An artist’s impression of plasma tubes in the Earth’s magnetosphere. Image credit: Mats Bjorkland / ARC Centre of Excellence for All-sky Astrophysics
Scientists using the Murchison Widefield Array in the Western Australian desert have confirmed the existence of tubular plasma structures between the plasmasphere and ionosphere of our planet, approximately 370 miles (600 km) above the ground.
“We saw a striking pattern in the sky where stripes of high-density plasma neatly alternated with stripes of low-density plasma,” said team member Shyeh Tjing Loi from the University of Sydney and the ARC Centre of Excellence for All-sky Astrophysics, Australia.
“This pattern drifted slowly and aligned beautifully with the Earth’s magnetic field lines, like aurorae.”
The Earth’s magnetosphere is filled with plasma that is created by the atmosphere being ionized by sunlight.
The innermost layer of the magnetosphere is the ionosphere, and above that is the plasmasphere. They are embedded with a variety of strangely shaped plasma structures including, as has now been revealed, the tubes.
“For over 60 years, scientists believed these structures existed but by imaging them for the first time, we’ve provided visual evidence that they are really there,” Ms Loi said.
According to the scientists, the structures are strikingly organized, appearing as regularly spaced, alternating tubes of overdensities and underdensities strongly aligned with the Earth’s magnetic field.
“We measured their position to be about 370 miles (600 km) above the ground, in the upper ionosphere, and they appear to be continuing upwards into the plasmasphere,” Ms Loi said.
“This is around where the neutral atmosphere ends, and we are transitioning to the plasma of outer space.”
Dr Tara Murphy, also from the University of Sydney and the ARC Centre of Excellence for All-sky Astrophysics, added: “when they first saw the data, many of her senior collaborators thought the results were literally ‘too good to be true’ and that the observation process had somehow corrupted the findings, but over the next few months, Ms Loi managed to convince them that they were both real and scientifically interesting.”
The findings are reported in a paper published online by the journal Geophysical Research Letters on May 25, 2015.
Courtesy of sci-news.com