长江三角洲南部雾霾天气的特点及其预报方法研究

Haze involves pollution emissions and the interaction between pollution composition and water vapor as well as cloud, but the mechanisms of haze formation are not been comprehensive understanding and the research on personalized problem of haze in subregion is not too much. In this project, based on the comprehensive observations of the complex atmospheric pollutions in the south of the Yangtze River Delta (Zhejiang), together with the routine meteorological data, MODIS satellite data and the aerosol sampling data, some researches will be carried out: The research on the space-time distribution and variation characteristics of haze weather in the south of the Yangtze River Delta; The research on the transportation and interaction of air pollutant between the Yangtze River Delta and its subregion-Zhejiang; The research on the weather and climate characteristics of haze formation and the atmospheric circulation characteristics in the Yangtze River Delta and Zhejiang; The research on localized method of Zhejiang haze forecast model. Through the above researches, the following purposes will be achieved: To reveal the key particulate types, the key emission and the pollutant distribution of haze weather in the south of the Yangtze River Delta; to gain the Qualitative even quantitative assessment of the transportation and interaction of air pollutant among different regions; to establish the weather and climate parameters database of haze formation; to obtain the parameterization scheme of weather model and the assimilation scheme of observation data. This project is benefit for us to promote the understanding of haze formation mechanism and improve the haze forecasting technology.

雾霾问题既涉及污染排放，也涉及污染成分与大气水汽及云雾的相互作用，但我们对其形成机理认识并不全面，对大区中小区域雾霾问题的个性化问题研究也不多。本项目利用长江三角洲南部（浙江省）大气成分的观测资料,结合常规气象观测资料、卫星观测资料、气溶胶采样资料，研究长江三角洲南部雾霾时空分布及其变化特征；研究长江三角洲大区与小区域之间大气污染物的传输和相互影响；研究长三角及浙江省雾霾天气特征及大气环流特征；研究长江三角洲南部雾霾预报本地化方法。项目研究结果将揭长江三角洲南部雾霾天气形成的关键颗粒物类型、关键排放物以及成分分布的地域性特征；获得区域污染物之间传输和影响的定性乃至定量评估；建立浙江省雾霾发生的各天气气候参数指标库；获得浙江省雾霾预报的天气模式参数化方案、观测资料同化方案。本项目的研究结果将提升对雾霾机理问题的认识，改善雾霾预报技术。

浙江省地处长江三角洲南冀，是经济活动最活跃、城市化水平最高的区域之一。本项目对该地区霾时空分布特征及成因、关键污染成分及来源、污染物区域间的输送、污染形成的天气及大气环流特征、霾数值预报方法等问题展开了研究。研究结果表明：.（1）受城市发展、地形、气候条件的影响，浙江省霾日分布呈东北部高于西南部、区域连接成片、超越城乡界线的分布特点；年霾日数在1979年和2000年左右出现两个跃变点，其中2000年后霾日的跃升幅度大于1979年。.（2）细颗粒物对浙江省霾形成的贡献大于粗颗粒物。细颗粒中主导无机水溶性离子为NO3-、NH4+和SO42-，不同离子具有不同的粒径分布特征及不同来源。细颗粒中含碳组分以OC为主，OC中又以二次有机物为主。.（3）高压控制下的天气形势、强对流天气诊断指数K<40、SI>-5的大气稳定度、逆温持续且低、风速小于2m/s比较容易诱发重霾天气。长江三角洲霾天气尤其是重霾天气发生的典型特征是前期北方冷空气南下，带来外来污染物，中后期冷、暖空气相持，造成本地污染物积累。.（4）WRF-Chem模式模拟效果优于CUACE／Haze模式。对WRF-Chem模式来说，RG_RG方案优于RM_GO方案，YSU方案优于MYJ方案；使用HTAP排放清单较INTEX-B、REAS排放清单模拟效果好；利用神经网络拟合和移动平均方法对预报值进行订正，能明显改善预报效果。单独减排效果较综合减排效果差。