Atmospheric Optics – Crayford Manor House Astronomical Society Dartford

Parhelia (Sun Dogs)

Sun dogs are a common bright circular spot on a solar halo. It is an atmospheric optical phenomenon primarily associated with the reflection or refraction of sunlight by small ice crystals making up cirrus or cirrostratus clouds. Often, two sun dogs can be seen (one on each side of the sun) simultaneously.

Jim Burchell’s Images

Terry Miles’ Images

Honor Wheeler’s Images

Images by John Howarth

I must admit that the picture does have a certain surreal quality, which will hopefully make up for any lack of scientific weight! When I first saw the mock-sun I genuinely thought for an instant that it was the real one behind high cloud, but then realised that it was in the wrong direction and the real sun was going down behind the houses on the right!

It was taken 4 January 2019 at 1427UT with an Alcatel One Touch Pixi 3 (not my choice of name, but so be it) Model 4009X and was allegedly 1680x1120 pixels before JPEG compression. It hasn’t been processed in any way.

The location was about halfway along Eastry Road, location 51deg 28′ 33″N, 0 deg 9′ 3″E to the nearest 100 feet or so.

The parhelion (to left) was visible from Bexleyheath train station at 1646hrs today 18th March 2019. The sun is partly obscured by the tree in both pictures. There was no parhelion on the right hand side of the sun.

The camera was in a Samsung GT-E3210B mobile phone, which was all that was to hand at the time.

Circumzenithal Arc’s

Images by Honor Wheeler

Noctilucent Cloud

Noctilucent clouds are phenomena seen during the summer twilight (June and July for the northern hemisphere and December and January for the southern). It is caused by sunlight striking stratus clouds at a height of around 82km.

Honor Wheeler’s Images

Simon Dawes’ Images

Martin Crow’s Images

Multiple Phenomena

If you are observant you will occasionally be rewarded with multiple phenomena in the sky as these images by members show.

Martin Crow’s Images

Honor Wheeler’s Images

Atmospheric Optic Picture of the Day

Our very own Honor Wheeler makes Optics Picture of the Day (20/03/2010) at the world renowned site for extra special atmospheric optics. “I live in Kent, in the Southeast of England and so don’t usually expect complexity in a halo display as the conditions are never quit right. Today, however, I was amazed and excited to photograph sundogs, a partial 22deg halo, an upper tangent arc, a Parry arc, circumzenithal arc and a partial supralateral arc. I’ve photographed all but the supralateral arc separately before but never all together! These photos were taken between 15.34 and 15.41UT but overall the display lasted for approx 20 minutes with the circumzenithal arc lasting the longest.”

If you have HaloSim installed, run the simulation yourself after downloading the simulation file kent.sim