，the first peaks of pollutant concentrations in the atmosphere appeared 3 h earlier in the morningwhile the second peaks appeared 12 h Iater at nightAt the moment people went to work or came off work， and traffic congestion was commonshowing that human activi ty was one of reasons for increased pollution 譬 墨 矗 8 莒 曼 兰 口0 0 0 00口 0 0 0 0 0 0 TiI【le Fig1 Daily changes in the concentrations of SO2，NO2 and PM10 in the atmosphere of Jining City in the heating period 要 鲁 8 晷 童 兰 nle Fig2 Daily variations in the concentrations of SO2，NO2 and PM1o in the atmosphere of Jining Clty from April to September 22 Seasonal variation According to Fig3there were ob vious seasonal variations in the concentrations of SO2，NO2 and PM10 in the atmosphere of Jining City，that is，air pollution was the most serious in winter but slightest in summerAnnual averages of SO2，NO2 and PM1n concentration in the atmosphere during2OO62D1Owere 0060，0038 and0103 mQm。respec- tivelyMoreover，the maximum concentrations of SO，and PM， appeared in December and January respectivelywhile their mini- mum values appeared in June and Julywhich was consistent with the heating peod of Jining CityHowever，there was rio oh- vious change in NO2 concentration in the whole year 1 2 3 4 5 6 7 8 9 10 11 12 Month Fig。3 Monthly changes in the concentrations of SO2，NO2 and PM1o in the atmosphere of Jining City during 2OO62010 23 AnnuaI variation To discuss annuaI variation in the at- mospheric pollution of Jining Citybased 0n the concentrations 0f S02，NO2 and PM10 in the atmosphere at each monitodng site of Jining City fr0m 2006 to 201 0the load coefficient of each atmospheric pollutant in Jining City during 2006-201 0 was calculated according to the second standard of daily aver age mass concentration of atmospheric pollutants in Atmos pheric Environmental Quality Standards Its formulas are as follows： Fi=P-P 尸=Pi P=cs； where Ft is the load coefficient of pollutant i；P is the compre- hensive index of atmospheric pollution；尸f is the subindex of pollutant，；c，is the actual concentration of pollutant f；S1 is the standard concentration of pollutant L Table 1 Annual variations in the load coefficients of atmospheric pollutants in Jining Clty from 2006 to 2010 According to Table 1the load coefficients of atmospheric poIlutants in Jining City showed an increasing trend fr0m 2o06 t0 201 0which is the pollution characteristic of a resource- based city rich in coal【”JTheir load coefficients were close to each other。and soot，construction dust and vehicle exhaust pollution were seriousMoreoverthe concentrations of SO， NO，and PM， in the atmosphere had greatly exceeded the na tional standards at Grade II Lg Jand the national standard con- 咖 啪0 m n n n a吼 皇IlI f0一= a。uo。 皇rI1l0d 10 Meteorological and Environmental Research 2013 centrations of SO2，NO2 and PM10 in the atmosphere were 015，010 and030 mgm。 3 Factors jnfluencing the temporaI distri- bution of atmospheric pollutants in Jining City There are meteorologica1human and geographical factors influencing the temporaI distribution of atmospheric pollutants In respect of geographical factorsbecause of the difference in surface naturallandscape and Iandformregional wind direction and speed as welI as temperature are differentwhich can Iead to regionaI circulation and thereby affect the transpoation and diffusion of atmospheric pollutantsIn factthe main reasons for the uneven distribution of atmospheric pollutants are meteor- ologicaI and human factorssuch as the distribution and emis sion intensity of pollution sources 31 Relationship between wind and atmospheric pollu- tants Wind is an important power faclor influencing pollutant diffusion in the boundary layerand wind direct and velocity de- termine the transportation direction and diffusion speed of at mospheric pollutants respectivelyMoreover。the changes of wind velocity and direction at Iow layers(below 20o m)can di- rectly aff