It is not inconceivable that even the most die-hard aurora borealis enthusiasts are starting to stiffen their necks now. Recently, there have been good conditions for those who wish to see the light phenomenon in the night sky. We are in a period where the sun is very active. And it will probably get better. It is expected that the activity in this solar cycle will peak in 2024 or 2025. On the night of Friday, a so-called “cannibal solar storm” produced strong northern lights over the whole of Norway. The sun always emits some particles towards the earth. A “cannibal solar storm” occurs when the sun sends out several clouds of particles towards the earth, one after the other. – One or more of the rearmost clouds lead the cloud, so that it ends up as a giant cloud on its way to earth. It is these particle clans that create the northern lights, says physicist Veronica Danielsen. But the play of colors in the sky can come at a price. Particle clouds that create the northern lights can also damage and affect important infrastructure. The Norwegian Directorate for Social Security and Preparedness (DSB) believes that aliens are one of the biggest threats to our society. More on that later. First, some questions and answers about the play of colors in the sky. What is a solar cycle, and what is a sunspot? Just like the earth, the sun has a magnetic north and south pole. These poles move, and over a period of around 11 years these magnetic poles switch places. In the end, they each end up at their own geographic pole, i.e. the northernmost and southernmost point on the sun. It is a solar cycle. I started counting this in the middle of the 18th century. Now we have reached cycle number 25, explains Danielsen. – When a magnetic pole is in the vicinity of a geographic pole, it is quite quiet on the sun, says Danielsen and continues: – But when the magnetic poles are around the equator, the sun becomes really active. There will be magnetic chaos, and we will get more solar storms and more northern lights than usual. Veronica Danielsen is a physicist and science communicator, and works at the ViteMeir science center in Kaupanger. Photo: Lina Hindrum It is called a solar maximum, which is now approaching us in 2024. Sunspots are areas on the sun where the magnetic field has “frozen” a little. If there are many sunspots, there is more activity than if there are few sunspots. – This year, for example, there hasn’t been a single day without a sunspot on the sun. When it’s calm, a whole year can go by without us seeing a single spot, says the physicist. What determines what color the northern lights have? Northern lights occur when particles collide with gases in the atmosphere and transfer energy to them. The gases cannot hold this energy for long, so they emit it again as light. – The various gases can only emit fixed amounts of energy. And the amount of energy determines the color of the light. The short explanation is that the color is the gas’s fingerprint. Northern lights over Jølster, early in November. Photo: Torje Bjellaas / news The different gases are at different heights above the sea surface, so the color of the northern lights can say something about how high above us it is. Danielsen explains: Red northern lights come from oxygen around 250 km above us Green northern lights come from oxygen between 100–200 km above us Pink northern lights come from nitrogen gases between 80–100 km above us Blue northern lights come from nitrogen gases, sometimes as high as 180 km above us, but usually less than 120 km above us – But the pink northern lights are not actually pink. It is a mixture of violet light that is emitted from electrically charged nitrogen gas, and dark red light that comes from neutral nitrogen gas. Between the biggest threats to our society In the Directorate for Social Security and Preparedness (DSB)’s analysis of the crisis scenario that could happen to Norway from 2019, they have given space a chapter of their own. DSB looks at previous solar storms that have knocked out or led to interruptions in telecommunications and electricity supply. It happened in 2003, when a powerful solar storm led to technical problems with satellites and satellite phones from several places in the world. In Malmö, the power went out for an hour. In South Africa many transformers were destroyed. Problems with communication and navigation affected aviation, and passengers were warned of increased radiation danger. The color of the northern lights says something about how high in the sky it is. Photo: Torje Bjellaas / news The costs associated with the solar storm were calculated at around NOK 40 billion. But solar storms cannot harm humans directly. As long as I’m on earth. The radiation can lead to health problems for aircrews who fly a lot over the polar region. DSB writes that if a solar storm is strong enough, it can lead to voltage drops in the power grid. If the power grid in several countries is switched off at the same time, American experts believe that the consequences could be enormous. We are now in a period with a lot of activity in the sun. The result is more northern lights. Photo: SOHO (ESA & NASA) / SOHO (ESA & NASA) The directorate also writes that the Norwegian power system is robust against solar storms, compared to other countries. They still do not rule out shorter periods of power outages in Norway, in the event of a strong solar storm.
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There will be more of this in the future – news Norway – Overview of news from various parts of the country
