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Solar Winds Spark Extra Lightning Strikes on Earth

Researchers remain puzzled over why high-speed solar winds appear to trigger higher rates of lightning strikes

2 min read
Solar Winds Spark Extra Lightning Strikes on Earth
Photo: Getty Images

Solar winds capable of triggering spectacular displays of the Northern Lights in the sky may also boost the rate of lightning strikes on the ground. The finding could allow researchers to use sun-monitoring satellites to improve weather forecasts of hazardous thunderstorms in the future.

The study of weather patterns over northern Europe found an average of 422 lightning strikes in the 40 days after a high-speed solar wind reached the Earth's atmosphere, according to BBC News. By comparison, just 321 lightning strikes occurred in the 40 days prior to the solar wind's arrival. Why this happened remains something of a mystery, as detailed in the journal Environmental Research Letters.

The solar wind originates when the sun's corona layer reaches temperatures of up to 1.1 million degrees Celsius. Such high temperatures excite particles to the point where they overcome the sun's gravitational pull and stream away in all directions, according to The solar wind carries along magnetic clouds as well as the charged particles.

Image: Solar Dynamics Observatory/NASA

Past studies have shown that galactic cosmic rays originating outside the solar system can boost the rate of lightning on Earth. But the solar wind connection with a higher rate of lightning surprised researchers at the University of Reading in the UK; they had expected the solar wind to bring along a stronger magnetic field that could help shield Earth against cosmic rays.

The researchers did observe a slight but rapid decrease in the rate of galactic cosmic rays coinciding with the arrival of a high-speed, high-intensity solar wind. But they also found an increase in lower-energy particles called solar energetic protons. Such particles may end up filtering down through Earth's atmosphere to storm clouds and acting as a trigger for lightning.

Researchers still need to test their hypothesis about the solar wind particles by tracking their progress through the atmosphere. They also hope to undertake a global study of the connection between lightning rates and solar wind—expanding the scope of the lightning data they use from the UK Met Office's records to a broader repository such as the World Wide Lightning Location Network.

Higher rates of lightning strikes may represent just the latest finding about the connection between the sun and life on Earth. Huge coronal mass ejections from the sun can lead to solar magnetic storms, such as one that knocked out telegraph systems across North America and Europe in 1859, or a similarly huge solar storm that Earth barely dodged in 2012.

Image: Solar Dynamics Observatory/NASA

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Economics Drives Ray-Gun Resurgence

Laser weapons, cheaper by the shot, should work well against drones and cruise missiles

4 min read
In an artist’s rendering, a truck is shown with five sets of wheels—two sets for the cab, the rest for the trailer—and a box on the top of the trailer, from which a red ray is projected on an angle, upward, ending in the silhouette of an airplane, which is being destroyed

Lockheed Martin's laser packs up to 300 kilowatts—enough to fry a drone or a plane.

Lockheed Martin

The technical challenge of missile defense has been compared with that of hitting a bullet with a bullet. Then there is the still tougher economic challenge of using an expensive interceptor to kill a cheaper target—like hitting a lead bullet with a golden one.

Maybe trouble and money could be saved by shooting down such targets with a laser. Once the system was designed, built, and paid for, the cost per shot would be low. Such considerations led planners at the Pentagon to seek a solution from Lockheed Martin, which has just delivered a 300-kilowatt laser to the U.S. Army. The new weapon combines the output of a large bundle of fiber lasers of varying frequencies to form a single beam of white light. This laser has been undergoing tests in the lab, and it should see its first field trials sometime in 2023. General Atomics, a military contractor in San Diego, is also developing a laser of this power for the Army based on what’s known as the distributed-gain design, which has a single aperture.

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