京津冀地区一次持续时间较长浮尘天气的分析  

Analysis of a Persistent Floating Dust Event Occurring over the Beijing-Tianjin-Hebei Region

作　　者：张迎新[1] 李林[2] 曹晓冲 李梓铭 马小会 张玉婷 ZHANG Yingxin;LI Lin;CAO Xiaochong;LI Ziming;MA Xiaohui;ZHANG Yuting(Beijing Weather Forecast Center,Beijing 100089,China;Beijing Meteorological Bureau Atmospheric Sounding Center,Beijing 100089,China;Hebei Meteorological Observatory,Shijiazhuang 050021,China;Beijing Environmental Meteorology Center,Beijing 100089,China;Hengshui Meteorological Observatory,Hengshui 053000,China)

机构地区：[1]北京市气象台,北京100089 [2]北京市气象局大气探测中心,北京100089 [3]河北省气象台,河北石家庄050021 [4]北京市环境气象中心,北京100089 [5]衡水市气象台,河北衡水053000

出　　处：《沙漠与绿洲气象》2021年第4期123-129,共7页Desert and Oasis Meteorology

基　　金：国家重点研发计划项目2018YFC1507305;河北省科技计划项目17275409D。

摘　　要：2017年5月3-4日京津冀地区出现了一次持续较长时间的浮尘天气,给京津冀地区的生产和生活带来了较大的影响。从气象条件方面分析了浮尘天气的成因及维持机制,并使用气象、环境观测、激光雷达探测、后向轨迹模式产品等分析了此次浮尘天气的观测事实。结果表明,此次过程是在蒙古气旋强烈发展东移的过程中,经过蒙古国中部、甘肃、内蒙中西部的沙源地后形成扬沙、沙尘暴,大量的沙尘粒子随高空偏西西北气流漂至京津冀上空后沉降而形成的,本地沙源没有补充。激光雷达可以清晰地监测到沙尘的传输高度基本在2~4 km。浮尘天气期间,沙尘高度在2 km以下。浮尘维持30 h以上的原因:(1)高空受东、西两槽间的纬向环流控制,地面处于鞍型场,风速小,不利于沙尘粒子的扩散;(2)边界层内湍流活动旺盛,且中低层基本是中性层结状态,沙尘粒子不易沉降。A severe floating dust event occurred in the Beijing-Tianjin-Hebei region during May 3rd and 4th,2017,which induced a great impact on the manufacture and life of the region.This paper mainly analyzed the formation of the floating dust event.Its source and transmission height were revealed by using meteorological and environmental observation,lidar detection,and backward trajectory model products.The results show that the floating dust event was formed when the Mongolian cyclone moved eastward,passing over the sand source area in the middle and western parts of Inner Mongolia,Gansu,central Mongolia.A large number of small dust particles which came from central Mongolia and western Inner Mongolia and followed the west-northwest airflow were carried high into the atmosphere of the Beijing-Tianjin-Hebei area and then subsided in the same place.During the transportation period,the dust transmission height was between 2 and 4 km,while after reaching the Beijing-Tianjin-Hebei region,the dust mainly concentrated below 2 km according to the lidar.The main meteorological reasons for floating sand maintaining over 30 hours were zonal flow in upper-level air and a saddle field on the ground,which caused weak wind when it was close to the surface.In addition,the middle and lower layers were basically in a neutral stratification state,with flourishing turbulent activity,which resulted in the dust particles are not easy deposition.

关 键 词：浮尘 传输高度 观测分析 京津冀 

分 类 号：P458.3[天文地球—大气科学及气象学]