HOW LIGHTNING WORKS - Weird World of Lightning

[Applause] how does lightning form as a strike up or down there are many outdated explanations is still scattered among whether science vlogs and whatnot exacerbating misunderstandings about lightning over the decades I've seen lightning do some freaky stuff in this video we're going to explore and explain the weird world of light thunderstorms have the ability to separate pools of positive and negative charges in and around them thus creating powerful electric fields lightning is born between two oppositely charged regions as a network of electrically conductive channels called leaders materialize and begin to tunnel a path through the poor conductive air in between think of leaders as a sort of jumper cable the leaders branch out in two directions each with opposite polarities toward both regions in an attempt to neutralize the charge separation most lightning flashes occur within the storm and are called cloud flashes or intra-cloud lightning but when one end of the bi-directional leader network connects to the ground or object on the ground we call it a ground flash or cloud to ground lightning CG for short in the most common CGS a negatively charged step leader approaches the ground the electric field between the step leader and the ground strengthens to the point that an oppositely charged positive leader begins reaching up bridging the gap between the two more than one upward leader may initiate an attempt to connect with the downward leader however the first to reach a downward propagating step leader will suddenly complete a channel path through the resisting air for the flow of powerful electrical current between the earth and cloud electrons then rapidly accelerate down the channel causing extreme heating and the brightest flash of the event this is the return stroke and rare photographs you can see failed upward connecting leaders that didn't reach the downward leader first and thus terminating into the air [Music] the leaders return stroke and all the complex components of a lightening event is simply called a flash the air around lightning becomes so hot that it explodes as a supersonic shockwave that transitions to an acoustic wave within a few meters this rapid expansion of air molecules creates sound waves that radiate outward about 1 mile every 5 seconds the sound we hear is thunder in this clip at 2,000 frames per second you'll notice two distinct types of leaders with different behavior you can see the positive end of a leader scouting a pathway through the air but notice the flickering segments that follow these leaders form on the decayed segments of highly branched positive leaders and are referred to as recoil leaders cloud-to-ground lightning strikes are characterized as positive or negative depending on the net charge of bolt shifts to the ground if a negative leader with a surplus of negatively charged electrons connects with the ground negative charge primarily in the form of three electrons is shifted toward the ground and the ground gains negative charge and so we call this flash a negative CG inversely if a positive leader with a deficit of electrons connects with the ground and induced surplus of electrons in the ground travel up the channel shifting negative charge away from the ground up into the storm the ground gains a net positive charge so we call this a positive CG sometimes you'll hear storm chasers and meteorologists identify negative C G's or positive C G's in the field so how can they tell the difference and why does it matter for starters if directly struck one could kill you and the other will likely kill you it's difficult to be a hundred percent sure eyeballing them but many positive CGS and negative C G's have visibly different behavior that you can see often after a negative CG return stroke multiple other return strokes follow causing the main channel to flicker this is called a multi stroke CG flash check out this multi stroke CG actually sailing the strong winds the strobing effect is partly due to the orientation of the charged regions in the storm most negative C G's initiate between a mid-level negatively charged region and a smaller positive charged region near the base of the storm but the return stroke of typical positive C G's rarely flicker many occur in a positive pool higher in the thunderstorm and the ground because of the greater distance the leaders have to blaze through the resisting air the return stroke of these positive C G's is often much hotter brighter and longer in duration the peak charge and positive CGS can be ten times more powerful than a typical negative CG and thus considerably more dangerous these are generally the most powerful CGS reaching temperatures up to thirty thousand degrees Celsius that's roughly five times hotter than the surface of our Sun positive C G's only account for about five to ten percent of all ground flashes worldwide but in Tornado Alley they are in a typically common sight I tend to see them just downstream of strong storm updrafts many of these positive CGS have a strange smooth and fluid channel near the ground due to a lack of branching and strong positive leaders we refer to this as smooth channel lightning the visible flash is often just the channel without any branching leaders and so it's sometimes referred to as branchless lightning but be assured there is leader branching it's just hidden in the clouds aloft sometimes a bolt of lightning can leap miles away from a storm jolting earthlings with surprise we call this a bolt from the blue outdated paradigms suggest that these clear air channels leaping out the back of storms were positive in polarity but the latest research using lightning mapping and high-speed cameras have shown most of these startling zaps are indeed negative if you capture a bolt from the blue and it has a lot of branching chances are it was a negative CG instead of a positive now that you know some different characteristics of positive and negative ground flashes see if you can tell if these CGS are likely positive or negative [Music] it's pretty easy to see these differences in slow motion now let's see if your eyes are quick enough to tell the difference in real time [Music] [Music] sometimes storms grow upscale in a massive complexes stretching across states these systems have horizontally layered charge regions that serves the conduit for lightning to travel over a hundred kilometers check out these massive horizontal flashes if these horizontally extensive flashes connect to the ground they are almost always positive in polarity they transfer huge amounts of charge it cause abrupt changes in the electric field which can trigger another flash and a sort of domino effect upward lightning travels up from tall objects on the ground into the storm and usually always have upward propagating positive leaders frequently these upward leaders will produce spectacular flickering from recoil leaders developing on decaying positive branches this is also called ground to cloud lightning almost all upward moving flashes are triggered by a nearby lightning flash either when leader activity or return stroke occurs close enough to the tall object causing an abrupt change in the electric field [Music] so if someone asks you this lightning strike up or down the answer is both if they ask you how lightning works just change the subject not only can massive horizontal ground flashes and trigger upward lightning they can act as the parent flashes triggering red sprites high above the thunderstorm in the mesosphere now that you have a general understanding of how lightning works and how one lightning flash can trigger another it'll be much more simple to understand red sprites guys I know there's a lot of health and economic concern out there right now and no shortage of scary headlines I'm gonna do my best to keep doing what I do as safely as I can and maybe at the very least I'll be able to provide some of you guys with a temporary distraction from the anxiety until this all blows over by showing you scary tornados in my next video we plan to showcase some incredible red sprites and discuss how these other transient luminous events work til next time friends happy trails

Channel: Pecos Hank

Views: 1,394,003

Keywords: how lightning works, how lightning works video, how lightning strikes, how lightning is formed, what causes lightning and thunder, how does lightning form, how lightning is made, how lightning starts, how lightning is caused, how does lightning work, lightning physics, the science of lightning, lightning, lightning pecos hank, lightning explained, lightning educational video, lightning science, science, how lightning travels, lightning strikes, lightning slow motion

Id: JXhif3E3l2s

Length: 10min 59sec (659 seconds)

Published: Thu Mar 26 2020