摘要
应用颗粒物质量浓度、降尘、卫星遥感以及激光雷达气溶胶消光系数监测等资料分析,结合沙尘天气物理量场分析,揭示出大连沙尘天气特征和动力机制。结果显示,沙尘天气空气中可吸入颗粒物浓度显著增高,沙尘对空气中总悬浮颗粒物浓度有显著贡献,并且增加城市的自然降尘量。经过大连上空传输的沙尘高度一般在4km以下,普遍分布在1～3km之间;沙尘气溶胶消光系数最大值超过2.0km-1;沙尘影响地面时,近地面附近气溶胶消光系数超过0.5km-1,强沙尘过程超过1.3km-1。大连的沙尘天气是在高空西风或西北风急流对沙尘的搬运前提下产生,大连附近锋面后部的下滑运动是地面沙尘浓度增高的主要原因;锋后下滑气流越强,地面沙尘污染越重。
Based on the particle concentration, descending dust, satellite remote observation, the aerosol extinction coefficient derived from Lidar observational data and physical quantity of sanddust weather process affecting Dalian, the characteristic and dynamical mechanism of sand-dusts invading Dalian were analyzed. The results show that the concentration of inhalational and total suspending particles was increased remarkably and the descending dusts added in sand-dusts. It transported at a level below 4 kilometers in Dalian, mostly located between 1 and 3 kilometers with the maximal aerosol extinction coefficient over 2.0km^-1. It exceeds 0.5km^-1 near the ground and may be 1. 3km^- 1 in the case of strong process. The precondition was that there were sand-dust transportations of west-wind or northwest-wind jet streams, the glide streams in therear of the front near Dalian contributed mainly to the rising of sand-dusts concentration near the ground. The stronger the glide streams moved, the heavier the pollution induced by sand-dusts near the ground.
出处
《气象》
CSCD
北大核心
2008年第10期34-39,共6页
Meteorological Monthly
关键词
沙尘
颗粒物
气溶胶消光系数
动力机制
sand-dusts particle aerosol extinction coefficient dynamical mechanism
