唐洁,郭学良,常祎. 2018. 第三次青藏高原大气科学试验气象学报专刊—2014年夏季青藏高原云和降水微物理特征的数值模拟研究[J]. 气象学报, (0):-, doi:10.11676/qxxb2018.054
第三次青藏高原大气科学试验气象学报专刊—2014年夏季青藏高原云和降水微物理特征的数值模拟研究
Numerical Studies on Microphysical Properties of Clouds and Precipitation in the summer of 2014 over the Tibetan Plateau
投稿时间:2018-03-09  修订日期:2018-05-24
DOI:10.11676/qxxb2018.054
中文关键词:  青藏高原,数值模拟,云微物理,降水形成
英文关键词:Tibetan Plateau, Numerical simulation, Cloud microphysics, Precipitation formation
基金项目:公益性行业(气象)科研重大专项-第三次青藏高原科学试验-边界层与对流层观测(GYHY201406001)
作者单位E-mail
唐洁 中国气象科学研究院云雾物理环境重点实验室 tjwork017@126.com 
郭学良 中国气象科学研究院云雾物理环境重点实验室 guoxl@mail.iap.ac.cn 
常祎 中国气象科学研究院云雾物理环境重点实验室 996846032@qq.com 
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中文摘要:
      为了加强对青藏高原云和降水微物理特征的深入认识,采用高分辨率中尺度数值预报模式(WRF),对第三次青藏高原科学试验2014年7月3日– 25日期间发生的6次不同强度云和降水过程进行了数值模拟分析。研究结果表明:(1)青藏高原夏季云和降水过程具有独特性。高原夏季对流的促发机制主要是午后高原加热造成的,云和降水具有明显的日变化。午夜后,对流性降水一般转化为层状云降水,具有明显的回波亮带,并且会产生强降水。大部分对流云云顶高度超过15 km(海拔高度),最大上升气流速度可达到10 – 40 m/s。(2)6次云过程中均具有高过冷云水含量,主要分布在0 – -20 °C层之间,冰晶含量主要分布在-20 °C层以上的区域,强盛的对流云中,可出现在-40 °C层以上区域;雨水分布集中在融化层之下,说明其主要依赖降水性冰粒子的融化过程;雪和霰粒子含量高,分布范围广,说明云中冰相过程非常活跃。(3)高原夏季云中水凝物的转化过程和降水的形成机理具有明显特点。霰粒子的融化过程是地面雨水的主要来源,暖雨过程对降水的直接贡献很小,但通过暖雨过程形成的过冷雨滴的异质冻结过程对云中霰胚的形成十分重要。霰粒子的增长主要依靠淞附过程以及聚并雪晶的增长过程。
英文摘要:
      Six cloud and precipitation processes with different intensities during the Third Tibetan Plateau Atmospheric Scientific Experiment on 3 July to 25 July, 2014 in the Naqu region of the Tibetan Plateau were investigated using mesoscale numerical prediction model (WRF) with high resolution. The results indicate that the summer clouds and precipitation processes over the TP had some unique properties. The initiation processes of clouds were closely associated with daytime strong solar radiation heating and the summer clouds and precipitation showed an obvious diurnal variation. The convective clouds were generally transformed into the stratiform–like clouds with an obvious bright band and often produced stronger rainfall in the midnight. The maximum cloud top could reach more than 15 km above sea level (ASL) and updrafts were ranged from 10 m/s to 40 m/s. The modeled all six cases had high amount of supercooled water content primarily located between 0 °C and -20 °C layers. Ice crystals were mainly formed above -20 °C layer and even appeared above -40 °C layer in the strong convective clouds. Rain water mostly appeared under the melting layer, indicating that its formation mainly depended on the melting process of precipitating ice particles. Snow and graupel particles had the characteristics of high content and deep vertical distribution, showing that the ice process was very active in the development of clouds and precipitation. The transformation of hydrometeor and formation of precipitation over the plateau has some obvious characteristics. The surface precipitation was mainly formed by the melting of graupel particles. Although the warm cloud microphysical process had small direct contribution in the formation of surface precipitation, it had an important contribution on the formation of supercooled raindrops, which were essential to form graupel embryos through heterogeneous freezing processes. Graupel particle growth mainly relied on the riming process with supercooled cloud water and aggregation of snow particles.
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