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Global lightning and lightning energy propagation. Erin Lay Dept. of Earth & Space Science Space Physics Group Advisor: Robert Holzworth (manager for World Wide Lightning Location Network). CDO Networking Day 15 November 2006. Outline. Intro to global lightning detection
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Global lightning and lightning energy propagation Erin Lay Dept. of Earth & Space Science Space Physics Group Advisor: Robert Holzworth (manager for World Wide Lightning Location Network) CDO Networking Day 15 November 2006
Outline • Intro to global lightning detection • Why study lightning-radiated energy globally? • My research: calculating strength and count rate of global lightning
WWLLN Station Hosts • University of Otago • Charles Darwin Univ. • Griffith University • Murdoch University • Nat. Univ. of Singapore • Osaka University • IZMIRAN, Russian Academy of Sciences • Eötvös Lorand University • University of Washington • Massachusetts Institute of Technology • University of KwaZulu-Natal • Brazilian Nat. Inst. for Space Research • University of the South Pacific • Los Alamos National Laboratory • Univ. Nac. Autonoma de México • Univ. de la Polynesie Francaise • Tel Aviv University • University of Sheffield • Portugal Meteorological Inst. • Inst. Geofisico del Peru • University of Puerto Rico • Univ. Nacional de Córdoba • Sodankylä Geophysical Observatory • University of Hawaii • British Antarctic Survey • CAREERI, Chinese Academy of Sciences • AND MORE ARE ON THE WAY
WWLLN n. /'wu-l&n/ (woolen) 1. World Wide Lightning Location Network, developed in New Zealand, sheep population: 45 million, human population: negligible (4 million).
VLF GPS Timing, VLF processing electronics preamp Sound card computer To central computer at UW via internet VLF Stations Univ. of WA antenna
Lightning energy propagation Rodger, J. Atmos. and Solar-Terr. Phys, 2003
Lightning EMP: Elves ~200-700 km horizontal width Optical emission +electron density enhancement ~100 km ~80 km electromagnetic pulse from lightning intense cloud-to-ground discharge (>50kA)
Mapping ionospheric modifications • Electron density changes Modifies waveguide for lightning energy Required information, globally: • stroke energy • stroke rate
WWLLN stroke energy Integrated waveform energy density at station – uncalibrated “Propagate” stroke backwards to source to get an estimated energy
Red storm: higher stroke rate Blue storm: higher energy strokes Each box: 2x2 degrees Blue box center: 6,440 km from Sao Paulo station Red box center: 5,660 km from Sao Paulo station
Summary • WWLLN: • Hardware fabrication • Detection efficiency • Current state of WWLLN: • relative energy of strokes from a given storm • which storms produce more energetic lightning. • First time this can be done globally! Absolute calibration: propagation modeling
Questions? WWLLN website: webflash.ess.washington.edu
Christian et. al, JGR, 108, D1, 4005, doi:10.1029/2002JD002347, 2003
Christian et. al, JGR, 108, D1, 4005, doi:10.1029/2002JD002347, 2003
Christian et. al, JGR, 108, D1, 4005, doi:10.1029/2002JD002347, 2003
Christian et. al, JGR, 108, D1, 4005, doi:10.1029/2002JD002347, 2003