2021年宁夏两次持续沙尘重污染天气对比分析  

Comparative and Analysis of Two Persistent Severe Dust Pollution Weather Events in Ningxia in 2021

作　　者：雍佳 王建英 田林锋 张肃诏 龚晓丽 顾驭程 严晓瑜[2] YONG Jia;WANG Jianying;TIAN Linfeng;ZHANG Suzhao;GONG Xiaoli;GU Yucheng;YAN Xiaoyu(Key Laboratory for Characteristic Agric-Meteorological Disaster Monitoring,Forecasting and Risk Management in Arid Regions,China Meteorological Administration,Yinchuan 750002,China;Ningxia Meteorological Service Center,Yinchuan 750002,China;Ningxia Ecological Environment Monitoring Center,Yinchuan 750002,China;Ningxia Meteorological Observatory,Yinchuan 750002,China)

机构地区：[1]中国气象局,旱区特色农业气象灾害监测预警与风险管理重点实验室,宁夏银川750002 [2]宁夏气象服务中心,宁夏银川750002 [3]宁夏生态环境监测中心,宁夏银川750002 [4]宁夏气象台,宁夏银川750002

出　　处：《环境科学研究》2024年第2期289-298,共10页Research of Environmental Sciences

基　　金：宁夏回族自治区重点研发计划项目(No.2021BEG03006);宁夏自然科学基金项目(No.2021AAC03487);宁夏回族自治区生态环境厅重大研究课题。

摘　　要：为探究气象条件变化对宁夏沙尘重污染天气过程的影响特征,利用常规气象观测数据、NCEP再分析资料及环境空气质量数据,选取2021年1月11-14日和2021年3月14-19日两次沙尘重污染天气(分别简称“0113”过程和“0315”过程)为研究对象,基于天气形势、后向轨迹模拟及物理量场诊断等方法,对比两次过程影响系统及传输轨迹,探讨形成和维持机制.结果表明:①“0113”过程主要影响宁夏北部四市,“0315”过程影响整个宁夏,两次沙尘过程中重度及以上污染平均持续时间分别为35.0和105.2h,沙尘污染暴发阶段PM_(10)浓度平均值分别为1735和5265μg/m3.②“0113”过程为一次强度一般的锋面过境引起的沙尘重污染天气,稳定少动的青藏高压与其北侧蒙古热低压之间形成显著的气压梯度带,高空脊前多股强西北气流引起动量下传,使宁夏及上游地区大风将沙尘输送至宁夏造成重污染;“0315”过程为一次较强的典型锋面过境及蒙古气旋造成的持续沙尘重污染天气,蒙古冷高压受强盛蒙古气旋和青藏高原热低压夹击稳定少动,其西南、东南及东部与两个热低压形成气压梯度带,加之受地面冷锋过境影响,宁夏及周边地区多方向大风将沙尘向宁夏上空输送造成“0315”过程较“0113”过程污染更严重.③两次过程中沙尘均为境外和境内同时输送,“0113”过程为西北和偏西路径,传输距离长且高度较低;“0315”过程为西北、偏北和偏东路径,传输距离短且高度较高.④“0315”过程中蒙古国及我国新疆-甘肃一带负水平螺旋度中心值为“0113”过程的1.75倍,较强的辐合上升运动和西风气流将沙尘持续向宁夏上空输送并与本地沙尘叠加,上升和下沉运动交替使沙尘长时间悬浮于空中,而“0113”过程受多股强下沉气流造成沙尘迅速沉降至地面,污染快速减弱.研究显示:冷锋和蒙古气旋是宁夏沙尘重污染�In order to explore the impact of meteorological conditions on the severe dust pollution in Ningxia,conventional meteorological observation data,NCEP reanalysis data and ambient air quality data are used.Two severe dust pollution events from the January 11th to 14th,th 2021 and March 14 to 19th,2021(referred to as‘0113’and‘0315’processes respectively)are selected as the research objects.Based on the methods of weather situation,backward trajectory simulation and physical quantity field diagnosis,the effects of the two processes on the system and transmission trajectory are compared,and the formation and maintenance mechanism are discussed.The results show that:(1)The‘0113’process mainly affected the 4 cities in northern Ningxia,and the‘0315’process affected the entire region of Ningxia.The average duration of severe pollution or above is 35.0 hours and 105.2 hours,respectively.The average PM_(10) concentration of the dust 3 pollution‘outbreak’stage is 1735μg/m and 5265μg/m3,respectively.(2)The‘0113’process is a severe dust pollution weather caused by the passing of the front of average intensity.A significant pressure gradient band is formed between the stable and low-moving Qinghai-Tibet high pressure and the Mongolia thermal low pressure to the north.Several strong northwest air currents in front of the upper ridge decreased the momentum,and the wind transported dust to Ningxia and the upstream area,causing severe pollution.The‘0315’process is a relatively strong and typical front transit and continuous severe dust pollution process caused by the Mongolian cyclone.The Mongolian cold high pressure is stable and less moved by the strong Mongolian cyclone and the Tibetan Plateau thermal low pressure.A pressure gradient band with two thermal low pressures is formed in its southwest,southeast and east.In addition,affected by the transit of the surface cold front,the multi-direction winds in Ningxia and the surrounding areas transported dust over Ningxia,resulting in heavier pollution in

关 键 词：沙尘重污染 污染浓度 天气系统 输送轨迹 物理量场 

分 类 号：X513[环境科学与工程—环境工程]