Experts link the recent observations of the northern lights in the Peninsula with greater solar activity. Jets of incandescent material from the sun loaded with energetic particles, which interact with the Earth's magnetic field, are responsible for these spectacular luminescent formations that have been seen in Spain in recent times.
On the Peninsula, several aurora observations have been documented in recent months, especially in Extremadura. Last week one could be seen in Cáceres, captured by astrophotographer Javier Caldera, and also (although more timidly) at the Pujalt observatory. In April, the sky over Casar (Cáceres) was dyed in pink and lilac tones, photographed by Lorenzo Cordero.
The detection and observation of boreal storms in Spain “is not a new phenomenon,” highlights meteorologist José Miguel Viñas, although “usually, solar storms do not have as great an intensity as the one that has occurred now,” he adds. Episodes of this type are recorded about twice a year, although in some years they are not seen. Furthermore, not all of them have the same intensity or spectacularity.
Naturally, the sun's wind sends a continuous flow of highly charged electrical particles that the Earth's magnetic shield drifts towards the poles, so that auroras occur in these areas without usually extending to mid-latitudes.
“Auroras are frequent in the polar areas; But in mid-latitudes they are rare, they need a disturbance of the magnetic field intense enough for them to occur and be appreciated,” says José Antonio Sosa, Aemet meteorologist. Furthermore, in urban areas it is impossible to detect them, even if they occur, due to light pollution.
Sosa points out that the possibility of an aurora occurring does not depend on the time of year but on the existence of disturbances in the Earth's magnetic field, something that in turn depends on magnetic activity of solar origin.
“There is a cycle of modulated solar activity every 11 years, and we are now approaching the maximum of solar activity, which is expected to occur around next year.”
Toni Barrera, meteorologist at the Servei Meteorològic de Catalunya, agrees that the observation of auroras is not usually common, and also relates it to the fact that “the sun is more active these days.” In this sense, he recalls that the British office (Met Office) also issued a warning and that these same observations have occurred in other places in Europe.
Auroras occur when jets or flows of charged particles (electrons, protons...) from the solar wind precipitate and collide with molecules and atoms in the Earth's atmosphere.
The result is that these elements ionize, emit radiation and cause the characteristic luminescent effect. Solar activity violently expels a large amount of incandescent material outward, although in a variable manner.
The color will depend on the particles. Oxygen is responsible for green and red-orange colors, while nitrogen promotes blue and purple colors. All this spectacle occurs just 100 kilometers above our heads.
Will we see more auroras in these parts? "Surely. What can't be said is when. All you need is a sufficiently intense geomagnetic storm,” says Sosa.
The sun is increasingly monitored with satellites, and when a large solar storm occurs there is a certain capacity for anticipation, says Viñas. The World Meteorological Organization requests that national services consider these observations.
Viñas highlights that to view the auroras two conditions are required: that the solar storm be powerful and that the main flow goes towards the Earth, since "many times the sun registers a great storm, which has been detected by the satellite, and fortunately not “It moves towards the Earth.”
The sun is increasingly monitored with satellites that are continuously measuring various parameters, and when a large solar storm occurs there is a certain capacity for anticipation. There are even applications that warn you when they can occur. The World Meteorological Organization requests that national meteorological services consider these observations.
