What are antibubbles?

Probably 10 years ago now there was an article in Physics Today about how a fluid bubble  can float above a fluid surface.  The mechanism was drive by the bubble having a lower temperature than the water surface.  The bottom of the bubble is slightly heated due to it's close proximity (but not touching) with the water surface.  Heating the bottom of the bubble increases it's surface tension which pulls the bubbles surface down.  The surface tension "powers" a torrid circulation pattern in the bubble.  Since there's a no slip condition with the air that's in contact with the bubble, the bubble drags air underneath it.  If the circulation is fast enough, it'll suspend the bubble above the warmer water surface until the temperature equalizes, killing the circulation and causing the bubble to drop down into the water surface.  This is hard to explain w/o diagrams...