On the Local Rain-Rate Extreme Associated with a Mesovortex over South China: Observational Structures, Characteristics, and Evolution

中尺度气象学 风暴 流出 气候学 环境科学 降水 大气科学 地质学 气象学 物理
作者
Zhilin Zeng,Donghai Wang
出处
期刊:Monthly Weather Review [American Meteorological Society]
卷期号:150 (5): 1075-1096 被引量:4
标识
DOI:10.1175/mwr-d-21-0033.1
摘要

Abstract Extreme short-term hourly rainfall accumulations are shown to be commonly attendant with rotation-featured mesovortices. This study aims to document the detailed aspects of mesovortex-related extreme rain rates in a record-breaking event that occurred over South China on 7 May 2017 through high-resolution observations, and to reveal how the mesoscale storm contributes to the extreme rain rates, with special attention given to the minute rain-rate enhancement episode (MREE). The event accumulation possesses highly local distribution, with a spatial rainfall core. Extreme rain rates are dictated by a meso- γ -scale storm, and it is found that the observed rain rate is well correlated to storm-related maximum reflectivity in the lowest 2 km above ground level (AGL) as well as its reflectivity centroid (i.e., reflectivity factor exceeding 50 dB Z ) depth. The cross section reveals that the storm structure evolves progressively into a single centroid, which subsequently descends to the near surface, resulting in the rain-rate peak (4.8 mm min −1 ). Extremely weak environmental mean flow interacts with the near-opposite storm propagation that determines the slow storm movement, prolonging local rainfall. Rainfall-induced cold outflow surges ahead unevenly, leading to an inhomogeneous mesoscale outflow boundary (IMOB) at low levels. A mesovortex subsequently develops along the IMOB in the lowest ∼5.5 km AGL, with a horizontal radius of 1.5–3 km. A mesoscale low-level jet observed over the upstream of the storm increases the low-level shear despite short duration, which provide potential dynamics for the storm and mesovortex development. These results help us better understand the generation of extreme rain rates in small spatiotemporal scale. Significance Statement Despite many extreme short-duration rainfall events linking to low-level rotation phenomenon, we are still exploring how these rotations develop within extreme-rainfall-producing storms. While past studies have found that these low-level rotations within such storms are conducive to enhancing rainfall, rotation characteristics are less understood. In this study, we examine how the rotations develop during an episode of observed-rainfall rise. The results reveal that the cold airflows resulted from the storm-inducing rainfall impinge unevenly on warm moist southerly wind, leading to such low-level rotation. The rainfall observed per minute is found to associate well with low-level rotation that develops upward. These results further motivate exploration of extreme short-duration rainfall and storm-related rotation.
最长约 10秒,即可获得该文献文件

科研通智能强力驱动
Strongly Powered by AbleSci AI
更新
PDF的下载单位、IP信息已删除 (2025-6-4)

科研通是完全免费的文献互助平台,具备全网最快的应助速度,最高的求助完成率。 对每一个文献求助,科研通都将尽心尽力,给求助人一个满意的交代。
实时播报
1秒前
organoid elegan完成签到,获得积分10
2秒前
3秒前
4秒前
5秒前
5秒前
6秒前
6秒前
爆米花应助不安的半梦采纳,获得10
8秒前
fuje发布了新的文献求助10
8秒前
空123发布了新的文献求助10
8秒前
雨天后完成签到,获得积分10
10秒前
11秒前
11秒前
Jasper应助wzx采纳,获得10
12秒前
乐观的仇天完成签到,获得积分10
12秒前
12秒前
腼腆的修杰完成签到,获得积分10
12秒前
情怀应助要减肥的访旋采纳,获得10
13秒前
武雨寒发布了新的文献求助10
13秒前
14秒前
刘强东发布了新的文献求助10
16秒前
17秒前
旺仔Mario完成签到,获得积分10
18秒前
18秒前
18秒前
18秒前
Dallas完成签到,获得积分10
19秒前
庾稀发布了新的文献求助10
19秒前
芜湖起飞完成签到 ,获得积分10
19秒前
21秒前
ckyyds完成签到 ,获得积分10
22秒前
wzx发布了新的文献求助10
23秒前
完美世界应助澡雪采纳,获得10
23秒前
星辰大海应助烛光采纳,获得30
24秒前
dongdong发布了新的文献求助10
24秒前
Dallas发布了新的文献求助10
24秒前
25秒前
旺仔Mario发布了新的文献求助10
25秒前
25秒前
高分求助中
A new approach to the extrapolation of accelerated life test data 1000
Picture Books with Same-sex Parented Families: Unintentional Censorship 700
ACSM’s Guidelines for Exercise Testing and Prescription, 12th edition 500
Nucleophilic substitution in azasydnone-modified dinitroanisoles 500
不知道标题是什么 500
Indomethacinのヒトにおける経皮吸収 400
Effective Learning and Mental Wellbeing 400
热门求助领域 (近24小时)
化学 材料科学 医学 生物 工程类 有机化学 生物化学 物理 内科学 纳米技术 计算机科学 化学工程 复合材料 遗传学 基因 物理化学 催化作用 冶金 细胞生物学 免疫学
热门帖子
关注 科研通微信公众号,转发送积分 3975836
求助须知:如何正确求助?哪些是违规求助? 3520174
关于积分的说明 11201364
捐赠科研通 3256576
什么是DOI,文献DOI怎么找? 1798362
邀请新用户注册赠送积分活动 877539
科研通“疑难数据库(出版商)”最低求助积分说明 806426