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On September 17th, I got a chance to see the world’s largest Tesla coil in operation at the Tesla Science Center at Wardenclyffe which is located in Shoreham, New York. As part of a belated birthday celebration of Nikola Tesla’s 166th birthday, which was on July 10th, Greg Leyh (@LightningOD on Twitter) operated his 40 ft tall Tesla coil in a spectacular and educational demonstration. The Tesla coil is a 1/3rd scale prototype for his endeavor to build two 121 ft tall Tesla coils. At his website, Lightning On Demand, you can read about the science behind this project and the objectives he hopes to achieve.
During the demonstration, Greg first had selected members of the audience hold onto fluorescent bulbs. He slowly raised the surrounding electric field by activating the coil and soon the bulbs lit up in their hands. Next he operated his own “Original Tesla Roadster” which used the invisible electric field to power a motor onboard the small “go kart sized” three wheeled buggy.
Turning things up a notch, Greg then demonstrated “Saint Elmo’s Fire” which is a cold corona discharge that occurs on pointed objects when the electric field reaches a certain breakdown threshold. These faint blue/purple arcs of light are cold streamers formed when that air ionizes without enough energy to cause significant thermal energy from kinetic collisions. The light comes from emissions during molecular and atom recombination or primarily nitrogen and oxygen after ionization or excitation to higher energy states.
He then demonstrated how these static discharges can ignite gasoline but not diesel fuel, followed by an impressive ignition of gun powder and hydrogen filled balloons.
Turning things up once again, Greg increased the voltage output of the Tesla coil and brilliant arcs finally began leaping from the Tesla coil itself as the air broke down under the electric stress produced by the tuned oscillators and coils. He zapped a long piece of wood which burst into flames as the power increased. His assistants then hoisted a human wood cutout holding an umbrella that had a covering of metal mesh spread out across its top. The Tesla coil struck the metal mesh which acted as a Faraday cage protecting the wood cutout below. After the metal mesh was removed, the arc did not hesitate to propagate down to the wood cutout burning a scar with ease.
I first met Greg in 2008 when he asked me if I could film his then smaller Tesla coils using my high-speed camera. I jumped at the opportunity and filmed them in action in San Francisco at recording speeds up to 66,000 images per second. The high-speed recordings, timelapes and integrated image stacks are below.
I learned then that Greg likes to run things until they break, and he did just that with his biggest coil in San Francisco. I suspected he would do the same at the Tesla Science Center, and sure enough he kept increasing the power to see what happens. Arcs shot up to the sky and down to the ground to the delight of all.
My research on upward lightning has involved human-made tall objects such as communication towers, tall buildings and wind turbines. However, upward lightning from natural rock formations is also possible as the conditions that allow for upward lightning require an object that enhances the electric field locally due to its shape. Any object that protrudes above it surroundings can enhance the electric field and this is the basic concept that allows for air terminals in lightning protection systems to serve as more favorable attachment points for descending lightning leaders.
However, in the case of upward lightning, in which a leader initiates and travels upward toward the overlying thunderstorm charge region, studies have shown that tall objects have to be of suitable size and shape to initiate the leader. These studies indicate that objects require an “equivalent height” of at least 100 m (~300 ft) or in the case of wind turbines, need to be rotating, in order to experience upward lightning. Equivalent height takes into account the object’s shape and nearby ground topography as a narrow object (e.g., communications tower) can enhance the electric field more so than a broader object of the same height such as a much wider building or a sloping mountain. However, a small narrow tower on top of a sloping mountain can have a much greater equivalent height than the height of just the small tower considered separately.
In addition, upward lightning can be triggered by nearby lightning activity in which a component of a triggering flash causes a rapid electric field change over the tall object resulting in the initiation of an upward leader. Alternatively, upward lightning can be self-initiated in which an upward leader initiates from the tall object without a preceding triggering flash. In this case, the strength of the electric field and possibly the removal of corona space charge by the wind allows for the initiation of the upward leader. If there are multiple tall objects, self-initiation upward lightning tends to occur from only one of the tall objects, whereas lightning-triggered upward lightning flashes can see multiple tall objects initiate upward leaders during the same flash.
I have not investigated upward lightning from natural rock formations as it seems to occur much less frequently based on the amount of images and videos captured of such events. Communication towers and tall buildings can be prolific upward lightning producers so we focus our research on those.
Paul M. Smith (@PaulMSmithPhoto on Twitter), who is an incredibly skilled transient luminous event photographer, shared an image posted on Instagram that showed apparent upward lightning from some rock formations in Canyonlands National Park in Utah. The image was captured at Mesa Arch, a beautiful arch that provides a wonderful framed sunrise canvas opportunity. The photographer was Chris Markes (@chrismarkes on Instagram). Because I had previously seen so few upward flashes from rock formations and the fact that these formations were in a canyon, which would be less favorable for electric field enhancement, I was skeptical of the validity of the image at first. However, Paul reached out to Chris and was able to obtain an approximate time of the event. With that information, I asked Chris Vagasky (@COweatherman on Twitter) who works for Vaisala, Inc. (@VaisalaGroup on Twitter) which operates the National Lightning Detection Network if he could see if there were any lightning events recorded. The data that he found strongly suggests that what Chris Markes recorded was in fact a lightning-triggered upward lightning flash that initiated upward positive leaders from at least three rock formations.
The data showed nine lightning events beginning at 005509 UT on 3 Oct 2022 (1855 MDT on 2 Oct 2022) and lasting just under 0.7 seconds. The first was a very strong 108.6 kA estimated peak current positive cloud ground return stroke 16 km south of the Airport Tower rock formation. This was followed by a -5.2 kA intracloud event close to the location of the return stroke. 326 ms after the +CG return stroke the first of seven small peak current negative intracloud events were recorded by the NLDN. All of these were less than -10 kA estimated peak current and all grouped within 400 m of Airport Tower as measured using Google Maps.
In the image captured by Chris, Airport Tower is the formation in which the middle lightning channel is attached and is 4.9 km from Mesa Arch. Monster Tower, to the right of Airport Rock in the image with the rightmost lightning channel attached is 2.3 km from Mesa Arch.
Based on the image and the NLDN data, I believe the nearby +CG flash caused the initiation of upward positive leaders from the rock formations, and in the case of the upward leader from Airport Tower, some of the upward positive leader branches decayed and subsequently formed recoil leaders in which the negative ends traveled back down the channel resulting in subsequent return strokes (if the main channel had also decayed) or impulsive m-components (if the main channel was still active). In the latter case, the negative end of the recoil leader would connect to the main channel at the branch point causing and impulsive current increase in the luminous main channel and branch. Below is an example of this process recorded by high-speed camera.
Our research has shown that the recoil leader generation and attachment process on decayed upward positive leader branches tend to register as low peak current negative intracloud events by the NLDN.
Regarding the topography and its potential to enhance the electric field locally, Airport Tower is 223 m taller than its lowest measured contour that encircles it (prominence height) and Monster Tower has a prominence height of 120 m. This suggests that they both have effective heights greater than 100 m as the canyon floor extends 8 km east and nearly 5 km to the south.
I would like to thank Chris Markes for allowing me to repost his image on my blog, Paul Smith for showing me Chris’ post as well as Chris Vagasky for sharing the lightning data.
Lightning Safety Awareness Week runs from Sunday, June 19th through Saturday, June 25th. There are many sites to learn about lightning safety and myths related to lightning. If you wish to learn more about the physics and behavior of lightning you can read through my education section.
Got the opportunity to witness the total lunar eclipse on the night of May 15th, 2022 from Montauk, New York. It had been rather foggy the preceding three days, and with no change in weather pattern forecasted, I thought my chances of seeing it were extremely low. I was thrilled when a brief period of thinning fog allowed for a beautiful lunar spectacle. I had positioned myself at the Montauk Lighthouse on the very eastern end of Long Island, New York. Alone with the lighthouse, the scene that unfolded was truly surreal as the light from the rotating beacon tried to penetrate the opaque fog created rotating beams of light. The moon periodically revealed its moody glow adding to the “mistical” scene accompanied by a symphony of waves crashing on the nearby rocks. My only companions were unknown critters that occasionally dashed across the grass field surrounding the lighthouse. It was something I will never forget.
Below are some selected images and video from this amazing night.
Back in Rapid City, South Dakota, my low-light surveillance cameras captured the lunar eclipse as the skies were clear. Below is a timelapse showing the eclipse’s moonlight transition which started shortly after moonrise.
This year I was able to capture upward lightning flashes from a newly installed wind turbine complex northeast of Newell, South Dakota as well as lightning associated with the monsoon season in the Colorado Plateau. There were also some spectacular lightning displays in the my home area in the Northern High Plains. Below are some of the images captured.
Standard- and high-speed video highlights from the 2021 storm season are now available on my YouTube channel.
Posted in Meteor on 01/11/2022
The Geminid Meteor Shower peaked on December 13th and both our Global Meteor Network cameras were able to record data. Below are the video segments created by each of the cameras for the two nights surrounding the peak. In the second video captured from Chamberlain, South Dakota. The radiant in Gemini translates across the field of view during some of the peak activity.
Posted in Astrophotography on 11/22/2021
In the early morning hours of November 19th, 2021, the fully illuminated moon passed through the Earth’s shadow. The moon did not pass entirely into the shadow reaching 97% percent coverage at max eclipse. Hence, this was a partial lunar eclipse. The fact that the moon was near apogee, the farthest distance from Earth in its elliptical orbit, meant that the moon was at its smallest as viewed from Earth. This also meant that the time it took to traverse the shadow was maximized.
At moonrise, high clouds blocked the moon, and it appeared the after midnight eclipse could be obscured. However, clouds cleared for the most part during the 12:19 – 03:47 am eclipse timeframe. I used a Paramount MYT telescope mount with a Nikon Z6 camera and Sigma 600mm lens to record the event. I also used a 1.4x teleconverter so the focal length was 840mm. I chose to only record UHD video and occasionally ventured outside in the subfreezing air to look at the spectacle with my own eyes. It was an amazing sight with Orion not far away.
Below is a timelapse video from the video recording. I also made a timelapse of my four low-light surveillance cameras to show how the light dimmed during the eclipse. The third video is the complete real-time recording which I have placed in my “Simply Being There” playlist. If you want to just watch the event as it took place, you can sit back an do so.
I am grateful that the clouds cleared out, and that I was able to see this wonderful wonderful event. Enjoy
Earlier this year, I joined the Global Meteor Network (GMN) in making scientific meteor observations using low light camera systems. I purchased two GMN camera systems and now manage these cameras which are located in Rapid City and Chamberlain, South Dakota. The cameras have overlapping fields of view which allows for orbit calculations for simultaneous captures of the same meteor. A dedicated website provides the latest overnight observations from all the cameras located around the world.
Last week, the Perseid meteor shower peaked, and South Dakota experienced clear skies for most of the nights in which Perseid meteor activity was clear visible. Based on radar and camera observations, there was an unexpected outburst from the Perseids between 0700-0900 UTC on August 14th. This was after the traditionally observed peak. Skies were clear in western South Dakota and the GMN cameras, along with my low light surveillance cameras at my observatory in Rapid City recorded this outburst.
I have posted highlights from the outburst on YouTube as well as the timelapse recordings from the GMN cameras.
For the 2020 storm season, I remained in Rapid City, South Dakota. Due to the Covid-19 pandemic, I chose to document storms either alone or with my daughter while isolating from the general public. Most of my high-speed cameras are currently in Johannesburg, South Africa as part of an ongoing research project, so this year I focused on the artistic side of lightning and storms. I did utilize a Phantom M321 camera which is a color camera capable of recording at 1920×1080 at 1,500 images per second along with digital still, 4K video cameras and various GoPro cameras recording timelapse or at 240 images per second. My goal was to focus on sites that are scenic and iconic South Dakota landmarks such as Bear Butte and the Badlands.
Overall, it was a rather active year with storms displaying typical behavior for the northern High Plains. This means that storms produced a large number of positive cloud-to-ground flashes which is common here. This is especially true when targeting the trailing part of organized mesoscale convective systems. I only documented one upward lightning flash from the towers in Rapid City, however, the towers were not my primary focus.
Below is a summary video showcasing the lightning that my daughter and I captured. There were some beautiful flashes captured with the high-speed camera and some stunning sunsets and scenery…a positive outcome from a rather challenging and concerning year for all of us. I hope that all who read this stay safe and healthy both physically and mentally. It is also my hope that by next summer, we are in a much better situation.