Many of us think that there is just one polar night that is dark, cold, and endlessly long. But in fact there are many types of polar nights, from light grey to pitch-dark black. There are plenty of things to do and to see during the dark season. The further north you head, the darker and longer the polar night gets. Longyearbyen – being one of the most northern settlements in the world – gives us the perfect opportunity to observe the exciting darkness.
Polar twilight occurs in areas that are located at the inner border of the polar circles. The sun will be on or below the horizon all day and there is no true daylight. The sun is less than 6° below the horizon. Person looking out from window may see their own reflection even at noon. But it is possible to conduct outdoor activities without any artificial light. In Longyearbyen the twilight season starts on the 26th of October. The next time sun reaches above the horizon is on the 16th of February.
Civil Polar Night
The civil polar night period produces only a faint glow of light visible at mid-day. Civil polar night occurs when the sun is 6° or more below the horizon. Therefore the civil polar night is limited to latitudes above 72° 33′. No place on the mainland Europe meet this definition. Here in Longyearbyen we have civil polar night from approximately the 14th of November until the 29th of January.
Nautical polar night
During the nautical polar night, there is only a small refecltion on the horizon around mid-day. During this period the sun is lower than 12° below the horizon, so nautical polar night is limited to latitudes above 78° 33′. Longyearbyen is located at 78° 13′, and is just on the border for nautical polar night.
The Astronomical Polar Night
Astronomical polar night happens when the sun is more than 18° below the horizon. It is limited to latitudes above 84° 33′. There are no permanent settlements anywhere in this range of latitude, and most of the area is covered by sea ice.