Thunderstorms are high-impact weather events that produce hazardous lightning,heavy rainfall,hail,gusty winds,and tornadoes.They have profound social and economic impacts on public safety,key infrastructure,the aviati...Thunderstorms are high-impact weather events that produce hazardous lightning,heavy rainfall,hail,gusty winds,and tornadoes.They have profound social and economic impacts on public safety,key infrastructure,the aviation and energy sectors,and even agricultural yields.Lightning,as a characteristic process of thunderstorms,has experienced a significant increase in some regions in the context of global warming[1].Furthermore,the frequency and intensity of extreme weather events are predicted to increase in the future[2],with the impact significantly amplified due to increasing urbanization,where by 2050 close to 70%of the world’s population will be concentrated in urban regions.展开更多
In this study,a latent heat nudging lightning data assimilation(LDA)method independent of the flash rate was developed and tested with data from the Lightning Mapping Imager(LMI)onboard the Feng-Yun-4A(FY-4A)satellite...In this study,a latent heat nudging lightning data assimilation(LDA)method independent of the flash rate was developed and tested with data from the Lightning Mapping Imager(LMI)onboard the Feng-Yun-4A(FY-4A)satellite based on the Weather Research and Forecasting(WRF)model.In this LDA method,the positive temperature perturbations at the lightning location are first calculated by the difference between the moist adiabatic temperature of a lifted air parcel and the model temperature.The positive temperature perturbations in the mixed-phase region are then assimilated by a nudging method to adjust the latent heat within the convective system.Meanwhile,the water vapor mixing ratio is adapted to the temperature perturbations accordingly to constrain the relative humidity to remain unchanged.This method considers the physical nature of the convective system,in contrast with other LDA methods that establish an empirical or statistical relationship between the lightning flash rates and model variables.The impact of this LDA method on short-term(≤6 h)forecasts was evaluated using two severe convective events in eastern China:a multi-region heavy rainfall event and a thunderstorm high-wind event.The results showed that LDA could add thermodynamic information associated with the convective system to the WRF model during the nudging period,leading to a more reasonable storm environment.In the forecast fields,the simulations with LDA produced more realistic convective structures,resulting in an improvement in forecasts of precipitation and high winds.展开更多
Thunderstorms are severe convective weather systems generating lightning,which can lead to various catastrophic weather when a large amount of lightning is produced.In the past decade,high spatiotemporal resolution li...Thunderstorms are severe convective weather systems generating lightning,which can lead to various catastrophic weather when a large amount of lightning is produced.In the past decade,high spatiotemporal resolution lightning detection technology has been developed,which has laid a solid foundation for investigating the propagation and development mechanism of lightning as well as associated physical effects.Based on the Doppler dual polarization weather radar and high-resolution numerical models,thunderstorm dynamics,microphysics,electrical processes,and their interactions have been well investigated,and some new insights into the thunderstorm charge distribution and its relation to the thunderstorm structure have been obtained.All these have promoted the lightning forecasting and lightning data assimilation.This paper reviews the recent research progress in detection,mechanism,and forecasting of thunderstorms and lightning in China in the last decade from four aspects:1)high-resolution three-dimensional(3D)lightning mapping technology and application,2)lightning in different thunderstorms and its relationship with cloud dynamics and microphysics,3)observation and simulation of lightning charge structure in thunderstorms,and 4)lightning prediction and lightning data assimilation for thunderstorm forecasting.Major challenges and the cuttingedge research directions in lightning and thunderstorms studies are also highlighted.展开更多
The Dynamical-microphysical-electrical Processes in Severe Thunderstorms and Lightning Hazards(STORM973)project conducted coordinated comprehensive field observations of thunderstorms in the Beijing metropolitan regio...The Dynamical-microphysical-electrical Processes in Severe Thunderstorms and Lightning Hazards(STORM973)project conducted coordinated comprehensive field observations of thunderstorms in the Beijing metropolitan region(BMR)during the warm season from 2014 to 2018.The aim of the project was to understand how dynamical,microphysical and electrical processes interact in severe thunderstorms in the BMR,and how to assimilate lightning data in numerical weather prediction models to improve severe thunderstorm forecasts.The platforms used in the field campaign included the Beijing Lightning Network(BLNET,consisting of 16 stations),2 X-band dual linear polarimetric Doppler radars,and 4 laser raindrop spectrometers.The collaboration also made use of the China Meteorological Administration’s mesoscale meteorological observation network in the Beijing-Tianjin-Hebei region.Although diverse thunderstorm types were documented,it was found that squall lines and multicell storms were the two major categories of severe thunderstorms with frequent lightning activity and extreme rainfall or unexpected local short-duration heavy rainfall resulting in inundations in the central urban area,influenced by the terrain and environmental conditions.The flash density maximums were found in eastern Changping District,central and eastern Shunyi District,and the central urban area of Beijing,suggesting that the urban heat island effect has a crucial role in the intensification of thunderstorms over Beijing.In addition,the flash rate associated with super thunderstorms can reach hundreds of flashes per minute in the central city regions.The super(5%of the total),strong(35%),and weak(60%)thunderstorms contributed about 37%,56%,and 7%to the total flashes in the BMR,respectively.Owing to the close connection between lightning activity and the thermodynamic and microphysical characteristics of the thunderstorms,the lightning flash rate can be used as an indicator of severe weather events,such as hail and short-duration heavy rainfall.Lightning data can also be assimilated into numerical weather prediction models to help improve the forecasting of severe convection and precipitation at the cloud-resolved scale,through adjusting or correcting the thermodynamic and microphysical parameters of the model.展开更多
文摘Thunderstorms are high-impact weather events that produce hazardous lightning,heavy rainfall,hail,gusty winds,and tornadoes.They have profound social and economic impacts on public safety,key infrastructure,the aviation and energy sectors,and even agricultural yields.Lightning,as a characteristic process of thunderstorms,has experienced a significant increase in some regions in the context of global warming[1].Furthermore,the frequency and intensity of extreme weather events are predicted to increase in the future[2],with the impact significantly amplified due to increasing urbanization,where by 2050 close to 70%of the world’s population will be concentrated in urban regions.
基金supported by the National Key Research and Development Program of China(2017YFC1501902)the Natural Science Foundation of Shanghai Science and Technology Committee(21ZR1457700).
文摘In this study,a latent heat nudging lightning data assimilation(LDA)method independent of the flash rate was developed and tested with data from the Lightning Mapping Imager(LMI)onboard the Feng-Yun-4A(FY-4A)satellite based on the Weather Research and Forecasting(WRF)model.In this LDA method,the positive temperature perturbations at the lightning location are first calculated by the difference between the moist adiabatic temperature of a lifted air parcel and the model temperature.The positive temperature perturbations in the mixed-phase region are then assimilated by a nudging method to adjust the latent heat within the convective system.Meanwhile,the water vapor mixing ratio is adapted to the temperature perturbations accordingly to constrain the relative humidity to remain unchanged.This method considers the physical nature of the convective system,in contrast with other LDA methods that establish an empirical or statistical relationship between the lightning flash rates and model variables.The impact of this LDA method on short-term(≤6 h)forecasts was evaluated using two severe convective events in eastern China:a multi-region heavy rainfall event and a thunderstorm high-wind event.The results showed that LDA could add thermodynamic information associated with the convective system to the WRF model during the nudging period,leading to a more reasonable storm environment.In the forecast fields,the simulations with LDA produced more realistic convective structures,resulting in an improvement in forecasts of precipitation and high winds.
基金Supported by the National Natural Science Foundation of China(42230609)Chinese Academy of Sciences Strategic Leading Science and Technology Project(XDB0760300)。
文摘Thunderstorms are severe convective weather systems generating lightning,which can lead to various catastrophic weather when a large amount of lightning is produced.In the past decade,high spatiotemporal resolution lightning detection technology has been developed,which has laid a solid foundation for investigating the propagation and development mechanism of lightning as well as associated physical effects.Based on the Doppler dual polarization weather radar and high-resolution numerical models,thunderstorm dynamics,microphysics,electrical processes,and their interactions have been well investigated,and some new insights into the thunderstorm charge distribution and its relation to the thunderstorm structure have been obtained.All these have promoted the lightning forecasting and lightning data assimilation.This paper reviews the recent research progress in detection,mechanism,and forecasting of thunderstorms and lightning in China in the last decade from four aspects:1)high-resolution three-dimensional(3D)lightning mapping technology and application,2)lightning in different thunderstorms and its relationship with cloud dynamics and microphysics,3)observation and simulation of lightning charge structure in thunderstorms,and 4)lightning prediction and lightning data assimilation for thunderstorm forecasting.Major challenges and the cuttingedge research directions in lightning and thunderstorms studies are also highlighted.
基金supported by the National Natural Science Foundation of China(Grant Nos.41630425,41671144074)the Key Research Program of Frontier Science,CAS(Grant No.QYZDJ-SSW-DQC007)the National Key Basic Research Program of China(Grant No.2014CB441401)。
文摘The Dynamical-microphysical-electrical Processes in Severe Thunderstorms and Lightning Hazards(STORM973)project conducted coordinated comprehensive field observations of thunderstorms in the Beijing metropolitan region(BMR)during the warm season from 2014 to 2018.The aim of the project was to understand how dynamical,microphysical and electrical processes interact in severe thunderstorms in the BMR,and how to assimilate lightning data in numerical weather prediction models to improve severe thunderstorm forecasts.The platforms used in the field campaign included the Beijing Lightning Network(BLNET,consisting of 16 stations),2 X-band dual linear polarimetric Doppler radars,and 4 laser raindrop spectrometers.The collaboration also made use of the China Meteorological Administration’s mesoscale meteorological observation network in the Beijing-Tianjin-Hebei region.Although diverse thunderstorm types were documented,it was found that squall lines and multicell storms were the two major categories of severe thunderstorms with frequent lightning activity and extreme rainfall or unexpected local short-duration heavy rainfall resulting in inundations in the central urban area,influenced by the terrain and environmental conditions.The flash density maximums were found in eastern Changping District,central and eastern Shunyi District,and the central urban area of Beijing,suggesting that the urban heat island effect has a crucial role in the intensification of thunderstorms over Beijing.In addition,the flash rate associated with super thunderstorms can reach hundreds of flashes per minute in the central city regions.The super(5%of the total),strong(35%),and weak(60%)thunderstorms contributed about 37%,56%,and 7%to the total flashes in the BMR,respectively.Owing to the close connection between lightning activity and the thermodynamic and microphysical characteristics of the thunderstorms,the lightning flash rate can be used as an indicator of severe weather events,such as hail and short-duration heavy rainfall.Lightning data can also be assimilated into numerical weather prediction models to help improve the forecasting of severe convection and precipitation at the cloud-resolved scale,through adjusting or correcting the thermodynamic and microphysical parameters of the model.
