重庆市主城区空气污染天气特征研究

利用2003～2008年重庆市主城区大气污染监测资料，分析了轻度污染以上天气的变化特征。结果表明重庆主城区的主要污染物为PM10，PM10浓度具有独特的“双峰双谷”日变化特征；污染天气具有明显的季节特征，主要污染期为秋末到初春；污染天气具有连续性特征，污染天气持续时间尺度主要集中在2～7 d；污染天气过程具有典型的大气环流和天气特征，本地地面天气类型主要以低压或均压场为主，中高纬度高空以纬向环流或西北气流为主，天气以阴天或阴晴相间为主；污染天气过程中本地气象要素变化呈现规律性，地面24 h气压变化总趋势为负变压，24 h变温为正变温，平均相对湿度维持在72%～85%，风速的变化趋势不大，基本维持在1～2 m/s，低层逆温明显。污染天气过程结束时气压明显回升，温度显著下降，相对湿度显著增加。

RESEARCH ON WEATHER CHARACTERISTICS OF AIR POLLUTION IN CHONGQING

According to the air pollution monitoring data in Chongqing city during 2003～2008,we analyzed the weather characteristics of the changes of pollution events.The results showed that the major pollutant was PM10 in Chongqing.The consistency of PM10 had a diurnal fluctuations called “Dual Peaks and Dual Valley”.The pollution weather had obvious seasonal and continuity characteristics that these pollution events mainly occurred from late autumn to next early spring with continuing period for 2～7 d.The process of the pollution weather had the typical characteristics of atmospheric circulation and weather.Local atmospheric circulations were equipped with low or mean pressure in the lower troposphere and zonal or northwest flows in the upper troposphere,resulting in overcast sky or rain sunshine.In the process of the pollution weather,local meteorological elements had regular changes，such as in 24 h the ground air pressure changed in negative,temperature changed in plus,〖JP2〗average relative humidity was between 72% and 85%,the wind speed changed little and kept 1～2 m/s,low level inversion was evident.When the pollution weather was over,air pressure would pick up obviously,temperature would drop，and the relative humidity would increase.〖