This morning, I saw a rainbow segment which turned the wrong way I expected it to go. It not only was between the sun and I (I expect to be between the sun and the rainbow), but it turned away from the sun, as opposed to around it.
Like this: ) *
instead of this: ( *
Is this normal? What causes this? It goes against what little I understand about rainbow formation.
It could have been a parhelia.
Parhelia aren’t arcs, so it couldn’t be one of them. There are several ice crystal arcs, however, that do curve away from the sun.
For instance, the circumzenith arc. As the name implies, it’s centered on the zenith, not the sun:
http://www.weatherscapes.com/album.php?cat=optics&subcat=circumzenith_arc
The Upper Tangent Arc and the Lower Tangent arc are two others:
The **Parry Infralateral Arc is another. You can also see some others on this page. I’ve seen the Parry arc. It looks uncannily like a rainbow, but in a completely wrong place:
Certainly not parhelia and not circumzenith. Upper tangent could be the one. I have no idea if that is reasonable for my location, time and weather (Puerto Rico, just before 7 am, warm and messy).
It didn’t look to be right above the sun, though. More like to a side.
Ice Crystal Halos have been visible in the hot desert – it only requires that the ice crystals be present somewhere, and cirrus clouds in the upper at,mosphere are cold enough. It doesn’t matter that it’s warm and messy down below where we are.
If it’s off-center, it could be the Infralateral Arc, as I’ve mentioned, or a Subhelic Arc. Both of these, however, are below the sun. There are a lot of weird arcs due to pyramidal ice crystals anbd other weird forms, but they’re much rarer.
Ok. It took me some time and brain sweat, but I just figured how to read that chart. Infralateral Arc looks like the most possible one. Pretty cool. Thanks.
In one hand is cool to think I am seeing something truly rare, but there is also the fact that a ton of people might have also seen it, but just never noticed they were seeing something unusual. In fact, it was my wife who pointed it out to me and said “look, a pretty rainbow”