A study of wire-deploying devices designed to trigger lightning
Development and characteristics of device for deployment of long wires as method of reducing hazards due to lightning during spacecraft launches
Rossow, V. J.↗
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Measurements and analysis of lightning-induced voltages in aircraft electrical circuits
Lightning induced voltages in aircraft wing structures, examining induced voltage across load impedances in electric circuits
Hacker, P. T.↗
The problem of lightning and static electricity at the Kennedy Space Center
Lightning and static electricity hazards at Kennedy Space Center, discussing meteorological aspects
Amman, E. A.↗
Whistlers with harmonic bands caused by multiple stroke lightning
Whistlers with harmonic bands caused by multiple stroke lightning, using Injun 5 VLF data
Gurnett, D. A.↗
Lightning observations by satellite
Lightning observation by OSO-E satellite, suggesting maximum thunderstorm incidence over North Atlantic Ocean
Ney, E. P.↗
Lightning flash detection system
Array of photodetectors and associated circuitry continuously monitors entire horizon to measure distance and direction of lightning flashes.
Borucki, W. J.↗
Ignition of Fuel Vapors Beneath Titanium Aircraft Skins Exposed to Lightning
Hot-spot and puncture ignition of fuel vapors by simulated lightning discharges was studied experimentally. The influences of skin coating, skin structure, discharge polarity, skin thickness, discharge current level, and current duration were measured and interpreted. Ignition thresholds are reported for titanium alloy constructed as sheets, sheets coated with sealants, and sandwich skins. Results indicated that the ignition threshold charge transfer for coated sheets, honeycomb, and truss skins is respectively about 200%, 400%, 800% that of bare alloy sheet of .102 cm (.040 in.)-thickness. It was found that hot-spot ignition can occur well after termination of the arc, and that sandwich materials allow ignition only if punctured.
Kosvic, T. C.↗
Lightning summary report through 1971
An updated summary is presented of the lightning activity recorded at the John F. Kennedy Space Center and the Cape Kennedy Air Force Station. Data was compiled during the periods 1903 through 1924, 1957 through 1962, and 1964 through 1971.
Source record↗
Currents in Florida lightning return strokes.
The transmission line return stroke model is used to derive individual current versus time wave forms from measured electric fields. A total of 98 strokes in 21 flashes at distances less than or equal to 10 km and 63 strokes in 18 flashes at distances between 10 and 32 km are analyzed for current wave shape and magnitude. For the closer strokes, return stroke velocity is also determined from the electric field wave forms. Eighteen detailed current and field wave forms and a statistical distribution of peak currents are presented. Return stroke channel currents are found to exhibit a sharp initial peak which currents measured in tall structures at the base of the lightning channel apparently do not exhibit. A complete discussion of errors is given.
Uman, M. A.↗
Electric radiation fields of lightning return strokes in three isolated Florida thunderstorms
Peak value and risetime distributions for the electric radiation fields produced by lightning strokes to ground in three isolated Florida thunderstorms are presented. The storm at 195 km produced about 1000 return strokes having an average peak radiation field (normalized to 100 km) of about 5.5 V/m, the storm at 110 km produced about 700 strokes having 2.0 V/m, and the storm within 10 km produced about 100 strokes having 15.0 V/m. For each storm the average peak radiation field for first strokes was only slightly greater than the average peak field for subsequent strokes. For the sample of three storms the average peak radiation field in a given storm was proportional to the number of subsequent strokes per flash in that storm. The field risetimes for the two distant storms have statistical properties which are essentially identical to those reported for distant storms in Pennsylvania, whereas the close Florida storm exhibited significantly faster risetimes.
Lin, Y. T.↗
A test and measurement technique for determining possible lightning-induced voltages in aircraft electrical circuits
Transient analyzer consists of four 0.5 microfarads capacitors chargeable by self-contained solid state 50 KV dc power supply operating from standard 110 Vac line voltage. Unit can circulate unidirectional current impulses of up to 500 amperes through aircraft at waveshapes similar to those of natural lightning strokes.
Plumer, J. A.↗
Correlated electric and magnetic fields from lightning return strokes
The first broad band (1 kHz to 5 mHz) correlated measurements of electric and magnetic fields from close lightning return strokes are presented. Sample wave forms are shown for the distance range 2-200 km. The transmission line return stroke model is used to find a typical current wave shape and return stroke velocity from the experimental data, and theoretical curves are given of electric and magnetic field as a function of time for 1, 5, 10, and 100 km by using this typical current and velocity.
Uman, M. A.↗
Radiation field wave forms produced by lightning stepped leaders
Broadband electric field data are presented which show stepped leader wave forms preceding records of distant lightning return strokes. The majority of leader pulses are characterized by a large initial peak with a small and slow opposite overshoot. Total pulse durations range from 15-40 microsec several milliseconds before the return stroke to 2-10 microsec immediately preceding the return stroke. Close to the ground the stepped leader pulses occur at regular 10- to 20-microsec intervals and are almost unipolar with rise times of about 1 microsec and full widths at half maximum in the range from 1 to 3 microsec. The ratio of the peak of the last leader pulse to the subsequent return stroke peak is typically 0.1, which suggests a peak step current near the ground of about 10% of the return stroke peak current.
Krider, E. P.↗
Electrostatic field changes and recovery curves produced by Florida lightning
Preliminary data on electric field changes produced by cloud-to-ground lightning and the subsequent field recoveries are presented. Both single-station and multiple-station observations were made. There is large variation in the data: total charge transfers range from 10 to 30 C and beyond, electric-field recovery times vary by a factor of 2 or more, and initial charge heights occur over a large interval. Only distance and angle dependencies are somewhat predictable, and then only in a few cases. Thus the field recovery mechanism is not a simple one.
Jacobson, E. A.↗
Regular radiation field pulses produced by intracloud lightning discharges
Sequences or bursts of uniform pulses have been recorded during a large fraction of intracloud lightning discharges in Florida and Arizona. The wave form of a typical pulse begins with a fast large-amplitude portion followed by a small and slowly varying overshoot. The full width and half maximum of the large amplitude peak is typically 0.75 microsec, and the time intervals between pulses are typically 5 microsec in both maritime and continental storms. The pulse shapes and interval times suggest that the source of these pulses in an intracloud dart-stepped leader process similar to that which has been photographed in discharges to ground.
Krider, E. P.↗
WING: Calculating lightning-induced voltages in electrical circuits within an aircraft wing
Computer program based on Biot-Savart and Faraday laws utilizes model of generalized aircraft wing to calculate resistive and inductive transfer impedances relating lightning current flowing through wing to voltage induced in conductor within wing.
Plumer, J. A.↗
The structure of lightning flashes HF-UHF: 12 September 1975, Atlanta, Georgia
Simultaneous measurement of sferics at 3, 30, 139, and 295 MHz were made during thunderstorms. Wideband electronics and an analogue tape recorder continuously recorded the radiation from lightning with about 300 kHz of bandwidth. The data were obtained during the passage of a cold front. Flashing rate, burst rate and the structure of individual flashes were recorded. The record of a typical flash begins with a sudden burst of closely spaced pulses whose temporal structure is typical of the stepped leader, and ends in a large pulse suggestive of a first return stroke. The remainder of the flash consists of a sequence of pulses of varying amplitude separated by quiet periods of the order of milliseconds. The shape of these pulses and the temporal structure suggest that the first few large pulses are return strokes. Other discharges begin with widely spaced discrete pulses and resemble the preceding discharge less the leader and return stroke phase. The radiation exhibits a similar structure, at each of the frequencies monitored.
Levine, D. M.↗
Electrostatic field changes produced by Florida lightning
The electrical behavior of thunderstorms triggered by local heating and sea-breeze convergence, a low pressure disturbance, and a weak frontal passage has been studied at the NASA Kennedy Space Center, Florida. A nonlinear least-squares minimization procedure has been developed to describe changes in the total electrostatic field produced by lightning in terms of point charge models for the cloud charge distributions. The results indicate that discharges to ground usually neutralize cloud charges in the range from -10 to -40 C. The computed charge altitudes for Florida are somewhat higher than for other geographical locations, 6 to 9.5 km, but the corresponding ambient air temperatures, -10 to -34 C, are similar. A large fraction of the discharges to ground show total field changes which are small or even reversed in polarity within 3 km of the discharges. It is suggested that ground discharges often neutralize a small positive charge, 0.5 to 4 C at altitudes of 1 to 3 km, in addition to the larger negative charge higher in the cloud.
Jacobson, E. A.↗