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Seasonal Variability of Rainfall and Thunderstorm Patterns in Kenya
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作者 Mary Kurgat Wilson Gitau 《Journal of Atmospheric Science Research》 2024年第1期106-117,共12页
This paper presents an analysis of spatial and temporal variation of rainfall and thunderstorm occurrence over Ken-ya from January 1987 to December 2017.The meteorological data used were obtained from the Kenya Meteor... This paper presents an analysis of spatial and temporal variation of rainfall and thunderstorm occurrence over Ken-ya from January 1987 to December 2017.The meteorological data used were obtained from the Kenya Meteorological Department(KMD)for the same period.This included the monthly thunderstorm occurrences and rainfall amounts of 26 synoptic stations across the country.The characteristics of monthly,seasonal and annual frequency results were presented on spatial maps while Time series graphs were used to display the pattern for annual cycle,seasonal varia-tions and the inter-annual variability of rainfall amounts and thunderstorm occurrences.A well-known non-parametric statistical method Mann Kendall(MK)trend test was used to determine and compare the statistical significance of the trends.Thunderstorm frequencies over the Eastern,Central and Coast regions of the country showed a bimodal pattern with high frequencies coinciding with March-April-May(MAM)and October-November-December(OND)rainy sea-sons.Very few thunderstorm days were detected over June-July-August(JJA)season.The areas to the western part of the country,near Lake Victoria,had the highest thunderstorm frequencies in the country over the three seasons:MAM,JJAS and OND.The annual frequency showed a quasi-unimodal pattern.These places near Lake Victoria showed sig-nificantly increasing thunderstorm trends during the MAM and OND seasons irrespective of the rainfall trends.This shows the effects of Lake Victoria over these areas,and it acts as a continuous source of moisture for thunderstorm for-mation.However,most stations across the country showed a reducing trend of thunderstorm frequency during MAM and JJA seasons.The importance of these findings is that they could support various policy makers,and users of cli-mate information,especially in the agriculture and aviation industries. 展开更多
关键词 RAINFALL thunderstorm Lake Victoria Kenya Mann Kendall
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Thunderstorm and Lightning Activities over Western Pacific,Northern Indian Ocean and South China Sea Along with Their Adjacent Lands
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作者 丁嘉欣 张义军 +2 位作者 郑栋 姚雯 张文娟 《Journal of Tropical Meteorology》 SCIE 2023年第3期347-358,共12页
The Lightning Imaging Sensor(LIS)and Radar Precipitation Feature(RPF)data are used to investigate the activities and properties of lightning and thunderstorms over a region including the Western Pacific,northern India... The Lightning Imaging Sensor(LIS)and Radar Precipitation Feature(RPF)data are used to investigate the activities and properties of lightning and thunderstorms over a region including the Western Pacific,northern Indian Ocean and the South China Sea along with their adjacent lands.The lands feature significantly more frequent lightning flashes and thunderstorms than the oceans,especially the open oceans.The highest densities of lightning and thunderstorm occur over the Strait of Malacca and the southern foothills of the Himalayas.Over the ocean regions,the Bay of Bengal and the South China Sea are characterized by relatively frequent lightning and thunderstorm activities.Larger average spatiotemporal size and optical radiance of flashes can be found over the oceans;specifically,the offshore area features the most significant flash duration,and the open ocean area is characterized by the greatest flash length and optical radiance.The smallest average values of flash properties can be found over and around the Tibetan Plateau(TP).The oceanic thunderstorms tend to have a significantly larger horizontal extent than the continental thunderstorms,with the former and latter having the average area of the regions with radar reflectivity larger than 20 dBZ,generally over 7000 km^(2) and commonly below 6000 km^(2),respectively.The TP thunderstorms show the smallest horizontal extent.Meanwhile,the oceanic thunderstorms exhibit greater 20 dBZ but smaller 40 dBZ top heights than the continental thunderstorms.The average flash frequency and density of the oceanic thunderstorms are typically less than 5 fl min^(-1) and 0.3 fl 100 km^(-2) min^(-1),respectively;in contrast,the corresponding values of continental thunderstorms are greater.It is explored that the regions associated with strong convective thunderstorms are more likely to feature small-horizontal-extent and low-radiance flashes. 展开更多
关键词 LIGHTNING thunderstorm land ocean thunderstorm structure lightning spatiotemporal size and radiance
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Prediction-Based Thunderstorm Path Recovery Method Using CNN-BiLSTM
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作者 Xu Yang Ling Zhuang +1 位作者 Yuqiang Sun Wenjie Zhang 《Intelligent Automation & Soft Computing》 SCIE 2023年第8期1637-1654,共18页
The loss of three-dimensional atmospheric electric field(3DAEF)data has a negative impact on thunderstorm detection.This paper proposes a method for thunderstorm point charge path recovery.Based on the relation-ship b... The loss of three-dimensional atmospheric electric field(3DAEF)data has a negative impact on thunderstorm detection.This paper proposes a method for thunderstorm point charge path recovery.Based on the relation-ship between a point charge and 3DAEF,we derive corresponding localization formulae by establishing a point charge localization model.Generally,point charge movement paths are obtained after fitting time series localization results.However,AEF data losses make it difficult to fit and visualize paths.Therefore,using available AEF data without loss as input,we design a hybrid model combining the convolutional neural network(CNN)and bi-directional long short-term memory(BiLSTM)to predict and recover the lost AEF.As paths are not present during sunny weather,we propose an extreme gradient boosting(XGBoost)model combined with a stacked autoencoder(SAE)to further determine the weather conditions of the recovered AEF.Specifically,historical AEF data of known weathers are input into SAE-XGBoost to obtain the distribution of predicted values(PVs).With threshold adjustments to reduce the negative effects of invalid PVs on SAE-XGBoost,PV intervals corresponding to different weathers are acquired.The recovered AEF is then input into the fixed SAE-XGBoost model.Whether paths need to be fitted is determined by the interval to which the output PV belongs.The results confirm that the proposed method can effectively recover point charge paths,with a maximum path deviation of approximately 0.018 km and a determination coefficient of 94.17%.This method provides a valid reference for visual thunderstorm monitoring. 展开更多
关键词 thunderstorm point charge atmospheric electric field(AEF) RECOVERY
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Analysis of Continuous Thunderstorm in One Week at Qingdao Airport Based on Sounding Data
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作者 Yuan LIU Xiaoxia HE +1 位作者 Xi LIU Jinghua ZHAO 《Meteorological and Environmental Research》 CAS 2023年第1期15-20,共6页
Continuous thunderstorm occurring at Qingdao Airport in China from August 7 to 13,2022 was analyzed based on sounding data.The weather was divided into thunderstorm gale,thunderstorm and heavy precipitation,and some p... Continuous thunderstorm occurring at Qingdao Airport in China from August 7 to 13,2022 was analyzed based on sounding data.The weather was divided into thunderstorm gale,thunderstorm and heavy precipitation,and some physical quantities and time variables which can effectively identify severe convective weather types were preliminarily obtained.The results show that CAPE was sensitive to different types of weather,but the uncertainty was relatively large.Convective temperature T_(CON),temperature difference between 500 and 850 hPa,and vertical wind shear can distinguish thunderstorm gale,thunderstorm and heavy precipitation weather obviously.Besides,K index,Showalter index,θ_(se) difference between 500 and 850 hPa were also important basis to distinguish thunderstorm and heavy precipitation weather.Thunderstorm gale can be distinguished by the 24-hour variations of K index,and the difference of dew point between 500 and 850 hPa.The 24-hour variations of(T-T_(d))_(500) and vertical wind shear can be used to distinguish between heavy precipitation and thunderstorm weather;the 24-hour variation of stratification stability Δθ_(se) can distinguish the three kinds of weather well.For the wind field,the existence of vertical wind shear was required for strong convective weather,and the 24-hour increment of thunderstorm gale and thunderstorm was larger than that of heavy precipitation. 展开更多
关键词 thunderstorm Sounding data Qingdao Airport
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Radio-Acoustic Study of Thunderstorms
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作者 Giancarlo T. Tomezzoli 《Journal of Sensor Technology》 2023年第3期51-58,共8页
The observation, in the past, that a thunderstorm perturbed the transmissions of an old vacuum tubes radio with noise discharges in correspondence with lightnings, suggested the possibility of radio-acoustic study of ... The observation, in the past, that a thunderstorm perturbed the transmissions of an old vacuum tubes radio with noise discharges in correspondence with lightnings, suggested the possibility of radio-acoustic study of thunderstorms. The noise discharges appeared to convey not only information about lightnings, but also about any other thunderstorm electromagnetic phenomena generating noise discharges. The low-cost instrumentation involved in the radio-acoustic study, comprised a radio Telefunken mod. T33B, a 15 m long indoor wire antenna, a mobile telephone Samsung Galaxy S20 FE 5G provided with the recorder App Enregistreur vocal, a computer HP Pavillion dv5-1254eg and the s/w audio analyser Audacity. A first thunderstorm on 20 June 2023 and a second thunderstorm on 22 June 2023, both above Munich, were radio-acoustic studied. The second thunderstorm was more active than the first and released much more energy. 展开更多
关键词 thunderstormS Radio-Acoustics Vacuum Tube Radio Noise Discharges
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Assessment of the Impacts of Thunderstorm on Flight Operations at Murtala Mohammed International Airport,Ikeja,Lagos State,Nigeria
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作者 I.C.Onwuadiochi O.S.Egede A.C.Udeogu 《Journal of Geographical Research》 2023年第1期17-27,共11页
The inefficiency of the aviation industry and the persistent rise in aviation hazards have been linked to weather phenomena.As a result,researchers are looking for better solutions to the problem.The study examined th... The inefficiency of the aviation industry and the persistent rise in aviation hazards have been linked to weather phenomena.As a result,researchers are looking for better solutions to the problem.The study examined the impact of thunderstorms on flight operations at Murtala Mohammed International Airport,Lagos.The data on thunderstorms and flight operations were sourced from Nigerian Meteorological Agency(NiMet)and Nigerian Airspace Management Agency(NAMA)respectively.In order to meet the research target,descriptive statistics(mean,standard deviation,and charts)and inferential statistics(Pearson’s Product Moment Correlation(PPMC)and Regression)were used.The significance level for all inferential analyses was set at 5%(0.05).The study revealed that 77.4%of thunderstorms occurred during the rainy season(April-October)while 22.6%occurred during the dry season(November-March).It also revealed some fluctuating movements of a thunderstorm in the study area.According to the findings,thunderstorms occur most frequently at the airport in June and less frequently in January and December.The study also discovered that thunderstorms at the airport are positively and significantly related to flight delays and cancellations,while the association between flight diversions and thunderstorm occurrence is positive but statistically insignificant.Furthermore,flight delays,flight diversions,and flight cancellations interact positively among themselves.The regression result of the study revealed that a 1%increase in thunderstorm occurrence leads to a 19.4%increase in flight delay,a 7.1%increase in flight cancellation,and a 4.3%increase in flight diversion.As a result,the study presented various regression models that may be utilized to make predictions.The study proposes consistent thunderstorm observation at the airport and steady forecasts using the regression models,based on the findings.However,it further recommends that pilots,air traffic controllers,and meteorologists be trained and retrained so that they can provide better and more efficient services. 展开更多
关键词 thunderstormS ASSESSMENT Impacts Flight operations AIRPORT
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Three-Dimensional Numerical Simulations of the Effects of a Cold Water Surface on the Evolution and Propagation of Thunderstorms
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作者 孔凡铀 黄美元 徐华英 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1993年第3期261-272,共12页
The influences of large areas of semi-unbounded cold water surface on the evolution, propagation and precipitation production of thunderstorms are simulated by using a fully elastic three-dimensional numerical hailsto... The influences of large areas of semi-unbounded cold water surface on the evolution, propagation and precipitation production of thunderstorms are simulated by using a fully elastic three-dimensional numerical hailstorm model. Real sounding profiles for temperature, humidity and wind are employed. The model has successfully simulated the significant modification of the propagation path of thunderstorms near the cold water area. The path change can be either' along-bank' or' toward-bank', depending on the position of the storm system relative to convergence zone of the water-land circulation. The simulations also show that thunderstorms developing or propagating within the convergence zone of local circulation will be intensified and produce much heavier hail, whereas those over cold water surface or the air that has been cooled by the water will be strongly inhibited.The influence of the cold water surface on thunderstorm characters is largely dependent upon the direction and intensity of the low-level wind. 展开更多
关键词 thunderstorm Numerical simulation Water-land circulation thunderstorm propagation
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Charge Structure of a Summer Thunderstorm in North China:Simulation Using a Regional Atmospheric Model System 被引量:16
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作者 LIU Dongxia QIE Xiushu +1 位作者 PENG Liang LI Wanli 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2014年第5期1022-1034,共13页
Electrification and simple discharge schemes are coupled into a 3D Regional Atmospheric Model System (RAMS) as microphysical parameterizations, in accordance with electrical experiment results. The dynamics, microph... Electrification and simple discharge schemes are coupled into a 3D Regional Atmospheric Model System (RAMS) as microphysical parameterizations, in accordance with electrical experiment results. The dynamics, microphysics, and electrifi- cation components are fully integrated into the RAMS model, and the inductive and non-inductive electrification mechanisms are considered in the charging process. The results indicate that the thunderstorm mainly had a normal tripole charge structure. The simulated charge structure and lightning frequency are basically consistent with observations of the lightning radiation source distribution. The non-inductive charging mechanism contributed to the electrification during the whole lifetime of the thunderstorm, while the inductive electrification mechanism played a significant role in the development period and the mature stage when the electric field reached a large value. The charge structure in the convective region and the rearward region are analyzed, showing that the charge density in the convective region was double that in the rearward region. 展开更多
关键词 RAMS electrification parameterization discharge parameterization charge structure thunderstorm
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Case Studies of Sprite-producing and Non-sprite-producing Summer Thunderstorms 被引量:4
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作者 杨静 杨美荣 +1 位作者 刘超 冯桂力 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2013年第6期1786-1808,共23页
Three summer thunderstorms in the eastern region of China were analyzed in detail using multiple data, including Doppler radar, lightning location network, TRMM (Tropical Rainfall Measuring Mission), MT- SAT (Multi... Three summer thunderstorms in the eastern region of China were analyzed in detail using multiple data, including Doppler radar, lightning location network, TRMM (Tropical Rainfall Measuring Mission), MT- SAT (Multi-Function Transport Satellite) images, NCEP (National Centers for Environmental Prediction) Reanalysis, and radiosonde. Two of the three storms were sprite-producing and the other was non-sprite- producing. The two sprite-producing storms occurred on 1 2 August and 2~28 July 2007, producing 16 and one sprite, respectively. The non-sprite-producing storm occurred on 29-30 July 2007. The major ob- jective of the study was to try to find possible differences between sprite-producing and non-sprite producing storms using the multiple datasets. The results showed that the convection in the 1-2 August storm was the strongest compared with the other storms, and it produced the largest number of sprites. Precipitation ice, cloud ice and cloud water content in the convective regions in the 1-2 August storm were larger than in the other two storms, but the opposite was true in the weak convective regions. The storm microphysical prop- erties along lines through parent CG (cloud-to-ground lightning) locations showed no special characteristics related to sprites. The flash rate evolution in the 1-2 August storm provided additional confirmation that major sprite activity coincides with a rapid decrease in the negative CG flash rate. However, the evolution curve of the CG flash rate was erratic in the sprite-producing storm on 27-28 July, which was significantly different from that in the 1 2 August storm. The average positive CG peak current in sprite-producing storms was larger than that in the non-sprite-producing one. 展开更多
关键词 SPRITE Doppler radar TRMM LIGHTNING thunderstorm
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A PRELIMINARY STUDY ON THUNDERSTORM FORECAST WITH LS-SVM METHOD 被引量:3
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作者 王振会 张祎 朱佳 《Journal of Tropical Meteorology》 SCIE 2013年第1期104-108,共5页
The LS-SVM(Least squares support vector machine) method is presented to set up a model to forecast the occurrence of thunderstorms in the Nanjing area by combining NCEP FNL Operational Global Analysis data on 1.0°... The LS-SVM(Least squares support vector machine) method is presented to set up a model to forecast the occurrence of thunderstorms in the Nanjing area by combining NCEP FNL Operational Global Analysis data on 1.0°×1.0° grids and cloud-to-ground lightning data observed with a lightning location system in Jiangsu province during 2007-2008.A dataset with 642 samples,including 195 thunderstorm samples and 447 non-thunderstorm samples,are randomly divided into two groups,one(having 386 samples) for modeling and the rest for independent verification.The predictors are atmospheric instability parameters which can be obtained from the NCEP data and the predictand is the occurrence of thunderstorms observed by the lightning location system.Preliminary applications to the independent samples for a 6-hour forecast of thunderstorm events show that the prediction correction rate of this model is 78.26%,false alarm rate is 21.74%,and forecasting technical score is 0.61,all better than those from either linear regression or artificial neural network. 展开更多
关键词 thunderstorm FORECAST LS-SVM NANJING area cloud-to-ground LIGHTNING NCEP
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A data complementary method for thunderstorm point charge localization based on atmospheric electric field apparatus array group 被引量:3
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作者 Xu Yang Hongyan Xing 《Digital Communications and Networks》 SCIE CSCD 2021年第2期170-177,共8页
Data loss or distortion causes adverse effects on the accuracy and stability of the thunderstorm point charge localization.To solve this problem,we propose a data complementary method based on the atmospheric electric... Data loss or distortion causes adverse effects on the accuracy and stability of the thunderstorm point charge localization.To solve this problem,we propose a data complementary method based on the atmospheric electric field apparatus array group.The electric field component measurement model of the atmospheric electric field apparatus is established,and the orientation parameters of the thunderstorm point charge are defined.Based on the mirror method,the thunderstorm point charge coordinates are obtained by using the potential distribution formulas.To test the validity of the basic algorithm,the electric field component measurement error and the localization accuracy are studied.Besides the azimuth angle and the elevation angle,the localization parameters also include the distance from the apparatus to the thunderstorm cloud.Based on a primary electric field apparatus,we establish the array group of apparatuses.Based on this,the data measured by each apparatus is complementarily processed to regain the thunderstorm point charge position.The results show that,compared with the radar map data,this method can accurately reflect the location of the thunderstorm point charge,and has a better localization effect.Additionally,several observation results during thunderstorm weather have been presented. 展开更多
关键词 Atmospheric electric field apparatus ARRAY thunderstorm point charge Data complementary
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Observations of NO_2 and O_3 during Thunderstorm Activity Using Visible Spectroscopy 被引量:1
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作者 D.B.Jadhav A.L.Londhe S.Bose 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1996年第3期359-374,共16页
Simultaneous observations for the total column densities of NO2,O3 and H2O were carried on using the portable Spectrometer (438-450 nm and 400-450 nm) and the visible Spectrometer (544.4-628 nm) during premonsoon thun... Simultaneous observations for the total column densities of NO2,O3 and H2O were carried on using the portable Spectrometer (438-450 nm and 400-450 nm) and the visible Spectrometer (544.4-628 nm) during premonsoon thunderstorms and embedded hail storm activity at Pune (18°32'N & 73°51'E),India.These observations confirm the fact that there is an increase in O3 and NO2 column densities during thunderstorms.The increase in O3 was observed following onset of thunderstorm,while the increase in NO2 was observed only after the thunder flashes occur.This implies that the production mechanisms for O3 and NO2 in thunderstorm are different.The observed column density of NO,value (1 to 3×1017molecules cm-2) during thunderstorm activity is 10 to 30 times higher than the value (1×10th molecules cm-2) of a normal day total column density.The spectrometric observations and observations of thunder flashes by electric field meter showed that 6.4×1025molecules/flash of NO2 are produced.The increased to-oil column density of ozone during thunderstorm period is 1.2 times higher than normal (clear) day ozone concentration.The multiple scattering in the clouds is estimated from H2O and O2 absorption bands in the visible spectral region Considering this effect the calculated amount of ozone added in the global atmosphere due to thunderstorm activity is 0.26 to 0 52 DU,and the annual production of ozone due to thunderstorm activity is of the order of 4.02×10 molecules/year The annual NO2 production may be of the order of 2.02×1035molecules/year. 展开更多
关键词 Visible Spectroscopy thunderstorm Ozone production NO2 production Atmospheric electricity Lightning flashes. Multiple scattering factor
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Lightning Nowcasting with an Algorithm of Thunderstorm Tracking Based on Lightning Location Data over the Beijing Area 被引量:1
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作者 Abhay SRIVASTAVA Dongxia LIU +6 位作者 Chen XU Shanfeng YUAN Dongfang WANG Ogunsua BABALOLA Zhuling SUN Zhixiong CHEN Hongbo ZHANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2022年第1期178-188,共11页
A thunderstorm tracking algorithm is proposed to nowcast the possibility of lightning activity over an area of concern by using the total lightning data and neighborhood technique.The lightning radiation sources obser... A thunderstorm tracking algorithm is proposed to nowcast the possibility of lightning activity over an area of concern by using the total lightning data and neighborhood technique.The lightning radiation sources observed from the Beijing Lightning Network(BLNET)were used to obtain information about the thunderstorm cells,which are significantly valuable in real-time.The boundaries of thunderstorm cells were obtained through the neighborhood technique.After smoothing,these boundaries were used to track the movement of thunderstorms and then extrapolated to nowcast the lightning approaching in an area of concern.The algorithm can deliver creditable results prior to a thunderstorm arriving at the area of concern,with accuracies of 63%,80%,and 91%for lead times of 30,15,and 5 minutes,respectively.The real-time observations of total lightning appear to be significant for thunderstorm tracking and lightning nowcasting,as total lightning tracking could help to fill the observational gaps in radar reflectivity due to the attenuation by hills or other obstacles.The lightning data used in the algorithm performs well in tracking the active thunderstorm cells associated with lightning activities. 展开更多
关键词 neighborhood technique lightning nowcasting thunderstorm tracking lightning location data
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Analysis on the Climate Characteristics of Thunderstorm in Fujian Province during 1960-2007 被引量:1
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作者 LIN Xiu-fang1,YOU Li-hang2,WEN Ming-zhang1 1.Fujian Climate Center,Fuzhou 350001,China 2.Meteorological Service Center in Fujian Province,Fuzhou 350001,China 《Meteorological and Environmental Research》 CAS 2011年第3期21-24,共4页
[Objective] The research aimed to study the activity characteristics and climate rule of thunderstorm in Fujian Province.[Method] Based on the daily thunderstorm data in 67 meteorological stations of Fujian Province d... [Objective] The research aimed to study the activity characteristics and climate rule of thunderstorm in Fujian Province.[Method] Based on the daily thunderstorm data in 67 meteorological stations of Fujian Province during 1960-2007,the spatial and temporal distribution characteristics of thunderstorm in Fujian Province were analyzed by using the climate tendency rate,the trend coefficient and so on.[Result] The distribution of thunderstorm days showed the northeast-southwest direction and increased gradually from the coast to the inland in Fujian Province during 1960-2007.The high value zone was in Longyan,and the thunderstorm days in the coastal islands were the fewest.The thunderstorm days had the obvious decrease trend in Fujian Province in 48 years.The decrease speeds in the central coastal area and most of inland mountain area were 3.5 and 4.5 d/10 a.The decrease speed was 5.5 d/10 a in the north of Ningde,the east of Sanming and some areas in Nanping.The trend coefficient variation of thunderstorm days had the obvious regional characteristic.Especially the decrease trend in the inland mountain area was more obvious than that in the coast.The decrease of thunderstorm day trend coefficient in the north of Nanping was the most,and the trend coefficient was-0.65.But the decrease trend in the central coastal area wasn’t obvious,and the coefficient was only-0.15.The thunderstorm day had the obvious seasonal variation.The multi-occurrence period of thunderstorm was during March-september and reached the maximum value in August.Started from September,the thunderstorm quickly decreased.From October to February in next year,the thunderstorm happened seldom.The average first thunderstorm date in the northwest area was earlier than that in the southeast area.The difference of average final thunderstorm date in the north and south areas wasn’t big.For the first thunderstorm date in the north and west of Fujian was early,and the final thunderstorm date was later,the thunderstorm activity time in the whole year was longer than that in the coast.They differed by nearly one month.[Conclusion] The research provided the scientific basis for the climate feasibility demonstration of major project items,provided the theory basis about the weather climate aspect for the thunder prevention and disaster reduction,and also laid the foundation for further studying the formation mechanism of thunderstorm in Fujian. 展开更多
关键词 thunderstorm Time and space characteristics Trend coefficient Fujian Province China
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Statistical Analysis of Thunderstorms on the Eastern Tibetan Plateau Based on Modified Thunderstorm Indices 被引量:2
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作者 YOU Wei ZANG Zengliang +2 位作者 PAN Xiaobin ZHANG Lifeng LI Yi 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2015年第4期515-527,共13页
The Tibetan Plateau, with an average altitude above 4000 m, is the highest and largest plateau in the world. The frequency of thunderstorms in this region is extremely high. Many indices are used in operational foreca... The Tibetan Plateau, with an average altitude above 4000 m, is the highest and largest plateau in the world. The frequency of thunderstorms in this region is extremely high. Many indices are used in operational forecasting to assess the stability of the atmosphere and predict the probability of severe thunderstorm development. One of the disadvantages of many of these indices is that they are mainly based on observations from plains. However, considering the Plateau's high elevation, most convective parameters cannot be applied directly, or their application is ineffective. The pre-convective environment on thunderstorm days in this region is investigated based on sounding data obtained throughout a five-year period(2006–10).Thunderstorms occur over the Tibetan Plateau under conditions that differ strikingly from those in plains. On this basis,stability indices, such as the Showalter index(including SI and SICCL), and the K index are improved to better assess the thunderstorm environments on the Plateau. Verification parameters, such as the true-skill statistic(TSS) and Heidke skill score(HSS), are adopted to evaluate the optimal thresholds and relative forecast skill for each modified index. Lastly, the modified indices are verified with a two-year independent dataset(2011–12), showing satisfactory results for the modified indices. For determining whether or not a thunderstorm day is likely to occur, we recommend the modified SICCLindex. 展开更多
关键词 thunderstorm Tibetan Plateau modified parameters skill score
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A Probe for Consistency in CAPE and CINE During the Prevalence of Severe Thunderstorms:Statistical – Fuzzy Coupled Approach 被引量:1
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作者 Sutapa Chaudhuri 《Atmospheric and Climate Sciences》 2011年第4期197-205,共9页
Thunderstorms of pre-monsoon season (April – May) over Kolkata (22° 32’N, 88° 20’E), India are invariably accompanied with lightning flashes, high wind gusts, torrential rainfall, occasional hail and torn... Thunderstorms of pre-monsoon season (April – May) over Kolkata (22° 32’N, 88° 20’E), India are invariably accompanied with lightning flashes, high wind gusts, torrential rainfall, occasional hail and tornadoes which significantly affect the life and property on the ground and aviation aloft. The societal and economic impact due to such storms made accurate prediction of the weather phenomenon a serious concern for the meteorologists of India. The initiation of such storms requires sufficient moisture in lower troposphere, high surface temperature, conditional instability and a source of lift to initiate the convection. Convective available potential energy (CAPE) is a measure of the energy realized when conditional instability is released. It plays an important role in meso-scale convective systems. Convective inhibition energy (CINE) on the other hand acts as a possible barrier to the release of convection even in the presence of high value of CAPE. The main idea of the present study is to see whether a consistent quantitative range of CAPE and CINE can be identified for the prevalence of such thunderstorms that may aid in operational forecast. A statistical – fuzzy coupled method is implemented for the purpose. The result reveals that a definite range of CINE within 0 – 150 Jkg-1 is reasonably pertinent whereas no such range of CAPE depicts any consistency for the occurrence of severe thunderstorms over Kolkata. The measure of CINE mainly depends upon the altitude of the level of free convection (LFC), surface temperature (T) and surface mixing ratio (q). The box-and-whisker plot of LFC, T and q are drawn to select the most dependable parameter for the consistency of CINE in the prevalence of such thunderstorms. The skills of the parameters are evaluated through skill score analyses. The percentage error during validation with the observation of 2010 is estimated to be 0% for the range of CINE and 3.9% for CAPE. 展开更多
关键词 Severe thunderstormS FORECAST CAPE CINE Statistics FUZZY Logic
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Characteristics of thunderstorms and lightning flashes in the Chinese inland plateau 被引量:1
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作者 TingLong Zhang Tong Zhang Yang Zhao XiangZhen Kong YanHui Wang 《Research in Cold and Arid Regions》 2010年第3期271-277,共7页
The electrical characteristics of thunderstorms in three different altitude regions of the Chinese inland plateau have been analyzed in this paper. The results show, according to the polarity of the surface electric ... The electrical characteristics of thunderstorms in three different altitude regions of the Chinese inland plateau have been analyzed in this paper. The results show, according to the polarity of the surface electric (E) field, that the thunderstorms can be divided into two categories in the study regions: one showing the normal tripole electrical charge structure (normal-type), and the other showing the special tripole charge structure with a larger-than-usual lower positive charge center (LPCC) at the base of thunderstorm (special-type), where the induced surface E field is controlled by the LPCC when a thunderstorm is overhead. We find that the two types of thunderstorms have different occurrences in different regions, and the percentage of special-type thunderstorms increases with the altitude. On the whole, the flash rate of thunderstorms is quite low, and the mean value is about 1-3 fl/min, while the flash rate of special-type is slightly greater than that of the normal-type thunderstorm. The statistical results of cloud-to-ground flash (CG) numbers indicate that the ratio of +CG flash increases with the altitude, with the value about 14.7 percent through 25.4 percent. 展开更多
关键词 thunderstorm flash rate cloud-to-ground flash
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On Thunderstorm Microphysics under Urban Heat Island, Sea Breeze, and Cold Front Effects in the Metropolitan Area of São Paulo, Brazil 被引量:2
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作者 Isidro Metódio Tuleni Johanes Ihadua Augusto José Pereira Filho 《Atmospheric and Climate Sciences》 2021年第3期614-643,共30页
This work discusses issues related to the impact of urbanization on the microphysical processes of precipitating systems associated with synoptic, mesoscale, and local scale systems. Among the issues addressed is the ... This work discusses issues related to the impact of urbanization on the microphysical processes of precipitating systems associated with synoptic, mesoscale, and local scale systems. Among the issues addressed is the impact of urban heat <span><span><span style="font-family:;" "=""><span style="font-family:Verdana;">island (UHI) in S<span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#f7f7f7;"=""><span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#f7f7f7;"=""><span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#f7f7f7;"=""><span style="color:#4F4F4F;font-family:-apple-system, "font-size:16px;white-space:normal;background-color:#F7F7F7;">&#227;</span></span></span></span>o Paulo city center and urban densification (UD) in the</span><span> </span><span style="font-family:Verdana;">Metropolitan Area of S<span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#f7f7f7;"=""><span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#f7f7f7;"=""><span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#f7f7f7;"=""><span style="color:#4F4F4F;font-family:-apple-system, "font-size:16px;white-space:normal;background-color:#F7F7F7;">&#227;</span></span></span></span>o Paulo (MASP) on the microphysical, dynamic, and</span><span style="font-family:Verdana;"> thermodynamic properties and distribution of precipitation and heavier rainfall from sea-breeze (SB) e cold-front (CF) combined during their space-time evolutions. For this purpose, it used four components: classification of hydrometeors with fuzzy logic, calculation of the raindrop diameters, an estimate of liquid water mass and ice mass from polarimetric-variables measured with dual-pola- rization X-band meteorological radar. The results indicated that urban densification (UD) and heat island (UHI) of the S<span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#f7f7f7;"=""><span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#f7f7f7;"=""><span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#f7f7f7;"=""><span style="color:#4F4F4F;font-family:-apple-system, "font-size:16px;white-space:normal;background-color:#F7F7F7;">&#227;</span></span></span></span>o Paulo city center impact the formation of precipitation, liquid water mass, and ice mass, depth, and duration of </span><span style="font-family:Verdana;">a thunderstorm. It was also observed the asymmetric configuration of the th</span><span style="font-family:Verdana;">understorm is induced by the strong convergence in the S<span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#f7f7f7;"=""><span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#f7f7f7;"=""><span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#f7f7f7;"=""><span style="color:#4F4F4F;font-family:-apple-system, "font-size:16px;white-space:normal;background-color:#F7F7F7;">&#227;</span></span></span></span>o Paulo city center, and this strong convergence is induced by the intense heat island (UHI) in the S<span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#f7f7f7;"=""><span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#f7f7f7;"=""><span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#f7f7f7;"=""><span style="color:#4F4F4F;font-family:-apple-system, "font-size:16px;white-space:normal;background-color:#F7F7F7;">&#227;</span></span></span></span>o Paulo city center. Was also observed that this event that is formed in the Metropolitan Area of S<span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#f7f7f7;"=""><span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#f7f7f7;"=""><span style="color:#4F4F4F;font-family:-apple-system, "font-size:16px;white-space:normal;background-color:#F7F7F7;">&#227;</span></span></span>o Paulo (MASP) depends on microphysical processes of mixed-phase of the cloud (water and ice) above the 0<span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#ffffff;"=""><span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#ffffff;"="">°</span></span>C isotherm for the production of intense rain and cold pool at the surface. These important microphysical processes within long-lasting secondary convective cells over the S<span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#f7f7f7;"=""><span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#f7f7f7;"=""><span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#f7f7f7;"=""><span style="color:#4F4F4F;font-family:-apple-system, "font-size:16px;white-space:normal;background-color:#F7F7F7;">&#227;</span></span></span></span>o Paulo city center should be taken into account on convective parameterization schemes as well as the associated cold pool dynamics.</span></span></span></span> 展开更多
关键词 Weather Radar Fuzzy Logic Sea Breeze Urban Densification HAIL Asymmetric thunderstorm Configuration
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Analysis of Lightning Disaster of Eight Mobile Base Stations in a County Suffering Thunderstorm on June 23,2015 and Countermeasures
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作者 Pei Jun Zhou Liping Ning Xia 《Meteorological and Environmental Research》 CAS 2016年第4期29-30,共2页
During the process of thunderstorm in a county on June 23,2015,eight mobile base stations in the region were damaged.The reasons for the damage caused by the thunderstorm were discussed through on-the-spot investigati... During the process of thunderstorm in a county on June 23,2015,eight mobile base stations in the region were damaged.The reasons for the damage caused by the thunderstorm were discussed through on-the-spot investigation,and some countermeasures were proposed. 展开更多
关键词 thunderstorm LIGHTNING disaster Mobile base STATIONS COUNTERMEASURES China
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Study on Occurrence Rule, Reason and Defense Measures of the Thunderstorm in Liaocheng in the Past 50 Years
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作者 Yin Zhang Junxiang Ge +1 位作者 Min Zhang Lin Ma 《Meteorological and Environmental Research》 CAS 2013年第10期19-21,共3页
[ Objective] The research aimed to study occurrence rule, reason and defense measures of the thunderstorm in Liaocheng in the past 50 years. [Method] By using meteorological observation records at 8 observatories of U... [ Objective] The research aimed to study occurrence rule, reason and defense measures of the thunderstorm in Liaocheng in the past 50 years. [Method] By using meteorological observation records at 8 observatories of Uaocheng during 1963 -2012, occurrence rule of the thunderstorm was studied. Occurrence reason and defense measures were also analyzed. [ Result] Annual thunderstorm days presented decreasing trend in Liaocheng. The earliest thunderstorm occurred in February, while the latest thunderstorm occurred in November. Thunderstorm mainly appeared in June, July and August, which occupied 77.6% of that in whole year. Thunderstorm days among each county had small difference. Thunderstorm days in Dong'e County reached the minimum, which was related to local underlying surface. Occurrence reason of the thunderstorm was analyzed from objective and subjective aspects. By combining the actual situation of Liaocheng, corresponding prevention countermeasures were put forward. [Conclusion] The research could provide reference basis for thunderstorm disaster prevention and reduction in Liaocheng. 展开更多
关键词 thunderstorm Occurrence rule REASON DEFENSE Liaocheng China
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