Urumqi Winter Inversion Temporal Variation And Atmospheric Environment Effect

With the rapid development of urban industrialization, urban air pollution problems have a huge impact on the production of human life. As the capital of Xinjiang, Urumqi, bear an important responsibility for the development of economy, politics and culture. But with the development of these years, Urumqi serious air pollution problems more obvious, and even affect people’s lives, the more serious problem of air pollution is a serious impact on the development of the city. Given the weather conditions are key processes affecting spatial and temporal distribution of atmospheric pollutants, the study of atmospheric processes in Urumqi city’s air pollution has significant influence mechanism.Urumqi air pollution problem is close to its special geographical environment, local meteorological conditions and pollution source status. Urumqi is more complex due to the terrain, previous studies are based on observations of individual contaminants and surface weather observations sites, only limited in a specific time and space, Difficult analysis of the causes of air pollution in the city with terrain, climate and emissions etc.In this paper, adoption the method of WRF numerical model combine with observations to Urumqi December 28,2012-January 1,2013and January 23,2013 -January 26 2013 two periods studied the accumulation of pollutants reason, Reproduction of these two periods Urumqi diurnal variation of temperature inversion strength and thickness and its causes, and the analysis of inversion and the surface wind field in the atmospheric environment effect field.The results showed that:1、In Winter, the inversion near the ground in Urumqi has a significant temporal variation. Influenced by topography and climate,Urumqi inversion generally has a longer duration, both daytime and nighttime temperature inversion exists, strength and thickness of inversion at night is greater than the day. The strongest areas of inversion strength appear in the northwest of Urumqi,the thickest inversion occurs in the northwest of Urumqi and Urumqi valley.2、Persistence of a certain intensity and thickness of the inversion layer over the city, it is not conducive to the spread of pollutants. The longer the duration of the inversion, the stronger the strength of the inversion, the thicker the thickness of the inversion layer and the lower the height of the inversion layer bottom provide favorable conditions for the accumulation of pollutants in the atmosphere, it seriously affect the city’s quality of atmospheric environment.3、Surface wind farm has an important impact on the diffusion of atmospheric pollutants, during rise or the peak concentration of pollutants, wind direction in East, North and West weather station has changed, mostly climbing wind direction, wind speed is low. It is not conducive to the spread of pollutants in the atmosphere, leading to an accumulation of pollutants. In addition, facing the wind of south and north will make the formation of a wind convergence zone in downtown area, exacerbated by air pollution situation.4、Influence of temperature inversion and surface wind field on the atmospheric concentration of pollutants have a certain lag.