Numerical Simulations of the Postsunrise Reorganization of a Nocturnal Mesoscale Convective System during 13 June IHOP_2002
Numerical Simulations of the Postsunrise Reorganization of a Nocturnal Mesoscale Convective System during 13 June IHOP_2002
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DOI：
10.1175/jas-d-11-0112.1
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发表时间：
2011-12
影响因子：
3.1
通讯作者：
S. Trier;J. Marsham;C. Davis;D. Ahijevych
中科院分区：
文献类型：
--
作者：
S. Trier;J. Marsham;C. Davis;D. Ahijevych
摘要利用一个允许对流的数值模式模拟了2002年6月13日在国际H2O（IHOP_2002）现场试验期间在俄克拉荷马州西部和中部观测到的夜间中尺度对流系统（MCS）日出后的重组。MCS重组是由日出前后的西北-东南向对流雨带转变为上午晚些时候的单一东北-西南向对流雨带并伴有尾随的层状降水组成的，表明环境预处理对MCS重组的重要性。特别是，东北-西南雨带，重新定义MCS组织的发展是由一个类似的定向区的前期中尺度向上运动，这增加了大的水汽混合比的深度促进。这使得对流上升气流主要由NE-SW方向雨带中1至2.5 km AGL的潮湿和有条件不稳定空气供给，该雨带在其活动期间缺乏表面冷池。
AbstractA convection-permitting numerical model is used to simulate the postsunrise reorganization of a nocturnal mesoscale convective system (MCS) observed over western and central Oklahoma on 13 June 2002 during the International H2O (IHOP_2002) Field Experiment. The MCS reorganization consists of a transition from northwest–southeast-oriented convective rainbands near sunrise to a single northeast–southwest (NE–SW)-oriented convective rainband with trailing stratiform precipitation later in the morning.Results indicate the importance of environmental preconditioning on MCS reorganization. In particular, the development of the NE–SW rainband that redefines the MCS organization is facilitated by a similarly oriented zone of antecedent mesoscale upward motion, which increases the depth of large water vapor mixing ratios. This allows convective updrafts to be fed primarily by moist and conditionally unstable air from 1 to 2.5 km AGL in the NE–SW-oriented rainband, which lacks a surface cold pool during its...