The sunset was too early

Today we had another clear morning with a temperature of -23 °C and not a single cloud. According to SMHI and The Photographer’s Ephemeris sunrise at our place in Obbola was at 07:32 today. While I was still walking on the sea ice to have a better view of the sunrise the sun already appeared – three minutes too early. The reason for this is atmospheric refraction due to an inversion above the ice that bends the light and so “lifts up” objects in the distance.

Sunrise and atmospheric refraction

To the right in the photo: The lighthouse Storbränningen, which I visited two days ago. It is about 4 km away. I could also spot the lighthouse Väktaren – 7 km away – although the distance to the horizon is technically only 4.5 km. I can even still see some construction far, far away on a bearing of 140° but I haven’t worked out what it is. Finland perhaps … ?

2 comments to “The sunset was too early”

  1. Stephen 2026-02-16 22:34

    I love reading reports like this! Refraction is a tricky variable to account for. In case you haven’t seen it, Andrew Young’s pages on the subject are fascinating if you enjoy geeking out over these topics: https://aty.sdsu.edu/mirages/mirintro.html

  2. way-up-north 2026-02-17 06:18

    That looks interesting, Stephen. Thanks for sharing!

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