| 摘要: |
| 利用杭州市气象局观测资料、NCEP再分析资料和中尺度天气预报模式WRF的数值模拟结果，对杭州市2011—2012年春、夏、秋、冬4个季节各一天的污染天气进行分析；同时选取2012年夏季有利于污染物扩散的天气个例进行对比分析。结果表明，杭州市容易发生轻度污染的天气类型主要有4类：高压前部、高压底部、高压控制和高压后部；500hPa高空系统稳定，受西南气流影响，850hPa有暖平流，1 000hPa风速较小时，容易造成污染物的积累，发生空气污染现象。WRF模拟结果显示，当杭州市为偏北风且风速较小时，容易发生空气污染事件，当为偏南风且风速较大时，空气质量一般较好。温度层结分析发现，当近地层以及高空出现较为深厚的逆温层且低层温度层结呈现中性或者稳定时，不利于污染物的扩散，污染物容易在底层积累，出现近地层空气污染现象。 |
| 关键词: 天气形势 空气污染 气象特征 数值模拟 杭州 |
| DOI： |
| 分类号:X823 |
| 文献标识码:B |
| 基金项目:国家自然科学基金资助项目（41305006；41575141）；江苏省自然科学基金资助项目（BK2012314） |
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| Analysis of the Characteristics of Different Weather Condition Impact on Air Quality in Hangzhou by Case Studies |
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WANG Xueyuan，JIANG Yaping，LIU Hongnian，ZHANG Ning
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School of Atmospheric Sciences，Nanjing University，Nanjing，Jiangsu 210023，China
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| Abstract: |
| Using the observation data of Hangzhou meteorological bureau，final reanalysis data provided by NCEP and the WRF model results，the meteorological and pollution characteristics of four cases by different weather types in each season （spring，summer，autumn，winter） from 2011 to 2012 were analyzed. By contrast，another case in the summer of 2012 which was propitious to the spread of pollutants also was analyzed. The results showed that there had four kinds of weather types（the forepart of high pressure，the bottom of high pressure，high pressure control and the back of high pressure）easily occurred light air pollution. The result indicated by the synoptic situation showed that when the 500 hPa level synoptic maps had stable high pressure system and simultaneously was affected by the southwest airflow，and the 850 hPa level synoptic maps had worm advection，and 1000hPa level synoptic maps had low wind speed would easily cause the accumulation of the pollutants，and occur air pollution episode. The WRF model results showed that the northerly direction and small wind speed was easily leading to the air pollution incidents. On the other hand，under the southerly direction and larger wind speed condition，the air quality was generally good. The analysis of the temperature stratification showed that the deep inversion layer and the neutral or stable temperature stratification at the surface layer and upper air would cause to the accumulation of pollutants at the bottom layer，and meanwhile leading to the air pollution. |
| Key words: Synoptic situation Air pollution Meteorological conditions Model simulation Hangzhou |
