The email from Chris Teren late last month was brimming with excitement:
"Hello Scott! I'm out on Stuart Island (10 miles north of Roche Harbor) and saw the most amazing yet strangest rainbow I've ever seen. The vertical rainbow popping up from the base of a double curved rainbow (over Waldron Island) is like nothing I could even have imagined. Have you ever seen anything like this? Can you explain it at all?"
It turns out, Teren was in the right geographical spot at the right time. The double rainbows are fairly common, but the vertical rainbow that connects from the base of the primary rainbow to the second rainbow is called a "reflection rainbow" -- caused simply by sunlight reflecting off the body of water and, in essence, making a second sun to create a new rainbow.
According to Crystallinks.com, "these rainbows share the same endpoints as a normal rainbow but encompass a far greater arc when all of it is visible. Both primary and secondary reflection rainbows can be observed."