机构地区:[1]中国环境监测总站,北京100012 [2]北京科技大学能源与环境工程学院,北京100083
出 处:《环境科学》2019年第12期5191-5201,共11页Environmental Science
基 金:国家自然科学基金项目(41875164)
摘 要:对京津冀区域2013年9月至2018年2月连续5个秋冬季PM2. 5的污染特征和气象影响因素,2015年10月至2018年2月连续3个秋冬季以及典型污染过程时NAQPMS、CMAQ和CAMx这3个模式PM2. 5的预报结果进行了分析评估,对模式预报的不确定性和改进措施进行了探讨.结果表明,5个秋冬季PM2. 5区域均值浓度分别为122、98、82、99和65μg·m-3,污染过程(中度及以上污染过程)期间浓度分别为229、198、210、204和180μg·m-3. 5个秋冬季累计发生64次PM2. 5为首要污染物的区域污染过程,2013~2014年秋冬季污染过程平均持续时间最长,2017~2018年持续时长最短.除2016~2017年外,其他年份PM2. 5浓度峰值和均值逐年降低,区域总体污染形势减轻.秋冬季PM2. 5浓度与相对湿度、风速和日照时数相关性相对较好,与温度和气压的相关性整体较弱.当风速小于2 m·s-1、大气相对湿度65%以上、主导风向为西南和东北风时,容易出现区域中度及以上污染过程.此外,3个模式均能够预测出京津冀区域秋冬季PM2. 5污染过程,预报值与监测值体现了较好地相关性. 3个模式对张家口、承德和秦皇岛的预报结果较好,对唐山、石家庄、保定、北京和天津等城市预报偏高,这与污染源清单、气象初始场和气象预报、以及大气化学反应机制的不确定性有一定关系.This paper discusses the concentration characteristics of PM2.5,as well as its relationship with meteorological factors in autumn and winter(from September to the following February),from 2013 to 2018 in the Beijing-Tianjin-Hebei(BTH)region.The accuracy and uncertainty of the air quality forecast models NAQPMS(nested air quality prediction modeling system),CMAQ(community multiscale air quality modeling system),and CAMx(comprehensive air quality model with extensions)were analyzed based on the model-predicted and measured PM2.5 concentration in autumn and winter from 2015 to 2018.The accuracy of NAQPMS,CMAQ,and CAMx during typical heavy air pollution was also tested.Moreover,methods to improve the accuracy of the model forecast were discussed.The results showed that the mean concentrations of PM2.5 in the BTH region were 122,98,82,99,and 65μg·m-3 in the five autumn and winter periods,respectively.When the air quality index(AQI)exceeded 150 during each autumn and winter,it reached 229,198,210,204,and 180μg·m-3,respectively.There were 64 occurrences of heavy regional PM2.5 air pollution in autumn and winter from 2013 to 2018.The average duration was longest in the 2013 to 2014 period,and shortest in the 2017 to 2018 period.The peak concentration and average concentration of PM2.5 decreased year on year,except for the period from 2016 to 2017.In autumn and winter,PM2.5 concentration had a relatively close relationship with relative humidity,wind and sunshine duration,compared with a weak relationship with temperature and air pressure.Regional heavy air pollution always happened under the condition of low wind speed(less than 2 m·s-1),higher relative humidity(greater than 65%),and southwest and northeast wind direction.In addition,the heavy air pollution of PM2.5 in BTH in autumn and winter can be effectively forecasted by NAQPMS,CMAQ,and CAMx.The predicted and measured PM2.5 concentration showed a close relationship.The models performed well in forecasting Zhangjiakou,Chengde,and Qinhuangdao,but by contrast over
分 类 号:X513[环境科学与工程—环境工程] X831
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