西北地区气溶胶垂直分布及其对云微物理影响的飞机观测个例研究  

A Case Study of Aircraft Observation of Aerosol Vertical Distribution and Its Effect on Cloud Microphysics in Northwest China

作　　者：王研峰[1] 冷文楠 庞朝云[1] 黄武斌[2] 把黎 WANG Yanfeng;LENG Wennan;PANG Zhaoyun;HUANG Wubin;BA Li(Gansu Weather Modification Office,Lanzhou 730020,Gansu,China;Lanzhou Central Meteorological Observatory,Lanzhou 730020,Gansu,China)

机构地区：[1]甘肃省人工影响天气办公室,甘肃兰州730020 [2]兰州中心气象台,甘肃兰州730020

出　　处：《高原气象》2023年第4期1031-1043,共13页Plateau Meteorology

基　　金：甘肃省自然科学基金项目(21JR7RA710);国家重点研发计划项目(2019YFC1510302);甘肃省青年科技基金计划项目(21JR7RA703);甘肃省气象局气象科研项目(2122rczx-英才计划-01,ZcMs2022-31,2122rczx-十人计划-05)。

摘　　要：气溶胶分布及其影响云微物理过程对地气系统的辐射平衡及区域乃至全球水循环产生复杂影响,也是气溶胶间接效应关注的热点和重点。利用2021年9月3日在西北地区开展的气溶胶和云的飞机观测个例资料,分析了气溶胶垂直分布及气溶胶与CCN、云滴浓度的关系。结果表明:(1)气溶胶数浓度垂直变化为四层,各层间气溶胶数浓度、有效直径、尺度谱分布均存在明显不同,大气逆温层结对气溶胶垂直分布有重要影响;近地层气溶胶数浓度可达8183.2 cm^(-3)。(2)垂直方向上CCN与气溶胶数浓度之间有较好的线性正相关性。气溶胶活化比率(CCN/Na)较低,低于0.5,气溶胶尺度越大、浓度越低越容易活化成为CCN。(3)对空中CCN的活化谱进行拟合表明西北地区属于清洁大陆型核谱。(4)同高度云内气溶胶数浓度与云滴数浓度和LWC之间有很强的负相关性,相比云外,云内气溶胶浓度明显降低,气溶胶谱增宽,云滴数浓度和LWC均增加,有效直径增大,云侧边界受夹卷混合过程和云滴未过饱和蒸发的影响导致气溶胶数浓度增加和有效直径增大。(5)云下气溶胶与云滴数浓度之间为线性正相关关系,气溶胶转化为云滴的比率为35%;过饱和度0.6%条件下,云下CCN与云滴数浓度之间为线性正相关关系,CCN转化为云滴的比率为38%。Aerosols have great influences on cloud microphysical properties,such as cloud droplet number concentration and cloud droplet size,which has effect on cloud albedo,cloud lifetime,precipitation formation and evolution by acting as cloud condensation nuclei(CCN)or ice nucleus(IN).The distribution characteristics of aerosols are crucial for determining the clouds and precipitation.The distribution of aerosols and their great effects on cloud microphysical processes have complex effects on the radiation balance of the earth-atmosphere system and the regional and even global water cycle,which are also the hot spot and focus of aerosol indirect effects.Based on the flight of aircraft measurements data of aerosols and clouds from aircraft in Northwest China on 3 September 2021,the vertical distribution of aerosols and the relationship between aerosol number concentrations,CCN number concentrations and cloud droplet concentrations were analyzed.The results show that:(1)The vertical variation of aerosol number concentrations could be divided into four layers from bottom to top.The distribution of aerosol number concentrations,effective diameter and scale spectrum was obviously different in different layers.The structure of atmospheric boundary inversion layer had an important effect on the vertical distribution of aerosol.The maximum aerosol number concentrations appeared close to the near-stratum,which could reach 8183.2 cm^(-3).(2)There was a good linear positive correlation between CCN number concentrations and aerosol number concentrations in the vertical direction at 0.6% supersaturation.The aerosol activation rate(CCN/Na)was lower than 0.5.The larger the size of aerosols and the lower the concentrations the easier they were to activate into CCN.(3)The size distribution of CCN in the sky was fitted with a power law function and was shown of the clean continental type nuclear spectrum.(4)At the same height,there was a strong negative correlation between the aerosol number concentrations and the cloud droplet number co

关 键 词：气溶胶 云凝结核 云滴浓度 飞机观测 西北地区 

分 类 号：P426.51[天文地球—大气科学及气象学]