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利用激光雷达、PM10观测、地面及探空等综合观测资料,针对大连地区2006年4月7—8日的沙尘过程,基于Fernald积分法反演了沙尘过程气溶胶消光系数,分析了沙尘过程的时空分布特征及沙尘气溶胶的垂直结构,并对沙尘严重影响地面的原因进行了初步探讨。结果表明,激光雷达探测可以精确反映沙尘气溶胶的垂直结构和时空变化信息,并且能弥补人工气象观测的不足;此次沙尘影响高度较低,主体过境时沙尘层中心高度小于0.5km。沙尘层内消光系数最大达到0.96km-1;激光雷达反演得到的180m高度处的气溶胶消光系数与地面PM10浓度吻合较好;沙尘影响地面时,地面PM10浓度增大,相对湿度明显降低。大气低层逆温和近地面风速等气象条件对沙尘影响地面的时间和程度有很大作用。
According to the comprehensive observation data of laser radar, PM10, ground and sounding, aiming at the dust process in Dalian from April 7 to April 8, 2006, the aerosol extinction coefficient of dust process was inverted based on Fernald integral method. The temporal and spatial distribution of dust process and the vertical structure of dust aerosol, and the reasons for the serious impact of dust on the ground were discussed. The results show that lidar can accurately reflect the vertical structure and temporal and spatial variation of dust aerosol, and can make up for the lack of artificial meteorological observation. The dust impact height is low, and the height of sand dust center is less than 0.5km . The extinction coefficient in dust layer reached 0.96km-1 at the maximum, and the aerosol extinction coefficient at 180m height obtained by Lidar reconciliation was in good agreement with the PM10 concentration on the ground. When the dust affected the ground, the PM10 concentration on the ground increased and the relative humidity was significant reduce. Meteorological conditions such as inversion of the lower atmosphere in the lower atmosphere and near-surface wind speed have a great effect on the time and extent of dust impact on the ground.