What is the “Saint Elmo fire” seen during storms such as Hurricane Idalia?

During his expeditions, Christopher Columbus saw the mighty “St. Elmus Fire” in the night sky during a storm.

He also thought Charles Darwin during a “cold and raucous” journey near the Río de la Plata, “The lightning was very lively, accompanied by heavy rain and gusts of wind,” he noted in his diary.

“Everything is on fire, the sky with lightning, the water with luminous particles, and even the masts themselves are seen with a blue flame,” the naturalist continued.

Both explorers talked about a atmospheric phenomenon in which several factors combine to create an impressive electromagnetic discharge Usually it is interpreted as lightning, although that is not the point.

The spectacle was also seen Tuesday by the pilots of a US Air Force plane chasing Hurricane Idalia as it approached Florida’s northwestern coast.

What is happening?

For centuries referred to as “Saint Elmo’s Fire”in honor of the saint of sailors (in English it is called St. Elmo’s fireby San Erasmo de Formia), the ancient sailors reported seeing it during the nights on the high seas.

As Darwin related, he was seen as a glow shooting from the tops of the masts of the boats.

Centuries later, atmospheric scientists provided an explanation for this phenomenon It is produced “by an extreme accumulation of electrical charge”explains the US National Oceanic and Atmospheric Administration Office (NOAA).

“When a pointed object (such as a ship’s mast) comes into contact with an extraordinarily high electric field and a large number of electrons, electrons can glow in different colorslike a neon sign, resulting in this rare phenomenon,” says NOAA.

The electric field can convert air molecules into electrically charged particles or “plasma”, which emit a glowing light. The result generates a discharge, not lightning as in a normal thunderstorm, but plasma.

Currently, merchant ships do not use the old masts. But some moldings, including lightning rods, can absorb this energy.

Also the wings of the aircraft they can be exposed, although this poses no danger to those traveling sheltered indoors.

A similar glow can be created in a lab.

But what has impressed sailors through the ages – and now pilots – is the glow produced on stormy nights Over the sea, where the darkness is deepest. (JO)

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