The email said these pictures were taken near Yellowknife in the Yukon Territory, Canada. As usual, I do not know the ownership or copyright status of these images.
They are pretty (but only green - I like the ones with reds in them as well), but you have to put up with the temperature.
The email said that this is a "fire rainbow", which is the rarest of all naturally ocurring atmospheric phenomena. The picture was taken on the border between the states of Idaho and Washington in the U.S. The event lasted about 1 hour. For this to happen, there has to be cirrus clouds, at least 20,000 feet in the air, with just the right amount of ice crystals. Also, the sun has to hit the clouds as precisely 58 degrees. More information (partially contradictory) can be found on Wikipedia.