Fantastic Aurora display

A magical night in the Swedish mountains. It started as a green glow in the north that developed into an arc that then increased in strength and went higher in the sky, finally to the zenith with curving green waves of light. The green glow flashed across the entire sky as if the atmosphere was shaking.

The northern lights (aurora borealis) affect the Earth's atmosphere, mainly in the upper layers such as the thermosphere and the ionosphere. The phenomenon occurs when charged particles from the sun collide with oxygen and nitrogen in the atmosphere at the magnetic poles. Main effects of the northern lights on the atmosphere: Energy input and heating: The northern lights are the result of an enormous energy input from the solar wind to the atmosphere. This causes local heating in the upper layers of the atmosphere. Electric currents: In connection with the northern lights, strong electric currents arise in the atmosphere, so-called auroral electrojet streams. These currents can affect the Earth's magnetic field. Ionosphere disturbances: Aurora activity can affect the ionosphere (the part of the atmosphere that is ionized), which in turn can disrupt radio communications and satellite navigation. Faint moonlight via a fine crescent moon and bright planet Jupiter also visible.

Aurora Corona

When the northern lights are really strong, you might be lucky enough to see them at their zenith, overhead like a corona. The picture shows the beginning of a corona last week.

An aurora corona is a spectacular form of aurora that occurs when you are directly under the magnetic field lines.

It looks as if all the light rays are radiating from a single point high in the sky (the zenith).

Why? It's a perspective effect, just like when parallel train tracks appear to meet on the horizon. In reality, the aurora rays are parallel and follow the Earth's magnetic field, but from the ground they appear to form a "crown" (corona in Latin).

Cabin Aurora

A week's stay in the family's mountain cabin where the starry sky is very dark. One night the northern lights played fantastically beautifully and went high up in the sky above the cabin. The Big Dipper is seen in the middle of the picture, upside down. It almost forms a corona of the northern lights just above. Earlier in the evening I was able to witness a corona right in the zenith, pictures will come later.