…thundersnow???
In the midst of a bizarre winter, Montrealers were treated to a rare sight on Monday night — a winter thunderstorm. Montrealers Jolyane Limoges and Pierre-Marc Doucet managed to capture the phenomenon during a snow squall, and post it on YouTube. The phenomenon is known as thundersnow — it's like a normal thunderstorm, but with snow as the primary form of precipitation. Thundersnow events happen when a mass of cold air settles on top of warm air, coupled with moist air closer to the ground.
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How Hot Is Lightning?
Lightning is one of the most destructive forces in nature. But for all the folklore and legends amassed over human history on lightning, we know surprisingly little about the inner workings of this powerful phenomenon, including something as simple as how the current that flows through a thunder-inducing flash is related to the temperature of the strike.
"The basic physics of lightning, such as lightning initiation and lightning propagation, is not fully understood at this point," said Robert Moore, a lightning researcher from University of Florida in Gainesville.
"We know the basics, but not the details. So when anybody makes headway, it is major news."
Lightning causes more than $5 billion in damages every year in the U.S., as well as more fatalities than hurricanes.
"A direct hit from a lightning strike can melt a power cable or start a forest fire, where the amount of heat from the lightning plays a major role," said Xiangchao Li, a scientist from China who specializes in lightning research. Li and his team discovered a mathematical relationship between the current intensity and the temperature inside lightning. Their result was published last month in the journal Scientific Reports.
Although there are approximately 100,000 lightning strikes on Earth every single day, the randomness of the occurrences makes it difficult for scientists to study them in an effective or systematic way. So until Thor, the Norse god of lightning as well as other meteorological events, joins a lightning research team, scientists are left to their own devices.
Luckily such a device does exist. Known as an impulse current generator system, the device can create artificial lightning with currents up to tens of thousands of amperes. For perspective, a household or automotive fuse is usually rated well below a hundred amperes, and an electric current of just a few amperes can easily kill you. A natural lightning strike typically carries around 20-30,000 amperes of current. Certainly there are other factors such as size and setting of natural lightning that cannot be replicated in a laboratory, but just in terms of sheer current output, the lightning generated by the device can really give Thor a run for his money.
By using their artificial lightning system, Li and his team were able to dial up lightning strikes at will, with currents between 5,000 to 50,000 amperes. This resulted in artificial lightning strikes with temperatures as high as 17,000 F, twice as hot as the surface of the Sun.
This creates a new problem -- at such high temperatures, a normal thermometer would explode. And even if it didn't, it wouldn't react quickly enough to register the temperature of the lightning strike. Fortunately, there is "light" in "lightning." Li and his team were able to record the lightning's temperature within a millisecond by measuring the intensity of the light at various wavelengths.
After striking lightning at the same place over and over again, they concluded that the relationship between the current and temperature of lightning is a highly logarithmic one, meaning that the temperature difference between lightning strikes with 1,000 and 10,000 amperes is similar to those with 10,000 and 100,000 amperes. This result provides solid evidence for previous theoretical predictions that lacked the support of data.
"The next step would be to compare with measurements from rocket triggered lightning, or natural lightning, which can be done throughout the U.S. or China," Moore suggested.
That's right, rocket-triggered lightning. Essentially a glorified version of Benjamin Franklin's wired kite, scientists today have ways to siphon natural lightning from the sky by launching an electrically grounded rocket, as shown in the video below.
With a better understanding of the physics of lightning, scientists can help engineers to improve current protocols and infrastructures to better deal with lightning -- from weather warning systems to the design of power grids. Perhaps we can one day limit the power of Thor to only smiting Loki on the silver screen.
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A man was blown out of boots after being hit by a lightning bolt!
A man in Atlanta, USA was lucky to be alive after he was struck by lightning, blowing him right out of his work boots. Sean O’Connor was doing yard work Saturday when he was struck by a bolt of lightning and knocked unconscious. According to the 30-year-old, the sun was shining and there appeared to be no threat of storms when he began working in his yard.
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Lightning knocked out Internet on Cayman’s Island!
A lightning strike along one of the submarine cables that connects Cayman’s Internet to the rest of the world knocked out Internet service for many on Grand Cayman Tuesday evening. The lightning hit a landing station at the U.S. end of the Maya-1 cable system between Cancun, Mexico and Hollywood, Florida, on Tuesday afternoon, affecting Internet access and some phone service in Cayman, according to local telecom companies and regulators.
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Why is lightning white?
Static charges form in a storm composed of ice crystals and liquid water drops. Turbulent winds inside the storm cause particles to rub against one another, causing electrons to be stripped off, making the particles either negatively or positively charged.
The charges get grouped in the cloud, often negatively charged near the bottom of the cloud and positively charged up high. This is an electric field and because air is a good insulator, the electric field becomes incredibly strong. Eventually a lightning bolt happens and the flow of electrons neutralizes the electric field.
This flow of electrons through the lightning bolt creates a very hot plasma, as hot as 50,000 degrees, that emits a spectrum of electromagnetic energy. Some of this radiation is in the form of radio waves and gamma rays.
Instruments that measure these electromagnetic waves allow us to detect lightning bolts that are very far away. Visible light is also part of the spectrum of energy.
At these temperatures, laws of physics state that most of the visible light will be at a wavelength perceived as the color blue, although all wavelengths will be emitted.
The notion of color applies to our perception of what we see, not to the light itself. When we talk about the color of light, we really mean the color we sense with our eyes and then interpret with our mind.
Thus, while the peak energy is at blue wavelengths, the intensity of all the colors tends to saturate our eyes, leading us to perceive the color white – which includes all wavelengths in the visible spectrum.
Over the last 20 years scientists have discovered that lightning also shoots upward out of the top of thunderstorms into the upper atmosphere. These lightning types have distinctive colors, including red sprites and blue jets.
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Which are the places more likely to be struck by lightning?
The place most likely to be struck by lightning in the world is one spot above Lake Maracaibo in Venezuela, according to new data. Over this mountain lake, there was a lightning show an astounding 297 days out of 365 days a year, on average. Even more surprising, the lightning strikes didn't occur just over the massive lake, but at one particular spot -- the point where the lake empties into the Catatumbo River, researchers said Dec. 14 at the annual meeting of the American Geophysical Union.
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Upside-down lightning strikes exist and pose a great threat to wind turbines!
Upward lightning strikes initiate on the ground and head skyward. These discharges, which usually begin at the top of tall and slender structures, pose a real risk for wind turbines. An EPFL study analyzes the mechanisms underlying this poorly understood phenomenon.
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On July 13, 1977, New York City endured a 25-hour blackout after lightning strikes power lines.
On July 13, 1977, New York City endured a 25-hour blackout after lightning strikes power lines, prompting widespread arson, looting, and riots. The blackout was to many a metaphor for the gloom that had already settled on the city. An economic decline, coupled with rising crime rates and the panic-provoking (and paranoia-inducing) Son of Sam murders, had combined to make the late 1970s New York’s Dark Ages.
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…about the Rochester ice storm?
The 1991 Ice Storm was one of the most damaging storms in Rochester history. It all began 25 years ago on Thursday. We took a look back with a woman who experienced it herself. For residents in our area that were around, the ice storm that began 25 years ago was an event unlike most had ever seen before and the memories of that storm are still as vivid and fresh as they were in 1991.
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...that Lightning produces afterglow of gamma radiation?
Lightning can produce X-rays and gamma radiation. In the past, researchers thought that this phenomenon only lasted for a very short time, about a ten thousandth part of a second. However, the ionizing radiation of lightning appears to shine much longer than presumed: an afterglow of gamma radiation arises, which lasts up to 10,000 times longer. This is demonstrated for the first time by computer simulations of researchers from Centrum Wiskunde & Informatica (CWI) in Amsterdam. Their article 'TGF afterglows: a new radiation mechanism from thunderstorms' was published on 22 October 2017 in the scientific journal Geophysical Review Letters. This discovery can provide more insight into how lightning develops.
Terrestrial gamma flashes
‘Terrestrial gamma flashes’ were discovered about two decades ago. When lightning starts, electrons can be accelerated to very high energies, which cause an explosion of gamma radiation when these electrons crash into air molecules: the so-called terrestrial gamma flashes'. Bursts of up to a trillion (‘a billion billion’) gamma particles are measured on the ground, in airplanes and by satellites. However, these measurements are difficult, since these bursts are very focused and only last for a short time, around 0,0001 seconds. There is still much unknown about how these terrestrial gamma flashes arise and what their role is in the development of lightning. The now discovered afterglow helps to study this phenomenon.
Afterglow in all directions
CWI researcher Casper Rutjes explains what happens in the newly discovered radiation mechanism. “The radiation of a terrestrial gamma flash is so strong that nuclear reactions can take place. When the gamma rays hit the atomic nuclei of the air molecules, the protons and neutrons, of which atomic nuclei exist, can be detached. The loose neutrons can wander longer and farther than protons because they don’t have electrical charge. After a while, the neutron is captured by another atomic nucleus, which can again produce gamma radiation. The high energy of the gamma ray flash, which is used in releasing neutrons, is, so to speak, temporarily stored in the released neutrons.” The CWI researchers calculated that in this way an afterglow of new gamma radiation occurs, which lasts for 1,000 to 10,000 times longer than the gamma ray flash itself and which is not focused but radiates into all directions, which facilitates measurements.
Afterglow measured
The CWI researchers found in the scientific literature hardly any measurements that corresponded to the predictions, because almost no one was done on the right time scale. Researcher Casper Rutjes says: “Recently, our simulations have also been confirmed by experiments. Almost simultaneously, G.S. Bowers et al. of the University of California Santa Cruz, have measured a clear afterglow of gamma ray flashes in Japan, after a lightning bolt struck a wind turbine. That article, ‘Gamma-ray signatures of neutrons from a terrestrial gamma-ray flash’, also appeared now in the scientific journal Geophysical Review Letters.
Radiation risk
About the radiation risk Rutjes says: “The chance of being hit directly by a terrestrial gamma ray flash is very small. If someone in a plane is hit directly by such a narrow terrestrial gamma ray flash, this person will receive a radiation dose approximately equal to 400 times an X-ray picture (30 mSv)[1]. The afterglow that we discovered radiates into all directions, increasing the chance that a plane flying above a thunderstorm is hit, but fortunately, that radiation is much weaker. The radiation dose of the afterglow after lightning is not dangerous: less than passengers already receive through background radiation when they fly for an hour.”
The research was conducted by Casper Rutjes, Gabriel Diniz, Ivan Ferreira and Ute Ebert from Centrum Wiskunde & Informatica (CWI) in Amsterdam, and it was funded by the Netherlands Organisation for Scientific Research (NWO).
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Lightning can strike at sea!
In a rare incident of its kind, a coastguard diver and a citizen were killed after they were struck by a lightning bolt off Khairan beach of Kuwait on the 8th of May 2016.
The Interior Ministry said in a statement that a jet ski of citizen Saad Khaled Al-Shereeda broke down and a coastguard boat was dispatched to rescue him.
The ministry added that the coastguard diver, Abdullah Othman Al-Doussary, jumped in the water to help the man, but they were both struck by lightning and were killed instantly.
In October last year, an Asian was killed by lightning in northern Kuwait during a freak storm. It is estimated that 6,000 to as many as 24,000 people are killed around the world by lightning strikes every year.
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There are 5 ways to be struck by lightning!
1. Direct strike
2. Side flash
3. Ground current
4. Conduction
5.Streamers
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Tiny lightning bolt explosions can vaporise the moon’s thin soil
Mini-lightning may flash in the coldest craters on the moon, melting and vapourising soil. All that sparking could have altered the surface as much as impacts from incoming rocks and dust.
The outer layer of the moon is a sort of history book recording the interactions between the moon and the rest of the solar system. To correctly interpret that history, we need to understand the mechanisms that shape it.
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Planes get hit by lightning frequently!
Airplanes get hit by lightning mid-flight! Contrary to what you might believe, it’s a common occurrence on airplanes.
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Lightning bolt hit Vatican twice, hours after Pope's Benedict XVI's shock resignation.
Lightning bolt hit Vatican twice, hours after Pope's Benedict XVI's shock resignation. The lightning touched the roof of St. Peter's Basilica, one of the holiest Catholic churches, hours after Pope’s shock announcement. The spooky moment, believed by some, to be a sign from God, was caught on camera by AFP photographer Filippo Monteforte.
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Lightning caused deaths are fewer every year, at least in the US!
This decade will go down in weather history as one of the wildest in modern times. Since 2010, we’ve seen both the widest and strongest tornado on record touch down in Oklahoma. Mexico felt the wrath of the strongest hurricane ever recorded in terms of wind speed. The American West is enduring a years-long drought with no end in sight. But it’s not all bad news. This decade is also on track to see the lowest number of lightning deaths we’ve ever recorded in the United States, and that’s quite the accomplishment.
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Animals get struck by lightning, too.
Lightning strikes about 100 times every second of the day, mainly in warmer regions of the world. About 240,000 people are injured by lightning every year, and 24,000 die after being struck. But humans aren’t the only victims of lightning — animals are, too, though reports of such deaths are far rarer than the deaths themselves.
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Lightning protection tents exist!
The probability of getting struck by lightning is statistically very rare, but alas, storm-attributed deaths and injuries stretch into the low thousands on an annual basis. About 96% of those struck were in open environments when hit. A majority — as you may expect — come from frequent participators in outdoor activities such as hiking, camping, and climbing. Industrial designer kama jania’s ‘bolt’ line of tents was created to increase the safety of those unfortunate to be in the wrong place when the weather turns.
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..that ship-emitted particles and increase lightning?
MODERN, broad-beamed merchant vessels are well able to withstand the rough and tumble of the waves, but sailors still prefer to avoid storms at sea if they can. Containers may come loose in heavy weather and there is always a chance of lightning knocking out communications. It is therefore ironic that some storms may be caused by ships themselves. That, at least, is the conclusion reached by Joel Thornton of the University of Washington, in Seattle, and his colleagues in a paper just published in Geophysical Research Letters. They demonstrate that lightning strikes the Indian Ocean and the South China Sea almost twice as often along shipping lanes as it does other areas of these waters.
Dr Thornton and his team considered 1.5bn strikes recorded in this part of the world by the World Wide Lightning Location Network (an international collaboration led by Dr Thornton’s colleague, Robert Holzworth) between 2005 and 2016. As the map shows, those strikes that happened over the ocean were concentrated in places most plied by ships. In particular, the shipping lane that passes from the south of Sri Lanka to the northern entrance of the Straits of Malacca, and thence down the straits to Singapore, positively glows with lightning. (Its westward extension to the Suez canal was outside the study area.) So do the lanes from Singapore and the western part of Malaysia that head north-east across the South China Sea.
Neither changes in vertical wind shear nor differences in horizontal air movements seem likely to be causing this concentration of thunderstorms, for other measurements suggest that these weather-modifying phenomena are the same inside shipping lanes as they are in neighbouring parts of the atmosphere immediately outside those lanes. Nor does it seem plausible that the ships themselves (admittedly made of metal, and also the tallest structures on what is otherwise a flat surface) are responsible for attracting all the extra strikes involved. Though the area of the lanes is small compared with the whole ocean, it is vast compared with the area actually occupied by vessels. Most of the extra bolts are hitting the sea rather than craft sailing across it.
The most likely explanation is particulate pollution emitted by the ships using the shipping lanes. Marine diesel burned offshore is generally high in sulphur, and its combustion produces soluble oxides of that element which act as nuclei for the condensation of cloud-forming droplets. Typical marine clouds in unpolluted areas are composed of large droplets and do not rise to high altitude, but Dr Thornton and his team reckon that smaller droplets, of the sort that condense around oxides of sulphur, might more easily be carried upward by convection—forming, as they rose, into towering storm clouds that would act as nurseries of lightning bolts.
As to what can be done about this extra lightning, change may already be in hand. At the moment, standard “bunker” fuel has an average sulphur content of 2.7%. From 2020 that should fall to 0.5% if refiners and shipowners obey rules being introduced by the International Maritime Organisation, the body responsible for trying to impose order on the world’s shipping.
Ships are also being sailed more efficiently, often by slowing them down, which reduces the amount of fuel consumed per nautical mile. That is how Maersk Line—one of the world’s biggest container-ship operators—has cut its fleet’s fuel consumption by 42% since 2007.
On top of this, ship propulsion is becoming more efficient, as heat-recycling systems and new types of engine are introduced. In a few decades, therefore, the storminess of shipping lanes may have returned to normal. In the meantime, for any who may doubt humanity’s ability to affect the weather, Dr Thornton’s work provides strong evidence that it can.
This article appeared in the Science and technology section of the print edition under the headline "Brimstone and fire"
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A 36-year-old diver was killed after lightning struck his oxygen tank!
A 36-year-old diver was killed off a Florida beach after lightning struck his oxygen tank, authorities have said. The man was diving with three others off a boat near Deerfield Beach on Sunday. When he surfaced, ‘lighting struck his tank,’ said Deerfield Beach fire Chief Gary Fernaays. ‘He was approximately 30 feet from the boat at the time.’
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