京津冀大气重污染过程数值预报与评估

发布时间：2018-06-02 02:44

本文选题：京津冀区域 + PM_(2.5)　；参考：《南京信息工程大学》2016年硕士论文

【摘要】：我国区域空气质量远未达标,大气重污染事件频发,京津冀区域尤为严重。因此,迫切需要大气污染业务预报。空气污染数值预报是一种有效的获知未来空气质量方法,它可以深入分析污染过程演变特征,解析污染物的来源和去向,及模拟预测应急控制效果等。2013年开始中国环境监测总站联合中国科学院大气物理研究所建立了京津冀预报预警业务化测试系统,从该年开始开展区域6项污染物及AQI预报预警服务,并重点关注京津冀区域的重污染天气过程。业务预报时,主要关注重污染天气过程的起始时间,持续时间以及污染影响的空间范围。因此,本文利用2013和2014年测试系统的预报产品,从上述三个方面着手发展了一种用于评估京津冀区域重污染过程数值预报能力的新方法,并探讨重污染天气过程早报、晚报及漏报的可能气象条件原因,以提高预报准确率。结果表明：(1)数值模式系统提前三天预告重污染天气过程的预报准确率可达57%,秋冬季预报效果好于其他季节,静稳型预报效果好于沙尘型和特殊型。(2)对模式AQI预报结果统计发现,当预报AQI值达到150以上时,实际发生重污染天气过程的概率较大,如定义AQI等于150作为重污染天气预警临界值,模式预报准确率可提高至70%以上。(3)天气系统对污染过程预报有重要影响,WRF气象模式对中低层天气系统位置及强度预报偏差是导致静稳型污染过程早报和晚报的一个重要原因。本文将发展的新方法应用于评估预测2006-2015年冬奥会同期发生重污染的风险。2022年冬季奥运会将在北京举行,届时北京地区空气质量要达到国家标准和世界卫生组织指导值要求。通过对2006-2015年冬奥会同期PM_(2.5)浓度研究表明,冬奥会同期北京PM_(2.5)浓度会出现不同程度超标现象,其中,2014年污染最为严重,2015年则相对较好,且在历年的2月13-16日易出现持续的重污染天气过程。假设2022的2月污染程度和气象条件介于2014和2015年之间,利用发展的新方法评估模式系统的这一过程模拟能力,并对2022年污染风险进行评估,在此基础上设计减排实验,使得会期不出现重污染。本文从气象和排放源两个方面,研究不同年份冬奥会同期污染物浓度变化的主要原因。研究对比2014年2月和2015年2月两组气象条件下北京和张家口PM_(2.5)浓度水平及模拟效果,结果表明：(1)减排方案使得2014年和2015年冬奥会同期PM_(2.5)浓度在130ug/m3以下,除13-16日外,其他日期空气质量达标。(2)对比2014和2015年冬奥会历史同期,2014年气象要素引起北京和张家口PM_(2.5)升高40%-60%,SO_2和NO_2浓度升高0-40%(3)2014年减排使得PM_(2.5),SO_2和NO_2浓度降低60%以上,2015年减排使得PM_(2.5)浓度降低40%-60%。
[Abstract]:The regional air quality in China is far from reaching the standard, and heavy air pollution events occur frequently, especially in Beijing, Tianjin and Hebei. Therefore, there is an urgent need for operational air pollution forecasting. Numerical prediction of air pollution is an effective way to know the future air quality. It can analyze the evolution characteristics of pollution process and analyze the source and destination of pollutants. In 2013, China Environmental Monitoring General Station and the Institute of Atmospheric Physics of the Chinese Academy of Sciences established the Beijing-Tianjin-Hebei early warning operational test system. From this year, six regional pollutant and AQI forecasting and early warning services have been developed, and the heavy pollution weather process in Beijing, Tianjin and Hebei regions has been focused on. Operational forecasting focuses on the starting time, duration and spatial range of heavy pollution weather processes. Therefore, using the forecast products of the 2013 and 2014 test systems, this paper develops a new method for evaluating the numerical forecast ability of heavy pollution processes in the Beijing-Tianjin-Hebei region from the above three aspects, and probes into the morning report of heavy pollution weather processes. In order to improve the accuracy of forecast, the possible meteorological conditions of the evening newspaper and the missing report are caused. The results show that the forecasting accuracy of the numerical model system for predicting heavy pollution weather process three days in advance can reach 57%, the prediction effect of autumn and winter is better than that of other seasons, and the prediction effect of static and stable model is better than that of sand dust type and special type. When the forecast AQI value is more than 150, the probability of serious pollution weather process is high, such as defining AQI equal to 150 as the critical value of heavy pollution weather warning. The prediction accuracy of the model can be increased to more than 70%.) the weather system has an important influence on the prediction of the pollution process. The deviation of the WRF weather model for the prediction of the position and intensity of the low and middle layer weather system is an important reason leading to the static and stable pollution process morning report and evening report. In this paper, the developed new method is applied to evaluate and forecast the risk of heavy pollution in the same period of the 2006-2015 Winter Olympics. The 2022 Winter Olympic Games will be held in Beijing when the air quality in Beijing will meet the requirements of national standards and WHO guidelines. According to the study of PMstack 2.5) concentration in the same period of the 2006-2015 Winter Olympic Games, it is shown that there will be different levels of exceeding the standard in the same period of the Winter Olympics in Beijing. Among them, the pollution in 2014 is the most serious, and the pollution in 2015 is relatively good. And on February 13-16 of the calendar year easy to appear the continuous heavy pollution weather process. Assuming that February pollution and meteorological conditions in 2022 are between 2014 and 2015, using a new developed method to assess the process simulation capability of the model system, and assessing the pollution risk in 2022, an emission reduction experiment is designed. Avoid heavy pollution during the session. In this paper, the main reasons of pollutant concentration change in different years of Winter Olympic Games are studied in terms of meteorology and emission sources. The study compared the concentrations of PM2. 5 in Beijing and Zhangjiakou in February 2014 and February 2015. The results showed that the emission-reduction scheme resulted in a concentration below 130ug/m3 in the same period of the 2014 and 2015 Winter Olympics, except for 13-16 days. Compared with the historical period of the Winter Olympics in 2014 and 2015, the meteorological elements in 2014 caused 40 to 60 higher levels in Beijing and Zhangjiakou than in the same period in the history of the Winter Olympic Games in 2015.) in 2014, the emission reduction resulted in a reduction of more than 60 percent in the concentrations of PMN 2.5 and NO_2, and a reduction of 40 to 60 in the concentration of PMS2 and NO_2, as a result of the increase in the concentrations of so 2 and NO_2 in 2014.
【学位授予单位】：南京信息工程大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X51

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