Just look at the sky again. It will always surprise you! Within the last 2 days, two very rare phenomenona were captured over Norway and Hawaii. The spotless sun sparked pink auroras over Tromso, while an extremely rare light pillar formed off the Mauna Kea volcano.
On Feb. 23rd the sun was completely blank, without sunspots and NOAA classified solar activity as “very low.” Nevertheless, a beautiful display of auroras with a vivid splash of pink were captured by Andrei Andritcu over Tromso, Norway:
In auroras, pink is a sign of nitrogen. Pink appears when the energetic particles descend lower than usual, striking nitrogen molecules at the 100 km level and below. The most common auroras appear green. These occur at about 100 kilometers high and involve atmospheric oxygen atoms excited by fast moving plasma from space. The next highest auroras – at about 200 kilometers up – appear red, and are also emitted by resettling atmospheric oxygen. Some of the highest auroras visible – as high as 500 kilometers up – appear blue, and are caused by sunlight-scattering nitrogen ions.
As Solar Minimum nears, it is kind of baffling to see such high-energy colors in the sky… And that on a spotless day! Perhaps solar wind emerging from the spotless sun is unusually penetrating. If so, we can expect to see more nitrogenous auroras in the years ahead. The sun is descending into a deep Solar Minimum, and the nadir (expected in 2019-2020) could be colored pink.
Meanwhile, in the sky over Hawaii, an extremely rare light pillar was captured by the automated Gemini webcam on Hawaii’s Mauna Kea volcano on Feb. 13th.
Light pillars usually occur in cold climates… So to see them this far south is very unusual. The source of the crystals, in this case, was probably a bank of altostratus/cumulus clouds shown in the video.
Light pillars appear when urban lights reflect from the flat faces of ice crystals fluttering down from high freezing clouds. They have been reported in recent days across Russia as seen on the Facebook page Meteor Shower Tonight:
These are two very strange sky phenomena: high-energy aurora during spotless sun and light pillar so far south or in a location like Hawaii… What’s going on?