Scientists have discovered a space hurricane above the North Pole for the first time, which offered an initial glimpse at a phenomenon that could also be taking place on other planets across the universe. The hurricane was raining electrons instead of water, spinning in an anticlockwise direction.
Researchers led by China's Shandong University used satellite data to analyze and identify the space hurricane, discovering that it was not a swirling pattern of air and water, but of plasma-ionized gas. The hurricane lasted about eight hours before dissipating.
"Until now, it was uncertain that space plasma hurricanes even existed, so to prove this with such a striking observation is incredible," said professor Mike Lockwood, a space scientist at the University of Reading.
Image: Illustration of space hurricane. Credit: Qing-He Zhang/Shandong University
Lockwood noted that the space hurricane could be a universal phenomenon at planets and moons with magnetic fields and plasma.
"Tropical storms are associated with huge amounts of energy, and these space hurricanes must be created by unusually large and rapid transfer of solar wind energy and charged particles into the Earth's upper atmosphere," he continued.
"Plasma and magnetic fields in the atmosphere of planets exist throughout the universe, so the findings suggest space hurricanes should be a widespread phenomenon."
The space hurricane, which happened during a period of low geomagnetic activity, was discovered to share main features with hurricanes in the Earth's lower atmosphere.
The scientists said the process may also be significant for the interaction between interstellar winds and other solar systems throughout the universe.
"A space hurricane over the Earth’s polar ionosphere" - He Zhang, Q., et al. - Nature Communications - https://doi.org/10.1038/s41467-021-21459-y
In Earth’s low atmosphere, hurricanes are destructive due to their great size, strong spiral winds with shears, and intense rain/precipitation. However, disturbances resembling hurricanes have not been detected in Earth’s upper atmosphere. Here, we report a long-lasting space hurricane in the polar ionosphere and magnetosphere during low solar and otherwise low geomagnetic activity. This hurricane shows strong circular horizontal plasma flow with shears, a nearly zero-flow center, and a coincident cyclone-shaped aurora caused by strong electron precipitation associated with intense upward magnetic field-aligned currents. Near the center, precipitating electrons were substantially accelerated to ~10 keV. The hurricane imparted large energy and momentum deposition into the ionosphere despite otherwise extremely quiet conditions. The observations and simulations reveal that the space hurricane is generated by steady high-latitude lobe magnetic reconnection and current continuity during a several hour period of northward interplanetary magnetic field and very low solar wind density and speed.
Featured image credit: Qing-He Zhang/Shandong University