It is a rare spectacle at low latitudes, more common in Nordic skies, but this time it was even visible in Portugal. This Friday night was marked by aurora borealis visible in several countries, at lower latitudes than usual, including in Portuguese territory. Tonight’s phenomenon, marked by skies painted in shades of pink or purple, could be observed with the naked eye in less lit places, away from urban areas.
Viseu, Coimbra, Guarda or Portalegre were some of the districts where the aurora borealis was observed in mainland Portugal, as evidenced by photographs and testimonies shared on social media by pages of meteorology enthusiasts such as Meteo Trás-os-Montes.
https://twitter.com/MeteoTrasMontPT/status/1789062614074454163
At the origin of the phenomenon is an electromagnetic storm of great intensity, potentially the largest in recent decades, within the framework of a cyclical period of great solar activity that reached its peak this year.
The aurora borealis occur when, during periods of solar activity, there is a projection of matter that reaches the Earth’s atmosphere. The particles expelled by the Sun interact with the Earth’s magnetic field, especially in the polar areas, resulting in the famous displays of colored lights, usually green or blue, that recur in the Arctic and Antarctic skies.
When very strong solar storms like the current one occur, the aurora borealis produce redder lights (pink, orange or purple tones) and are visible at low latitudes – that is, further away from the polar areas.
According to the North American meteorological services, we are currently witnessing a “series of solar explosions and coronal mass ejections that began on May 8”, originating from a spot on the solar surface 17 times larger than the Earth, and which could generate new northern lights throughout this weekend. In other words, there may be a new opportunity to watch the phenomenon on the night of Saturday to Sunday.
In Europe, and according to images disseminated by news agencies and testimonies shared on social media, it was possible to see night skies in shades of pink in areas as far south as the Iberian Peninsula, including in Portugal, and in Italy, in addition to a range that includes France, Switzerland, Germany and Austria. They are also visible in Eastern Europe, including Ukraine and Russia.
In North America, in addition to Canada, the aurora borealis will be visible in much of the United States. States further south such as California and Alabama could be the stage for a show that is unusual for their latitude.
In the Southern Hemisphere, in turn, there are records of colored lights in the skies over New Zealand and the Antarctic Peninsula.
Solar storms, like the one occurring now, are not associated with harmful effects on health. They can, however, cause disturbances in more sensitive devices, including telecommunications satellites, and in electrical distribution networks.
