Elliptical halo today

[Michael Ellestad]

Hi,


For the second time this year I get another elliptical halo and this one was a lot better. My brother and I were driving our ATV down the road and happened to look and spotted a whitish elliptical halo and I was like stop the quad!!! I got the camera and snapped on the macro lens and fired away. The halo persisted for at least 15 to 20 minutes and there was only one ellipse present. This is the third observation this year in the USA.


All of the best,

Michael

[Michael Ellestad]

Hello again,


Images of last weekends elliptical halo are on my gallery at spacew.com


http://www.spacew.com/gallery/image005133.html

This is of great interest to the Czech Republic halo watchers.

Take care,

Michael

[Jan Hattenbach]

Hello Michael,

this looks very similar to the ellliptical moon halo presented on www.spaceweather.com a few days ago. Do you know any explanation for elliptical halos on the web?

Jan

[Michael Ellestad]

Hello Jan,


Elliptical halos are formed when light refracts through a special type o fpyramidal crystal that is similar to the one that forms the familiar odd radius halos but unlike the standard pyramidal crystal, the type that forms elliptical halos has a gentle sloping pyramid instead of a pointy one. To form the ellipse the crystals have to have the same orientation just like orinted plates and the resulting halo(s) are elliptical in shape and the upper and lower vertical radius can vary with sun elevation. The crystals that form these unusual halos form from AC clouds that are dissapating and the day the halo appeared there were AC clouds. I have never heard of any reports of this halo with ordinary cirrus clouds.




Greetings,

Michael USA

[Jan Hattenbach]

Hello Michael,

thank you for this explanation. I will look out for this phenomenon, of which I have not heard of until a few days ago. Unfortunately, we have St clouds here for days, no moon or sun visible at all :-(

Regards,

Jan