摘要
应用常规观测资料、NCEP 1°×1°再分析资料,分析2013年山东分别出现雾和霾的两次严重污染过程,结果表明:(1)大气静稳状态时,500 h Pa为脊前西-西北气流,850 h Pa为暖脊,有弱暖平流,地面气压场较弱,易出现逆温、混合层高度低、风速小,导致大气水平和垂直扩散能力差。850 h Pa弱上升和700 h Pa弱下沉,造成高空干洁大气和地面"脏"空气对峙的局面,垂直交换停滞是雾-霾和污染持续的根本原因。(2)强冷空气驱散雾-霾的过程,正是打破了空气垂直交换停滞的状态,使得高空清洁大气能够下沉到地面。空气质量的根本改善由垂直交换完成。(3)弱冷空气伴随的弱下沉运动和锋面附近整层上升运动能够减轻污染。(4)冷锋过后剧烈下降的地面露点温度即是高空干洁大气到达地面的标志。
Using conventional observations and the NCEP 1°×1° analysis,one severe fog process and one severe haze process occurred in Shandong province in 2013 are analyzed. The main results are as follows：（ 1） The stagnancy of vertical exchanges is the critical characteristic for the duration of fog and haze. The meteorological conditions for fog and haze are west-northwestlies to the east of the 500 h Pa ridge,the weak warm advection near the 850 h Pa warm ridge,and the weak pressure system on the surface. The conditions are propitious to temperature inversion,lowmixed layer height and small winds,thus leading to weak horizontal and vertical diffusions.The weak ascent at 850 h Pa and the weak descent at 700 h Pa cause the stalemate between the upper clean air and the lower dirty air.（ 2） The restoration of vertical exchanges is the key to air quality improvement. The strong cold air breaks the stable meteorological conditions,hence the upper dry and clean air can sink to the ground.（ 3） The fog and haze can be mitigated by the weak descent of the weak cold air and the near-front ascent of the whole atmosphere.（ 4） The dramatic decrease of surface dewpoint after the passage of the cold front indicates that the upper dry and clean air has reached the ground.
出处
《高原气象》
CSCD
北大核心
2017年第4期1106-1114,共9页
Plateau Meteorology
基金
山东省气象局重点项目(2014sdqxz01)
关键词
雾-霾及污染
垂直交换
高空干洁大气下沉
地面露点温度
Severe haze and polluted fog
Vertical exchange
The dry and clean air at upper layer
Surface dew point
作者简介
孙兴池（1963-），女，山东莱州人，正高级工程师，主要从事天气预报和相关技术研究．E—mail：sdqxts@163．com
