For the first–time, a hurricane detected in Earth’s upper atmosphere. In 2014, satellites recorded an enormous flowing swirl of plasma extending high into the magnetosphere that lasted for hours, before dispersing.
Although we have never seen anything like this before, its detection suggests, space hurricanes, as they’re known, might be a common planetary phenomenon.
“Until now, it had been uncertain that space plasma hurricanes even existed, so to prove this with such a striking observation is incredible,” said space environment physicist, Mike Lockwood of the University of Reading in UK.
Hurricanes in Earth’s lower atmosphere are common powerful, rotating weather systems around a relatively calm center, accompanied by strong winds & lashing rain which can cause vast amounts of damage in a very short-time.
They aren’t uncommon on other bodies, either: Jupiter & Saturn, especially, are extremely turbulent places, to not mention roiling plasma tornadoes deep in the atmosphere of the Sun.
Space hurricanes, the new work reveals, aren’t dissimilar to their lower atmosphere cousins.
The detections made on 20 August 2014 and revealed during a retrospective analysis led-by Shandong University in China. Consistent with the data, hurricane appeared over the North Pole, extending to a diameter of 1000 kilometers (621 miles).
It reached from 110 kilometers to 860 kilometers in altitude and consisted of plasma with multiple spiral arms, swirling in an anti-clockwise direction at speeds up to 2100 meters per second (6900 feet per second). The center, however, was almost still, a little like in hurricanes at lower altitudes.
Unlike other hurricanes, however, space hurricane rained electrons into the ionosphere. This had a wonderful effect: an enormous, cyclone-shaped aurora below the hurricane. The entire thing lasted nearly 8 hours, depositing vast amounts of energy & momentum into the ionosphere.
Conditions were other-wise quiet, which posed a mystery. A rain of charged-particles into the ionosphere from the solar wind is what usually produces glowing green aurorae at Earth’s higher latitudes, but solar conditions at the time were relatively quiet. Therefore, the team turned to modelling to find-out what caused the plasma ruckus.
“Tropical storms are associated with huge amounts of energy and these space hurricanes must be created by unusually large & rapid transfer of solar wind energy and charged particles into the Earth’s upper atmosphere,” Lockwood explained.
We know, reconnecting magnetic field lines can transfer solar wind energy into the magnetosphere & ionosphere, therefore, the team modelled this process & found that a re-connecting interplanetary magnetic field can produce the features they observed in the space hurricane, even when the solar wind is low. In fact, the low solar wind could be key, it allows for more efficient magnetic re-connection.
It also means, such storms might be quite common.
“Plasma & magnetic fields in the atmosphere of planets exist throughout the universe, so the findings suggest space hurricanes should be a widespread phenomenon,” Lockwood said.
There are implications for Earth, too. Knowing that aurorae can-be the product of space hurricanes and what these aurorae look like, could help-us identify other such storms in the future.
It also shows that even when geomagnetic conditions are relatively quiet, space can whip-up extreme weather, which can impact life on Earth and the skies above it.
“This study suggests that there’re still existing local intense geomagnetic disturbance & energy depositions which is comparable to that during super storms. This can update our understanding of the solar wind magnetosphere ionosphere coupling process, under extremely quiet geomagnetic conditions,” said space physicist & first author, Qing-He Zhang of the Shandong University.
“In additional, the space hurricane will lead-to important space-weather effects like increased satellite drag, disturbances in High Frequency radio communications and increased errors in over the horizon radar location, satellite navigation & communication systems.”
The research has been published in Nature Communications.