What kind of rainbow is toward the sun?

Factual Questions
1

This morning, I saw a rainbow, looking toward the sun. How is that possible? About 90 minutes after sunrise, looking toward the northeast, I saw a small segment of a rainbow. It was a short segment, less than 2x the width of the arc, red band toward the sun, same elevation as the sun, and maybe about 40 degreees to the left of it. It remained the same size and persisted at least ten minutes, with blue skies or cumulus clouds drifting behind it. It was too faint to photograph, due to the brightness of the sun, but stood out strongly when viewed through amber lenses while standing in the shade.

Rainbows are seen with the sun behind the observer’s back, the arc centered at a point diametrically opposite the sun. This one was just the reverse. My wife saw it first, and pointed it out to me, so this was not imaginary.

2

Did it look anything like this : 22° halo - Wikipedia ?

3

46° halo? Supralateral arc? Circumzenithal arc? Did you photograph it?

4

A sun dog is a related phenomenon to the ones in 2 & 3, and is usually pretty short.

5

There is a large variety of prismatic effects that can be seen in the sky under different conditions. This is a good site that describes many of them:

6

It was a bifurcated trans-lateral. No, seriously if the red was towards the sun it was a secondary rainbow.

Dennis

7

I don’t think so. Like the primary, the secondary bow is centered on the antisolar point and is only a little (9 degrees) larger than the primary bow. The OP says what he saw was only 40 degrees from the sun.

8

Sun dogs have the red side toward the sun and are very commonly seen. They are caused by ice crystals (rainbows are caused by spherical water droplets).

9

Already answered, I see. Must be brain damage due to staring at the sun.

10

Tertiary (third-order) rainbow? 3rd & 4th order rainbows

Third- and fourth-order rainbows. Quadruple Rainbow Photographed for First Time | Live Science

11

Doesn’t a tertiary rainbow have the blue band towards the sun? Also, the post didn’t mention any rain.

12

Thanks folr your replies. I can’t really add anything more of relevence. No, there was no rain in sight, all morning. Just sunny day with some cumulus. There was nothing in the sky that would suggest a more conventional rainbown down-light, nor any weather that would indicate one.

13

It sounds very much like a sundog. As noted, sundogs have their red side towardthe sun, if the ice crystals are large enough to provide color separation.
Sundogs* are caused by hexagonal (or, less often, triangular) ice crystals that are oriented with the symmetry axis horizontal in the air. (If the crystals aren’t thus oriented, you get a halo around the sun) They lie at 22 degrees from the sun, so if you hold your hands out at arms length with your thumb and little finger fully spread, the tip of your pinky and your thumb will just bout touch the sun and the sundog.

The sundogs are caused by ice crystals, which might be not in visible clouds, but are more commonly gathered to form cirrus clouds. Since these clouds are far above the earth, they can form at any time of year, in any season. You can get such ice crystals in the summer, over a desert. But sun dogs seem to be more common in the winter.

Because the ice crystal has to be horizontally oriented, sundogs are most visible near sunrise or sunset. as the sun rises, the sundog actually moves away from the sun, more than the 22 degrees the halo sits at. It also becomes less visible. Above about forty degrees from the horizon, it disappears. (By contrast, the 22 degree halo can be seen at any altitude of the sun)
Sundogs are actually extremely common. My own estimate is that they are about an order of magnitude more likely than rainbows (which other researchers agree with), but are less commonly reported mainly because most people are unaware of them, don’t look for them, and usually can’t recognize them when they see them. (I used to point them out to passersby, often having to tell them precisely where to look, until my wife Pepper Mill told me that I was embarrassing her.) The fact is that, although most pictures of sundogs that are published or put up on the internet show the full-blown, full-color, spectacular sundog, most sundogs are actually pretty understated. To get that full color separation, you need a lot of crystals, all oriented the right way, and they need to be large (several microns at least, and almost a millimeter for really good results). If you have much smaller crystals, as is likely, then diffraction prevents the colors from being separated, and it’s less likely that the crystals will be properly oriented, so you end up with a sort of bright patch in the clouds that’s a sort-of-yellow color, and people just think it’s the way the sunlight is illuminating that particular cloud.

*AKA Parhelia or Mock Suns

14

Icebows are opposite rainbows, arc and colors. Ice particles refracts light differently then water droplets. Never heard it called a sundog till today.

15

I’ve never heard of an “icebow”. Do you mean some sort of ice crystal arc? The Sundog is just one of the many phenomena associated with ice crystals. The 22 degree and 46 degree halos are arguably “icebows”, since they form circles centered on the sun, as the primary and secondary rainbows are centered on the anti-solar point, but there is a huge range of ice crystal arc phenomena that is NOT centered on the sun. This is due to the fact that rainbows are caused by raindrops, which are basically essentially spherical, which limits the combinations of orientations relative to the sun. Ice crystals, which have definuite forms, can have a bewildering variety of orientations relative to the sun.

16

I haven’t heard it called an “icebow” since I was a kid.

17

That souinds like a pretty accurate representation. When clouds passed through, the color was still visible against the cloud background.

I’m guessing you are Asplergers. My wife had he same reaction to me talking to strangers.

18

No, not Asbergers – just an enthusiastic Nerd