As the heatwave began and developed during July, each day we, the population of the UK, cringed in fear that it would break and start to rain thereafter, as had happened so miserably in the previous year. But it went on, and on, and on. The met Office say it was the hottest July recorded in Scotland. And even after fierce thunderstorms hit at the end of the month, the heatwave continued in the South East of England with temperatures reaching 33 degrees celsius on 1st August.
We are not used to thunderstorms here in the Scottish Borders, certainly none so violent as hit much of the UK on the 19th/20th July. I have never taken an interest in such amazing events and how they happen. I have read explanations and still must go back to a glossary of definitions to make it meaningful to me. So I write this at a simple level such that I can look up at the sky and recognise the signs of an imminent storm.
As Mary Wollstenecraft Shelley brilliantly wrote ‘Frankenstein’ in 1818, she already foresaw the power of science and the power of Nature in thunderstorms. She also foresaw how the product of understanding Nature through scientific enquiry might lead to misuse and result in the destruction of society.
The relationship between physical phenomenon such as electricity, and magnetism has been theorised upon as far back as ancient Greek philosophical enquiry.
What is stuff composed of? What is the structure of material objects? Is there a basic unit from which all objects are made? As early as 400 B.C., some Greek philosophers proposed that matter is made of indivisible building blocks known as atomos. (Atomos in Greek means indivisible.) To these early Greeks, matter could not be continuously broken down and divided indefinitely. Rather, there was a basic unit or building block that was indivisible and foundational to its structure. This indivisible building block of which all matter was composed became known as the atom.
……….English scientist J.J. Thomson’s cathode ray experiments (end of the 19th century) led to the discovery of the negatively charged electron and the first ideas of the structure of these indivisible atoms. Thomson proposed the Plum Pudding Model, suggesting that an atom’s structure resembles the favorite English dessert – plum pudding. The raisins dispersed amidst the plum pudding are analogous to negatively charged electrons immersed in a sea of positive charge.
And as recently as 1991 http://en.wikipedia.org/wiki/Terrestrial_gamma-ray_flash
we are learning about Terestrial Gamma-ray Flashes
Terrestrial gamma-ray flashes were first discovered in 1991 by BATSE, or Burst and Transient Source Experiment, on the Compton Gamma-Ray Observatory, a NASA spacecraft. A subsequent study from Stanford University in 1996 linked a TGF to an individual lightning strike occurring within a few ms of the TGF. BATSE detected only a small number of TGF events in nine years (76), due to its having been constructed to study gamma rays from outer space, which last much longer.
The newer RHESSI satellite has observed TGFs with much higher energies than those recorded by BATSE. In addition, the new observations show that approximately 50 TGFs occur each day, more than previously thought but still only representing a very small fraction of the total lightning on Earth (3-4 million lightning events per day on average). However, the number may be much higher than that due to the possibility of flashes in the form of narrow beams that would be difficult to detect, or the possibility that a large number of TGFs may be generated at altitudes too low for the gamma rays to escape the atmosphere.
……The role of TGFs and their relationship to lightning remains a subject of ongoing scientific study.
In Japan, a group of researchers noted the rings of ancient cedar trees revealed a rare event around 774 or 775 A.D. There was evidence of a sharp rise in the amount of radioactive carbon-14 and beryllium-10 which can be created by incoming particles from space. Trying to work out what might have happened back then, two astronomers Valeri Hambaryan and Ralph Neuhauser of the Astrophysics Institute of the University of Jena in Germany, think it was a gamma-ray burst. These bursts can be caused when two compact objects, such as black holes or neutron stars, slam into each other and release a flood of high-energy gamma-ray radiation. The researchers calculated that a gamma-ray burst at a distance of 3,000 and 12,000 light-years from Earth best fits the data.
“If the gamma-ray burst had been much closer to the Earth it would have caused significant harm to the biosphere,” Neuhauser said in a statement. “But even thousands of light-years away, a similar event today could cause havoc with the sensitive electronic systems that advanced societies have come to depend on.”
My use of the ‘gamma ray’ was more from the literary world of Science Fiction. I remember The Incredible Hulk series which my children loved. It was dreamed up by comic book legend Stan Lee, where the kind hero turns into a massive, super strong and green giant, due to receiving a mega dose of the otherwise deadly gamma radiation.3.
So Thunderstorms still fascinate scientists and novelists alike. There is obviously much more to be learned from these powerful forces within the clouds above us.
As headlines such as:
UK Weather: Heatwave To End This Weekend With Thunderstorms And Heavy Rain
became the norm, I watched the The Boltek PCI StormTracker output on the Isle of Wight Storm Data website http://www.isleofwightweather.co.uk/live_storm_data.htm. At the time the storms were all over France and other parts of Europe, but moving in toward the isle of Wight. As they hit England, I watched the amazing number of lighning strikes as the storm tracked north. It took until the next evening to move to Scotland. The strike data was in the hundreds. It was a massive storm. Above the UK a giant cloud factory was moving over, a ‘cumulonimbus’ the weathermen name this phenomenon. The appearance can be that of an anvil, which all pilots of aircraft are warned to avoid. As the storms lasted for hours, we can assume there were numerous cumulonimbus present.
Electrons are the fundamental sub-atomic particles carrying a negative electric charge which move incredibly fast when lightning occurs as the path around them glows. An atom contains a Proton which has a positive charge, a Neutron which has no charge, and an Electron which has a negative charge. Electrons cling to the positively charged centre of the atom because they have a negative electrical charge. During a thunderstom, some of the atoms in the cloud lose their electrons and the others gain extra ones. Water droplets form inside a storm cloud. A strong updraught of wind within the cloud directs the water droplets upward where they turn into ice. This ice can be very small or can grow very large. The larger pieces fall back down colliding with the smaller ice moving upward; this causes a transfer of a negative charge of some electrons to the hail and ice The small particles which have lost electrons gain a positive charge and as they move upward the top of the cloud is given a positive charge. The heavier, negatively charged ice hangs in the lower part of the cloud. Positive and negative atoms create lightning when they are attracted in a path toward one another.
The negative charges in the base of the cloud repel the electrons near the ground’s surface, leaving a positive charge on the ground and objects thereon. Electrons shoot down from the cloud in a path spreading in different directions, called a stepped leader. The average speed of this branching path through the air is 270,000 miles per hour!
A friend living in London spoke of her fear as massive hailstones hit her loft apartment skylight. She was sure the glass must break, but thankfully it held.
In my case, one of my elderly dogs had an urgent need for the garden to do her toilet. The storm was directly overhead but I had to rush out with her, no time for putting on my wellingtons. As I stood in the rain helping her an almighty flash of lightning struck down around me and I must have been so close to being hit. Instead it struck our phone and rendered it useless. I had not disconnected it as we found out later we should have done. Then there was an ear splitting crack of thunder which was truly frightening, though thunder can’t hurt it can certainly frighten. Some young lad was trying to take a photo of the lightning with his mobile device, about 20 miles from us. His phone was struck and destroyed, and he suffered paralysis for 24 hours. The only reason he was not dead was that he, by chance, was standing on a rubber mat at the time!
By 10th to 12th August we were still gazing at the heavens for another reason, The magnificent annual occurrence of the Perseid Meteor Shower. Marvellous timelapse images were made available on the Internet, such as ‘Universe Today’ said this
We’re still swooning over the great images and videos coming in from this year’s Perseid Meteor Shower. Here are a couple of timelapse videos just in today: the first is from P-M Hedén showing 25 Perseid meteors, but you can also see Noctilucent clouds, a faint Aurora Borealis, airglow, satellites passing over and lightning. “It was a magic night!,” P-M said.
It was amazing to watch from here in the Scottish Borders as we have Dark Skies status. Monday, the 12th was the best night to see as many as 10 bursts in 4 seconds at times. To think this “Swift-Tuttle” named comet has supplied us with this display since it was first recorded in 36AD. It appears to radiate from the constellation Perseus, and indeed, time lapse images over a long period show a concentric image of bursts with the centre being Perseus. Lewis Swift and Horace Tuttle named the comet in 1862. Every August we can expect to see the debris as it comes close to the sun and leaves a trail, but this year it passed closer so that we got an exceptionally great display. It last did this in 1992 and will again in 2025. I do not remember seeing or hearing about it in 1992, but then we did not have an educative internet so fine tuned in those days. I also lived in a city where the thought of Dark Skies was unimaginable.
To me the most dramatic and favourite picture of mine is of the Lindisfarne Castle at Holy Island, taken by Peter Greig (http://www.flickr.com). It makes us realise how spiritually meaningful it must have seemed to those who saw this so many centuries ago. The fact it came around each year would have been used by the observant to warn of omens or derive some benefit for people to whom they ‘prophesised’ the coming of the event.
Whether we choose to be scientific or not, no-one can deny the uplifting sight of something so indescribably beautiful as the Milky Way above and the streaking, sudden unexpected balls of light hurtling at great speeds from so many directions which are the Perseid Meteor Shower. For all of you still around in 2025, be sure not to miss it and try to remember this night in 2013.