1. Lightning Climatology Oklahoma Lightning Mapping Array May - September, 2004 - 2005 Paul Krehbiel New Mexico Tech September 28, 2005

2. Lightning Mapping Arrays (LMAs) ● Utilize time-of-arrival technique ● Consist of 10-12 stations over 50-70 km diameter area ● Passive system: locates impulsive radio frequency signals produced by lightning (radio 'static') ● Listens in a locally unused VHF TV channel (e.g., Ch 3, 5, 8) ● Produce observations in near real-time (1-2 minute delay) ● Provide good spatial accuracy and temporal resolution Existing systems: ● New Mexico Tech LMAs: Northern Alabama (NASA/Huntsville), Oklahoma (OU/NSSL), Langmuir Laboratory (NMT), WSMR,... ● Vaisala (formerly GAI) LDAR II: Dallas/Ft. Worth, Houston (TAMU), Kennedy Space Center.

3. Oklahoma LMA data: Real time observations: Cover a large area (400-500 km diameter) 3D over 200-300 km diameter area Data are simultaneous; short update times (2 min) Useful information: Plan source densities (vertically integrated) Altitude vs. time source density plots Lightning activity shows where strong convection is occurring, and if intensifying or weakening (See lightning.nmt.edu)

4. Texas Zoomed-in example: Density of Points Display Moore, OK tornadic storm May 10, 2003 10 min of observations (NLDN events in green) -> xlma analysis software

5. Climatology Data from Oklahoma LMA The following slides show on a month-by-month basis the number of located LMA sources as a function of the day of the month and the hour of each day, in the form of a 3- dimensional bar graph (generated using the ‘bar3’ plotting tool of Matlab). The vertical bars indicate the number of sources per hour on a logarithmic scale to prevent large mesoscale systems from dominating the plots. The units are kilosources/hour, with a threshold value of 1000 sources/hour being applied to discriminate against weakly-detected, distant storms from cluttering up the presentation (any storm of reasonable size and within range of the LMA will produce several thousand sources/hour). To determine what the storms look like during an active period, see http://lightning.nmt.edu/oklma. (Bar graphs are shown only for April through September but are available for the entire year.)

6. Number of located LMA sources, April 2004, Oklahoma (Daylight ~12-24 UTC; 7 am – 7 pm CDT)

7. Number of located LMA sources, April 2005, Oklahoma (Daylight ~12-24 UTC; 7 am – 7 pm CDT)

8. Number of located LMA sources, May 2004, Oklahoma (Daylight ~12-24 UTC; 7 am – 7 pm CDT)

9. Number of located LMA sources, May 2005, Oklahoma (Daylight ~12-24 UTC; 7 am – 7 pm CDT)

10. Number of located LMA sources, June 2004, Oklahoma (Daylight ~12-24 UTC; 7 am – 7 pm CDT)

11. Number of located LMA sources, June 2005, Oklahoma (Daylight ~12-24 UTC; 7 am – 7 pm CDT)

12. Number of located LMA sources, July 2004, Oklahoma (Daylight ~12-24 UTC; 7 am – 7 pm CDT)

13. Number of located LMA sources, July 2005, Oklahoma (Daylight ~12-24 UTC; 7 am – 7 pm CDT)

14. Number of located LMA sources, Aug. 2004, Oklahoma (Daylight ~12-24 UTC; 7 am – 7 pm CDT)

15. Number of located LMA sources, Aug. 2005, Oklahoma (Daylight ~12-24 UTC; 7 am – 7 pm CDT)

16. Number of located LMA sources, Sept. 2004, Oklahoma (Daylight ~12-24 UTC; 7 am – 7 pm CDT)

17. Number of located LMA sources, Sept. 2005, Oklahoma (Daylight ~12-24 UTC; 7 am – 7 pm CDT)

18. For real-time data plots, archived daily and hourly, see http://lightning.nmt.edu/oklma

19. Lightning Climatology STEPS 2000 Lightning Mapping Array (NW Kansas, E Colorado, SW Nebraska) May 24 – August 10, 2000

20. Two supercell storms in NW Kansas–SW Nebraska - June 7, STEPS 2000 -13 station LMA network - Close storm: Low Precip - Far storm: High Precip - 10 min time interval - ~Continuous IC lightning - Inverted polarity storms (deep mid-level + charge) - Only one NLDN event - negative CG (real?) - Major advantage of total lightning vs. CG only Note: Major Ch 3 TV interference, data processed with auto- thresholding.

21. Aircraft track and storms, May 25, STEPS 2000 (Aircraft being charged while flying through down- wind cirrus/anvil cloud)

22. Height vs Time Plan View Height vs E-W Height vs N-S Example of Highly Dendritic Negative CG flash

23. Number of located LMA sources, May 2000, STEPS (Daylight ~12-02 UTC; 6 am – 8 pm MDT)

24. Number of located LMA sources, June 2000, STEPS (Daylight ~12-02 UTC; 6 am – 8 pm MDT)

25. Number of located LMA sources, July 2000, STEPS (Daylight ~12-02 UTC; 6 am – 8 pm MDT)

26. Number of located LMA sources, August 2000, STEPS (Daylight ~12-02 UTC; 6 am – 8 pm MDT)

27. (The End)

28. impulsive lightning event at (x, y, z; t) Time-of-Arrival Concept: x y z

29. Oklahoma Lightning Mapping Array 11 station network, 50 km diameter Real-time processing & display University of Oklahoma/National Severe Storms Laboratory

30. Oklahoma LMA Station

31. North Alabama Lightning Mapping Array (NASA) Map (10 stations) http://branch.nsstc.nasa.gov/ One hour of real-time data

32. New Mexico LMA Networks

33. Portable LMA System (Vortex II, DC Network, DC3?) Electronics housed in shielded thermoelectric cooler enclosure Operate from external 12 VDC battery and/or power supply. ~12 (+48) watts power Battery operation: 48+ hours (w/out cooling) 20+ hours (with cooling) Lightweight (10 lbs) ¼ wave ground plane antenna (Ch. 8 shown; 180-186 MHz) Connected to receiver in box by coaxial cable Other external connectors: GPS antenna, ethernet, 12 VDC