Recent Significant Tornadoes in China

1.Introduction Compared with the United States,whose annual number of tornadoes can exceed 1000,the average number of tornadoes per year in China over the past half a century is estimated to be fewer than 100（Fan and Yu,2015）,even though both countries are located in a similar latitudinal zone of the Northern Hemisphere.

Mathematical modeling of tornadoes and squall storms

Recent advances in modeling of tornadoes and twisters consist of significant achievements in mathematical calculation of occurrence and evolution of a violent F5-class tornado on the Fujita scale, and four-dimensional mathematical modeling of a tornado with the fourth coordinate time multiplied by its characteristic velocity. Such a tornado can arise in a thunderstorm supercell filled with turbulent whirlwinds. A theory of the squall storms is proposed. The squall storm is modeled by running pertur- bation of the temperature inversion on the lower boundary of cloudiness. This perturbation is induced by the action of strong, hurricane winds in the upper and middle troposphere, and looks like a running solitary wave （soliton）; which is developed also in a field of pressure and velocity of a wind. If a soliton of a squall storm gets into the thunderstorm supercell then this soliton is captured by supercell. It leads to additional pressure fall of air inside a storm supercell and stimulate amplification of wind velocity here. As a result, a cyclostrophic balance inside a storm supercell generates a tornado. Comparison of the radial distribution of wind velocity inside a tornado calculated by using the new formulas and equations with radar observations of the wind velocity inside Texas Tornado Dummit in 1995 and inside the 3 May 1999 Oklahoma City Tornado shows good correspondence.

Flows’ Similarities between Tornadoes or Cyclones Kinematics and Motions Resulting from Weather Phenomena Coupling Geostrophic Wind with Passive Convection

Tornadoes and cyclones, as is stated in numerous literary and audiovisual works dedicated to these out of balance physical systems, are two powerful and spectacular atmospheric phenomena whose vertical and horizontal profiles of winds and temperatures are not yet well known. Indeed, data and routine observations accumulated in the World Meteorological Organization (WMO) databases, regardless of their diversity and perfection of the instruments used to achieve these data (e.g. satellites, onboard cameras, wind profilers, ultra modern calculators, etc.), offer mind-blowing performances on the extent of damage caused by these disturbances, but information provided by these ground and space based observations will never allow access to real profiles of winds associated with tornadoes and cyclones both at the ground’s surface and aloft. The works recently carried out by C. Mbane Biouele allow us to discover that winds associated with tornadoes and hurricanes result from vectors addition of troposphere’s horizontal geostrophic winds and vertical movements associated with passive convection. Unfortunately, geostrophic wind and passive convection are two familiar meteorological phenomena described with much awkwardness and monumental mistakes by all scientific books written by authors who have remained loyal to Hadley principle which states (for centuries) that hot air is lighter than cold air. It is very important to know that C. Mbane Biouele’s very recent publications demonstrate that Hadley principle is not valid in the troposphere’s regions occupied by Ferrell cells. Indeed, it is urgent for the development of meteorology to highlight with great insistence to everyone that there is a Physics principle diametrically opposed to popular Hadley one which provides thermodynamic reasons of the formation of Ferrell cells. This Principle will be named Mbane Biouele Principe and be clearly stated in this paper.

Temporal and Spatial Distribution Characteristics of Tornadoes in Liaoning Province and Countermeasures

Based on the data of tornadoes in Liaoning Province from 1951 to 2005,the spatial and temporal distribution characteristics of tornadoes were analyzed by means of moving average,Daniel trend test and other methods.The results show that the frequency of tornadoes in coastal areas was obviously higher than that in land.Tornadoes mainly occurred in the central plains,the coastal areas of Liaodong Peninsula and the junction of plain and sea.The frequency of tornadoes was the highest in the 1980s and the lowest in the 1990s,and suddenly increased in 2005.The occurrence of tornadoes had an obvious seasonal change.They mainly happened in summer,peaking in September.During a day,most of them appeared from 13:00 to 21:00,and lasted for only a few minutes to dozens of minutes.The frequency of tornadoes showed a significant downward trend during 1991-2000 and a significant upward trend during 1961-1970 and 2001-2005.There were eight serious tornadoes in the 55 years,among which the tornado occurring in 1988 was the severest,and the number of deaths caused by the tornado in 1969 was the largest.

Quantifying the effect of improved school and residential building codes for tornadoes in community resilience

Tornadoes can destroy or severely damage physical infrastructure including buildings in a community.This can result in direct losses but also indirect losses such as the closure of key social institutions reverberating further through the community(e.g.,schools).Despite significant losses in past events,building codes and standards have not previously included tornado hazards because of the relatively low probability of a direct strike.The recent release of the ASCE 7-22 standard considers tornadoes for Risk Category 3 and 4 buildings,i.e.ranging from schools to critical facilities.This study proposes a series of design combinations of a reinforced masonry school building with different performance targets intended to enable schools to reopen sooner.Tornado fragilities were developed for a school building having improved designs using tornado loads determined based on the new tornado chapter in ASCE 7-22,and then integrated into a community level model with school attendance zones to examine the effect.The ultimate goal in this study is to investigate the effect of improving school building designs would have on maintaining school continuity(and more rapid return)for school children.

Climatology of tropical cyclone tornadoes in China from 2006 to 2018

We surveyed the occurrence of tropical cyclone(TC) tornadoes in China from 2006 to 2018. There were 64 cataloged TC tornadoes, with an average of five per year. About one-third of the landfalling TCs in China were tornadic. Consistent with previous studies, TC tornadoes preferentially formed in the afternoon shortly before and within about 36 h after landfall of the TCs. These tornadoes mainly occurred in coastal areas with relatively flat terrains. The maximum number of TC tornadoes occurred in Jiangsu and Guangdong provinces. Most of the TC tornadoes were spawned within 500 km of the TC center. Two notable characteristics were found:(1) TC tornadoes in China mainly occurred in the northeast quadrant(Earth-relative coordinates) rather than the right-front quadrant(TC motion-relative coordinates) of the parent TC circulation;and(2) most tornadoes were produced by TCs with a relatively weak intensity(tropical depressions/storms), in contrast with the United States where most tornadoes are associated with stronger TCs. Further analyses showed that TC tornadoes in China tend to be spawned in an environment with large low-level storm relative helicity and large convective available potential energy taking entrainment effects into account. TC tornadoes were particularly active in 2018, with 24 reported tornadoes accounting for 37.5% of the total surveyed samples. The first recorded tornado outbreak in the modern history of China occurred in the envelope of TC Yagi(2018), in which 11 tornadoes were reported in association with significant midlevel intrusions of dry air and the interaction of Yagi with an approaching midlatitude midlevel trough.

Climate Analysis of Tornadoes in China

Based on analysis of historical tornado observation data provided by the primary network of national weather stations in China for the period from 1960 to 2009, it is found that most tornadoes in China （85%） occurred over plains. Specifically, large numbers of tornado occurrences are found in the Northeast Plain, the North China Plain, the middle-lower Yangtze Plain, and the Pearl River Delta Plain. A flat underlying surface is conducive to tornado occurrence, while the latitudal variation of tornado occurrence in China is not so obvious. Tornadoes mainly occur in summer, and the highest frequency is in July. Note that the beginning and the time span of tornado outbreaks are different in North and South China. Tornadoes occur during May-September in South China （south of 25°N）, June-September in Northeast China （north of 40°N）, July-September in the middle-lower Yangtze Plain, and July-August in North China （between 25° and 40°N）. More than 80% of total tornadoes occurred during the above periods for the specific regions. The 1960s and 1970s have seen about twice the average number of tornadoes （7.5 times per year） compared to the mean for 1960-2009. The most frequent occurrence of tornado was in the early and mid 1960s; there were large fluctuations in the 1970s; and the number of tornadoes in the 1980s approached the 50-yr average. Tornado occurrences gradually decreased in the late 1980s, and an abrupt change with dramatic decrease occurred in 1994. The decrease in the tornado occurrence frequency is consistent with the simultaneous climatic change in the meteorological elements that are favorable for tornado formation. Tornado formation requires large vertical wind shear and sufficient atmospheric moisture content near the ground. Changes in the vertical wind shear at both 0-1 and 0-6 km appear to be one important factor that results in the decrease in tornado formation. The changing tendency of relative humidity also has contributed to the decrease in tornado formation in China.

Forecasting tropical cyclone tornadoes and impacts:Report from IWTC-X

This report synthesizes global tropical cyclone(TC)tornado research and operational practices to date.Tornadoes are one of the secondary(and lesser researched)hazards contributing to the devastation TCs leave in their wake.While gale-force winds and storm surge produce the majority of damage and fatalities globally,TC tornadoes also pose a fatal threat,complicating evacuation plans and protective actions as the storm moves inland.Climatological studies characterize TC-spawned tornadoes as usually weak and short-lived,primarily originating from miniature supercells in the outer rainbands.These tornadic features pose challenges to forecasting and radar detection.Additionally,TC tornadoes can pose a threat to communities 12 h prior to and beyond 48 h after a TC makes landfall.Research,both basic and operational,has increased globally over the last few years in efforts to move from a climatological to ingredientsbased approach to detect and forecast TC tornadoes.While the United States has led the charge,given the increased exposure to tornadoes year round,other nations such as China,Japan,and Australia have increased their efforts to record and detect TC tornadoes.Despite these advancements,more work needs to be done globally to understand the TC environment conducive for tornadic activity.Recommendations for future forecasting and research for TC tornadoes include i)develop a comprehensive global tornado database to improve research and forecasting efforts;ii)apply innovative technology to detect tornadoes;and iii)conduct field campaigns to thoroughly sample TC tornado environments,particularly along coastlines.

Characterization and Application of S-Band Polarimetric Radar and X-Band Phased Array Radar for a Tornadic Storm Event on June 16,2022

The X-band phased array radar offers faster scanning speed and higher spatial resolution compared to the S-band radar,making it capable of enhancing tornado monitoring and early warning capabilities.This study analyzed the characteristics and nowcasting signals of a tornado case that occurred on June 16,2022 in the Guangzhou region.Our findings indicate that the violent contraction of rotation radius and the dramatic increase in rotation speed were important signal characteristics associated with tornado formation.The X-band phased array radar,with its high temporal and spatial resolution,provided an opportunity to capture early warning signals from polarimetric characteristics.The X-band phased array radar demonstrated noteworthy ability to identify apparent tornado vortex signature(TVS)features in a 10-minute lead time,surpassing the capabilities of the CINRAD/SA radar.Additionally,due to its higher scanning frequency,the Xband phased-array radar was capable of consistently identifying TVS with shorter intervals,enabling a more precise tracking of the tornado's path.The application of professional radars,in this case,provides valuable insights for the monitoring of evolutions of severe local storms and even tornadoes and the issuance of early warning signals.

Influence of Irregular Coastlines on a Tornadic Mesovortex in the Pearl River Delta during the Monsoon Season. Part Ⅰ:Pre-storm Environment and Storm Evolution

The Pearl River Delta(PRD),a tornado hotspot,forms a distinct trumpet-shaped coastline that concaves toward the South China Sea.During the summer monsoon season,low-level southwesterlies over the PRD’s sea surface tend to be turned toward the west coast,constituting a convergent wind field along with the landward-side southwesterlies,which influences regional convective weather.This two-part study explores the roles of this unique land–sea contrast of the trumpet-shaped coastline in the formation of a tornadic mesovortex within monsoonal flows in this region.Part I primarily presents observational analyses of pre-storm environments and storm evolutions.The rotating storm developed in a lowshear environment(not ideal for a supercell)under the interactions of three air masses under the influence of the land–sea contrast,monsoon,and storm cold outflows.This intersection zone(or“triple point”)is typically characterized by local enhancements of ambient vertical vorticity and convergence.Based on a rapid-scan X-band phased-array radar,finger-like echoes were recognized shortly after the gust front intruded on the triple point.Developed over the triple point,they rapidly wrapped up with a well-defined low-level mesovortex.It is thus presumed that the triple point may have played roles in the mesovortex genesis,which will be demonstrated in Part II with multiple sensitivity numerical simulations.The findings also suggest that when storms pass over the boundary intersection zone in the PRD,the expected possibility of a rotating storm occurring is relatively high,even in a low-shear environment.Improved knowledge of such environments provides additional guidance to assess the regional tornado risk.

一种基于RocketQA与ChatGLM模型的问答机器人系统研究与设计

随着信息技术的快速发展,用户对高效获取精准信息的需求日益增长。此外,为了支持国产操作系统软件生态,文章基于Deepin操作系统,集成RocketQA和ChatGLM模型,设计并实现了一个智能文档问答系统。系统首先使用RocketQA模型将问题向量化,利用Faiss进行检索和排序,然后由RocketQA模型二次搜索和排序,对结果进行增强,检索到的文档通过ChatGLM模型转化为自然语言答案,以“参考链接 + 答案”的格式呈现给用户。最后,在deepin wiki数据集上进行了广泛的测试,结果表明系统在问答准确性和响应速度方面均表现优异。With the rapid development of information technology, users’ demand for efficiently obtaining accurate information is growing. In addition, to support the ecosystem of domestic operating system software, this paper designs and implements an intelligent document question-answering system based on the Deepin operating system, integrating the RocketQA and ChatGLM models. The system first uses the RocketQA model to vectorize the question, utilizes Faiss for retrieval and sorting, then uses the RocketQA model for a second search and sorting to enhance the results. The retrieved documents are converted into natural language answers by the ChatGLM model and presented to the user in the format of “reference link + answer”. Finally, extensive testing was conducted on the deepin wiki dataset, and the results show that the system performs excellently in both question-answering accuracy and response speed.

Influence of Irregular Coastlines on a Tornadic Mesovortex in the Pearl River Delta during Monsoon Season.Part II:Numerical Experiments

As demonstrated in the first part of this study(Part I),wind-shift boundaries routinely form along the west coast of the Pearl River Delta due to the land-sea contrast of a“trumpet”shape coastline in the summer monsoon season.Through multiple numerical simulations,this article(Part II)aims to examine the roles of the trumpet-shaped coastline in the mesovortex genesis during the 1 June 2020 tornadic event.The modeling reproduced two mesovortices that are in close proximity in time and space to the realistic mesovortices.In addition to the modeled mesovortex over the triple point where strong ambient vertical vorticity was located,another mesovortex originated from an enhanced discrete vortex along an airmass boundary via shear instability.On the fine-scale storm morphology,finger-like echoes preceding hook echoes were also reproduced around the triple point.Results from sensitivity experiments suggest that the unique topography plays an essential role in modifying the vorticity budget during the mesovortex formation.While there is a high likelihood of an upcoming storm evolving into a rotating storm over the triple point,the simulation's accuracy is sensitive to the local environmental details and storm dynamics.The strengths of cold pool surges from upstream storms may influence the stretching of low-level vertically oriented vortex and thus the wrap-up of finger-like echoes.These findings suggest that the trumpet-shaped coastline is an important component of mesovortex production during the active monsoon season.It is hoped that this study will increase the situational awareness for forecasters regarding regional non-mesocyclone tornadic environments.

Optical trapping capability of tornado circular Pearcey beams

We systemically investigate optical trapping capability of a kind of tornado waves on Rayleigh particles.Such tornado waves are named as tornado circular Pearcey beams(TCPBs)and produced by combining two circular Pearcey beams with different radii.Our theoretical exploration delves into various aspects,including the propagation dynamics,energy flux,orbital angular momentum,trapping force,and torque characteristics of TCPBs.The results reveal that the orbital angular momentum,trapping force,and torque of these beams can be finely tuned through the judicious manipulation of their topological charges(l_(1)and l_(2)).Notably,we observe a precise control mechanism wherein the force diminishes with|l_(1)+l_(2)|and|l_(1)-l_(2)|,while the torque exhibits enhancement by decreasing solely with|l_(1)+l_(2)|or increasing with|l_(1)-l_(2)|.These results not only provide quantitative insights into the optical trapping performance of TCPBs but also serve as a valuable reference for the ongoing development of innovative photonic tools.

基于H.264/AVC的视频通信抗分组丢失方法研究

H．264／AVC是新的视频编码标准，其高效的编码效率和良好的网络适配性，使它在多媒体通信中得到广泛应用，然而由于Internet网络是一种不保证QOS的“尽力”网络，基于Internet网络的视频业务将不呵避免地受到数据分组丢失的影响，因此文中基于H．264编码算法的特点提出多种新颖的视频抗分组丢失方法，包括Tornado码的不等保护，利用SEI域自适应改变纠错能力和交互式防误码扩散等．综合使用该文提出的多种抗分组丢失方法，在高丢包率环境下，与使用简单误码掩盖算法相比，恢复图像的平均PSNR可以提高8～15dB，且算法与H．264标准兼容，没有过多增加信道负担和运算复杂度，具有实用价值．

基于Vx Works的嵌入式系统实验教学设计

介绍了重庆大学通信工程学院嵌入式系统实验课程教学的基本现状,重点讲述用于实验教学的几个具体实验内容,分析了这些实验的目的、内容以及相互关系,最后给出了一个综合设计环节,实践证明这些实验内容对促进嵌入式系统教学有着重要意义。

千兆以太网信息平台嵌入式图形界面设计

针对在VxWordks系统下直接利用Wind ML提供的API进行图形界面开发存在的人员要求高、代码编写量大、开发周期长、界面程序可移植性差等问题,设计基于VxWorks系统的嵌入式终端图形界面。以千兆以太网为信息平台,以陆军装备信息交互与控制处理为对象,采用Wind ML、Tilcon图形开发软件和Tornado集成环境搭建相结合的方法。结果表明:该设计在功能和性能方面都满足VxWorks实时系统窗口图形界面开发要求,已成功应用于千兆以太网嵌入式炮长终端。

分布式存储方案的设计与研究

针对基于纠删码的分布式存储方法中信息分割算法IDA在运算中涉及构造拆分矩阵,计算开销大,且单纯基于纠删码的方案无法确保所存储数据的完整性、机密性等特性,只能够容忍系统中存在的良性故障,无法容忍入侵者的恶意入侵。提出了分布式系统中一种基于Tornado码的浏览器-服务器工作模式的数据存储方案。在数据写入过程中通过构造编码后数据分块的Hash值级联(即数字指纹),并与每个数据分块一起分布在存储服务器集中的不同服务器中,当需要读出时对分块及数据指纹进行验证,然后利用Tornado译码方法恢复原始文件,即可实现Byzantine环境数据的完整性保护,并提高了系统的容错能力。

VxWorks系统时钟获取和定时功能分析

主要探讨VxWorks嵌入式实时操作系统下的系统时钟及定时器的获取和实现。详细说明了看门狗和POSIX(可移植操作系统接口)定义的时钟接口在VxWorks下的实现方式,同时通过Tornad开发工具软件逻辑分析仪分析了不同定时器的运行情况和执行情况,结果显示在其定时精度范围内,定时器时间进行了圆整。

基于VxWorks的综合导航系统数据记录仪软件设计

以PC/104为硬件平台,基于VxWorks嵌入式实时多任务操作系统,结合面向模式的软件体系结构的思想,提出了一种综合导航系统数据记录仪软件设计实现方案,并详细论述各分步程序结构设计。通过测试验证了系统设计的正确性和有效性。

基于MPC860嵌入式处理器和Vx Works的文件与实时图像传输

利用WindRiver公司的实时操作系统 (RTOS)VxWorks提供的丰富而标准的sockets编程接口 ,多任务机制 ,高效的实时任务的产生、调度、资源分配机制以及对外界输入产生最快响应的能力 ,运用嵌入式软件开发系统TornadoⅡ ,介绍了基于研制的MPC860嵌入式处理器进行软件开发的过程 ,在底层使用以太网作为传输媒介 ,在传输媒介的上一层 ,使用TCP/IP和UDP/IP协议 ,完成局域网间IP数据的转发 ,实现了嵌入式系统控制的文件。