What caused the Quadruple Rainbow?

[OmCheeto]

I've done this synthetically, in the past.
I've never seen a natural set before.

Photo of quadruple rainbow in New York colors the Internet awestruck

Amanda Curtis has created an Internet sensation with this photo she took that features four -- count 'em, four -- rainbows.

I wonder what caused the second set. A lake?

 

[Subductionzon]

The photo makes it look like a double rainbow with a reflection rainbow. Wikipedia has a nice article on rainbows. Many years ago I saw what I now realize was a supernumerary rainbow in the Rocky Mountains of Colorado. I had never seen one before and have never seen one since. But I still remember how awesome it was.

http://en.wikipedia.org/wiki/Rainbow

 

[artyb]

Yep - looks to be a double rainbow, with a reflected one, taken near sunrise/set. IIRC I photographed a simpler one a decade ago; single and a reflected single that came off the ocean.

Edit: Found the slide film, popped on the monitor and photographed; it was a double and a fainter reflected double.

 

[OmCheeto]

After a bit of research, it had to have been the Long Island Sound that reflected the sunlight.

The yellow pin is where Amanda was standing, and she was looking in the direction of the arrow.

Glen Cove LIRR station on Long Island, NY: 40.865189°N 73.616976°W
photo capture: 4/21/2015 6:30 am

 

[marcusl]

The photo makes it look like a double rainbow with a reflection rainbow. Wikipedia has a nice article on rainbows. Many years ago I saw what I now realize was a supernumerary rainbow in the Rocky Mountains of Colorado. I had never seen one before and have never seen one since. But I still remember how awesome it was.

http://en.wikipedia.org/wiki/Rainbow

I live in Colorado near the Rockies and see supernumerary rainbows often, typically two to four at a time. I never realized that they were rare!

 

[OmCheeto]

I live in Colorado near the Rockies and see supernumerary rainbows often, typically two to four at a time. I never realized that they were rare!

I went back and re-read the entry on "Supernumerary rainbows". That is really interesting.

It is not possible to explain their existence using classical geometric optics. The alternating faint rainbows are caused by interference between rays of light following slightly different paths with slightly varying lengths within the raindrops.
...
Supernumerary rainbows are clearest when raindrops are small and of uniform size. The very existence of supernumerary rainbows was historically a first indication of the wave nature of light, and the first explanation was provided by Thomas Young in 1804.

I did not know that.

Here's an interesting simulation I just found, showing the effect with the required droplet size:
(The slider they mention, is the inverted skinny grey triangle to the right of the image)

Supernumeraries & Drop Size

 

[OmCheeto]

Today, my last Facebook friend from work, posted the following, having taken the picture about 2 hours ago:

Like her, it really had me puzzled.
So I went through the wiki entry on Rainbows, and found the following:

Circumhorizontal arc

... In its full form, the arc has the appearance of a large, brightly spectrum-coloured band running parallel to the horizon, located below the Sun...

The misleading term "fire rainbow" is sometimes used to describe this phenomenon, although it is neither a rainbow, nor related in any way to fire. The term, apparently coined in 2006,[3] may originate in the occasional appearance of the arc as "flames" in the sky, when it occurs in fragmentary cirrus clouds.
...

Not a rainbow? pfft!
If it's not a rainbow, then what's it doing in the "Rainbow" section?
Answer me that, wiki...