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Assessment of Agricultural Drought Risk in the Sichuan Basin Based on Information Diffusion Theory

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Meteorological and Environmental Research 2014年第5期5卷 15-21页

作者： Luan Jian Chen Jianjie Lin Zhongguan Wang Peng Wang Di Liaoning lightning Protection Technical Service Center Zhumadian Meteorological Bureau Liaoning Meteorological Service Center

Based on data of agricultural drought situation and sown area of main crops in each county or district of the Sichuan Basin, the spatial distribution and probability of agricultural drought risk at different risk levels were studied using normal information diffusion method, and the risk zoning was carried out. The results showed that normal information diffusion method could fit the distribution of agricultural drought risk in the Sichuan Basin. By comparison with the end of the 20^th century, agricultural drought risk in Meishan, Chongqing City and so on increased at the beginning of the 21^st century when x1≥ 10% or x1≥40%. Agricultural drought risk was low in the west of the Sichuan Basin, which was related to rich precipitation here, but it was high in Bazhong, Zhongjiang, Luxian and so forth. The risk zoning results can provide scientific references for disaster prevention and emergency management of government.

关键词： Information diffusion Ratio of area covered by drought to sown area of crops Risk assessment Risk zoning China

lightning electromagnetic field generated by grounding electrode considering soil ionization

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Progress in Natural Science:Materials International 2006年第9期16卷 1002-1006页

作者： ZENG Rong , HE Jinliang, ZHANG Bo and GAO Yanqing (State Key laboratory of Power Systems, Department of Electrical Engineering, Tsinghua University, Beijing 100084, China) State Key laboratory of Power Systems Department of Electrical Engineering Tsinghua University Beijing 100084 China

A circuit model with lumped time-variable parameter is proposed to calculate the transient characteristic of grounding electrode under lightning current, which takes into consideration the dynamic and nonlinear effect of soil ionization around the grounding electrode. The ionization phenomena in the soil are simulated by means of time-variable parameters under appropriate conditions. The generated electromagnetic field in the air is analyzed by using electrical dipole theory and image theory when the lightning current flows into the grounding electrode. The influence of soil ionization on the electromagnetic field is investigated.

关键词： electromagnetic field grounding electrode soil ionization transient characteristic.

Particle bursts in the inner radiation belt related to global lightning activity

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Science China(Technological Sciences) 2013年第11期56卷 2658-2667页

作者： WU Fei HAO YongQiang ZHANG DongHe Institute of Space Physics and Applied Technology Peking University State Key laboratory of Space Weather Chinese Academy of Sciences

Particle bursts （PBs）, the phenomena characterized by short-term increases of particle counting rates （CRs）, were observed by space-borne radiation belt particle detectors. With the electron CR data obtained by National Oceanic and Atmospheric Ad- ministration （NOAA）-18 satellite, the occurrence of PBs in the inner belt （I〈~L〈2 and B〉20.5 gT） were derived for years 2006-2011. The monthly occurrence number of PBs exhibits a strong maximum in northern summer （May-August）. In associ- ation with global lightning data, the seasonal occurrence of PBs is found to be consistent with the lightning activity, especially if only lightning flashes at latitudes 〉20~ are taken into account. The positive correlation between PBs and mid-latitude light- ning discharges indicates the role of lightning-induced whistler waves, and is consistent with the expected pitch-angle scatter- ing by wave-particle interactions. The contribution of lightning is so significant that it forms a non-negligible seasonal back- ground of PBs. If one connects PBs to seismoelectromagnetic emissions （SEME） in attempt to find the earthquake precursor, the lightning background needs to be considered with great care.

关键词： particle burst (PB) wave-particle interaction lightning-induced VLF seismo-electromagnetic emissions (SEME)

Estimation of lightning-Generated NO_(x) in the Mainland of China Based on Cloud-to-Ground lightning Location Data

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Advances in Atmospheric Sciences 2023年第1期40卷 129-143页

作者： Qi LI Fengxia GUO Xiaoyu JU Ze LIU Mingjun GAN Kun ZHANG Binbin CAI Key laboratory of Meteorological Disaster Ministry of Education(KLME)/Joint International Research Laboratory of Climate and Environment Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)/Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological AdministrationNanjing University of Information Science&TechnologyNanjing 210044China Huangshi Meteorological Bureau Huangshi 435002China Anhui meteorological disaster prevention center Hefei 230061China

lightning-generated nitrogen oxides(LNO_(x))have a major influence on the atmosphere and global climate ***,it is of great importance to obtain a more accurate estimation of LNO_(x).The aim of this study is to provide a reference for the accurate estimation of the total LNO_(x) in the mainland of China based on cloud-to-ground lightning(CG)location data from 2014 to *** energy of each CG flash was based on the number of return strokes per CG flash,the peak current of each return stroke,and the assumed CG breakdown *** energy of intracloud lightning(IC)was based on the estimated frequencies of IC and the assumed energy of each IC *** the energy of lightning and the number of nitric oxide(NO)molecules produced by unit energy(ρno),the total LNO_(x) production in the mainland of China was *** LNO_(x) in the mainland of China estimated in this study is in the range(0.157-0.321)×10^(9) kg per year[Tg(N)yr-1],which is on the high end of other scholars’*** cloud-to-ground lightning(NCG)flashes produce the most moles of NO_(x),while positive cloud-to-ground lightning(PCG)flashes produce the least total moles of NO_(x).The breakdown voltage of PCG is greater than that of IC or NCG,while the latter has a greater output of LNO_(x).

关键词： cloud-to-ground lightning location lightning peak current lightning breakdown voltage nitrogen oxide(NO_(x))

lightning Activity and Precipitation Characteristics of Typhoon Molave(2009) Around Its Landfall

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Acta meteorologica Sinica 2013年第5期27卷 742-757页

作者：张文娟张义军周秀骥 State Key laboratory of Severe Weather Chinese Academy of Meteorological Sciences University of Chinese Academy of Sciences

Cloud-to-ground （CG） lightning data,storm intensity and track data,and the data from a Doppler radar and the Tropical Rainfall Measuring Mission （TRMM） satellite,are used to analyze the temporal and spatial characteristics of lightning activity in Typhoon Molave （0906） during different periods of its landfall （pre-landfall,landfall,and post-landfall）.Parameters retrieved from the radar and the satellite are used to compare precipitation structures of the inner and outer rainbands of the typhoon,and to investigate possible causes of the different lightning *** results indicate that lightning activity was stronger in the outer rainbands than in the eyewall and inner *** mainly occurred to the left （rather than ＂right＂ as in previous studies of US cases） of the moving typhoon,indicating a significant spatial *** maximum lightning frequency in the tropical cyclone （TC） eyewall region was ahead of that in the whole TC region,and the outbreaks of eyewall lightning might indicate deepening of the *** lightning in the outer rainbands is found to be associated with stronger updraft,higher concentrations of rain droplets and large ice particles at elevated mixed-phase levels,and the higher and broader convective clouds in the outer *** to the contribution of large cloud nuclei,lightning intensity in the outer rainbands has a strong positive correlation with radar *** ratio of positive CG lightning in the outer rainbands reached its maximum 1 h prior to occurrence of the maximum typhoon intensity at 2000 Beijing Time （BT） 18 July *** the pre-landfall period （0300 BT 18 July-0050 BT 19 July）,the typhoon gradually weakened,but strong lightning still *** the typhoon made landfall at 0050 BT 19 July,CG lightning density rapidly decreased,but the ratio of positive lightning ***,after the landfall of the outer rainbands at 2325 BT 18 July （approximately 1.5 h prior to the l

关键词： Molave typhoon landfall lightning precipitation structure

Investigating lightning Characteristics through a Supercell Storm by Comprehensive Coordinated Observations over North China

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Advances in Atmospheric Sciences 2020年第8期37卷 861-872页

作者： Dongxia LIU Xiushu QIE Yichen CHEN Zhuling SUN Shanfeng YUAN Key laboratory of Middle Atmosphere and Global Environment Observation(LAGEO) Institute of Atmospheric PhysicsChina Academy ScienceBeijing 100029China State Key laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China Beijing Weather Modification Office Beijing 100089China

Electrical characteristics of an isolated supercell storm observed on 13 June 2014 over Beijing were investigated using lightning data obtained from the Beijing lightning Network,radar reflectivity,and hydrometeor retrievals during the 6-h *** cloud-to-ground(+CG)lightning took a high percentage of CG *** and during a hail event,+CG lightning was more frequent than negative cloud-to-ground(-CG)lightning,except that+CG lightning took a high percentage at the beginning and in the dissipating *** the hail event ended,-CG lightning dominated and reached its maximum *** analysis of hydrometeors retrieved by X-band polarimetric radar revealed that the discharge concentrated in the convective region with graupel particles and hailstones,whereas graupel,snow and ice crystals in the stratiform *** radiation sources were located mainly in the convective region,some of which were distributed along a gradient of radar reflectivity from the convective region to the stratiform *** indication is that the supercell demonstrated an inverted tripole charge structure before the hail event,which converted to a normal tripole structure after the hail event.

关键词： lightning supercell Beijing lightning Network charge structure

Protection of Elevators against lightning

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Meteorological and Environmental Research 2018年第5期9卷 44-46页

作者： Zhang Jinsong Zhao Xi Neijiang lightning Protection Center Neijing 641000China Sichuan Anxin Dacheng lightning Protection Co. Ltd.Chengdu 610051China

In the thunderstorm process on August 3,2016,among the nine elevators in a housing estate in the middle of Neijiang City,six elevators were damaged by lightning. In this study,the impact of lightning stroke on elevators was analyzed firstly,and then measures to protect elevators against lightning were proposed,which provides a practical basis for the improvement of protection of elevators against lightning.

关键词： Elevators lightning protection Measures

A Multi-physics Methodology for Four States of Matter

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Communications on Applied Mathematics and Computation 2020年第3期2卷 487-514页

作者： Louisa Michael Stephen T.Millmore Nikolaos Nikiforakis laboratory for Scientifc Computing Cavendish LaboratoryDepartment of PhysicsUniversity of CambridgeCambridgeUK

We propose a numerical methodology for the simultaneous numerical simulation of four states of matter:gas,liquid,elastoplastic solids,and *** distinct,interacting physical processes are described by a combination of compressible,inert,and reactive forms of the Euler equations,multi-phase equations,elastoplastic equations,and resistive MHD *** of systems of equations are usually solved by coupling finite element for solid modelling and CFD models for fluid modelling or including material effects through boundary conditions rather than full material *** simultaneous solution methodology lies on the recasting of all the equations in the same,hyperbolic form allowing their solution on the same grid with the same finite volume numerical *** use a combination of sharp-and diffuse-interface methods to track or capture material interfaces,depending on the *** communication between the distinct systems of equations(i.e.,materials separated by sharp interfaces)is facilitated by means of mixed-material Riemann solvers at the boundaries of the systems,which represent physical material *** this end,we derive approximate mixed-material Riemann solvers for each pair of the above models based on characteristic *** demonstrate the applicability of the new methodology,we consider a case study,where we investigate the possibility of ignition of a combustible gas that lies over a liquid in a metal container that is struck by a plasma arc akin to a lightning *** study the effect of the metal container material and its conductivity on the ignition of the combustible gas,as well as the effects of an additional dielectric coating,the sensitivity of the gas,and differences between scenarios with sealed and pre-damaged metal surfaces.

关键词： Plasma modelling Four states of matter lightning Ignition Combustible gas Elastoplastic solids

A Short-Range Quantitative Precipitation Forecast Algorithm Using Back-Propagation Neural Network Approach

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Advances in Atmospheric Sciences 2006年第3期23卷 405-414页

作者：冯业荣 David H.KITZMILLER Department of Atmospheric Science Hydrology laboratory

A back-propagation neural network （BPNN） was used to establish relationships between the shortrange （0-3-h） rainfall and the predictors ranging from extrapolative forecasts of radar reflectivity, satelliteestimated cloud-top temperature, lightning strike rates, and Nested Grid Model （NGM） outputs. Quan- titative precipitation forecasts （QPF） and the probabilities of categorical precipitation were obtained. Results of the BPNN algorithm were compared to the results obtained from the multiple linear regression algorithm for an independent dataset from the 1999 warm season over the continental United States. A sample forecast was made over the southeastern United States. Results showed that the BPNN categorical rainfall forecasts agreed well with Stage Ⅲ observations in terms of the size and shape of the area of rainfall. The BPNN tended to over-forecast the spatial extent of heavier rainfall amounts, but the positioning of the areas with rainfall ≥25.4 mm was still generally accurate. It appeared that the BPNN and linear regression approaches produce forecasts of very similar quality, although in some respects BPNN slightly outperformed the regression.

关键词： quantitative precipitation forecast BP neural network WSR-88D Doppler radar lightning strike rate infrared satellite data NGM model