The increase in solar activity has become quite obvious on Earth, thanks to the increase in auroras caused by geomagnetic storms, but while astronomers had previously believed that the Earth might be stripped temporarily of its radiation belts, causing the charged electrons to inundate the atmosphere, new data has shown that the deadly particles will actually be blown back into space.
The Van Allen radiation belts circling Earth include streams of highly charged electrons. When the particles from the sun collide with the magnetic field that shields Earth from the worst effects, the resulting geomagnetic storms can decrease the number of dangerous electrons.
These charged electrons can create havoc on telecommunications satellites and post a danger to astronauts in space, but astronomers had yet to find where these particles ended up. Each geomagnetic storm results in a strange dip, also known as dropouts, in the number of charged particles in the radiation belts. These dropouts happen a few times a year, but when the sun enters an active phase, as it is now, this can happen several times each month.
Scientists from the University of California, Los Angeles, observed a geomagnetic storm in January 2011 with their instruments. They noticed intense solar activity pushes against the outer edge of the Earth’s magnetic field, sliding the lines across, allowing the electrons to escape into space.
The findings were published in the journal Nature Physics. Coronal mass ejections from Sol can deplete the Earth’s outer radiation belt, but the belt is resupplied within a few days. Eleven different satellites, including NASA’s five Themis spacecraft and two weather satellites operated by the National Oceanic and Atmospheric Administration and the European Organization for the Exploitation of Meteorological Satellites were pooled together to capture a complete picture of the interaction.
The upcoming launch of NASA’s Radiation Belt Storm Probes Mission, scheduled for later this year in August, may help further the studies.