The fact that during the 11-year cycle that the Sun lives, the solar storms that can reach the Earth’s atmosphere are amplified or weakened is due to the fact that our star goes through a type of seasonal variability, according to the latest study. carried out by a team of researchers from the National Center for Atmospheric Research (USA) included in the journal Nature Communications .
We are currently in Solar Cycle 24 , which officially began on January 8, 2008 and until now it was unknown why its activity increased and decreased within the same cycle until it culminates in “solar maximum” every 11 years or so.
The truth is that the Sun goes through two variations, like two seasons, driven by bands of strong magnetic fields in each solar hemisphere. Examining the influence of magnetic bands on several interrelated cycles of solar magnetism they discovered two overlapping parallel bands of opposite magnetic polarity that slowly move over a period of almost 22 years from the hemispheres towards the Sun’s equator .
“By better understanding how these bands of activity form on the Sun and cause seasonal instabilities , we have the potential to greatly improve forecasts of space weather events,” explains Scott McIntosh, study leader.
The work proposes that the superimposed bands are fed by the internal rotation of the Sun ; thus, as the bands move within the hemispheres, the activity peaks over a period of about 11 months and then begins to decline. This variation could be equated on Earth as the passage from a rainy to a dry season (as in the equatorial and tropical zones).
This discovery has been made possible thanks to data from various NASA satellites as well as ground-based observatories that collect daily information on the structure of the Sun and the nature of solar flares and coronal mass ejections.
It will help, among other things, to obtain better predictions of massive geomagnetic storms in the Earth’s outer atmosphere that sometimes disrupt the operations of satellites, communications, power grids and other technologies.
