青藏高原中东部和四川盆地的夏季雨滴谱对比分析研究  

A Comparative Study on the Summer Raindrop Size Distribution Among Areas over the Central and Eastern Qinghai-Xizang (Tibetan) Plateau and the Western Sichuan Basin

作　　者：刘艳霞 文军 谢晓林 LIU Yanxia;WEN Jun;XIE Xiaolin(Northwest Institute of Ecological Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,Gansu,China;Universityof ChineseAcademyof Sciences,Beijing100039,China;College of Atmospheric Sciences,Chengdu University of Information Technology/Sichuan Key Laboratory of Plateau Atmosphere andEnvironment,Chengdu610225,Sichuan,China;Meteorological observation data center of Sichuan province,Chengdu 610072,Sichuan,China)

机构地区：[1]中国科学院西北生态环境资源研究院,甘肃兰州730000 [2]中国科学院大学,北京100039 [3]成都信息工程大学大气科学学院/高原大气与环境四川省重点实验室,四川成都610225 [4]四川省气象探测数据中心,四川成都610072

出　　处：《高原气象》2024年第1期28-41,共14页Plateau Meteorology

基　　金：国家自然科学基金项目(41905084);民航飞行技术与飞行安全重点实验室开放项目资助(FZ2020KF04);成都信息工程大学人才引进项目(KYTZ201821)。

摘　　要：为了进一步认识青藏高原中东部和下游四川盆地的降水微观特征和差异,本文利用2019年7-8月和2020年7-8月那曲、玉树、林芝、巴塘、泸定和成都6个地区的雨滴谱观测资料,研究了不同地区之间的雨滴谱特征和差异,并提出了各个地区降水的Gamma谱形状参数-斜率参数关系和反射率因子-雨强关系。结果表明:因更多强对流降水的贡献,盆地和邻近地区(成都和泸定)的雨滴谱整体比高原地区(那曲、玉树、林芝和巴塘)的更宽,中大雨滴(直径≥1.0 mm)数浓度更高;而高原地区的降水主要来自层云和弱对流,整体雨滴谱更窄,小雨滴(直径<1.0 mm)数浓度更高。6个地区的雨滴谱均随雨强增大而变宽,数浓度也逐渐升高。不同地区之间的雨滴谱差异也会随雨强变化而改变,当雨强超过0.1 mm·h-1后,那曲和林芝的小雨滴数浓度随雨强增大而增大的幅度明显比其他地区更大;当雨强达到5 mm·h-1后,成都和泸定的中大雨滴数浓度与其他高原地区的差异也逐渐变大。在谱形状参数相同情况下,成都和泸定的谱倾斜率更小,反映了这两个地区雨滴数浓度随粒径增大而减小的速率比高原地区的更慢。在相同雷达回波强度(反射率因子)情况下,那曲和林芝层云降水的雨强比其他地区大;林芝对流降水在雷达回波低于40 dBZ时,雨强也比其他地区的大,而那曲对流降水在雷达回波大于40 dBZ后,雨强比其他地区的小。To promote the understanding of precipitation microphysical characteristics and differences in the central and eastern Qinghai-Xizang(Tibetan)Plateau and the Sichuan Basin,disdrometer measurements collected at Naqu,Yushu,Linzhi,Batang,Luding,and Chengdu from July to August 2019 and 2020 are utilized to comprehensively investigate the characteristics and differences of raindrop size distributions(RSDs)among the six different areas.Meanwhile,local empirical relations between the Gamma shape parameter and slope parameter and between the reflectivity factor and rain rate are proposed and compared.The results show that RSDs in the basin and adjacent areas(Chengdu and Luding)are generally wider and have higher number concentrations of medium-to-large raindrops(diameter≥1.0 mm)than those in the plateau areas(Naqu,Yushu,Linzhi,and Batang)due to the contribution of more strong convective precipitation.In contrast,RSDs in the plateau areas are narrower and possess higher number concentrations of small raindrops(diameter<1.0 mm)due to more occurrences of stratiform and weak-convective precipitation.RSDs gradually become wider with higher number concentrations as the increase of rainfall intensity both in the six observation areas.The RSD differences among the six observation areas can also change with the rain rate.Specifically,when the rain rate exceeds 0.1 mm·h-1,the increase of the number concentration of small raindrops with increasing rain rate is significantly greater in Naqu and Linzhi than in other areas,and can gradually exceed that in Chengdu.When the rain rate exceeds 5 mm·h-1,the differences in the number concentrations of medium-to-large raindrops between Chengdu and Luding and other plateau areas also gradually become larger.With the same shape parameters,the slope parameters in Chengdu and Luding are smaller than in other areas,indicating that they possess a slower decreasing rate of raindrop number concentration with increasing particle size than that in other plateau areas.Under the same radar echo inte

关 键 词：青藏高原 四川盆地 雨滴谱 降水微观特征 

分 类 号：P426.62[天文地球—大气科学及气象学]