黑龙江省西南部一次大范围霾的天气分析

Analysis of haze process on large-scale in southwest of Heilongjiang province

利用地面观测资料以及NCEP/NCAR再分析资料,分析了2011年1月20-24日黑龙江省西南部一次大范围持续性霾过程的变化特点及环流背景;诊断分析了该次过程中动力、水汽及不稳定条件。结果表明:该次过程表现为明显的日变化特征。霾过程持续期间,黑龙江省处于纬向型环流的控制之下,冷空气势力弱;黑龙江西南部整体处于地面高压内的均压场中,有利于霾维持。近地面气象要素中相对湿度和风速与霾的严重程度相关很好,能够解释霾的日变化特点。近地层弱的辐合上升、中高层的辐散下沉运动,有利于逆温增强,并使水汽和污染物扩散到一定高度,使霾维持,抑制其消散。

A large scale continuous process of haze occurred in the southwest of Heilongjiang province in20-24 January, 2011 is comprehensively analyzed based on the observed data and NCEP/NCAR reanalysis data. The results are that： the process shows obvious diurnal variation. In the duration of the haze process, Heilongjiang was under the control of zonal circulation, and the cold air is weak, The southwest of Heilongjiang is in the overall mean high pressure filed which is conductive to maintaining of the haze. The correlation between near surface meteorological element relative humidity and wind speed and ~s severity of haze is very well, it can explain the diurnal variation of haze.Weak convergence in the Lower level and divergence in the middle-high level is conductive to the enhancement of inversion. It made the water vapor and poUutants diffuse to a certain height and maintained haze for a long time.