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At least 19 recordsLinked to original sources
PubMed2000

Ball lightning caused by oxidation of nanoparticle networks from normal lightning strikes on soil

Observations of ball lightning have been reported for centuries, but the origin of this phenomenon remains an enigma. The 'average' ball lightning appears as a sphere with a diameter of 300 mm, a lifetime of about 10 s, and a luminosity similar to a 100-W lamp. It floats freely in the air, and ends either in an explosion, or by simply fading from view. It almost invariably occurs during stormy weather. Several energy sources have been proposed to explain the light, but none of these models has succeeded in explaining all of the observed characteristics. Here we report a model that potentially accounts for all of those properties, and which has some experimental support. When normal lightning strikes soil, chemical energy is stored in nanoparticles of Si, SiO or SiC, which are ejected into the air as a filamentary network. As the particles are slowly oxidized in air, the stored energy is released as heat and light. We investigated this basic process by exposing soil samples to a lightning-like discharge, which produced chain aggregates of nanoparticles: these particles oxidize at a rate appropriate for explaining the lifetime of ball lightning.

Journal Article↗
PubMed1986

When lightning strikes. Pathophysiology and treatment of lightning injuries.

Lightning accidents are responsible for several hundred deaths and thousands of injuries each year in this country. Survivors sustain a variety of cardiac, neurologic, musculoskeletal, and dermatologic injuries. Eye and ear injuries are also occasionally noted. Education on how to minimize the possibility of such an accident is the best method of dealing with the problem. When prevention fails, prompt cardiopulmonary resuscitation and supportive treatment for the patient's particular injury are indicated.

Adult↗
PubMed1987

Optical efficiencies of lightning in planetary atmospheres.

Spacecraft observations show that the presence of lightning activity is not confined to the terrestrial atmosphere, but is also found in the atmospheres of Venus, Jupiter and Saturn. Lightning activity may also occur in Titan's thick atmosphere. Calculations show that lightning produces a significant fraction of the nitric oxide that reacts with the ozone and chlorine compounds in the terrestrial stratosphere. In the atmosphere of the primordial Earth, lightning could have been the major source of many of the molecules required for the formation of life. To determine the effects of lightning activity in the atmospheres of other planets from spacecraft images requires a knowledge of the optical properties of the lightning discharge. Here we report the first simulations of lightning in planetary atmospheres by laser-induced plasmas. These simulations show that the fraction of the energy in lightning discharge channels that is radiated in the visible spectrum is similar for Earth, Venus and Titan, but quite different for Jupiter. One implication of our results is that the amount of trace gases produced by lightning in the jovian atmosphere must be larger than previously estimated.

Astronomy↗
PubMed1995

Lightning and transportation.

It is a little-known fact that lightning casualties often involve travel or transportation. López and colleagues, in their studies on the epidemiology of lightning injuries, have reported that 10% of lightning injuries are categorized under transportation. In the majority of their cases, victims were struck while standing outside or near their vehicles during a thunderstorm. During my review of the neurologic complications of lightning injuries, I was impressed by the number of case reports in which the victim was struck while either in or near a vehicle, airplane or vessel. In this article, I shall put forth information on four aspects of lightning that relate to the danger to people traveling in vehicles, boats, and airplanes. First, I shall deal with lightning safety on ships and boats. People who enjoy recreational sailing, including the "weekend sailor" and those who enjoy fishing from a boat, should be fortified with knowledge about lightning protection. Second, I shall consider the matter of lightning strikes to aircraft. In the third section, I shall discuss the question of lightning safety in automobiles. Fourth, I shall review those cases found in my literature review in which the victim was struck while in or near a vehicle, boat, or airplane.

Adult↗
PubMed2001

Lightning injuries in sports: situations to avoid.

There is no absolute protection against lightning because of its random and capricious nature. However, the risk of being struck by lightning can be substantially reduced. There are general safety rules that apply to all athletic and recreational events. The athlete should have a proactive plan that can be instituted when storms approach. He/she should go to a safe shelter before the storm arrives and stay there until the danger is gone. Because the location, climate, terrain and playing site vary with different sporting activities, safety plans may have distinct elements for different recreational activities. Mountain climbers should know the weather patterns of their locale. The highest frequency of lightning strikes in the Rocky Mountains occurs between 11 am and 9 pm during the months of April to September. There is less chance of a hiker encountering lightning during the early morning hours. Many tourists are unaware of this pattern, which may possibly explain the finding that most lightning victims are visitors from other states. The bicyclist is as vulnerable as anyone in the open. In the event of lightning he/she should seek safe shelter and get off the bike. Rubber tires do not provide protection from lightning. Golfers continue to make the same mistakes year after year. Golfers should know to seek safe shelter (clubhouse or closed metal vehicle) before the storm arrives and not return prematurely to the golf course. They should avoid isolated trees, open fields, unsafe sheds and metal poles. They should separate from each other rather than gather together. Swimmers should get out of the pool and find a safe shelter. Safe areas do not include poolsides, under awnings or under trees. A nearby closed automobile may be the safest place until the danger is gone. Applying precautions when engaging in these sporting or recreational activities will help to minimise the risk of casualties or fatalities caused by lightning.

Female↗
PubMed2001

Non-detection at Venus of high-frequency radio signals characteristic of terrestrial lightning.

The detection of impulsive low-frequency (10 to 80 kHz) radio signals, and separate very-low-frequency (approximately 100 Hz) radio 'whistler' signals provided the first evidence for lightning in the atmosphere of Venus. Later, a small number of impulsive high-frequency (100 kHz to 5.6 MHz) radio signals, possibly due to lightning, were also detected. The existence of lightning at Venus has, however, remained controversial. Here we report the results of a search for high-frequency (0.125 to 16 MHz) radio signals during two close fly-bys of Venus by the Cassini spacecraft. Such signals are characteristic of terrestrial lightning, and are commonly heard on AM (amplitude-modulated) radios during thunderstorms. Although the instrument easily detected signals from terrestrial lightning during a later fly-by of Earth (at a global flash rate estimated to be 70 s(-1), which is consistent with the rate expected for terrestrial lightning), no similar signals were detected from Venus. If lightning exists in the venusian atmosphere, it is either extremely rare, or very different from terrestrial lightning.

Journal Article↗
PubMed2002

Lightning safety guidelines.

On average, lightning causes more casualties annually in the United States than any other storm-related phenomenon except floods. Although 90% of those injured survive, they may have permanent sequelae and disability. Many of these people incur injuries or are killed by lightning because of misinformation and inappropriate behavior during thunderstorms. A few simple precautions can reduce lightning injury risk. To standardize recommended actions during thunderstorms, the Lightning Safety Group (LSG), composed of lightning experts from many lightning-related backgrounds, met at the American Meteorological Society meeting Phoenix, AZ, in January 1998 to collectively address personal lightning safety. This paper is a summary of the recommendations developed by the LSG.

Humans↗
PubMed1995

Deaths and injuries as a result of lightning strikes to aircraft.

Aircraft are at risk of being struck by lightning or triggering lightning as they fly through clouds. Commercial and private airplanes have been struck, with resultant deaths and injuries to passengers and crew. We were interested in learning how large a problem existed to the American public from lightning strikes to airplanes. We analyzed data from the National Transportation Safety Board (NTSB) on lightning-related accidents in the United States from 1963-89. NTSB recorded 40 lightning-related aircraft accidents. There were 10 commercial airplane accidents reported, 4 of which were associated with 260 fatalities and 28 serious injuries. There were 30 private aircraft accidents that accounted for 30 fatalities and 46 serious injuries. While lightning remains a potential risk to aircraft passengers and crew, modern airplanes are better equipped to lessen the dangers of accidents due to lightning.

Accidents, Aviation↗
PubMed1985

Spectra of simulated lightning on Venus, Jupiter, and Titan.

Laser-induced plasmas in various gas mixtures were used to simulate lightning in other planetary atmospheres. This method of simulation has the advantage of producing short-duration, high-temperature plasmas free from electrode contamination. The laser-induced plasma discharges in air are shown to accurately simulate terrestrial lightning and can be expected to simulate lightning spectra in other planetary atmospheres. Spectra from 240 to 880 nm are presented for simulated lightning in the atmospheres of Venus, Earth, Jupiter, and Titan. The spectra of lightning on the other giant planets are expected to be similar to that of Jupiter because the atmospheres of these planets are composed mainly of hydrogen and helium. The spectra of Venus and Titan show substantial amounts of radiation due to the presence of carbon atoms and ions and show CN Violet radiation. Although small amounts of CH4 and NH3 are present in the Jovian atmosphere, only emission from hydrogen and helium is observed. Most differences in the spectra can be understood in terms of the elemental ratios of the gas mixtures. Consequently, observations of the spectra of lightning on other planets should provide in situ estimates of the atmospheric and aerosol composition in the cloud layers in which lightning is occurring. In particular, the detection of inert gases such as helium should be possible and the relative abundance of these gases compared to major constituents might be determined.

Ammonia↗
PubMedDate not supplied

Lightning-related mortality and morbidity in Florida.

Cases of lightning-related deaths and injuries that occurred in Florida in 1978-87 were reviewed to determine the factors involved, to quantify the morbidity and mortality related to lightning strikes, and to describe epidemiologically the injuries and circumstances involved. Statewide information on deaths was obtained from death certificates, autopsy reports, and investigative reports. Information about morbidity was obtained from the Florida Hospital Cost Containment Board data base and the National Climatic Data Center data base for all Florida counties, as well as from hospitals in selected counties. Lightning-related deaths totaled 101 in Florida during the period 1978-87, an annual average of 10.1. Eight percent of the victims were from other States. The overall yearly death rate for State residents was 0.09 per 100,000 population, with the highest rate being that for men aged 15-19 years, 0.38 per 100,000. Thirteen percent of victims were females. The ratio of lightning-related injuries to deaths in Florida was estimated at about four to one. Thirty percent of all deaths were occupationally related. The first strikes of lightning from a thunderstorm may be the most dangerous, not in terms of impact, but because of the element of surprise. During thunderstorms, people may seek shelter under isolated trees because they believe erroneously that a tree offers protection from lightning, or perhaps because their top priority is to escape from rain rather than lightning. People may not seek adequate shelter during thunderstorms because they do not know the dangers of remaining outdoors or their judgment is impaired by drugs or alcohol.

Adolescent↗
PubMed1995

Safety in the presence of lightning.

Not enough emphasis is usually placed on the proactive ability to recognize the lightning hazard. Instead, most literature and training materials treat the reactive mode. The latter approach emphasizes the posture to take when a person is caught by surprise in the open by a thunderstorm when the lightning threat is at its greatest; in other words, it is too late for precautions. The same reactive approach concentrates on what a person is wearing or holding when lightning is overhead instead of how the person came to be in this situation in the first place. Rather than focusing on these last-minute factors, the primary issue must be on the ability of a person, whether in a baseball game, riding a bike, or on a golf course, to recognize in advance the existence of a major lightning threat. This proactive approach emphasizes advance planning and recognition of a potential threat from lightning. A complete plan involves a sequence of decisions on a time scale from days to seconds. Although most of the available information in pamphlets and safety guidelines is correct concerning the reactive phase of lightning safety, the hazard remains important because of the lack of emphasis on planning and awareness.

Humans↗
PubMed1993

Electrical shock and lightning strike.

Cardiac arrest from electrical shock or lightning strike is associated with significant mortality and requires modification and extension of standard advanced life support measures to achieve successful resuscitation. Patients who experience electrical shock or lightning strike may sustain cardiac and respiratory arrest secondary to the direct effects of current. However, the majority of victims have associated multisystem involvement, including neurologic complications, cutaneous burns, and associated blunt trauma. As a result, a combination of advanced cardiac life support measures and advanced trauma life support techniques is indicated. Victims with cardiac arrest from electrical shock or lightning strike require prompt, aggressive resuscitation using standard methods for airway control, ventilation, and chest compressions, as well as usual measures for defibrillation and cardiac pharmacotherapy. Unique considerations include vigorous fluid resuscitation and spinal immobilization for victims of electrical shock and reversal of normal multiple casualty triage priorities when managing several lightning strike victims. Because the majority of victims are relatively young and seldom have significant underlying cardiac disease, the chance for successful resuscitation may be greater for patients who experience sudden death from electrical shock or lightning strike than for those with other causes of cardiac arrest, even among patients with initial rhythms traditionally unresponsive to therapy. Although numerous specialized aspects are required for the successful management of victims of electrical shock and lightning strike, the following article focuses on the unique considerations necessary for immediate care of cardiac arrest victims, with emphasis on the underlying mechanisms of sudden death and currently recommended guidelines for resuscitation.

Electric Injuries↗