庐山两次冷雾过程宏微观物理特征
Macroscopic and Microscopic Physical Characteristics of Two Supercooled Fog Processes in the Lushan Mountain
摘要
Abstract
Comprehensive fog observation campaigns were conducted in the Lushan Meteorological Bureau of Jiangxi Province with a fog drop spectrometer and an automatic weather station in January and December 2016.This study investigated the macrophysical and microphysical characteristics of supercooled fog and elucidated its evolution mechanism.Combining observational data with the NCEP 1°×1°reanalysis data,the macrophysical and microphysical characteristics of two supercooled fog events(case 1 occurred on January 16 and 17,2016;case 2 happened on December 25-27,2016)were analyzed.Results revealed that the evolutions of the two supercooled fogs were strongly correlated with the movement of the cold front.From the formation to the development stages,the dominant wind direction below 800 hPa changed from southwest to northerly,the front edge of the cold front arrived at the study area,and temperature near the surface decreased sharply in both cases.At the mature stages of the two supercooled fog events,the rain stopped at the near-surface,and the wind force weakened;meanwhile,the front inversion layer appeared in case 2.During the dissipation stages,wind direction in 900-500 hPa changed to north in both cases and wind speed below 800 hPa increased.For microphysical characteristics,average droplet spectra exhibited bimodal distributions in both cases,with main peaks observed at 4.9 μm.However,secondary peaks were noted at 8.9 and 11.0 μm in cases 1 and 2,respectively.Both cases presented instantaneous droplet spectra with the main peaks occurring at 10-14 μm,and the frequencies were 12.4%and 46.3%for cases 1 and 2,respectively.Furthermore,both cases exhibited a transition from warm fog to supercooled fog.Compared with the warm fog,the number density of supercooled fog droplets increased for each droplet size,especially for droplets with particle size below 14 μm.The correlation between fog droplet number concentration-and average diameter was weak in the whole process of case 1,which may be affected by factors such as fog droplet collision-coalescence and droplet competition for water vapor.Meanwhile,case 2 showed a positive correlation among fog droplet number concentration,average diameter,and water content in the whole process,which indicated that the fog process was dominated by condensation nucleus activation and condensation growth.A strong low-level jet in the southwest,an obvious temperature drop in the near-surface,and a temperature inversion layer were all observed in case 2,resulting in a wider droplet spectrum,with peaks between 10 and 14 μm diameter more prominent in the droplet spectrum,and higher number concentration,average diameter,and water content than case 1.关键词
冷雾/庐山/锋面逆温/尺度谱分布Key words
Supercooled fog/Lushan Mountain/Frontal inversion/Scale spectrum distribution分类
天文与地球科学引用本文复制引用
王天舒,袁薇,张鸿伟,牛生杰,王莹,赵俊杰,梁绵,王元,段婧,樊栋樑,杨霏云..庐山两次冷雾过程宏微观物理特征[J].大气科学,2025,49(2):507-521,15.基金项目
中国气象局气象干部培训学院青年项目2022CMATCQN04,中国气象局气象干部培训学院重大项目2023CMATCZDA02,国家自然科学基金项目42075063,中国气象局云降水物理与人工影响天气重点开放实验室开放课题 2020Z00725,国家自然科学基金项目42175109,中央级公益性科研院所基本科研业务费专项 2023YSKY-42,国家自然科学基金青年科学基金项目42205072,陕西省自然科学基础研究计划项目2022JQ-249 Funded by Project of China Meteorological Administration Training Center(Grant 2022CMATCQN04),Project of China Meteorological Administration Training Center(Grant 2023CMATCZDA02),National Natural Science Foundation of China(Grant 42075063),Open Project of China Meteorological Administration Cloud Precipitation Physics and Weather Modification Key Laboratory(Grant 2020Z00725),National Natural Science Foundation of China(Grant 42175109),the Fundamental Research Funds for the Central Public-interest Scientific Institution(Grant 2023YSKY-42),National Natural Science Foundation of China(Grant 42205072),Natural Science Basic Research Project of Shaanxi Province(Grant 2022JQ-249) （Grant 2022CMATCQN04）
