检索结果-南通市图书馆

Understanding Simulated Causes of Damaging Surface Winds in a Derecho-Producing Mesoscale Convective System near the East China Coast Based on Convection-Permitting Simulations

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Advances in atmospheric sciences 2024年第11期41卷 2112-2130页

作者： Liping luo Ming XUE Xin XU Lijuan LI Qiang ZHANG Ziqi {2. College of Civil Aviation Nanjing University of Aeronautics and AstronauticsNanjing 211106China State Key Laboratory of Numerical Modeling for atmospheric sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Key Laboratory of Mesoscale Severe Weather/Ministry of Education and School of atmospheric sciences Nanjing UniversityNanjing 210023China Center for Analysis and Prediction of Storms and School of Meteorology University of OklahomaNormanOklahoma 73072USA Civil Aviation North China Air Traffic Management Bureau Meteorological Center Beijing 100621China

A mesoscale convective system(MCS) occurred over the East China coastal provinces and the East China Sea on 3.April 2.2., producing damaging surface winds near the coastal city Nantong with observed speeds reaching 45 m s^(–1). A simulation using the Weather Research and Forecasting model with a 1.5-km grid spacing generally reproduces the development and subsequent organization of this convective system into an MCS, with an eastward protruding bow segment over the sea. In the simulation, an east-west-oriented high wind swath is generated behind the gust front of the MCS. Descending dry rear-to-front inflows behind the bow and trailing gust front are found to feed the downdrafts in the main precipitation regions. The inflows help to establish spreading cold outflows and enhance the downdrafts through evaporative cooling. Meanwhile, front-to-rear inflows from the south are present, associated with severely rearward-tilted updrafts initially forming over the gust front. Such inflows descend behind(north of) the gust front, significantly enhancing downdrafts and near-surface winds within the cold pool. Consistently, calculated trajectories show that these parcels that contribute to the derecho originate primarily from the region ahead(south) of the east-west-oriented gust front, and dry southwesterly flows in the low-to-middle levels contribute to strong downdrafts within the MCS. Moreover, momentum budget analyses reveal that a large westward-directed horizontal pressure gradient force within the simulated cold pool produced rapid flow acceleration towards Nantong. The analyses enrich the understanding of damaging wind characteristics over coastal East China and will prove helpful to operational forecasters.

关键词： damaging surface winds convection-permitting simulations mesoscale convective system gust front cold pool

Investigation of fine and complex vortex circulation structures

在线全文

学校读者我要写书评

暂无评论

Science China Earth sciences 2010年第10期53卷 1552-1558页

作者： luo zhexian1,MA GeLan1 & {2. {3.2.1 Remote Sensing College,Nanjing University of Information Science and Technology,Nanjing 2.0044,China 2.Laboratory of Cloud-Precipitation physics and Severe Storms(LACS),{3. of atmospheric physics,Chinese Academy of sciences,beijing 10002.,China 1. Remote Sensing College Nanjing University of Information Science and Technology Nanjing 210044 China2. Laboratory of Cloud-Precipitation Physics and Severe Storms (LACS) Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

The formation and evolution of fine and complicated vortex circulation structures were investigated using a two-dimensional quasi-geostrophic barotropic model *** find that the highly localized asymmetric and complex configuration of energy transfer flux between large-and small-scale components is caused by the nonlinear interaction between a large-scale vortex with an initial axi-symmetric flow and four beta meso-scale *** complex structure is characterized by a fine pattern,which contains seven closed systems with spatial scales of less than 100 km,embedded in a positive flux wave train and a negative wave train,*** average wind speed decreased with time in the positive flux region,but was nearly unchanged in the negative flux *** pattern reveals the evolutionary asymmetry and localization of wind speed of the major *** track of the major vortex center has a trend toward the center of the negative flux center,indicating that there is a certain relation between the complex structure of the energy transfer flux and the motion of the major vortex *** results imply that the formation and evolution of the fine and complex structure should be attributed to the nonlinear interaction between the vortices at different spatial scales.

关键词： vortex complex structure non-linear interaction energy cascade

Differences between dynamics factors for interannual and decadal variations of rainfall over the Yangtze River valley during flood seasons

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2006年第8期51卷 994-999页

作者： ping fan {2. {3. JU Jianhua institute of atmospheric {2. Chinese Academy of Sciences Beijing 100029 China Nanjing University of Information Science & Technology Nanjing 210044 China China Meteorological Administration Training Center Beijing 100081 China

The rainfall over the Yangtze River val- ley during flood seasons (June to July) shows both interannual and decadal variations. The rainfall has been increasing since 1990, showing a decadal sig- nal. The variations of rainfall are influenced by the multi-scale interactions in the atmosphere-ocean coupled climate system. The rainfall, SST, and cir- culation are analyzed with the Chinese 160 station data, and other observational/reanalysis data, re- spectively. The separation between the interannual and decadal variations is carried out. The key areas affecting the Yangtze rainfall are the western Pacific warm pool on the interannual time scale and the EINO3.area on the decadal time scale, respectively. The circulation anomaly associated with the interan- nual variation occurs in the upper troposphere whereas that associated with the decadal variation appears in the lower troposphere.

关键词：长江流域降雨量动力学因素比较分析

Projected near-surface wind speed and wind energy over Central Asia using dynamical downscaling with bias-corrected global climate models

在线全文

学校读者我要写书评

暂无评论

Advances in Climate Change Research 2024年第4期15卷 669-679页

作者： Jin-Lin ZHA Ting CHUAN Yuan QIU Jian WU De-Ming ZHAO Wen-Xuan fan Yan-Jun LYU Hui-ping JIANG Kai-Qiang DENG Miguel ANDRES-MARTIN Cesar AZORIN-MOLINA Deliang CHEN Key Laboratory of atmospheric Environment and Processes in the Boundary Layer over the Low-Latitude Plateau Region Department of Atmospheric ScienceYunnan UniversityKunming 650091China Key Laboratory of Regional Climate and Environment for Temperate East Asia Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China Center for Energy&Environmental Policy Research Beijing Institute of Technology Beijing 100081China Key Laboratory of Regional Sustainable Development Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China International Research Center of Big Data for Sustainable Development Goals Beijing 100094China School of atmospheric sciences Sun Yat-sen Universityand Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai 519082China Centro de Investigaciones Sobre Desertificacion Consejo Superior de Investigaciones Cientificas(CIDECSIC-UV-Generalitat Valenciana)ClimateAtmosphere and Ocean Laboratory(Climatoc-Lab)Moncada 46113Spain Regional Climate Group.Deparment of Earth sciences University of GothenburgGothenburg 40530Sweden

Wind energy development in Central Asia can help alleviate drought and fragile ***,current studies mainly used the global climate models(GCMs)to project wind speed and *** simulated biases in GCMs remain prominent,which induce a large uncertainty in the projected *** reduce the uncertainties of projected near-surface wind speed(NSW)and better serve the wind energy development in Central Asia,the Weather Research and Forecasting(WRF)model with bias-corrected GCMs was *** with the outputs of GCMs,dynamical downscaling acquired using the WRF model can better capture the high-and low-value centres of NSWS,especially those of Central Asia's ***,the simulated NSWS bias was also *** future changes in wind speed and wind energy,under the Representative Concentration Pathway 4.5(RCP4.5)scenario,NSWS during 2.3.-2.50 is projected to decrease compared with that in *** magnitude of NSwS reduction during 2.3.-2.50 willreach 0.1 m s^(-1).and the maximum reduction is projected to occur over the central and western regions(>0.2.m s^(-1)).Furthermore,future wind power density(WPD)can reveal nonstationarity and strong volatility,although a downward trend is expected during *** addition,the higher frequency of wind speeds at the turbine hub height exceeding 3.0 m s^(-1)can render the plain regions more suitable for wind energy development than the mountains from 2.3. to *** study can serve as a guide in gaining insights into future changes in wind energy across Central Asia and provide a scientific basis for decision makers in the formulation of policies for addressing climate change.

关键词： Near-surface wind speed Wind power density Dynamical downscaling Central Asia WRF

A Convective Vorticity Vector Associated With Tropical Convection:A 2. Cloud-Resolving Modeling Study

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

A Convective Vorticity Vector Associated With Tropical Conve...

雷达资料循环同化对2.2.年“4·3.”南通雷暴大风模拟的影响研究

中国气象学会2.04年年会

作者： Gao Shouting~1 ping fan~1 Li Xiaofan~2.Tao Weikuo~3.(1 LAPC, {3. of atmospheric {3. Chinese Academy of sciences beijing, China 2.Joint Center for Satellite Data Assimilation and NOAA/NESDIS/Office of Research and Applications Camp Springs, Maryland, 3.NASA/GSFC/Laboratory for Atmospheres Greenbelt, Maryland)

＜正＞Although dry/moist potential vorticity is a useful physical quantity for meteorological analysis, it cannot be applied to the analysis of 2. simulations. A new vorticity vector （convective vorticity vector, CVV） is introduced in this study to analyze 2. cloud-resolving simulation data associated with 2. tropical convection. The cloud model is forced by the vertical velocity, zonal wind, horizontal advection and sea surface temperature obtained from the TOGA COARE, and is integrated for a selected 10-day period. The CVV has zonal and vertical components in the 2. x-z frame. Analysis of zonally-averaged and massintegrated quantities shows that the correlation coefficient between the vertical component of the CVV and the sum of the cloud hydrometeor mixing ratios is 0. 81, whereas the correlation coefficient between the zonal component and the sum of the mixing ratios is only 0. 18. This indicates that the vertical component of the CVV is closely associated with tropical convection. The tendency equation for the vertical component of the CVV is derived and the zonally-averaged and mass-integrated tendency budgets are analyzed. The tendency of the vertical component of the CVV is determined by the interaction between the vorticity and the zonal gradient of cloud heating. The results demonstrate that the vertical corr ponent of the CVV is a cloud-linked parameter and can be used to study tropical convection.

关键词：

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

大气科学 2024年第4期48卷 1593-1607页

作者：汪卫国平凡周括李建阳南京信息工程大学遥感与测绘工程学院南京210044 中国科学院大气物理研究所云降水物理与强风暴重点实验室(LACS) 北京100029

基于多普勒天气雷达资料、ERA5再分析资料与地面自动站观测资料,利用WRF(Weather Research and Forecasting)模式、雷达径向风质控及三维变分同化系统(GSI)循环同化对2.2.年4月3.日江苏南通的一次雷暴大风过程进行数值模拟研究,对比分... 详细信息

基于多普勒天气雷达资料、ERA5再分析资料与地面自动站观测资料,利用WRF(Weather Research and Forecasting)模式、雷达径向风质控及三维变分同化系统(GSI)循环同化对2.2.年4月3.日江苏南通的一次雷暴大风过程进行数值模拟研究,对比分析不同试验方案模拟的雷达反射率、风场与热动力的时空演变和结构特征。结果表明:逐3. min循环同化的Exp3.案较未同化和非临近循环同化方案模拟效果有较好提升,表明循环同化和增加频次有效改善了初始场;UNRAVEL退模糊算法质控有效消除了速度模糊,退模糊处理雷达资料后循环同化方案(Exp4)对此次雷暴大风的雷达反射率和地面风场模拟结果有显著调整,其相应特征和演变趋势与观测基本一致,表明UNRAVEL退模糊质控后循环同化更好的改善了初始场;从热动力场结果来看,Exp4方案动热力结构改善较明显,上层辐散下层辐合,存在“冷—暖—冷”的热动力结构,伴随着强烈上升运动、北高南低的气压分布和强垂直风切变,有助于下沉气流将中高层的水平动量向近地面底层传递,从而激发此次雷暴大风。

关键词：雷暴大风数值模拟循环同化速度退模糊

维普期刊数据库博看期刊

一次北京冰雹形成的数值模拟及微物理机制研究

在线全文

学校读者我要写书评

暂无评论

大气科学 2024年第5期48卷 1796-1816页

作者：朱好奇平凡谭桂容沈新勇殷蕾南京信息工程大学气象灾害教育部重点实验室/气候与环境变化国际合作联合实验室/气象灾害预报预警与评估协同创新中心南京210044 中国科学院大气物理研究所北京100029 南方海洋科学与工程广东省实验室(珠海) 珠海519082

本文利用WRF模式对2.2.年6月2.日一次发生在北京地区的冰雹天气进行高分辨率数值模拟研究。从雷达反射率和降水来看,数值模拟基本再现了冰雹风暴的宏观特征。在此基础上分析了冰雹风暴不同发展阶段的中尺度热力、动力和微物理特征。最... 详细信息

本文利用WRF模式对2.2.年6月2.日一次发生在北京地区的冰雹天气进行高分辨率数值模拟研究。从雷达反射率和降水来看,数值模拟基本再现了冰雹风暴的宏观特征。在此基础上分析了冰雹风暴不同发展阶段的中尺度热力、动力和微物理特征。最后通过输出微物理过程的中间转化项,着重分析雹粒子和雨滴的质量收支和潜热收支情况,给出冰雹形成的云微物理概念模型图。研究结果表明:本次冰雹过程可分为多单体回波、线状对流和飑线三个阶段。此次冰雹天气主要以雪粒子为雹胚在对流层中高层与雨水和云水发生撞冻作用形成雹粒子,雹粒子生成后不断地撞冻雨水和云水增长,冰晶直接撞冻雨水形成雹的转化率很低。气流在风暴的前部低层流入,多单体阶段的两股弱上升气流不断地合并,而线状对流和飑线阶段低层入流减弱,中高层较干冷气流的流入明显。气流在飑线阶段强烈上升,在高层向前流出。被上升气流抬升的暖湿空气与中高层流入的干冷空气相遇凝结为云水或凝华为冰相粒子,释放大量潜热,导致云内浮力增强,促进云内气流强烈上升,将有更多的云水和冰相粒子生成,同时促进了雹粒子的生成和累积。雪和雹粒子的融化吸收大量潜热,导致融化层升高,因此在飑线阶段有大量过冷雨水生成并与雪粒子发生撞冻作用形成更多的雹粒子。大雹粒子降落产生的更强的水物质拖曳力将促进低层下沉气流增强。下沉运动导致低层雨水蒸发冷却,在近地面形成冷池,与高层的潜热加热配合增强对流,从而正反馈于经向环流。环流导致的垂直上升气流促进低层的水汽抬升至融化层以上凝结形成过冷水和凝华为雪粒子,而垂直下沉气流促进雪和雹降落至融化层以下形成雨水以及雨水在融化层以下蒸发,进而正反馈于云内热力环境。如此反复,产生降雹和强降水。

关键词：冰雹 WRF模式云微物理过程云内热动力场垂直速度诊断

Comparative Studies of Different Mesoscale Convection Parameterization Schemes in the Simulation of Mei-Yu Front Heavy Rain

维普期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

atmospheric and Oceanic Science Letters 2010年第3期3卷 132-138页

作者： ping fan {2. Zhe-Xian Remote Sensing College Nanjing University of Information Science and Technology Nanjing 210044 China Laboratory of Cloud-Precipitation physics and Severe Storms (LACS) Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

The mei-yu front heavy rainstorms occurred over Nanjing on 3.5 and 8 9 July 2.03.and were simulated in this paper using the Weather Research and Forecasting Model (WRFv3.1) with various mesoscale convection parameterization schemes (MCPSs). The simulations show that the temporal and spatial evolution and distribution of rainstorms can be modeled; however, there was incongruity between the comparative simulations of four different MCPSs and the observed data. These disparities were exhibited in the simulations of both the 2.-hour surface rainfall total and the hourly precipitation rate. Further analysis revealed that the discrepancies of vertical velocity and the convective vorticity vector (CVV) between the four simulations were attributed to the deviation of rainfall values. In addition, the simulations show that the mid-scale convection, particularly the mesoscale convection system (MCS) formation, can be well simulated with the proper mesoscale convection parameterization schemes and may be a crucial factor of the mei-yu front heavy rainstorm. These results suggest that, in an effort to enhance simulation and prediction of heavy rainfall and rainstorms, subsequent studies should focus on the development and improvement of MCPS.

关键词： mesoscale convection parameterization schemes vertical velocity the convective vorticity vector the mesoscale convection system

3.p NMR study of magnetic phase transitions of MnP single crystal under 2.GPa pressure

在线全文

学校读者我要写书评

暂无评论

Science China(physics,Mechanics & Astronomy) 2016年第5期59卷 7-10页

作者： GuoZhi fan Bo Zhao Wei Wu ping Zheng JianLin {2. beijing National Laboratory for Condensed Matter physics Institute of Physics Chinese Academy of Sciences Beijing 100190 China Collaborative Innovation Center of Quantum Matter Beijing 100190 China

Superconductivity on the border of the long-range magnetic order has been discovered in Mn P under high pressures. In order to investigate the nature of the magnetic properties adjacent to the superconducting state, we performed zero-field 3. P NMR for Mn P single crystal under ambient and hydrostatic pressure of 2.GPa, respectively. Radio frequency power level was used to determine whether NMR signal originates from a helical state or not. When 2.GPa pressure was applied, the signal from helical state exists even above 160 K, while that from the ferromagnetic phase was not observed. Our NMR results indicate that the magnetic phase which is adjacent to the superconducting state is in a helical magnetic structure.

关键词： superconducting materials magnetic phase transitions nuclear magnetic resonance MnP