Strange circle of sunshine spotted in Pacific

Photo of ring cloud in Pacific Ocean. (Courtesy: Timothy Durkan)

Although the headline sounds like something anyone would say when the skies finally parted the persistent overcast in Seattle, this is a bit different.

Timothy Durkan snapped this photo a few months ago while flying over the Pacific Ocean between Seattle and Maui on his own search for sunshine.

The perfect ring of clouds was likely caused by some sort of sinking air in the center that would explain the dry slot in the middle, but I'm not sure what would cause it to be so perfectly round. It's as if someone tossed a rock into the center of the clouds there and the sinking air just melted any clouds around.

I've asked a few other weather friends for help; so far one leading explanation was a "Cloud Arc" as seen on this site but Durkan's photos don't have the clouds in the center. Hmmm....

Anyway, quite the cool photo, even if it's creation is a bit of a mystery.