Author Topic: Does lightning strike twice in the same place  (Read 10523 times)

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Offline Craig Eccles

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Does lightning strike twice in the same place
« on: 30 January 2011, 05:14:25 PM »
Its always been a myth, does anyone have photographic evidence that lightning does strike the same place twice. I have the pics to prove it. Please give me your thoughts.
« Last Edit: 30 January 2011, 06:35:01 PM by Craig Eccles »
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Offline Jimmy Deguara

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Re: Does lightning strike twice in the same place
« Reply #1 on: 30 January 2011, 06:00:59 PM »
Hi Craig,

Welcome to the forum. It is not impossible for lightning to strike the same place twice but highly unusual I guess.

Can't wait to see your pictures.

Regards,

Jimmy Deguara
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Offline Richary

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Re: Does lightning strike twice in the same place
« Reply #2 on: 30 January 2011, 06:41:08 PM »
I don't have photographic evidence, but remember from my times near Lismore as a teenager that the hill over the valley regularly got struck in the one storm and it looked like the same tree was copping it from my vantage point. Also I recall seeing timelapse on the TV news that shows one of the Harbour Bridge pylons getting hit more than once in the one storm.

Offline Mike

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Re: Does lightning strike twice in the same place
« Reply #3 on: 31 January 2011, 07:00:47 AM »
Welcome Craig and a neat first post!

Lightning does and can strike the same location or object more than once.  There is a vast difference between lightning flashes that pulse (as we see it) to actual repeated hits to one thing.  The so-called myth is spun rom when we see lightning strikes that pulse several times at the time of observation.  In essence this looks as if it is striking several times, but it is not, it is the return strokes that illuminate the channel as the thunderstorm discharges its energy earthward.

What your images show are lightning flashes that are simply striking in the same area, not necessarily the same object again and again.   Lightning that in fact strikes the same object repeatedly - aka the first stike was completed with return stroke{s} and finishes, then another new flash strikes the same object again some seconds later even from a discharge not close to the object.  Video footage would have been more of assistance for obvious reasons!

Scientists refer to a lightning strike as a 'flash' because that's technically what it is as we cannot see the initial 'strike' becuase it happens so fast to the naked eye.   So just to give some info on this...

Thunderstorms have three regions of charge.  Positive at the base, negative in the middle and positive in the upper regions, BUT they have the ability to reverse their polarity due to certain lightning strikes, either - or +.  A large percentage of lightning is +, regardless of where you see it eminate.  Only with polarity instruments and other devices can you determine what charge type it is - visually you can ascertain that if it eminates from the top of the storm it is more likely + etc, etc because that's where the pool of + charge is carried during a storm's lifecycle.  So in fact a visible lightning strike may well be originally + but secondary strokes may be - and so on!

There are several types of leaders that initiate a flash..or strike.  Stepped leaders, connecting leaders, recoil leaders, dart leaders, avalanches, and with all sorts of other phenomena such as trident leaders etc that can determine what type of flash it was and the list goes on...still images can tell us what type of polarity it is, although quite difficult depending on how much leader movement/direction is captured.  

Step leaders originate anywhere surrounding a thunderstorm, whether it be below, to the sides - whatever.  They dart out for a distance of about 100m then dissipate, with othe leaders doing the same thing thousands of milliseconds in time...so these are the things we cannot see whilst we're out there in the open taking photos!

If a favorable path is found then during the return phase of the leader another leader takes its place and deepens the channel left by the previous one...kind of like drilling a channel in the air...one leader searches, leaves an empty canal and another leader may seize the opportunity and follow the same path. This continues right through the leader phase, and happens in hundreds of areas around the storm.  Every intracloud or cloud base flash you see are these leaders punching their way ever so closer to ground, which is why I never stand out in the open taking photos...ever.

When these leaders reach about 100-200m above the ground a positive upward leader from earth reaches up towards this downward leader whereby a connecting leader completes the connection.   The connection is made (something we do not see)and a return stroke discharging from the storm is seen, any subsequent pulses we see are repetetive return strokes from the storm to ground.  This can be as little as one discharge or up to 14.  Of course we may only see up to 5 or 6 bright return strokes but in actual fact it is much higher and high speed footage of more than 1500fps shows this.  ANY object in the vicinity can be the connecting point.  Throw out any misunderstandings that only tall objects get hit first, whilst they are more 'prone'to being a target, even your belt buckle or a rock next to your foot can be the targetted point of downward leaders...what makest he difference is whether the upward leader is strong enough to complete the connection.  If the tree next to you does not have a strong upward leader then the old saying goes - the path of least resistence applies - so your shiny new watch or the fence in front of you certainly may have just what the downward leader is looking for!

I must add that I used to always stand out in the field taking photos...but since doing research on lightning there is absolutely no way in hell I stand out in the open if I can hear thunder or see lightning.  As a lightning photographer I love being in the elements, but recent education and information from lightning physicists overseas has changed my outlook forever!

anyway...not to waffle to much...

In essence a lightning flash will indeed strike the same object twice if favorable conditions surround that same thing polarity wise.  An electric field surrouns all things on this planet, no matter how small or large, how many times it gets struck is another matter!  As mentioned earlier, tall objects are likely to get hit first - so if you are out in the bush try and find trees of similar height and stand under those but some distance from the tree next to you!   Evidence as found that tall structures can protect each other from being hit. Some objects may be struck more times than a taller object next to it, which goes against the grain, but they have found that the electric field surrounding these objects (towers, communication antenna etc) actually repel any strikes because the polarity (like a magnet) is +,+ or -,- rather than -.+ so the connection is obviously favorable.

When lightning strikes the same region several times, such as your images show, that's something quite normal.  I have seen large - and + CG's from the top of a thunderstorm dome strike the same region 12 times - repeatedly.  Something I have never seen before.  So many long dog leg discharges to the same area non-stop...incredible.

anyway hope this helps dispell any gossip!



 
 
« Last Edit: 07 February 2011, 05:53:33 AM by Mike »
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Offline rogeressig

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Re: Does lightning strike twice in the same place
« Reply #4 on: 31 January 2011, 01:49:05 PM »
hi there, this video i took last april shows at the 0.36 mark what appears to be lightning striking twice.

Frankston Storm Chase, lightning sequences 250fps April 2010, Roger Anthony Essig

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Re: Does lightning strike twice in the same place
« Reply #5 on: 31 January 2011, 01:52:23 PM »
also check out this video! (not mine)

Lightning Storm and Cloud Timelapse (HD 1080p)

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Re: Does lightning strike twice in the same place
« Reply #6 on: 31 January 2011, 10:05:36 PM »
Like I commented...it is the return strokes that you see.  The video confirms this.  It does not matter how long between strobes, the channel is still active and charged.  The average strike or flash only takes 1/2 a millisecond, the average bolt lasts about a second in actual time to the human eye.  The flash can use the old channel if dart leaders participate further, otherwise new flashes will occur with new channels.
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Offline Mike

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Re: Does lightning strike twice in the same place
« Reply #7 on: 01 February 2011, 09:44:16 PM »
Sorry but the two images don't show anything striking the powerline pole.  The strikes are behind it and target different areas.  It is easy to think that they are hitting poles, it's just the perspective of the things.  I've included a recent strike which looks like it comes off the communication tower but in actual fact this strike was several km's in the background.



Here's a photo which actually shows several things previously mentioned with - and + flashes in the one bolt.  Slight movement of the camera during the capture actually shows distinct polarity for the lightning.  Even though it is a single snapshot, the slight blurr from the camera actually highlights both types of strike with positive leaders.  I did not know this until a friend in the USA disected the image!

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Offline Mike

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Re: Does lightning strike twice in the same place
« Reply #8 on: 07 February 2011, 05:46:40 AM »
This is probably the most insane video I've seen of a close strike.  It was filmed by two friends here in Darwin whilst chasing rural.  What is significant, and which ultimately swayed my decision re standing out in the open whllst photographing lightning is the info gained from experts on the video.

I sent this video to Tom Warner in the US, who is a Phd in lightning physics and assisting me in my own research.  What he found out is that there was an audible pop just prior to the actual strike grounding.  Colleagues of his determined that this popping sound was in actual fact an aborted upward leader discarded by the downward leader channel to complete the connection and the location of this upward leaders was in fact the barbed wire fence in front of the photographer!  She was milliseconds from being struck. Period.

You can see the raised dust from the actual strike grounding in the field...insane.

This video should highlight the real danger of standing anywhere around a thunderstorm in the open, regardless of where you are.  Upward leaders from ground originate from anything and anywhere....you cannot see them and are rarely captured.

The scientists who viewed this footage agreed that the photographers WERE the initial targets for the leader, but the leader from the fenceline was rejected for a leader behind the tree.  The pop you can hear prior the strike is weak thunder produced by the upward leader.

Enjoy!

Close positive CG!


Just to add something to this...(photos courtesy Jacci Ingham)







There was a storm set last week here in Darwin and about 15 strikes eminated from a region close to the top of the storm.  Now, general concencous is that all lightning coming from the tops of storms is + in polarity.  This is not so due to not knowing the actual polarity of the entire storm itself at the time.  I have mentioned somewhere here that storms are typically +. - and + in polarity.  Bolts from the Blue daytime or night are concieved to be + in polarity.  The images above (used with permission) was one of several taken by chasers and myself around the rural area.  There was some heated debate about whether or not this is a positive strike or negative strike.  After much arguing with nameless people and information from experts in the US, this image, and the six I sent ( of crap quality due to being at work and distance) revealed they are in fact negative strikes.  Althogh they appear to be from the top of the storm, in fact they are exiting the central region of the storm which is the negative pool of charge.

Thunderstorms can and do change polarity from tripolar to unipolar and bipolar and inverted polarity.  One strike can change the electrical field surrounding a storm and then return it to the norm.  So for information sake, any large dog leg you see may well not be positive in charge ;)  Generally positive charged strikes are in the dissipating stage of the storm where the net negative pool is diminished through lifecycle of the storm and the only charge left is positive aloft.  But bear in mind that different storms carry differing charges...location, storm type, atmospherics etc all play an important role as to what the storm will produce lightning wise.  Winter storms generally are + charged, whereas sumer storms are the opposite.  Less than 10% of lightning is positively charged worldwide, so they are not that common.

i was sent a Google map overlay with lightning strike data from Tom Warner re the night in question re these storms and they were all negative strikes with only a few positive types recorded by WLDN.  He was a little suspicious, but agreed that the majority of the strikes were negative at that time re the photo.
« Last Edit: 07 February 2011, 06:07:57 AM by Mike »
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Offline Chris.

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Re: Does lightning strike twice in the same place
« Reply #9 on: 08 February 2011, 01:59:22 AM »
That is just insane!!

Yes, you can hear the pop for sure!

So essentially, we humans form a part of the electric field if we are standing in the open near or under a thunderstorm Mike? More so than a metal object, fence line etc??



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Re: Does lightning strike twice in the same place
« Reply #10 on: 08 February 2011, 09:38:30 AM »
Exactly.

The electrical field is just enhanced during thunderstorm activity surrounding you...which is why people with long hair find it standing straight up in hot humid environments in stormy weather.  Static.  

Thunderstorms have a huge electrical field, but lightning grounds only when the charge is at a maximum at that very point underneath or nearby.  Which is why they send up those copper wires attached to rockets into storms at a given moment.  They will wait until the charge is maximised and fire them up promoting a connection...akin to cheating....they will give the leaders something to target and use the copper wire as an upward leader.

Upward leaders, because they are unseen to the naked eye can be captured by still and video - moreso with high speed units naturally - but they are there.  Lightning is 'small' in comparison to the storm's size for example, no wider than 5cm or so, so it's not big and fat - that's just the optical thing of the return stroke(s) and distance.  It's the downward propogating leaders which are the fascinating thing.  Everytime you see a flash in the cloud or below these could be either one, two or hundreds of stepped leaders searching...they move in all directions, darting out, retreating, changing direction, appearing in a totally different region - all continuous, all unseen.  You'll see what I mean with this link from Tom Warner from South Dakota who recently completed his PhD in lightning physics.  He's done some incredible work with high speed filming and Martin Uman, one of the world prioneers in lightning research works closely with Tom.  Tom is an expert on upward leader lightning and films mostly between 1500-74,000 fps using Phantom cameras.

You can go through his videos in the archive menu on the lower RHS.  You will note in this video linked the thousands of leaders flickering away...this is the stuff you cannot see during the day or night...these are the things that search for something to connect with!

http://ztresearch.blogspot.com/2010_05_01_archive.html

and from Tom's home page...a CG in high speed...you will see the leaders doing their thing...fascinating!

http://www.ztresearch.com/

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Offline Michael Bath

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Re: Does lightning strike twice in the same place
« Reply #11 on: 09 February 2011, 04:00:27 AM »
The thread has been very informative Mike - thanks for posting what you've been learning. A fascinating subject.

I'm not sure it will change the way I take pictures of storms though. The risks are always in the back of your mind and sometimes it does feel a lot more risky than other situations. The whole act of storm chasing is risky.


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Couldn't resist ... imagine if the car was going 88 mph  :)

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A vehicle is struck by lightning while driving 75 mph on I-90 east of Rapid City, SD on 9/11/09. The 20 second exposure from a digital still camera shows the moment when the bright return stroke illuminated the vehicle and water spray kicked up from the rain-soaked road. The bright lines from the wheel wells shows that the current from the lightning strike arced to ground from the vehicle rims.

.... might have sent him back to the future
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Offline Mike

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Re: Does lightning strike twice in the same place
« Reply #12 on: 09 February 2011, 04:51:47 PM »
Yeah is an amazing capture.  Tom always remains in his van...mainly due to the plethora of video and camera equipment!  Usually nowadays when I set up I will hang about for a bit, but if the lightning is coming close or there's thunder overhead I have to admit I stay in the car.  Not for wanting to be out in the elements...love that bit of it...but just won't risk it albeit the odds are somewhat 1:400,999 of being struck.  So much has come since the early days eh Michael - am loving the challenge this is bringing.

Here's two photos for comparison from a few weeks back.  Storm was about 70km from me and had some pesky weeds and stuff hindering my view so I deliberately kept the exposure times down, the other is from Jacci Ingham who was a lot closer! They are the same storm and show negative flashes even though they come close to the storm's crown.  I thought they were positive flashes, alas not to be!  Just goesto show that those big dog legs are not what they seem.  From reading articles, positive lightning accounts for less than 10% of all lightning worldwide.  It is not that common but winter based storms appear to be of that polarity due to the storms' makeup and high volume of water droplets.   Might be something worth looking into through lightning detection networks as to whether NSW/ QLD etc have more + flashes also.



(photo courtesy Jacci Ingham)



Tom provided me with a googlemap overlay with lightning data from WLDN from 10pm 30Jan to 10am 31Jan 2011, all strikes in the NT were - polarity.  Although he was sure some positive flashes occured, he was checking the data with the provider, but def said that these were negative based flashes.  Learn something every day!

« Last Edit: 09 February 2011, 05:05:47 PM by Mike »
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Offline Chris.

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Re: Does lightning strike twice in the same place
« Reply #13 on: 09 February 2011, 06:55:12 PM »
Fascinating Mike, very grateful for the info and I now have a much better understanding myself of the risks involved i can help explain to fellow photographers who are unaware or have very little understanding of the risks while photographing storms.

I certainly take too many risks and have had a few experiences as I am sure many, including yourself, have.

Also, I wanted to ask, you seem disappointed the flashes in both yours and Jacci's image are not positive, although you thought they were. Is that because they were close to the positive upper regions? was there no other way of telling?. Is it only the rarity of the capture or is there something else more important like the severity of the storm or amount of ice that makes a positive flash more significant?

Re the topic, I found two images taken of the same storm where it appears the lightning is striking in the same place.
« Last Edit: 09 February 2011, 07:08:49 PM by Chris. »

Offline Mike

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Re: Does lightning strike twice in the same place
« Reply #14 on: 10 February 2011, 04:06:38 AM »
Hi, Chris.

Re the positive flashes.  No, it does not make any difference to me what polarity the lightning is when photographing - well, it never used to be!  The misonception is that all big dog leg or similar flashes are positive in polarity because of what you mentioned, being at the top of the storm.   Sure there is a positive pool aloft, but where does it originate inside the storm?  Did a negative leader shoot vertical and then outward?  Was it a negative upward leader that connected? And so on...not knowing 'where' the leader started from within the cloud is something I posed to Prof Earl Williams.  In the easrly days i sent him some images of what i thought was positive lightning - he wanted proof or data to show him they were positive, because they are not all that frequent in storms.  That's not to say storms don't produce them, they do, just not that regularly and if they did they could be intracloud flashes or flashes you can't because of cloud or rain...remember that this does not necessarily mean that some of these large leaping bolts are not positive...they def can be!

You can tell by looking at the image what type it could be, there are things called M components, the structure of the branching, the tips of the leaders, their actual direction...so indeed, one can tell but it takes a little expertise to do that.  

The hardest thing is to break the misinterpretation of what people are seeing.  A lot of research has been done since the early days and people are kinda stuck in that mindset that everything coming from the upper regions is positive, the photos i added actually show the flash exiting the middle portion of the storm which gave it away. I've taken heaps of positive lightning, as have most people, we just don't know it.  We all think that cloud based lightning is negative...yeah most often it is, but....did the leader start at the base of the storm (+) or inside it (-)...the same problem sticks its head out.

Your images show two flashes and they are grounding in the same location, not the same spot.  It's not uncommon for this to happen. A location will get belted by several strikes, but in the same actual spot by millimeters, unlikely.  When i replied to lightning hitting the same thing twice, yes it does, but with return strokes first and then can be hit again several seconds later...these are usually communication towers and the like which are high targets because their charge is enhanced at their tips.  Objects at ground level are rarely hit more than once because there are more targets to choose from but most are at the same level height wise.  If you do see lightning hitting the same region more than once that is just showing you an enhanced highly charged region as the storm moves over the top of it.  A thunderstorm does that, it acts like a generator to things it passes over.  Why some objects produce upward leaders and some don't is complicated!

Here's a good photo I took.  Is it positive or negative looking at it's location?  Truth be known it is negative.  Another chaser was several km's past me and took a full framed image of this storm.  It produced two large 'dog legs' from the negative pool in the middle of the storm, but these punched through the outflow flanking region of the storm.  So, in my eyes this would be a positive strike because as far as I can see it came from that lower region right?  Wrong!

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