Positions

Research Areas research areas

Overview

  • I am a professor of Physics and Astronomy, with a joint appointment in Space Science Center of Institute for the Study of Earth, Oceans, and Space (EOS). My research interests lie in the areas of plasma discharge physics, ionospheric physics, radio science, remote sensing, optical imaging, computational electrodynamics, and numerical methods. My study focuses on understanding electrical discharges in earth’s atmosphere such as lightning, jets and sprites, and their effects in near-earth space environment. My students and I work on developing simulation tools, building radio and optical instruments, and analyzing various data to answer fundamental questions about these phenomena. Our work has been published in Nature Communications, Physical Review Letters, Geophysical Research Letters, Journal of Geophysical Research, Journal of Atmospheric and Solar-Terrestrial Physics, Applied Physics Letters, Plasma Sources Science and Technology, etc. Our research has also been covered by The Washington Post, USA Today, The Huffington Post, Popular Science, New Scientist, TIME Magazine for Kids, BBC, Reuters, etc.

    I enjoy working with researchers of diverse background, expertise, and experience. My undergraduate and graduate students have won numerous awards at scientific meetings and have also received university Outstanding Student Award. If you are interested in learning our research or joining our group, please feel free to contact me.
  • Selected Publications

    Academic Article

    Year Title
    2022 Upward propagation of gigantic jets revealed by 3D radio and optical mapping.Science advances.  8:eabl8731. 2022
    2022 Implications of Multiple Corona Bursts in Lightning Processes for Radio Frequency Interferometer ObservationsGeophysical Research Letters.  49. 2022
    2022 LOFAR Observations of Lightning Initial Breakdown PulsesGeophysical Research Letters.  49. 2022
    2022 Interferometric imaging of intensely radiating negative leadersPhysical Review D.  105. 2022
    2022 Quantification of Electric Fields in Fast Breakdown During Lightning Initiation From VHF-UHF Power SpectraGeophysical Research Letters.  49. 2022
    2021 Radio Frequency Emissions From Streamer Collisions in Subbreakdown FieldsGeophysical Research Letters.  48. 2021
    2021 The Spontaneous Nature of Lightning Initiation RevealedGeophysical Research Letters.  48. 2021
    2021 Study on Dominant Parameters Determining Streamer Initiation From Hydrometeors in Thundercloud FieldsJournal of Geophysical Research: Atmospheres.  126. 2021
    2021 Distinguishing features of high altitude negative leaders as observed with LOFARAtmospheric Research.  260:105688-105688. 2021
    2021 Time resolved 3D interferometric imaging of a section of a negative leader with LOFARPhysical Review D.  104. 2021
    2021 A distinct negative leader propagation mode.Scientific Reports.  11:16256. 2021
    2021 Examining the Capacity of Hurricane Matthew (2016) in Spawning Halo/Sprite-Producible Lightning Strokes During Its LifetimeJournal of Geophysical Research: Atmospheres.  126. 2021
    2021 Understanding the dependence of streamer initiation on hydrometeors size using Raether-Meek criterionJournal of Electrostatics.  112:103602-103602. 2021
    2021 VHF Radio Spectrum of a Positive Leader and Implications for Electric FieldsGeophysical Research Letters.  48. 2021
    2021 Vertical Temperature Profile of Natural Lightning Return Strokes Derived From Optical SpectraJournal of Geophysical Research: Atmospheres.  126. 2021
    2020 Thunderstorm High-Frequency Radio Bursts With Weak Low-Frequency RadiationGeophysical Research Letters.  47. 2020
    2020 Radio Interferometer Observations of an Energetic in-Cloud Pulse Reveal Large Currents Generated by Relativistic DischargesJournal of Geophysical Research: Atmospheres.  125. 2020
    2020 Analysis of a Gigantic Jet in Southern China: Morphology, Meteorology, Storm Evolution, Lightning, and Narrow Bipolar EventsJournal of Geophysical Research: Atmospheres.  125. 2020
    2020 Negative Streamer Initiation From an Isolated Hydrometeor in a Subbreakdown Electric FieldGeophysical Research Letters.  47. 2020
    2020 Electromagnetic Radiation Spectrum of a Composite System.Physical Review Letters.  125:025101. 2020
    2020 Streamer discharge initiation from an isolated spherical hydrometeor at subbreakdown conditionJournal of Electrostatics.  106:103457-103457. 2020
    2019 Understanding the Radio Spectrum of Thunderstorm Narrow Bipolar EventsJournal of Geophysical Research: Atmospheres.  124:10134-10153. 2019
    2019 Modeling of a New Electron Acceleration Mechanism Ahead of StreamersJournal of Geophysical Research.  124:7301-7319. 2019
    2019 First Observations of Gigantic Jets From Geostationary OrbitGeophysical Research Letters.  46:3999-4006. 2019
    2019 Fast negative breakdown in thunderstorms.Nature Communications.  10:1648. 2019
    2019 VHF and UHF Electromagnetic Radiation Produced by Streamers in LightningGeophysical Research Letters.  46:443-451. 2019
    2018 Thunderstorm charge structures producing gigantic jets.Scientific Reports.  8:18085. 2018
    2018 Characteristics of Thunderstorm Structure and Lightning Activity Causing Negative and Positive SpritesJournal of Geophysical Research: Atmospheres.  123:8190-8207. 2018
    2018 A Gigantic Jet Observed Over an Mesoscale Convective System in Midlatitude RegionJournal of Geophysical Research: Atmospheres.  123:977-996. 2018
    2017 Three-Dimensional Modeling of Two Interacting StreamersJournal of Geophysical Research: Atmospheres.  122:10189-10196. 2017
    2017 Elves Accompanying Terrestrial Gamma Ray FlashesJournal of Geophysical Research.  122:10563-10576. 2017
    2017 Characterizing the source properties of terrestrial gamma ray flashesJournal of Geophysical Research.  122:8915-8932. 2017
    2017 Sprite possibly produced by two distinct positive cloud-to-ground lightning flashesTAO: Terrestrial, Atmospheric and Oceanic Sciences.  28:609-624. 2017
    2017 The impact on the ozone layer from NOx produced by terrestrial gamma ray flashesGeophysical Research Letters.  44:5240-5245. 2017
    2017 Analysis of a mesoscale convective system that produced a single spriteAdvances in Atmospheric Sciences.  34:258-271. 2017
    2016 Properties of relatively long streamers initiated from an isolated hydrometeorJournal of Geophysical Research: Atmospheres.  121:7284-7295. 2016
    2016 Observation-constrained modeling of the ionospheric impact of negative spritesGeophysical Research Letters.  43:2365-2373. 2016
    2016 An analysis of five negative sprite-parent discharges and their associated thunderstorm charge structuresJournal of Geophysical Research: Atmospheres.  121:759-784. 2016
    2016 Modification of the lower ionospheric conductivity by thunderstorm electrostatic fieldsGeophysical Research Letters.  43:5-12. 2016
    2015 High-altitude electrical discharges associated with thunderstorms and lightningJournal of Atmospheric and Solar: Terrestrial Physics.  136:98-118. 2015
    2015 A Thermodynamic, kinematic and microphysical analysis of a jet and gigantic jet-producing Florida thunderstormJournal of Geophysical Research: Atmospheres.  120:8469-8490. 2015
    2015 Sprite streamer initiation from natural mesospheric structures.Nature Communications.  6:7540. 2015
    2015 Streamer formation and branching from model hydrometeors in subbreakdown conditions inside thundercloudsJournal of Geophysical Research: Atmospheres.  120:3660-3678. 2015
    2015 Effects of small thundercloud electrostatic fields on the ionospheric density profileGeophysical Research Letters.  42:1619-1625. 2015
    2015 Upward electrical discharges observed above Tropical Depression Dorian.Nature Communications.  6:5995. 2015
    2014 An analytical approach for calculating energy spectra of relativistic runaway electron avalanches in airJournal of Geophysical Research.  119:7794-7823. 2014
    2014 The structure of X-ray emissions from triggered lightning leaders measured by a pinhole-type X-ray cameraJournal of Geophysical Research: Atmospheres.  119:982-1002. 2014
    2013 Formation of sprite streamers at subbreakdown conditions from ionospheric inhomogeneities resembling observed sprite halo structuresGeophysical Research Letters.  40:6282-6287. 2013
    2013 Properties of the thundercloud discharges responsible for terrestrial gamma-ray flashesGeophysical Research Letters.  40:4067-4073. 2013
    2013 Modeling terrestrial gamma ray flashes produced by relativistic feedback dischargesJournal of Geophysical Research.  118:2359-2376. 2013
    2012 Observation of a gamma-ray flash at ground level in association with a cloud-to-ground lightning return strokeJournal of Geophysical Research.  117:n/a-n/a. 2012
    2012 Luminosity and propagation characteristics of sprite streamers initiated from small ionospheric disturbances at subbreakdown conditionsJournal of Geophysical Research.  117:n/a-n/a. 2012
    2012 Formation of streamer discharges from an isolated ionization column at subbreakdown conditions.Physical Review Letters.  109:025002. 2012
    2012 Effects of pressure and humidity on positive corona inception from thundercloud hydrometeorsJournal of Atmospheric and Solar: Terrestrial Physics.  80:179-186. 2012
    2012 Multiple ion species fluid modeling of sprite halos and the role of electron detachment of O- in their dynamicsJournal of Geophysical Research.  117:n/a-n/a. 2012
    2011 Sprite Streamers Imaged at Different Exposure TimesIEEE Transactions on Plasma Science.  39:2710-2711. 2011
    2010 NO-gamma emissions from streamer discharges: direct electron impact excitation versus resonant energy transferJournal of Physics D: Applied Physics.  43:082001-082001. 2010
    2010 Model of sprite luminous trail caused by increasing streamer currentGeophysical Research Letters.  37. 2010
    2009 Assessment of sprite initiating electric fields and quenching altitude of a(1)Pi(g) state of N-2 using sprite streamer modeling and ISUAL spectrophotometric measurementsJournal of Geophysical Research.  114:n/a-n/a. 2009
    2009 Comparison of acceleration, expansion, and brightness of sprite streamers obtained from modeling and high-speed video observationsJournal of Geophysical Research.  114:n/a-n/a. 2009
    2008 Photoionization and optical emission effects of positive streamers in air at ground pressureIEEE Transactions on Plasma Science.  36:942-943. 2008
    2007 Application of photoionization models based on radiative transfer and the Helmholtz equations to studies of streamers in weak electric fieldsApplied Physics Letters.  91:211501. 2007
    2007 Modeling studies of NO‐γ emissions of spritesGeophysical Research Letters.  34. 2007
    2007 Efficient models for photoionization produced by non-thermal gas discharges in air based on radiative transfer and the Helmholtz equationsPlasma Sources Science and Technology.  16:656-678. 2007
    2006 Monte Carlo model for analysis of thermal runaway electrons in streamer tips in transient luminous events and streamer zones of lightning leadersJournal of Geophysical Research.  111. 2006
    2006 Effects of photoionization on similarity properties of streamers at various pressures in airJournal of Physics D: Applied Physics.  39:327-334. 2006
    2006 Comparison of results from sprite streamer modeling with spectrophotometric measurements by ISUAL instrument on FORMOSAT‐2 satelliteGeophysical Research Letters.  33:n/a-n/a. 2006
    2005 Molecular nitrogen LBH band system far‐UV emissions of sprite streamersGeophysical Research Letters.  32. 2005
    2004 Effects of photoionization on propagation and branching of positive and negative streamers in spritesJournal of Geophysical Research.  109. 2004

    Conference Paper

    Year Title
    2018 Broadband VHF Interferometry Observations at the Kennedy Space Center25th International Lightning Detection Conference (ILDC) and 7th International Lightning Meteorology Conference (ILMC). 2018
    2018 Field Enhancement and Radio Emissions from Head-on Collision of StreamersURSI National Radio Science Meeting. 2018
    2017 A high-speed spectroscopy system for observing lightning and transient luminous eventsAGU Fall Meeting. 2017
    2017 RAPID for Interferometry of LightningNortheast Radio Observatory Corporation (NEROC) Symposium. 2017
    2017 Overview of lightning effects research at the University of New HampshireThe 1st International Symposium on Lightning Physics and Lightning Meteorology. 2017
    2017 Streamer interpretation of fast breakdown in narrow bipolar eventsThe 1st International Symposium on Lightning Physics and Lightning Meteorology. 2017
    2017 Elves associated with terrestrial gamma-ray flashesURSI General Assembly. 2017
    2017 High-speed broadband radio interferometry for mapping and imaging lightningCASPER Workshop. 2017
    2017 Lightning Narrow Bipolar Events produced by fast negative breakdownGeneral Assembly and Scientific Symposium (URSI GASS). 2017
    2017 Elves associated with terrestrial gamma-ray flashesNSF CEDAR workshop. 2017
    2017 Fractal properties of lightning from high-speed video observationsNSF CEDAR workshop. 2017
    2013 Long recovery of the lower ionosphere from the quasi-electrostatic effects of cloud-to-ground lightning2013 US NATIONAL COMMITTEE OF URSI NATIONAL RADIO SCIENCE MEETING (USNC-URSI NRSM). 2013
    A Gigantic Jet Observed Over an Mesoscale Convective System in Midlatitude Region
    A high-speed spectroscopy system for observing lightning and transient luminous events
    Balloon-borne instrumentation for detection of gamma-ray glows from lightning
    Branching of sprite streamers propagating at an angle from the vertical direction
    Explaining the spectrum of narrow bipolar events with a system of streamers
    Ground-level terrestrial gamma-ray flashes produced by upward positive leaders
    High–energy atmospheric physics theory and modeling
    High–energy atmospheric physics theory and modeling
    Lightning interferometry using RAPID, AGU Fall Meeting
    Modeling multi-pulsed terrestrial gamma-ray flashes
    New insight into an EIP event from detailed interferometric imaging
    Progress toward understanding lightning initiation
    Simulations of radio emissions from TGFs
    Streamer discharge initiation from an isolated hydrometeor modeled as a conducting sphere with rigid surface
    The radio emissions from streamers
    The radio frequency emission spectrum of colliding streamers
    The role of streamers in the initiation of electrical discharges in the earth’s atmosphere
    XVI International Conference on Atmospheric Electricity

    Teaching Activities

  • Doctoral Research Taught course
  • Doctoral Research Taught course
  • Electricity and Magnetism I Taught course
  • Senior Design Project Taught course
  • Senior Design Project Taught course
  • Thermodynamics&Statistic Mech Taught course
  • Doctoral Research Taught course 2024
  • Doctoral Research Taught course 2023
  • Electricity and Magnetism I Taught course 2023
  • Doctoral Research Taught course 2022
  • Electromagnetic Theory I Taught course 2022
  • Doctoral Research Taught course 2021
  • Doctoral Research Taught course 2021
  • Electromagnetic Theory I Taught course 2021
  • Electromagnetic Theory I Taught course 2021
  • Doctoral Research Taught course 2020
  • Thermodynamics&Statistic Mech Taught course 2020
  • Doctoral Research Taught course 2020
  • Electricity and Magnetism I Taught course 2020
  • General Physics I Recitation Taught course 2020
  • Doctoral Research Taught course 2019
  • Thermodynamics&Statistic Mech Taught course 2019
  • Doctoral Research Taught course 2019
  • General Physics I Recitation Taught course 2019
  • Doctoral Research Taught course 2018
  • Electricity and Magnetism II Taught course 2018
  • Thermodynamics&Statistic Mech Taught course 2018
  • Doctoral Research Taught course 2018
  • Electricity and Magnetism I Taught course 2018
  • Electricity and Magnetism I Taught course 2018
  • Electricity and Magnetism II Taught course 2017
  • General Physics II Recitation Taught course 2017
  • Electricity and Magnetism I Taught course 2017
  • General Physics I Recitation Taught course 2017
  • Doctoral Research Taught course 2016
  • Education And Training

  • B.S. Electrical Engineering, Zhejiang University
  • M.S. Electrical Engineering, Zhejiang University
  • Ph.D. Electrical&Electronic Eng. Tec, Pennsylvania State University
  • Full Name

  • Ningyu Liu
  • Mailing Address

  • The University of New Hampshire

    Department of Physics & Space Science Center (EOS)

    8 College Road, 312 Morse Hall

    Durham, NH  03824

    United States