检索结果-南通市图书馆

Formation of low-level jets over Southern China in the Mei-yu Season

Advances in Atmospheric Sciences 2023年第10期40卷 1731-1748页

作者： Xuanyu LIU Guixing CHEN Sijia ZHANG Yu DU School of Atmospheric Sciences Sun Yat-sen Universityand Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai 519082China Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies Sun Yat-sen UniversityZhuhai 519082China Key Laboratory of Tropical Atmosphere-Ocean System(Sun Yat-sen University) Ministry of EducationZhuhai 519082China

This study examines the diversity of low-level jet(LLJ)formation and related physical processes over southern China.A total of 171 LLJ formation events with enhanced daily southwesterlies and early-morning maximum wind speeds were observed during the mei-yu seasons of 1989–2018.The LLJs can be further categorized into four types based on the increases in the daily mean and diurnal amplitude of the low-level winds.Analysis of the synoptic-scale disturbances shows that the two types of LLJ formation(Q1 and Q4),which feature large increases of daily southerly wind components,are mainly induced by west-east dipole patterns of pressure change,in association with the enhanced southwest vortex and/or the western Pacific subtropical high(WPSH).In contrast,the other two types(Q2 and Q3),which feature relatively large increases in their daily westerly components,are related to a northwest-southeast dipole pattern of pressure change due to the mid-latitude trough and the WPSH.We further analyze the considerable variations in the diurnal thermal forcing among the LLJ formation events.The strong(weak)daytime heating of solar radiation leads to relatively large(small)increases in the diurnal amplitude of low-level winds in Q1 and Q2(Q3 and Q4)types.Therefore,different combinations of synopticscale disturbances and diurnal thermal forcings are found to account for the diversity in LLJ formation and associated differences in downstream rainfall patterns.These results help to improve our understanding and prediction of the formation of LLJs.

关键词： low-level jets formation processes diurnal variations synoptic-scale disturbances

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Comparison between the Roles of low-level jets in Two Heavy Rainfall Events over South China

引用

Journal of Meteorological Research 2022年第2期36卷 326-341页

作者： Xinyu ZHOU Zhengquan CHENG Haowen LI Dongming HU Guangzhou Meteorological Observatory Guangzhou 511430 Guangdong Meteorological Observatory Guangzhou 510080

Two heavy rainfall events occurred over the Pearl River Delta during 20-22 May 2020:the first was a warm-sector event and the second a frontal event.Based on ERA5 reanalysis data and observations from wind profilers and Doppler weather radars,the structures and roles of low-level jets(LLJs)during these two heavy rainfall events were analyzed.The results show that:(1)South China was affected by a low-level vortex and a low-level shear line during the two processes.The two heavy rainfall events were both associated with a synoptic-system-related low-level jet(SLLJ)and a boundary layer jet(BLJ).The coupling of the convergence at the exit of the BLJ and the divergence at the entrance of the SLLJ produced strong lifting for the warm-sector heavy rainfall,and the strong convergence between the LLJs and northerly winds as the cold front moved southwards was the main lifting reason for the frontal heavy rainfall.(2)The BLJ was the main transport of water vapor during the two processes.The coupling of the BLJ and SLLJ caused the water vapor convergence to be concentrated in the boundary layer during the first process,whereas the strong convergence between the LLJs and northerly winds led to the lower and middle troposphere having strong water vapor convergence during the second process.(3)During the period of these two heavy rainfall events,the lower and middle troposphere remained unstable.Further analysis show that the differences in the intensity,location,and direction between the BLJ and SLLJ resulted in the pseudo-equivalent potential temperature advection in the boundary layer being significantly larger than in the lower and middle troposphere,which compensated for the energy loss caused by heavy rainfall and maintained the convective instability.These findings add to our knowledge on the roles of LLJs in the pre-summer rainfall over South China.

关键词： pre-summer heavy rainfall South China low-level jets water vapor convective instability

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Heavy Rainfall Associated with Double low-level jets over Southern China

Heavy Rainfall Associated with Double Low-level Jets over So...

引用

第35届中国气象学会年会

作者：杜宇陈桂兴中山大学大气科学学院

＜正＞Introduction Heavy rainfall over southern China during the early-summer rainy season （May-June） often occurs near the quasi-stationary front （hereafter, frontal heavy rainfall） and in the warm sector of a surface baroclinic wave cyclone a few hundred kilometers away from the front （hereafter, warm-sector heavy rainfall）, causing large economic and human losses （Huang 1986;Ding 1994;Luo et al. 2017;Chen et al. 2018）. These two types of heavy rainfall are

关键词： Heavy rainfall low-level jets

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：