Lightning comes in all shapes and forms, it is a highly complex series of events to which to the naked eye we only see an end result...


This page has been updated Feb 2011


 Mr Site Takeaway Website. Build a professional website in minutes.

Mention StormscapesDarwin.com when you order your website! 

* Remember, Lightning is the number one killer of people in storms.  You can be struck anytime, anywhere many miles from the storm itself..  Don't take unnecessary risks just for a photo - stay in the car or seek shelter out of the storm.


 

LIGHTNING:  THE TYPES, HOW AND

WHY

 


 

LIGHTNING IS ONE OF NATURE'S NATURAL FIREWORKS DISPLAY.   LIGHTNING PLAYS AN IMPORTANT ROLE IN THE EARTH'S TEMPERATURE AND MAGNETIC FIELD.  I'VE FOUND MYSELF TO BE TOTALLY IMMERSED AND OBSESSED WITH SUCH PHENOMENA, A JOURNEY THUS FAR THAT HAS BEEEN VERY REWARDING AND LIFE CHANGING.  I HOPE YOU GAIN SOME INSIGHT AND EDUCATION FROM THIS PAGE.  MY SOLE PURPOSE FOR PHOTOGRAPHING LIGHTNING IS TO CAPTURE ITS RAW POWER, AT THE MOMENT.  TO FREEZE IT IN TIME.

 

 

 

 
CLOUD TO GROUND LIGHTNING

 



CLOUD TO GROUND LIGHTNING OR CG'S AS THEY ARE KNOWN ARE DISCHARGES VISUALLY SEEN BY THE HUMAN EYE EXITING ANY REGION OF THE STORM CLOUD, WHETHER THEY BE BENEATH, TO THE SIDE BUT WHICH CONTACT GROUND.  THEY CAN BE EITHER POSITIVE OR NEGATIVE IN POLARITY AND IN THE GENERAL OVERVIEW IT IS THE RETURN STROKE THAT WE SEE VISUALLY.  POSITIVE DISCHARGES TEND TO RETURN STROKE LESS, NO MORE THAN USUALLY THREE TIMES.  POSITIVE LIGHTNING ACCOUNTS FOR LESSTHAN 10% OF ALL LIGHTNING WORLDWIDE, SO IT IS NOT THAT COMMON COMPARED TO NEGATIVE TYPE DISCHARGES OR FLASHES.

BECAUSE WE ARE UNABLE TO DETERMINE THE EXACT INITIATION POINT OF A LIGHTNING STRIKE IT IS DIFFICULT TO DETERMINE BY PURE STILL IMAGE WHAT POLARITY IN FACT IT IS.  THERE ARE MANY FACTORS THAT MAKE UP LIGHTNING AND NOT ALL LARGE LIGHTNING STRIKES FROM THE UPPER REGIONS ARE POSITIVE IN POLARITY.  THE USE OF HIGH SPEED VIDEO CAPTURE, LIGHTNING DETECTION DATA AND A RANGE OF OTHER RESOURCES CAN ONE PINPOINT A STRIKE'S EXACXT POLARITY.

VISUAL ANALYSIS OF STILL IMAGES CAN IN FACT BE DECIPHERED AS TO WHAT TYPE OF DISCHARGE IT WAS, BUT THIS IS AN EXPERT FIELD WHICH REQUIRES A GOOD  KNOWLEDGE OF LIGHTNING PHYSICS, BUT  WITH A LITTLE HOMEWORK YOU CAN PICK TELL TALE SIGNS.  IT'S NOT AN IMPORTANT ISSUE IF YOU ARE JUST AFTER THE PHOTOGRAPH OF COURSE, BUT FOR THOSE OF YOU THAT WANT TO DELVE A LITTLE DEEPER IT'S QUITE A FASCINATING FIELD!

 SEVERAL TYPES OF CG LIGHTNING

 

 

 


 

 


 

BOLTS FROM THE BLUE

THIS TYPE OF LIGHTING IS THE TYPE THAT LEAPS OUT HORIZONTALLY FROM THE MID-SECTION OR UPPER REGIONS OF THE STORM AND TRAVELS DOWNWARD TO GROUND AND ARE VERY LONG IN LENGTH, TYPICALLY THE DISTANCE OF THE STORM VERTICALLY..   THEY SEEM TO COME OUT OF NOWHERE, HENCE THEIR NAME.  IT IS THOUGHT THAT ALL THESE TYPES OF STROKES ARE POSITIVE IN POLARITY, THIS IS INCORRECT.  RESEARCH OVER THE YEARS HAS PROVED WITHOUT A DOUBT THAT THEY ARE GENERALLY NEGATIVE STRIKES - BUT GIVEN THE POSITIVE POOL OF CHARGE IS IN THE REGIONS ALOFT, THERE IS UNDOUBTEDLY POSITIVE DISCHARGES.  

  THE DISPERTION OF LIGHTNING THROUGH ITS CYCLE WITHIN A STORM CLOUD BEGINS AT THE LOWER REGIONS, IT THEN TRAVELS VERTICALLY UP THROUGH THE CORE OF THE STORM AND WHEN IT REACHES THE UPPER REGIONS OF THE STORM, PARTICULARLY THE ANVIL AREA, THE LIGHTNING WILL MOVE HORIZONTALLY IN BOTH DIRECTIONS.   DISCHARGES CAN BE ANYWHERE WITHIN THE STORM, SO VALIDATING IT'S TYPE IS DIFFICULT BECAUE YOU CANNOT SEE WHERE IT STARTED OR WHAT STARTED IT.

POSITIVE LIGHTNING CARRIES AN ENORMOUSLY LARGER CHARGE.  FOR THIS REASON IT IS HIGHLY ADVISED NOT TO STAND OUT IN THE OPEN DURING A THUNDERSTORM.  IN REALITY THE RULE OF THUMB IS NOT TO DO IT ANYWAY, BUT STANDING UNDER THE ANVIL REGION IS ASKING FOR TROUBLE GIVEN A LARGER AMPERAGE IS AVAILABLE TO THE STORM TO DISCHARGE.

 LIGHTNING CAN AND WILL STRIKE ANY OBJECT, NO MATTER HOW SHORT OR TALL SURROUNDING YOU.  IT IS NOT THE DOWNWARD LEADER THAT IS YOUR PROBLEM, IT'S THE POSITIVE UPWARD LEADER FROM OBJECTS SURROUNDING YOU THAT ARE THE TARGET FOR THE DOWNWARD LEADERS.  YOU CANNOT SEE THEM WHICH MAKES IT MORESO DANGEROUS TO BE OUTSIDE.  THESE LEADERS EMINATE FROM AN ENAHNCED ELECTRICAL CHARGE AREA UNDERNEATH THE STORM, SO IF YOU ARE IN THE VICINITY CHANCES ARE YOU COULD BE A TARGET.




HIGH SPEED VIDEO FOOTAGE HAS IN RECENT YEARS BEEN AN ASTOUNDING TOOL IN WATCHING HOW LIGHTNING IS CREATED AND HOW IT WORKS.  TOM WARNER FROM THE USA IS A WORLD AUTHORITY IN THIS FIELD AND I HIGHLY RECOMMEND YOU VIEWING HIS SITE.


  Credited to http://smh.com.au/ and shows what happens when lightning strikes 20 feet away.  Check the step leader in the trees!

 

 
A shot that I captured of a pulsing cloud to ground strike. During this storm off the marina in Darwin the storm produced some wonderful strikes but this one was very close and pulsed several times.




 

ANVIL  CRAWLER  OR  SPIDER LIGHTNING

Anvil lightning happens during the dying or dissipating stage of the thunderstorm.  As the updraught pushes the cloud top to the upper regions of the atmosphere the cloud cap spreads out laterally and the discharges 'crawl' underneath the anvil.

  This lightning is also called 'spider' or 'crawlers' and is excellent to view as it is a lot slower in motion compared to single bolts.  Anvil lightning can still be dangerous as there is the potential to have a cloud to ground strike from this area. 

You should avoid taking photographs from underneath the anvil.

This type of lightning can stretch the full length of the spread anvil taking up over 50-200kms!  Often I stay until the anvil lightning fully disappears if there is nothing else around to chase, some beautiful images can be caught - so don't discount their potential once the storm stops spitting out ground strikes.


 


Streamer lightning

Probably the most unpredictable and most beautiful.  Lines of lightning streak below the cloud base in all directions.  Most often you see them stretch great distances, but this is what can happen as the connection meets ground - or ocean in this case. 

I was less than 200 metres from these strikes when one grounded and there were people fishing on the wharf below it!

 













 

Intracloud lightning

 

Intracloud lightning is purely discharges within the cloud or combination of cloud. 

They can be short leaps or long and this gives the thunderstorm dome its characteristic light bulb look when it flashes constantly but you cannot see any visible strike to earth.  Sometimes there well may be a strike to the ground but it's just hidden by the cloud obscuring the view.  

Thunderstorms that have an abundance of this type of lightning can last up to 10 hours flashing away..they make excellent chase targets due to their longevity.





 

Transient Luminous Events

 

The rarest and astonishing lightning types.  extremely hard to see with the naked eye unless you have an image enhancer on the end of your lens or video camera.  You need to be in total darkness with a perfect view of a lightning active storm, if you see them or capture them on video contact your local weather service and send it to them with a report - they would be very interested in it as not much is known about them.

(GRAPHIC AND TEXT COURTESY OF NOAA)


Large thunderstorms are capable of producing other kinds of electrical phenomena called transient luminous events (TLE's). The most common TLE's include red sprites, blue jets, and elves.

Red Sprites can appear directly above an active thunderstorm as a large but weak flash. They usually happen at the same time as powerful positive CG lightning strokes. They can extend up to 60 miles from the cloud top. Sprites are mostly red and usually last no more than a few seconds, and their shapes are described as resembling jellyfish, carrots, or columns. Because sprites are not very bright, they can only be seen at night. They are rarely seen with the human eye, so they are most often imaged with highly sensitive cameras.

Blue jets emerge from the top of the thundercloud, but are not directly associated with cloud-to-ground lighting. They extend up in narrow cones fanning out and disappearing at heights of 25-35 miles. Blue jets last a fraction of a second and have been witnessed by pilots.

Elves are rapidly expanding disk-shaped regions of glowing that can be up to 300 miles across. They last less than a thousandth of a second, and occur above areas of active cloud to ground lightning. Scientists believe elves result when an energetic electromagnetic pulse extends up into the ionosphere. Elves were discovered in 1992 by a low-light video camera on the Space Shuttle.



 

LIGHTNING - HOW IT ALL WORKS: 


As a thunderstorm moves over the Earth's surface, an equal but opposite charge is induced in the Earth below, and the induced ground charge follows the movement of the cloud.

An initial bipolar discharge, or path of  ionized air, starts from a negatively charged mixed water and ice region in the storm. The discharge ionized channels are called leaders. The negative charged leaders, called a "stepped leader", proceed generally downward in a number of quick jumps, each up to 50 meters long. Along the way, the stepped leader may branch into a number of paths as it continues to descend. The progression of stepped leaders takes a comparatively long time (hundreds of milliseconds) to approach the ground.

This initial phase involves a relatively small current (tens or hundreds of amperes), and the leader is almost invisible compared to the subsequent lightning channel.When a stepped leader approaches the ground, the presence of opposite charges on the ground enhances the electric field. The electric field is highest on trees and tall buildings. If the electric field is strong enough, a conductive discharge (called a postive streamer) can develop from these points.



(the Democratic Republic of Congo is the lightning capital of the world...)

 

This was first theorized by Heinz Kasemir. As the field increases, the positive streamer may evolve into a hotter, higher current leader which eventually connects to the descending stepped leader from the cloud. It is also possible for many streamers to develop from many different objects simultaneously, with only one connecting with the leader and forming the main discharge path. Photographs have been taken on which non-connected streamers are clearly visible. When the two leaders meet, the electric current greatly increases. The region of high current propagates back up the positive stepped leader into the cloud with a "return stroke" that is the most luminous part of the lightning discharge.

 




 
Aircraft struck by lightning courtesy of Zen Kawasaki
Department of Electrical Engineering
Faculty of Engineering, Osaka University
Yamada-Oaka 2-1, Suita, Osaka)

 

When the electric field becomes strong enough, an electrical discharge (the bolt of lightning) occurs within clouds or between clouds and the ground. During the strike, successive portions of air become a conductive discharge channel as the electrons and positive ions of air molecules are pulled away from each other and forced to flow in opposite directions.

The electrical discharge rapidly superheats the discharge channel, causing the air to expand rapidly and produce a shock wave heard as thunder. The rolling and gradually dissipating rumble of thunder is caused by the time delay of sound coming from different portions of a long stroke



(NOAA radar sequence of lightning over Colorado USA)

HIGH SPEED LIGHTNING VIDEO

THERRE ARE SEVERAL UNITS IN USE AROUND THE WORLD.  NHK JAPAN WHO FILMED A DOCUMENTARY WITH ME ON LIGHTNING IN DARWIN USED SUCH A CAMERA IN CONJUCTION WITH SONY JAPAN.  THIS UNIT FILMS AT A RATE OF 1MILLION FRAMES PER SECOND.  THE UNIT IS VERY EXPENSIVE AS YOU WOULD EXPECT.  THE MOST COMMON UNIT USED BY THOSE THAT FILM IN HIGH SPEED 9AND NOT JUST FOR LIGHTNING ARE PHANTOM VIDEO CAMERAS.  PHANTOM CAMERAS CAN FILM FROM 1500 FPS TO 75,000FPS.  THE UNITS REQUIRE SOME TECHNICAL KNOWLEDGE IN THEIR USE AND BASE MODEL PHANTOMS ARE AROUND $15,000 WITHOUT REQUIRED ACCESSORIES!

 

 

 

LIGHTNING TRACKER COUNT OVER A VERY ACTIVE DAY IN THE NORTHERN TERRITORY WHERE I LIVE, PARTICULARLY IN DARWIN.  THE ONLY PROBLEM WITH LIGHTNING DETECTION NETWORKS HERE IN AUSTRALIA.  THESE ARE USEFUL FOR DISTRIBUTION OF LIGHTNING, BUT TELL NOTHING OF THE POLARITY.  LIGHTNING TRACKERS DO GIVE SEPARATE INCIDENCES OF TYPES, POLARITY BUT DO NOT GIVE POLARITY WHERE THE MARKERS ARE SITUATED FOR EACH STRIKE.  IN OTHER WORDS, THE TRACKER COULD SHOW +CG,-CG +IC ETC, BUT DO NOT SHOW 'WHERE'THESE POLARITIES ARE IN THE STORM AREAS.OF INTEREST.

 


 

TO GIVE SOME COMPARISON TO LIGHTNING DETECTION SYSTEMS, THIS GRAPHIC BELOW (COURTESY TOM WARNER) HIGHLIGHTS THE AMOUNT OF NEGATIVE STRIKES OVER THE TOP END REGION FOR A FULL NIGHT IN JANUARY.  WHILST THERE WERE POSITIVE DISCHARGES ACCOUNTED FOR, THIS MAP REINFORCES DATA THAT SHOWS 90% OF LIGHTNING IS NEGATIVELY CHARGED.  WINTER STORMS SEEM TO EXHIBIT HIGHER RATES OF POSITIVE DISCHARGE, THIS MAY BE DUE TO AN ABUNDANCE OF WATER DROPLETS SATURATING THE STORM, BUT FURTHER RESEARCH NEEDS TO BE DONE IN THIS AREA.  TYPICALLY, TROPICAL THUNDERCLOUDS ARE BRIEF IN DURATION ELECTRIFICATION WISE, NO MORE THAN 30 MINUTES

 

 

YOU CAN COMPARE BOTH GRAPHICS.  ONE HIGHLIGHTS THE AMOUNT OF STRIKES BUT NOT THE POLARITY.  THE ABOVE GRAPHIC HIGHLIGHTS BOTH DISTRIBUTION AND POLARITY. 

 

 

 


 

 


LIGHTNING SAFETY SHOULD ALWAYS BE THE FOREMOST IN YOUR MIND WHEN OUT TAKING THUNDERSTORM PHOTOS.  IF YOU HEAR THUNDER THEN TAKE SOME KIND OF SHELTER.  INSIDE THE CAR, UNDER A COVERED AREA.  IF YOU ARE UNABLE TO THEN AT LEAST TRY NOT TO BE THE TALLEST OBJECT IN A FLAT REGION.  POSITIVE CHARGE ALWAYS COLLECTS AROUND THE TOPS OF OBJECTS, AND THIS IS WHERE UPWARD LEADERS PROPOGATE.  IF LIGHTNING DOES STRIKE CLOSE TO YOU AND YOU ARE UNABLE TO SEEK SHELTER, THEN SQUAT DOWN ON YOUR FEET INTO A BALL AND WAIT TILL THE DANGER PASSES...IN HINDSIGHT YOU SHOULD NOT BE LEFT ALONG IN AN OPEN AREA AND IF THERE ARE TREES AROUND YOU TRY AND STAY WITHIN A GROUP OF TREES OF THE SAME HEIGHT TO LESSON YOUR CHANCES OF BEING HIT.

NO PHOTO IS WORTH BEING STRUCK OVER, NO MATTER HOW BRAVE YOU THINK YOU ARE OR HOW GOOD THE SHOT.  THUNDERSTORM AND LIGHTNING PHOTOGRAPHY IS HIGHLY DANGEROUS. EVEN THE MOST EDUCATED IN LIGHTNING RESEARCH ABSOLUTELY DO NOT STAND OUTSIDE DURING A STORM.  SO TAKE THAT AS A HINT.  I CERTAINLY HAVE FOUND OUT THAT IT'S FAR BETTER TO STAY IN THE CAR, STICK YOUR CAMERA ON THE DASHBOARD OR LEAVE THE CAMERA ON THE TRIPOD OUTSIDE THE CAR...YOU CAN CHECK THE IMAGES LATER WHEN YOU GET HOME!