List of Figures

1. Electric field and electrical breakdown strength above a discharge.
2. Ionization and attachment of air versus E/N.
3. Electron avalanche in a laboratory experiment.
4. 1976 U.S. Standard Atmosphere
5. 1966 U.S. Standard Atmosphere Supplement
6. Model of atmospheric conductivity between 40-90 km altitude.
7. Simulated relaxation time profile just prior to sprite initiation
8. Calculated electric field at $Z\!=\!78$ km vs. the number of images.
9. Electric field at $Z\!=\!78$ km as a function of disk radius and height.
10. The sprite initiation threshold for 70-81 km altitude.
11. Diagram of a positive streamer.
12. Storm development for 23-1 UT on June 21st-22nd, 1997
13. Storm development for 1-3 UT on June 22nd, 1997
14. Video sequence and NEXRAD radar for 01:42:57 UT event
15. Spatial development of 01:42:57 UT flash
16. Height histogram of VHF sources for 01:42:57 UT flash
17. Video sequence of 01:47:52 UT sprite event
18. Spatial development of 01:47:52 UT flash
19. Azimuth and Elevation of 01:47:52 UT sprite event
20. Height histogram of VHF sources for 01:47:52 UT flash
21. Video sequence and NEXRAD radar for 01:51:02 UT event
22. Spatial development of 01:51:02 UT flash
23. Height histogram of VHF sources for 01:51:02 UT flash
24. Video sequence and NEXRAD radar for 01:55:47 UT event
25. Spatial development of 01:55:47 UT flash
26. Height histogram of VHF sources for 01:55:47 UT flash
27. Spatial development of 02:15:19 UT flash
28. Sferics and photometry for sprite event at 05:38:00.77 UT, July 24, 1996.
29. Visible and infrared satellite images at 23:15 UT, August 14, 1998
30. NLDN data for MCS on August 14, 1998
31. Electric field waveform of 23:19:48 UT +CG and daytime sprite.
32. Largest charge moment change discharges on August 14, 1998
33. Profiles of $n_e$ and $\tau _r$ on August 14, 1998.
34. Sprite initiation threshold for daytime sprites.
35. October 7, 1997, NLDN strokes for 01:30-4:30 UT.
36. Initial 4.5 ms of the October 7, 03:03:59 UT sprite cluster development.
37. Subsequent 4.5 ms of the October 7, 03:03:59 UT sprite cluster development.
38. Enhanced image sequence of the 03:03:59 UT sprite cluster's initial development.
39. Electric field and photometer data for the 03:03:59 UT event.
40. Formation of a carrot shape for sprite B of the 03:03:59 UT sprite cluster.
41. Development of the October 7, 03:40:37 UT sprite cluster.
42. Development of the October 7, 03:40:38 UT sprite cluster.
43. Electric field waveform and frame periods for the 03:40:38 UT sprite cluster
44. Correlated charge moment change and high-speed video of 04:37:05 UT sprite cluster.
45. Correlated charge moment change and high-speed video of the 04:45:48 UT sprite cluster.
46. VME Data Acquisition System
47. Star alignment for a normal-speed video image.
48. Normal-speed video timing via a Horita GPT-50.
49. Determination of high-speed video timing from LED transitions.
50. Effect of refraction on height estimates.
51. The slow antenna calibrator.
52. Determination of magnetic loop orientation.
53. Calibration of E and B from NLDN data as a function of source azimuth.
54. Calculated electric field at $r\!=\!80$ km vs. the number of images.
55. The effect of the ionosphere on the static electric field at 40-100 km range.