What causes plasma jets in sun’s atmosphere, Indian scientists explain

They have said that convection in the lower layer of the atmosphere, just like a boiling vessel of water, gives a kick to the plasma in the chromosphere.

The existing consensus has been that the physics behind the short spicules is different from that of taller and faster spicules. The new study challenges this widespread belief and shows that solar convection can by itself form all kinds of jets.

The study of the spicules is of immense interest among plasma astrophysicists as it may explain the process by which plasma is supplied to the solar wind and the solar atmosphere is heated to a million degree Celsius.’

Led by Piyali Chatterjee at the Indian Institute of Astrophysics, a team of interdisciplinary researchers from India and the UK found that the physics underlying paint jets when excited on a speaker is analogous to solar plasma jets.

The pattern in which the jets shoot out is similar to paint on a bass speaker, the researchers have shown.

When a liquid is placed above a bass speaker and the music is turned on, the free surface of the liquid becomes unstable beyond a particular frequency and starts vibrating. However, a fluid-like paint or shampoo will result in unbroken jets when excited on a speaker since its long polymer chains give it directionality.

The authors of the article realised that the physics underlying these paint jets must be analogous to the solar plasma jets. They found that the jets are kept intact against instabilities by the magnetic field in the sun, and by the polymer chains in the polymeric solution respectively.

Sahel Dey, from the Indian Institute of Astrophysics (IIA), and the first author of the study in a release said: “The solar plasma can be imagined as threaded by magnetic field lines, much like the long chains in polymer solutions. This makes both the systems anisotropic, with properties varying with the direction in space.”

“Spurred by the visual similarity between the solar spicules and the jets of paint on the speaker, we investigated the roles of magnetic fields on the sun using numerical simulations of the solar plasma. In parallel, we explored the role of polymer chains by using slow-motion videography, Murthy OVSN, co-author from the Azim Premji University, said in the release.