北京地区空气质量指数时空分布特征及其与气象条件的关系

Relation Between the Spatial-temporal Distribution Characteristics of Air Quality Index and Meteorological Conditions in Beijing

分析了北京地区2013年1-2月空气质量指数AQI的时空分布特征,及紫外吸收性气溶胶指数(AAI)、气象观测要素(相对湿度、气压和风速)、大气环流特征、混合层高度、总体理查森数(RB)与AQI的相关性等;同时对气象观测要素与AQI关系进行了拟合,建立了回归方程。研究结果及主要结论如下:北京地区AQI呈现出了一种自东南向西北递减的分布趋势;紫外吸收性气溶胶指数(AAI)与AQI之间呈明显正相关关系,相关系数r=0.456,可以作为污染物监测的参考;相对湿度、气压与AQI有着较好的相关性,相关系数分别为0.67、-0.49,建立的最优回归方程得到的拟合结果与实际观测效果对比良好;500 hPa乌拉尔山至贝加尔湖地区的高压脊是北京地区是否形成持续性污染的重要天气系统;AQI与1-2月混合层高度呈明显的负相关关系,相关系数为-0.511,持续低于459 m的混合层高度有利于污染物堆积;总体理查森数≥10.63时,有利于次日污染持续或发展等。

The paper analyzed the spatial-temporal distribution characteristics of air quality index （AQI） from January to February, 2013 in Beijing and the correlation of UV absorbing aerosol index （AAI） , meteorological observational elements（ relative humidity, barometric pressure and wind speed） , atmospheric circulation characteristics, mixed layer height, RB with AQI was also analyzed. Meanwhile the relationship between meteorological observational elements with AQI was fitted and the regression equation was established. The main results were as follows. AQI in Beijing showed a trend from southeast to northwest distribution decreasing. AAI and AQI showed a positive correlation, and the correlation coefficient r was 0.456, which can be used as a reference to monitor pollutant. Relative humidity, barometric pressure and AQI had a good correlation, and the correlation coefficient were 0.67 and - 0.49 respectively, the results of regression equation established compared well with the observed effects. High-pressure ridge from the Ural Mountains to the Lake Baikal region at 500 hPa was an important weather system of forming persistent contamination whether or not; AQI and the mixed layer height had a significant negative correlation, the correlation coefficient was - 0. 511, the mixed layer height of below 459 m consistently was in favor of the pollutant accumulation. When RB was great than or equal to 10.63, it was in favor of the pollutant sustained or development in the next day.