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Michael wrote:
> BTW: Anyone seen any good halos lately?
I have, actually. I recently took a transatlantic flight,
and there were several phenomena to see. I saw a subsun,
as I often do on flights, and this set me wondering on a
philosophical question - if there were such things like sundogs
as a subsun is to the sun, then should it be called subsundog or
sunsubdog? I couldn't remember whether there was an official name
for such a thing, but I eventually settled on "subsundog" and went
back to snoozing. I was then surprised a few minutes later, to
see a subsundog (actually, several at intervals of several minutes).
The first of these was quite faint, as I'd expect from a
subsundog, but I was excited to see it nevertheless, and it
faded within a few minutes. It then set me wondering whether
you could get stronger ones, maybe anything approaching the
strength of sundogs you might see in the sky, like the strong
ones you get from a contrail?
I didn't have to wonder long. A few minutes later, the subsundog
was back with a vengeance. Boy, were the colours strong! Not only
that, but there was more. You know how when sundogs appear on
the 22deg halo circle, and although you might not get much in
the way of halo, you may get "spikes" of light outside the halo,
pointing away from the sun? And these spikes of light appear to
curve upwards, the more so, the higher the sun is (I understand that
they don't actually curve higher in the sky, they just curve further
round the altitude circle the sun is on, which technically makes
them curve level but not up, but relative to the field of view, they
curve up). Well, this subsundog had a spike, a perfect down-curving
spike.
No subhalo was visible, nor a sundog, although interestingly enough,
the halo of the sun was visible, and made for an interesting view!
Sharon
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