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**GordMay** · 30-04-2022, 03:45

“How the pandemic caused less lightning around the world”

Published in the journal PubMed Central [1], researchers found that global lightning activity decreased by nearly eight per cent, in 2020, due to lockdowns triggered by the pandemic. This was potentially caused by the reduction in atmospheric aerosols.

Atmospheric aerosols [AKA: particulate matter] is the suspension of liquid droplets, or fine solid particles, in the air. They can arise from the burning of fossil fuels, forest fires, volcanic eruptions, and sea salt. Some aerosols in the atmosphere can collect water vapor, thus forming into a water droplet.

In a thunderstorm, ice particles and water droplets collide. These collisions cause positive and negative charges within a cumulonimbus cloud. Warm, moist air rises, while cool, dry air sinks. This is the basic principle to the formation of thunderstorms. As the warm air rises within the atmosphere, it cools, thus condensing into a cloud. Once there is ample moisture and humidity with the presence of high temperatures, which results in Convective Available Potential Energy (CAPE), powerful updrafts can form. This results in an increase in thunderstorms, and hence, lightning activity. They then interact with charges on the ground, producing lightning strikes.

As the world came to a halt back in 2020, human activities were put on pause, which resulted in the reduction of burning of fossil fuels. This study [1] has shown that, due to the pandemic, there were notable changes in carbon dioxide, air temperature and humidity, which correlated to the decrease in lightning activity.

Lightning can also be triggered by atmospheric aerosols due to transportation and industrial activities. Cloud Condensation Nuclei (CCN) [AKA: cloud seeds] are used to advance the cloud-making process, in order for precipitation to occur, through cloud microphysics processes. During the lockdown, many transportation and industrial activities came to a halt. Therefore, according to this study [1], the reduction of aerosols, and CCN, within the atmosphere, prevented rapid cloud formation, decreasing overall thunderstorm formation, and lightning activity.

This study [1] was conducted with atmospheric data from Europe and Oceania, incorporating statistical analysis, showing the variation trend of lightning strikes count (LSC) was reduced by more than 50 per cent, compared to the last five years.

[1] “Lightning Behaviour during the COVID-19 Pandemic” ~ by Fazandra Yusfiandika et al
➥ https://pubmed.ncbi.nlm.nih.gov/34804502/
Full paper ➥ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8573680/

See also:

“Significant decrease of lightning activities during COVID-19 lockdown period over Kolkata megacity in India” ~ by Indrajit Chowdhuri et al
➥ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7385625/

“Effect of COVID-19 pandemic on air quality: a study based on Air Quality Index” ~ by Sadhan Gope et al
➥ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8148414/

**GordMay** · 30-04-2022, 03:50

Can lightning strike the same place twice?

Lightning never strikes the same place twice, right?
Wrong!
This long-held myth is far from true.

While the odds of being struck by lightning are low [but not unheard of], the chances of lightning striking the same place twice are high. Lightning can, and often will, hit the same spot multiple times. These strikes can occur during the same weather event, or on different occasions.

There are approximately 8 million flashes of lightning a day worldwide, which is about 100 strikes a second.
On average, Canada , for instance [not a ‘hot spot’ for lightning], sees about 2.4 million lightning strikes per year.

Positive charges from the ground usually build on tall objects and structures, like sailboat masts, trees, poles and buildings. It is more likely for lightning to strike tall structures, like skyscrapers [and masts] multiple times, due to the accumulation of positive charges, and the short[er] path from the cloud to the surface.

Hence, once an object has demonstrated a proclivity towards receiving a lightning strike, it remain a likely target, for further strikes.

How lightning works ➥ https://www.canada.ca/en/environment...ing-works.html

Chotu · 30-04-2022, 03:51

Makes a lot of sense. I you would never, but I’m just so glad the title didn’t say “lightening”. Ha ha

**GordMay** · 30-04-2022, 04:38

“Lightning Imaging Sensor (LIS)” ~ NASA
The Lightning Imaging Sensor is a small, highly sophisticated instrument that detects and locates lightning over the tropical region of the globe. Looking down from a vantage point aboard the Tropical Rainfall Measuring Mission (TRMM) observatory, 250 miles (402 kilometers) above the Earth, the sensor provides information that could lead to future advanced lightning sensors capable of significantly improving weather "nowcasting."
➥ https://gpm.nasa.gov/missions/TRMM/satellite/LIS

TRMM LIS Data Sets ➥ https://ghrc.nsstc.nasa.gov/lightnin..._lis_trmm.html

The LIS field-of-view and the orbital track of the TRMM satellite during a 24 hour period.

**GordMay** · 30-04-2022, 04:41

Lightning Statistics:

The odds of getting struck by lightning are about one in a million.

But if you own a boat, the odds of it being struck by lightning are significantly higher – about one in a thousand.

However, not all boats are created equal, when it comes to lightning.

According to US insurance claims [from BoatUS Marine Insurance] the odds of a boat being struck by lightning, in any year, are about 1 per 1,000, increasing to 3.3 per 1,000 in lightning prone areas, such as Florida.
Pantaenius reports that while high-risk areas include the Caribbean, Florida and Mexican Gulf, the incidence in other areas is rising: 10-12% were in the Mediterranean, and that is coming from below 5% in the last decade [2010 - 2020].

Both UK and US-based insurers also report that multihulls are two to three times more likely to be struck by lightning, than monohulls, due to the increased surface area, and the lack of a keel, causing difficulties with adequate grounding.

“How Likely Is Your Boat To Be Struck By Lightning” ~ BoatUS
➥ https://www.boatus.com/expert-advice...k-by-lightning

“Striking Lightning Facts” ~ BoatUS
An analysis of 10 years of lightning claims reveals which boats are most at risk.
➥ https://boatus.com/expert-advice/exp...ightning-facts

“Lightning Strikes” ~ Pantaenius
➥ https://www.pantaenius.com/au-en/ins...tning-strikes/

“Lightning Protection On Yachts: Thunderstruck” ~ Pantaenius
➥ https://www.pantaenius.com/de-en/sup...thunderstruck/

Chotu · 30-04-2022, 04:53

This one confuses me.

Both UK and US-based insurers also report that multihulls are two to three times more likely to be struck by lightning, than monohulls, due to the increased surface area, and the lack of a keel, causing difficulties with adequate grounding.

Yes, it’s a fact, but the causation is not clear to me.

A poorly grounded boat or mast (or house with no lightning rods) shouldn’t be struck more often. Also, there is less WETTED surface area on a (good) multihull, right? Yes, there is more deck area, but is it true that lightning is coming that close to hitting monohulls that the extra 10-12ft of width on a multi is taking a strike where a narrow miss would have happened on a monohull? My understanding is the lightning nearly always strikes the mast anyway.

Is it possibly a product of the typical cruising locations of each type of boat?

You see less multihulls in higher latitudes where there are statistically less strikes overall. You see a higher concentration of multihulls in lower latitudes where there are more lightning strikers overall.

Could this be the real reason?

The given causation doesn’t make a lot of sense. I’ve always wondered about this.

**GordMay** · 30-04-2022, 05:01

Good question(s), Chotu.
I’d expect Insurance Companies to be much better sources of accurate statistics, than of theoretical/practical science.

In this page [A] we [Ewen Thomson, MLP] present strike statistics based on Boat US insurance claims, explain why catamarans get struck twice as often, and outline our approach for lightning protection.

Catamarans have their own special set of issues:
According to Boat US insurance claims, they are struck twice as frequently as monohulls of similar length.
They do not come with an in-built lead ballast that can be used as part of the grounding system.
Their two hulls mean that there is twice as much waterline to contend with.
The bridge deck being suspended above the water introduces yet another vulnerability for sideflashes.
The bridge deck suspended above the water also introduces a desirable grounding location away from crewed areas. See our "New products" discussion below.
The only viable solution is a permanent installation. See our FAQ page for some first hand accounts of problems with temporary systems.
With one or two rare exceptions (see for example Tag Young 60' sail cat) comprehensive lightning protection systems are NOT installed in the factory. Ask your builders what they have done for lightning protection and prepare to be amazed at the reply!

[A] Here ➥ Catamarans

In 1992, Dr. Ewen Thomson wrote a [classic] Sea Grant pamphlet, “Lightning and Sailboats” [1], and co-produced a 23 minute video, to communicate the science of lightning protection to the general, and boating public.

During a sabbatical in 2000-2001, Ewen revisited some of the more perplexing observations that could not be explained a decade before. After this decade of reflection, he finally realized that the scientific theories he, and others, had used previously were incomplete. A more complete theory could indeed explain the more puzzling data. This theory also made possible a new device for grounding, the SiedarcTM electrode, which, in turn, can be integrated into a far more comprehensive lightning protection system comprising a network of external conductors, just as in a building. And, in a major departure from the ineffective status quo, NFPA-2008 now addresses the earlier concerns [see "A Critical Assessment of the U.S. Code for Lightning Protection of Boats" 2]. Marine Lightning Protection Inc. [MLP] was founded in May 2001 as a commercial vehicle for supporting the design, fabrication and installation of grounding components and systems using this new technology.

More from MLP ➥ Science & Technology
[1] "Lightning and Sailboats" [SGEB-1] ~ by Ewen M. Thomson [for Florida Seagrant]
➥ http://marinelightning.com/ECE/SGEB17.pdf

[2] "A Critical Assessment of the U.S. Code for Lightning Protection of Boats" ~ by Ewen M. Thomson
➥ http://marinelightning.com/IEEE.pdf

sailingharry · 30-04-2022, 05:22

Interesting stuff. Which leads to a ponder, and a question.

Modern boats are highly dependent upon electronics (and I, for one, enjoy that fact!). While there is always the thought that the Russians or the Martians could blow the GPS satellites out of the sky, a much more realistic threat is a lightning strike offshore. In an instant, you have a recollection of where you are, and an idea of which way to land. It's not the end of the world -- if I was halfway to Bermuda and this happened, I would go west with a DR, heave to at night, and go till I can see land.

But what about a backup to a backup to the electronics? No, I'm not going to take a sextant and reduction tables. Unless you have paper almanac/tables and a windup chronometer, that doesn't help anyway! I'm thinking of an old smartphone with OpenCPN installed. Even where you haven't paid for charts for it, the background chart will help you get to a major port. It doesn't need service, or even a useful battery life.

The question is how to make it survive a lightning strike. We've all heard the story about putting things in the oven, but that just seems impractical for every thunderstorm -- and if you don't do it every time, it's not a solution.

My thought is taking the cell phone and wrapping it in aluminum foil (and maybe then a ziplock bag for protection). It could then be tossed in a locker.

Would this provide decent protection from a lightning strike?

two-rocks · 30-04-2022, 05:32

We keep a small waterproof bag (roll top type) of backup emergency electronics in the microwave (or rarely, the oven). The microwave is only used for short times and the bag is then put back.

The oven can be done the same way if you don’t have a microwave, but the oven is used for longer cook times and stays hot for a long time - thus the bag often gets overlooked once sitting out.

Chotu · 30-04-2022, 05:37

Quote:

Originally Posted by sailingharry

Interesting stuff. Which leads to a ponder, and a question.

Modern boats are highly dependent upon electronics (and I, for one, enjoy that fact!). While there is always the thought that the Russians or the Martians could blow the GPS satellites out of the sky, a much more realistic threat is a lightning strike offshore. In an instant, you have a recollection of where you are, and an idea of which way to land. It's not the end of the world -- if I was halfway to Bermuda and this happened, I would go west with a DR, heave to at night, and go till I can see land.

But what about a backup to a backup to the electronics? No, I'm not going to take a sextant and reduction tables. Unless you have paper almanac/tables and a windup chronometer, that doesn't help anyway! I'm thinking of an old smartphone with OpenCPN installed. Even where you haven't paid for charts for it, the background chart will help you get to a major port. It doesn't need service, or even a useful battery life.

The question is how to make it survive a lightning strike. We've all heard the story about putting things in the oven, but that just seems impractical for every thunderstorm -- and if you don't do it every time, it's not a solution.

My thought is taking the cell phone and wrapping it in aluminum foil (and maybe then a ziplock bag for protection). It could then be tossed in a locker.

Would this provide decent protection from a lightning strike?

Just a metal container where there are no openings (when closed) and where a current on the surface of the container can flow easily will do.

So, special attention would have to be paid to the lid. A rubber gasket that keeps water out, would not be good for a faraday cage because it would keep the lid electrically isolated from the rest of the container. You want Current to be able to flow with ease all around the entire container. Every surface. From one point to another without interruption.

So the lid has to be in contact with the rest of the container. In an electrical sense. It has to make an electrical contact.

That would protect your phone.

**GordMay** · 30-04-2022, 05:38

Quote:

Originally Posted by sailingharry

... Modern boats are highly dependent upon electronics ...
... But what about a backup to a backup to the electronics? ...
... The question is how to make it survive a lightning strike...

I expect you'd be interested in our MANY discussions about Faraday Cages:
➥ https://cse.google.com/cse?siteurl=w...day+cage&sa=Go

Our early sailing [Lk. Superior] was all done w/out ANY electronics. We used a paper chart, magnetic compass, digital watch, pocket calculator, and small sticks [no chip log], to do our Dead [deduced] Reckoning mathematically [using estimates of speed, course, and elapsed time], often in dense fog. I might prefer electronic ease & accuracy, but it's not essential - especially if one keeps an hourly deck log [to provide starting position/fix].

I’d be more concerned with sideflashes, that made holes, in the hull, at [near & below] the waterline. Fiberglass is such a good insulator, that it is used to make insulators for high voltage installations. Nevertheless, the lightning voltage is more than enough to cause electrical breakdown through a fiberglass hull, if no alternative path is provided, and frequently even if one is. Each penetration leaves a charred hole, and much more extensive internal damage.
Dr. Thomson covers these, and MANY other lightning issues, on his ‘Marine Lightning Protection’ website.
Home ➥ Marine Lightning Protection Inc.

FWIW: Over the years, I’ve participated in numerous “Lightning” discussions, on CF:
➥ https://cse.google.com/cse?siteurl=w...+gordmay&sa=Go

**skipmac** · 30-04-2022, 05:58

Quote:

Originally Posted by GordMay

Can lightning strike the same place twice?

Lightning never strikes the same place twice, right?
Wrong!
This long-held myth is far from true.

While the odds of being struck by lightning are low [but not unheard of], the chances of lightning striking the same place twice are high. Lightning can, and often will, hit the same spot multiple times. These strikes can occur during the same weather event, or on different occasions.

There are approximately 8 million flashes of lightning a day worldwide, which is about 100 strikes a second.
On average, Canada , for instance [not a ‘hot spot’ for lightning], sees about 2.4 million lightning strikes per year.

Positive charges from the ground usually build on tall objects and structures, like sailboat masts, trees, poles and buildings. It is more likely for lightning to strike tall structures, like skyscrapers [and masts] multiple times, due to the accumulation of positive charges, and the short[er] path from the cloud to the surface.

Hence, once an object has demonstrated a proclivity towards receiving a lightning strike, it remain a likely target, for further strikes.

How lightning works ➥ https://www.canada.ca/en/environment...ing-works.html

I can personally confirm this. Had a pine tree in my yard struck twice, a year apart. Friend had a 26' sailboat, one of the smallest in his marina that was struck twice, also about a year apart, while the boats docked next to him with much taller masts escaped.

Tetepare · 30-04-2022, 06:45

Unpowered, disconnected electronics are unlikely to be effected. Keep them away from wires to be safe. Wrap them in foil if you like. Ovens and certainly the microwave are a faraday cage so long as the microwave isn’t plugged in.

A handheld VHF is unlikely to be effected even by a direct hit unless near metal and the lightning couples to it. Same for phones. If they are plugged in and charging this does not apply. Ditto handheld GPS and EPIRB.