AsianScientist (Dec. 2, 2016) – A team of researchers in India and Japan have discovered a new danger to our technologically advanced society: The weakening of the Earth’s transient magnetic field, which may pose a threat to astronauts in space as well as modern infrastructure. Their work was published in Physical Review Letters.
Solar storms emit energetic charged particles including cosmic rays, which are detrimental to modern technology and electronics. Our Earth is protected from these particles by its geomagnetic field, which deflects them over several Earth radii. While some of these storms have reached our planet and been recorded in history with little event, a similar occurrence today could severely affect our technological society, crippling smart devices and satellites with the high radiation environments.
One such eruption of solar flares occurred on June 21, 2015, triggering radio blackouts as the radiation reached Earth. To better understand these solar flares, the research team collected the data surrounding the radiation bursts with the large area GRAPES-3 tracking muon telescope.
GRAPES-3, located at the Tata Institute of Fundamental Research’s (TIFR) Cosmic Ray Laboratory, detected a two hour burst of galactic cosmic rays on June 22, 2015. Using a series of corrections to account for atmospheric pressure variations and instrumental factors, the team analyzed about 20 gigabytes of data per day and found that the burst of cosmic rays was strongly correlated to a surge in the interplanetary magnetic field.
Their results suggest that the burst originated close to Earth, possibly within the magnetosphere. This finding was verified by the extremely short time offsets of the bursts between the vertical direction (V) and three other cardinal directions (namely NE, E, SE). Testing their hypotheses using simulations methods, the researchers found that their predictions correlated strongly with the observed data.
Secondly, the detected increase over the duration of the burst also implies a two-hour weakening of the Earth’s protective shields, affecting not only radio systems, but potentially exposing astronauts to a high dose of radiation.
“Space weather is of paramount importance since it affects astronauts and satellites in space, as well as communications on the ground,” said project leader Professor Sunil Gupta of TIFR, reflecting on the implications of such an occurrence.
“However,” he added, “our recent detection of the transient weakening of the geomagnetic field has shown that equal attention needs to be devoted to space weather aspects as well.”
The team also hopes that the analysis of this data may hold clues for better understanding of future superstorms.
The article can be found at: Mohanty et al. (2016) Transient Weakening of Earth’s Magnetic Shield Probed by a Cosmic Ray Burst.
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Copyright: Asian Scientist Magazine; Photo: Sunil Gupta/TIFR.
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