20 January 2021.

Introduction:

Scientists on the International Space Station spotted a bright-blue lightning bolt shooting upward from thunderclouds. These blue jets can be difficult to spot from the ground, since the electrical discharges erupt from the tops of thunderclouds. But from space, scientists can peer down at this cerulean lightshow from above.

Highlights:

• This event of blue jet lighting was published in the journal Nature on 20 Jan 2021.
• The event occurred on Feb. 26, 2019.
• Instruments aboard the space station captured a blue jet shooting out of a thunderstorm cell near Nauru, a small island in the Pacific Ocean.
• The scientists first saw five intense flashes of blue light, each lasting about 10 to 20 milliseconds.
•  The blue jet then fanned out from the cloud in a narrow cone shape that stretched into  the atmospheric layer- the stratosphere that extends from about 6 to 31 miles (10 to 50 kilometers) above the Earth’s surface

About the blue jets:

• Blue jets appear when the positively-charged upper region of a cloud interacts with the negatively charged boundary between the cloud and the air above.
• . The blue jet appears as a result of this “electric breakdown,” where the opposing charges swap places in the cloud and briefly equalize, releasing static electricity.
• However, the properties of blue jets and the altitude to which they extend above clouds “are not well characterized.

• The blue colour of the jets is the result of blue and near-ultraviolet emission lines from neutral and ionized molecular nitrogen.
• The blue jets were recorded on October 21, 1989 for the first time.

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Thunderstorm

• It is also known as an electrical storm or a lightning storm. It is characterized by the presence of lightning and the acoustic effect on the Earth’s atmosphere that is thunder.
•  This phenomenon is usually taking place in the cumulonimbus cloud, the thunderstorm is also accompanied by strong winds and heavy rain.
•  It could also lead to snow, sleet, or hail.

Cumulonimbus Cloud

• It is a dense and towering vertical cloud. This cloud is formed by the water vapor which is carried by the powerful upward air currents.

What are ‘’elves”?

• Four of the flashes preceding the blue jet came with a small pulse of (UV),- Ultra violet light.
• The scientists  identified these emissions as so-called “elves,” another phenomenon seen in the upper atmosphere.