摘要
2023年12月,位于塔克拉玛干沙漠南缘的民丰地区经历了一次长达十余天的沙尘污染天气,为了探究本次污染过程的沙尘传输机制及其影响因素,基于气溶胶激光雷达数据,并结合地面气象观测数据、ERA5再分析资料和HYSPLIT后向轨迹模式,对本次污染过程中的气象要素变化、天气形势变化和沙尘气溶胶的垂直分布及其潜在来源进行了分析.结果表明:①本次污染过程持续时间较长,根据地面气象要素与颗粒物浓度的实时变化情况可以划分为污染前、重污染和污染消散3个阶段.②污染过程中近地面主要受偏西风与东北风影响,并以东北风为主要的沙尘传输气流.污染前期低温高湿和高风速的条件下易使得颗粒物浓度升高,而较高的颗粒物浓度会造成能见度降低,进而促进污染天气的发生,而污染后期较高的风速能促进污染物的扩散,加速污染的消退.③本次过程污染物以沙尘气溶胶为主,传输高度最高可达1.5km,平均高度为0.55km,消光系数与退偏振比在垂直方向上整体呈现出随高度升高而递减的变化趋势.④气旋与冷锋是影响本次过程的主要天气系统,而来自塔里木盆地东北方向途经塔克拉玛干沙漠的气流则是主要的沙尘传输气流,塔克拉玛干沙漠内的沙尘气溶胶为主要的污染物来源.
In December 2023,the Minfeng region situated at the southern fringe of the Taklamakan Desert endured a prolonged episode of sand and dust pollution spanning over ten days.To investigate the transmission mechanisms and influencing factors of this pollution event,a comprehensive analysis was conducted.This analysis integrated aerosol LiDAR data,surface meteorological observations,ERA5 reanalysis datasets,and the HYSPLIT backward trajectory model to examine the changes in meteorological elements,the weather patterns,the vertical stratification,and the potential origins of sand and dust aerosols throughout this pollution episode.The findings indicate the following:①The pollution occurrence persisted for an extended duration and comprised three distinct phases—pre-pollution,peak pollution,and pollution dissipation—categorized by real-time variations in surface meteorological conditions and particulate matter concentrations.②Prevalent westerly and northeasterly winds predominantly influenced the near-surface environment during the event,with the northeasterly flow chiefly responsible for dust conveyance.Initial low temperatures,high humidity,and strong winds facilitated an increase in particulate concentration,leading to reduced visibility and fostering the onset of polluted conditions.Conversely,later increases in wind speed aided the dispersion of pollutants,thus expediting the amelioration of pollution.③The primary pollutants during this event were dust aerosols,rising to a peak transport altitude of approximately 1.5 km and an average altitude of 0.55 km.A general trend showed the extinction coefficients and depolarization ratios diminishing with altitude.④Cyclones and cold fronts were the prominent weather systems impacting the event.Airflows originating from the northeast of the Tarim Basin and traversing the Taklamakan Desert were the principal contributors to dust transport,pinpointing the desert as the primary source of pollutants.
作者
李晶晶
何清
阴璐璐
付光祥
徐月月
张乾
LI Jingjing;HE Qing;YIN Lulu;FU Guangxiang;XU Yueyue;ZHANG Qian(College of Geography Science and Tourism,Xinjiang Normal University,Urumqi 830054;Xinjiang Key Laboratory of Desert Meteorology and Sandstorm,Taklimakan Desert Meteorology Field Experiment Station of China Meteorological Administration,National Observation and Research Station of Desert Meteorology,Taklimakan Desert of Xinjiang,Institute of Desert Meteorology,China Meteorological Administration,Urumqi 830002;Minfeng County Meteorological Bureau,Hetian,Xinjiang Uygur Autonomous Region,Minfeng 848599)
出处
《环境科学学报》
CAS
CSCD
北大核心
2024年第9期93-102,共10页
Acta Scientiae Circumstantiae
基金
国家自然科学基金重点项目(No.42030612)
第三次新疆综合科学考察项目(No.2021xjkk030501)。
