As anyone who has witnessed the aurora australis or aurora borealis, the lights created by solar winds meeting Earth’s magnetic field are a beautiful site to behold. As any who has lived through power outages, haywire computers and disrupted communications can attest, the meeting of solar winds and magnetic fields can also be catastrophic. If only there was a place where their effects were lessened of minimized. It turns out there is. New research using data from the European Space Agency’s (ESA)’s Swarm satellite constellation found a "surprising" imbalance, with solar winds heading to the North Pole far more frequently than the South Pole. Are reindeer antlers acting as solar lighting rods? The actual reason is just as strange and mysterious.
“Here we advance a paradigm which can explain the observed persistent asymmetry and northern preference for incoming Poynting flux at Swarm altitudes based on the known offset of the magnetic dipole moment from the centre of the Earth towards the northwest Pacific. This offset generates different relative effective solar illumination of the auroral ovals in the northern and southern hemispheres arising from the rotation of the Earth. The offset can also introduce asymmetries in the magnetic fields in the auroral zones as well.”
What? Fortunately, a University of Calgary press release gives a simpler summary of the paper, published in Nature Communications, written by a team from that school and the University of Alberta. The University of Calgary developed and operate the electric field instruments (EFIs) on the three Swarm satellites. The EFIs give precise measurements of ionospheric winds and temperatures – measurements which show a clear preference of north over south by solar winds. “North” and “south” in this case refer to the magnetic field poles. In an ESA press release, lead author Ivan Pakhotin attempts to explain the preference.
“Because the south magnetic pole is further away from Earth’s spin axis than the north magnetic pole, an asymmetry is imposed on how much energy makes its way down towards Earth in the north and south. There seems to be a differential reflection of electromagnetic plasma waves, known as Alfven waves. We are not yet sure what the effects of this asymmetry might be, but it could also indicate a possible asymmetry in space weather and perhaps also between the Aurora Australis in the south and the Aurora Borealis in the north. Our findings also suggest that the dynamics of upper-atmospheric chemistry may vary between the hemispheres, especially during times of strong geomagnetic activity.”
In simpler terms, somehow the Earth’s magnetic field itself is routing more energy, in the form of plasma waves, north rather than south. It could be caused by space weather anomalies, unexplained differences in upper atmospheric chemistry or even some kind of weird preference by the Sun for the northern hemisphere. Whatever the reason, us non-scientists can see the difference in the Northern and Southern lights, especially during different seasons.
Ultimately, it starts with the magnetic South Pole being father way from the axial South Pole than the magnetic North pole is from its axial counterpart. More research is needed, especially because it will tell us how to interpret solar winds and electromagnetic fields when searching on other planets for life or possible settlement sites. Finally, it leads us to potentially safer locations on Earth when that apocalyptic solar flare ultimately hits.