Thursday 9 March 2023

Unusual Elliptical Halos May 8th 2022 in Japan


On May 8, strange elliptical halos were captured by Pipibun in Kunimi, Fukushima prefecture, Japan.

At 14:30 that day, there were cirrus and cirrostratus clouds in the sky, and some frequent halo forms appeared. After taking pictures for a while, the observer moved about 20 km to the north. 


At about 16:10, looking at the sky again, altocumulus clouds over the sun and the double elliptical halos appeared above it. The display lasted for 20 minutes. With the sun 23-26° high, major axis of outer ring was about 10° and minor one was 5°. 

The shapes of the elliptical halos are varied and are thought to be affected by apex angle of the flat pyramidal crystals (or possibly dendritic snow-type crystals.) Additionally, they are known to become sometimes multiple and inner rings are basically similar ellipsoid. Therefore, were there at least two different gradient responsible crystal groups in that sky?

1 comment:

  1. Welcome to the platform Ryota! This one is truly an eye-opener. Can't wait to see more great stuff from Japan.

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