The Meteorological Characteristics Of Effecting Concentration Of PM₁₀ And PM_2.5 In Yanta District Of Xi’an City

PM10 and PM2.5 is one of the main atmospheric pollutants in our country.If the condition of the total particulate matter are not change, PM10 and PM2.5 is mainly affected by meteorological conditions. This article based on monitoring PM10 and PM2.5 and meteorological data in January to December 2013.And analysis the meteorological characteristics of effecting concentration of PM10 and PM2.5 in Yanta district of Xi’an..The main conclusions are as follows:(1) According to the month distribution characteristics and hour variation characteristics of PM10 and PM2.5, that has a great relevance. The variation trend of PM10 is bigger, and PM2.5 is lesser. That means PM2.5 space-time distribution is more homogeneous. Human activities have a certain influence on PM2.5, but not influence PM10. The conclusion has come from the statistics of the number of excellent, fine and polluted days during the four seasons of PM10 and PM2.5 in 2013: winter and spring pollution most, most optimal level in summer.(2) With the adoption of statistical approaches, the distribution laws of PM10 and PM2.5 concentration in different seasons were made clear. Besides, various meteorological elements easy to cause contaminated weather in different seasons were concluded. The following meteorological conditions prone to pollution days in spring: temperature of 10-20 ℃,sunshine time in 5-10 hours, wind speed 0 to 2 m/s, relative humidity is less than 40%. The following meteorological conditions prone to pollution days in summer: temperature of 20-30 ℃, sunshine time in the 0 to 5 hours, 2-3 m/s wind speed, air pressure is less than 990 pa. The following meteorological conditions prone to pollution days in autumn: 10-20 ℃ temperature, sunshine time in 5 to 10 h. The following meteorological conditions prone to pollution days in winter: 0-10 ℃ temperature, air pressure is greater than 995 pa, relative humidity between 60% and 80%.(3) With the adoption of statistical approaches,the conclusion of PM10 and PM2.5 impacted meteorological elements are follows: PM10 with average temperature, daily average pressure and the daily average humidity has good correlation; PM2.5 with average temperature, daily average pressure and sunshine time have good correlation.