大气科学2025，Vol.49Issue(5)：1324-1340,17.DOI:10.3878/j.issn.1006-9895.2407.23157
2022年冬奥赛期及2020年同期北京两次雨雪过程的微物理特征及其积雪效率差异
The Differences of Microphysical Characteristics and Snow-to-Liquid Ratios for Two Rain and Snow Processes in Beijing during Winter Olympics in 2022 and the Same Period in 2020
摘要
Abstract
The differences of microphysical characteristics and snow-to-liquid ratios for two rain and snow processes in Beijing during Winter Olympics in 2022 and the same period in 2020 were analyzed based on Parsivel data,densely artificial snow-depth measurements,and microscopic snowflake shape observations.The results show:(1)The average particle spectrum showed a unimodal pattern,with the highest and lowest peak number concentrations attributed to the snowflake spectrum and raindrop spectrum,respectively.During the snowfall process,the peak number concentration of plate-or column-like ice crystals was higher than that of dendritic snowflakes.(2)An average falling speed of particles below 2 m s-1 could be used as an indicator of phase transfer.The average falling speed of dry snow particles was less than 1 m s-1.(3)The ambient air temperature during the rain-to-snow process was high on 13 and 14 February 2020.The growth of snowflakes in the sleet stage was mainly due to the riming process.With a decrease in the temperature at lower levels and a significant increase in humidity in the layer with temperatures from-18℃ to-12℃,the precipitation process changed to snowfall,and the riming process continued to exist.Under the joint action of riming and adhesive aggregation processes,the maximum crystal diameter reached 19 mm,but the snow-to-liquid ratio was low(0.6 cm mm-1).(4)In the snowfall process during the Beijing Winter Olympics,the temperature was lower in the low-level cloud region(between-18℃ and-12℃),and the falling velocity was close to the classical curve of the unrimed ice crystals;therefore,the snowflakes were all unrimed.The combined action of sublimation,the Bergeron process,and hook aggregation caused a growth in the particle diameter to 11 mm.However,a change in snowflake shape to plate-or column-like geometries was observed at the Shougang Big Air Venue during the Beijing Winter Olympics,resulting in an increase in the number concentration and a reduction in the particle spectrum width,with a corresponding sharp reduction in the SLR.关键词
粒子谱/微物理特征量/积雪效率/雪花形态Key words
Particle size distribution/Microphysical characteristic quantities/SLR(snow-to-liquid ratios)/Ice crystal morphology分类
大气科学引用本文复制引用
杜佳,于波,符娇兰,戴翼,李桑,徐路扬,李林,荆浩..2022年冬奥赛期及2020年同期北京两次雨雪过程的微物理特征及其积雪效率差异[J].大气科学,2025,49(5):1324-1340,17.基金项目
北京市自然科学基金项目8214058、8192019,国家重点研发计划项目2018YFF0300104 Beijing Natural Science Foundation(Grants 8214058,8192019),National Key Research and Development Program of China(Grant 2018YFF0300104) （Grants 8214058,8192019）
