淮河流域中部强浓雾和重度霾环流形势对比分析  

Comparative Analysis of the Circulation Patterns of Extremely Dense Fog and Heavy Haze in the Central Area of the Huaihe River Basin

作　　者：王苏瑶 石春娥[2] 吴照宪 李欣然 殷晗 WANG Suyao;SHI Chune;WU Zhaoxian;LI Xinran;YIN Han(Huaibei Meteorological Bureau,Huaibei,Anhui Province 235000;Anhui Institute of Meteorological Sciences/Anhui Province Key Laboratory of Atmospheric Sciences and Satellite Remote Sensing,Hefei 230031;ChiZhou Meteorological Bureau,Chizhou,Anhui Province 247000)

机构地区：[1]安徽省淮北市气象局,安徽淮北235000 [2]安徽省气象科学研究所/大气科学与卫星遥感安徽省重点实验室,合肥230031 [3]安徽省池州市气象局,安徽池州247000

出　　处：《气候与环境研究》2025年第1期51-66,共16页Climatic and Environmental Research

基　　金：国家自然科学基金项目41875171;安徽省自然科学基金项目2408085MD085;中国气象局创新发展专项CXFZ2023J022。

摘　　要：为探究重度霾向强浓雾转化的关键气象因子,利用多要素斜交旋转主成分分析法和ERA5再分析资料分别对淮河流域中部地区连续40 a(1980~2019年)强浓雾高发时段(08:00,北京时间)247个强浓雾和96个重度霾个例近地层环流客观分型,分析各类环流形势特征及强浓雾形成机制,对比大尺度环流形势相似的重度霾和强浓雾地面和边界层气象条件的差异。结果表明:1)强浓雾时的近地层环流可分为5类,每一类形势场上,中国西北或东北都有一冷高压,淮河流域都有弱高压、锋面或倒槽等次天气尺度系统;雾区位于弱高压北部(33%)或内部(19%)、锋前(29%)、倒槽前(11%)或冷高压底部(7%),地面为西南风、南风或东风,平均风速≤1.6 m/s;925 hPa,研究区域位于暖脊内、低湿度区,平均风速2 m/s;相对湿度随高度迅速下降,有利于地面辐射降温,平均降温幅度≥3.0℃,形成深厚的近地层逆温,975 hPa与地面温差2~4°C。2)重度霾时近地面环流可分为3类,研究区域分别位于地面高压的前部(56%)、底部(19%)和后部(26%),但淮河流域无次天气尺度系统或系统较弱。3)相似背景条件下重度霾不能发展为强浓雾的原因有:水汽来源不足(地面偏北风,占比56%);地面降温幅度偏低(均值低于3.1°C),且风速偏大(≥2.2 m/s),占比44%。4)研究区域附近的次天气尺度系统是重度霾能否发展为强浓雾的关键原因,该系统决定了局地气象条件,如是否具备小风、显著降温和充足的水汽来源。还分析了各环流形势下强浓雾的月际变化和生消时间,前者与研究区域的季风气候有关,后者与不同环流形势下雾的形成机制有关。To explore the key meteorological factors affecting the transformation from heavy haze(HH)to extremely dense fog(EDF),the near-surface circulation patterns of 247 EDF and 96 HH cases in the central area of the Huaihe River Basin(HRB)at 0800 BT(a high-intensity period)for 40 years(1980–2019)were objectively classified.This classification utilized the multi-element oblique rotation principal component analysis method,together with the ERA5 reanalysis data.The classification outcomes facilitated an analysis of the formation mechanisms for EDF under various circulation patterns and enabled a comparison of the meteorological conditions at the surface and boundary layers for HH and EDF cases that share similar large-scale circulation patterns.The results show the following:1)The circulation patterns of EDF can be divided into five types,each characterized by a cold high-pressure system located either in Northwest or Northeast China,accompanied by a subsynoptic system in the HRB,such as a weak high,frontal,or inverted trough.The study area is located in the northern(33%)or internal(19%)sections of the weak high,in front of the frontal zone(29%)or the invert trough(11%),or beneath the cold high(7%),with prevalent winds from the southwest,south,or east.These winds maintain an average wind below 1.6 m/s at ground level.At 925 hPa,the study area is located in a warm ridge and low-humidity area,with wind speeds averaging 2 m/s.Vertically,relative humidity decreases rapidly with height,dropping below 60%at 925 hPa or 850 hPa,thereby promoting surface radiation cooling.This process leads to an average temperature decrease range exceeding 3°C,forming a deep near-surface inversion,with a temperature difference of 2–4℃ between 975 hPa and the ground level.2)Near-surface circulations for HH are divided into three types,all related to high-pressure systems.The study area is located in the front of(56%),beneath(19%),or behind(26%)the surface high but either lacks a subsynoptic scale system or has only a weak one in the HRB.3)

关 键 词：强浓雾 重度霾 环流形势 客观分型 对比分析 次天气尺度系统 

分 类 号：P426.4[天文地球—大气科学及气象学]