基于激光测风雷达的兰州冬季风场特征及其与大气污染的关系  

Characteristics of Winter Wind Field in Lanzhou Based on Scanning Lidar and Its Relation to Air Pollution

作　　者：王倩倩 余晔 董龙翔[1,3,4] 赵素平 赵果 张彤[1,3,4] Wang Qianqian;Yu Ye;Dong Longxiang;Zhao Suping;Zhao Guo;Zhang Tong(Key Laboratory of Land Surface Process and Climate Change in Cold and Arid Regions,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,Gansu,China;University of Chinese Academy of Sciences,Beijing 100049,China;Pingliang Land Surface Process&Severe Weather Research Station,Pingliang 744015,Gansu,China;Gansu Land Surface Process&Severe Weather Observation and Research Station,Pingliang 744015,Gansu,China)

机构地区：[1]中国科学院西北生态环境资源研究院寒旱区陆面过程与气候变化重点实验室,甘肃兰州730000 [2]中国科学院大学,北京100049 [3]中国科学院平凉陆面过程与灾害天气观测研究站,甘肃平凉744015 [4]甘肃省陆面过程与灾害天气野外科学观测研究站,甘肃平凉744015

出　　处：《高原气象》2020年第3期641-650,共10页Plateau Meteorology

基　　金：国家重点研发计划项目(2018YFB1502801);国家自然科学基金项目(41575014)。

摘　　要：利用激光测风雷达2017年12月1日至2018年2月28日在兰州城区获取的风场资料,分析了兰州冬季风场结构特征,并通过聚类分析得到了冬季影响兰州地区的天气形势,分析了不同天气形势下的风场特征,在此基础上分析了局地环流主导下的风场和污染物浓度日变化特征及两者之间的相关性。结果表明,兰州2017年冬季低空水平风速整体较小,平均风向以偏东风为主;风场日变化特征明显,午后至傍晚水平风速大于其他时刻,03:00(北京时,下同)-08:00250~650 m维持偏西风,650 m以上偏南风增加,其余时刻各高度均以偏东风为主。兰州地区受弱高压控制时,局地环流占主导,城区污染严重。各高度污染系数最大值对应的风向存在差异,200 m以上污染系数迅速减小,增加污染物的排放高度至200 m以上可有效减少近地面污染物浓度。Based on wind profiles obtained from Scanning Lidar,the characteristics of wind field from 1 Decem‐ber 2017 to 28 February 2018 in Lanzhou were analyzed.Through the cluster analysis,the weather types affecting Lanzhou area in winter was obtained.The characteristics of wind field under different weather types and the diur‐nal variation characteristic were analyzed.The results show that,winter low-level wind speed during the study pe‐riod were very low,and were dominated by easterly wind.The diurnal variation of wind field was obvious,with higher wind speed from the afternoon to the evening than during other times.There was westerly wind at the height between 250 m and 700 m from night to the next morning,while easterly wind prevailed the rest of time below 800 m.In addition,local circulation was dominant when the study area was controlled by weak high-pressure,and the related low wind and strong downdraft led to serious pollution.The wind direction with the maximum air pollu‐tion index was different at each height and the pollution index decreased rapidly above 200 m.Increase the emis‐sion height of pollutants above 200 m can effectively reduce the concentration of near-surface pollutants.

关 键 词：激光测风雷达 兰州冬季风场 天气形势 污染物 

分 类 号：P404[天文地球—大气科学及气象学]