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Total Lightning Observations With New and Improved Los Alamos Sferic Array (LASA) Xuan-Min Shao,

Total Lightning Observations With New and Improved Los Alamos Sferic Array (LASA) Xuan-Min Shao, Mark Stanley, Jeremiah Harlin, Amy Regan, Morrie Pongratz, Mike Stock Space and Remote Sensing Sciences Group, ISR-2 Los Alamos National Laboratory.

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Total Lightning Observations With New and Improved Los Alamos Sferic Array (LASA) Xuan-Min Shao,

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  1. Total Lightning Observations With New and Improved Los Alamos Sferic Array (LASA) Xuan-Min Shao, Mark Stanley,Jeremiah Harlin,Amy Regan,Morrie Pongratz, Mike Stock Space and Remote Sensing Sciences Group, ISR-2 Los Alamos National Laboratory Southern Thunder Workshop , Ft. Worth, 07/25-27/05

  2. Florida LASA Eight stations deployed in April, 2004 Operated via Internet Deployed April, 2004 Sensor on Roof

  3. GPS Block IIF: V-GLASS (VHF Global Lightning And Severe Storm Monitor) MISSION Global VHF Lightning and Total Electron Content (TEC) Monitoring Lightning detection as proxy for monitoring deep convection An extension of an already- scheduled DoD mission using existing h/w and s/w PLATFORM Platform: GPS Constellation (24 Block IIF/III satellites) Altitude: 20,000 km Launches: 2007-2011 SENSORS Type: Broadband VHF receivers Capability: Event time, 3D location, TEC Lightning/sec/sat: ~ 1 - 10 Coverage: 1 gnd stat. (regional, real-time) ~ 4 gnd stats. (global, real-time) V-Sensor

  4. Samples of E-Field Changes IC +CG ELVES observed by ISUAL Energetic -CG -CG 1 ms 8 ms

  5. New processing algorithm allows each peak detected and located (1) Convert E-field to power, (2)detect power peaks, (3) match peaks among stations, (4) time-tag matched peaks, (5) locate peaks. Match peaks among stations Hilbert Transform

  6. Air mass, afternoon storms monotonically produce ~3-4 time more ICs than CGs, and uniformly produce NBs

  7. Frontal storms associated with variable IC/CG ratios, depending on storm stages, and only selectively produce NBs

  8. LASA vs. NEXRAD: able to outline structures of active storm cells. Can be used to now-cast severe storms Radar EdotX

  9. 2-D location accuracy, < 0.5 km near the dense array • Located 8 of 13 triggered return strokes at Camp Blanding in 2004 • Peak currents: 3.6-17.8 kA • Location errors: 20-156 m with an average 91 m.

  10. Detection efficiency A few kAs within 100km, 25 kA at 600 km. 2-5 more ICs than CGs within 100 km

  11. Daily trigger rate: 106 – 107

  12. 3-D capability for lightning near the dense array Total of 724 in 4 minutes, 120 are return strokes

  13. 3-D observation of small cell Notice the source height development. 498 pts in 50 min

  14. Great Plains Array deployed in April, 2005 Algorithms development underway

  15. LASA captured a handful lightning events that are tightly associated with TGFs detected by RHESSI satellite. All waveforms are similar but exotic. No NB was found associated with TGF

  16. Measured attenuation agrees with simulation: a possible tool for soil conductivity and water content mapping (meters deep into earth, progress underway) LB cutoff freq • Spectrum ratios between inland and DAB stations. • More attenuation at farther stations. • Path to TPA more conductive than to GNV? Blue: PLK Green: GNV Red: TPA Black: TLH

  17. Summary • New LASA FLN operated continuously since April, 2004 • Captures full waveforms without any trigger dead time • Detects several to several tens events per flash • Can readily distinguish ICs, CGs, and NBs • 3-D capability for lightning near the dense array • Great Plains Array started operation in April, 2005 • Compared to other observations, e.g., TGF, Sprit.

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