南京地区一次灰霾天气的微脉冲激光雷达观测分析

摘要

A haze event in Nanjing during October 2012 was intensively measured with micro pulse lidar (MPL). By combining the MPL-measurements with the observations of meteorology, PM10 and PM2.5, we analyzed the variations of PM-concentrations, meteorological elements, vertical aerosol profiles with the optical property and mixing layer height (MLH) and their relations. The differences of extinction coefficients and MLH between the haze event and the non-haze period of November 11-12, 2012 were also comapared. The analysis show that the diurnal changes of PM-concentrations and extinction coefficients were in the relatively similar pattern with the high values in night and the low values in afternoon during the haze event. The peak of MLH lagged 2hours behind the peak of air temperature. There was a negative correlation between MLH and PM2.5 during the haze event, correlation coefficient was-0.57. Compared to the non-haze period, the MLH was much lower during the haze event and most of the extinction coefficients exceeded 1.0km-1, which was much higher than the extinction coefficients from 0.1 to 0.25 km-1during the non-haze period.%利用微脉冲激光雷达(MPL)对2012年10月南京地区的一次灰霾天气进行了不间断观测,结合地面气象要素和PM10、PM2.5质量浓度资料分析了此次污染过程颗粒物质量浓度、气象要素、气溶胶垂直方向光学特性和混合层高度(MLH)日变化趋势以及相关性并与11月11~12日非灰霾天气做了消光系数和 MLH 的比较.结果表明,本次灰霾天气颗粒物浓度与近地面消光系数日变化较相似,基本上呈现夜间高午后低的趋势；灰霾期间MLH峰值滞后于地面温度峰值2h,MLH与PM2.5呈现负相关关系,两者相关系数为-0.57；霾天MLH远低于非灰霾天；霾期间近地面消光系数大部分时刻大于1.0km-1,远大于非霾日0.1~0.25km-1范围的消光系数.