乌鲁木齐市低空温度层结与采暖期大气污染的关系

为了找出乌鲁木齐市低空逆温对大气污染的影响规律,为治理和预测大气污染提供科学依据,利用2000年6月至2006年4月的乌鲁木齐市空气污染监测资料和气象站的探空、地面资料,分析了大气污染与逆温的对应特征。结果表明:乌鲁木齐市低空逆温的出现频率与大气污染指数具有相似的时间分布特征。采暖期空气污染指数API值越大,相对应出现逆温日的比例越高,以贴地逆温多;在污染源排放量一定的情况下,大气中污染物浓度与低空逆温层厚度、逆温层底高、逆温层顶底温差有显著的统计关系,而与逆温层中的逆温强度统计关系不显著。随着逆温层底高度降低,逆温层平均顶高、厚度、逆温层顶底温差的增大,日平均气温、最低气温、最高气温的降低,污染级别呈增加趋势;在采暖期同一时段内,要达到同样的污染级别,悬浮逆温日污染物容纳量比贴地逆温大,贴地逆温更容易造成空气污染;在污染物排放量相同的情况下,污染的程度主要取决于悬浮逆温层的底高和厚度及持续日数。

Relation between the low altitude temperature stratification and the heating period atmospheric pollution in Urumqi City

For finding out the regulation of the impact of ground inversion to the atmospheric pollution in Urumqi City,the characteristics of parallelism between ground inversion and air pollution were analyzed by means of the monitoring data of air pollution and weather factors in Urumqi City from Jun.,2000 to Apr.,2006.The results showed that the emergence frequency of the ground inversion and the air pollution index take on similar temporal distribution characteristics in Urumqi City.The higher the heating period air pollution index API value,the bigger the proportion of inversion occurence with the ground inversion being prior.Under the condition of pollution source emission to be definite,the statistical relations between the concentration of atmospheric pollution and the low altitude inversion thickness,the inversion base height and the temperature-difference of inversion from top to bottom were apparent,while the relation between the concentration of the atmospheric pollution and the inversion intensity was insignificant.When the inversion base lowered,the average ceiling-height,the thickness,the temperature-difference of the inversion from top to bottom augmented and mean daily temperature,daily minimum temperature,daily maximum temperature declined,the pollution scale displayed an aggravating trend.Under the condition of the same pollution emission quantum,the polluting degree was depended on the base-height and thickness of the suspended inversion,and its persistence days.The results could provide scientific gist for the management and prediction of the atmospheric pollution.