沙尘气溶胶加热对深积云对流系统的影响  

Impact of dust aerosol heating on deep convective cloud system

作　　者：景治坤 黄建平[1] 刘玉芝 谢永坤 JING Zhi-kun;HUANG Jian-ping;LIU Yu-zhi;XIE Yong-kun(Collaborative Innovation Center for Western Ecological Safety,Key Laboratory of Semi-arid Climate Changes with the Ministry of Education,Lanzhou University,Lanzhou 730000,China)

机构地区：[1]兰州大学半干旱气候变化教育部重点实验室,西部生态安全省部共建协同创新中心,兰州730000

出　　处：《兰州大学学报（自然科学版）》2024年第3期296-303,共8页Journal of Lanzhou University(Natural Sciences)

基　　金：国家自然科学基金项目(41991231;91937302)。

摘　　要：基于动力模型,分析在水汽充足的深对流天气系统中沙尘气溶胶的加热作用及其对周围大气稳定性、积云对流及降水的影响.结果表明,沙尘气溶胶可在550 hPa对流层中层被输送至水汽充足的深积云对流系统中,其加热效应使大气温度升高,增强对流扰动的进一步发展,使得大气稳定性减弱,促进积云对流发展及其潜热释放;积云对流引起的对流加热与涡度混合,进一步增强垂直运动和积云对流发展;这种正反馈效应使整个深积云对流系统变得更加不稳定.正反馈强度随着扰动水平尺度的减小而增强,涡度混合引起的强垂直运动可将积云中的沙尘由低层向高层输送.当沙尘同时存在于550和950 hPa两个高度时,上、下两层的加热作用可共同加速深积云对流系统的不稳定化过程,其中上层沙尘的作用更显著.Based on a dynamic model,we analyzed the impact of dust aerosol heating on the stability in the surrounding atmosphere,cumulus convection and precipitation in deep convective weather systems with sufficient water vapor.The results show that when dust aerosols are transported to deep convective systems with sufficient water vapor at a height of 550 hPa,dust heating effect will warm the atmosphere,enhance disturbance development,reduce atmospheric stability,and promote cumulus convection development and its latent heat release.Cumulus convection will cause convective heating and vorticity mixing,which will lead to strong vertical motion and further strengthen cumulus convection.This positive feedback process makes the entire deep convective weather system more unstable.The strength of positive feedback will increase as the disturbance horizontal scale decreases.The strong vertical motion caused by vorticity mixing can transport dust in cumulus clouds from low to high levels.When dust exists at both 550 and 950 hPa heights at the same time,the heating effects of high and low layers will jointly accelerate the instability process of deep convective weather systems,among which the role of high-level dust is more significant.

关 键 词：沙尘气溶胶 深积云对流 加热作用 不稳定增长率 正反馈 

分 类 号：P40[天文地球—大气科学及气象学]