Scientists have revealed new evidence of space wind, confirming a theory proposed 20 years ago. ‘Plasmaspheric wind’ is an elusive phenomenon and its existence helps scientists understand how the atmosphere protects us from violent solar winds.
Proof of space wind was uncovered in a study in European
Geosciences Union journal Annales Geophysicae. The so-called
‘plasmaspheric wind’ is actually created by the Earth.
Essentially, an imbalance between centrifugal and pressure forces
and gravitational pull causes the steady flow of ionized
particles from inside the atmosphere to the magnetosphere.
The magnetosphere is the region of space surrounding the earth that is governed by the planet’s magnetic field.
"After long scrutiny of the data, there it was, a slow but steady wind, releasing about 1 kg of plasma every second into the outer magnetosphere: this corresponds to almost 90 tons every day," said Dr Iannis Dandouras, author of the study. He added the discovery was “one of the nicest surprises I've ever had."
From the data, Dandourus calculated that the winds carry plasma (superheated gas) a day from the lower atmosphere into the magnetosphere at speeds of some 5,000 kilometers per hour.
Dandourus collated data from the EU Space Agency’s Cluster
mission which was launched back in 2000. The Cluster mission is
made up of four satellites that monitor the relationship between
the Earth’s magnetosphere and solar winds.
The study will help scientists increase their understanding of how different layers of the Earth’s atmosphere interact with each other and protect the planet from solar winds. Furthermore, the findings indicate that other planets and celestial bodies that have similar atmospheres and rotations should also generate ‘plasmasphereic wind.’
The violent solar winds
composed of charged particles that are ejected from the Sun would
be quite deadly to Earth’s inhabitants if it were not for the
Earth’s atmosphere and magnetic field. The two work in tandem to
block x-rays, ultraviolet radiation and charged particles from
reaching the planet’s surface.
"[The discovery] shows how interconnected different layers of the atmosphere are in protecting Earth from solar wind," says Dr David Neudegg from the Bureau of Meteorology's Ionospheric Prediction Service, which monitors space weather.
Researchers first proposed the idea of the existence of space wind flowing from the lower atmosphere into the magnetosphere 20 years ago, but were unable to prove their theories.