Could air bubbles prevent tropical cyclones?
Depending on where in the world they occur, tropical cyclones are also known as hurricanes or typhoons. No matter what you call them, though, they're caused by the evaporation of warm ocean surface water. Norwegian scientists are now looking at stopping them, by using bubbles to cool that water down.
The idea was first conceived of by Olav Hollingsæter, founder of the company OceanTherm AS, after Hurricane Katrina struck New Orleans. He contacted Norwegian research group SINTEF about developing the concept further, resulting in preliminary studies that are now underway.
Basically, the idea is that perforated pipes will be lowered into the ocean, in areas where tropical cyclones are likely to occur. Air will then be continuously pumped through these horizontally-laid pipes, causing them to release a sheet of bubbles known as a "bubble curtain."
As these bubble curtains rise to the surface, they will bring cold water from the depths up with them, thereby cooling the surface water to a temperature below 26.5° C (79.7 ºF) – that's the minimum water temperature at which the storms can form.
The pipes could conceivably be deployed from offshore oil rigs, or simply run out into the ocean from the shore.
"Our initial investigations show that the pipes must be located at between 100 and 150 meters depth [328 and 492 ft] in order to extract water that is cold enough," says SINTEF scientist Grim Eidnes. "By bringing this water to the surface using the bubble curtains, the surface temperature will fall to below 26.5° C, thus cutting off the hurricane's energy supply. This method will allow us quite simply to prevent hurricanes from achieving life-threatening intensities."
SINTEF has previously experimented with using bubble curtains to contain oil spills. And back in 2010, Japanese manufacturing firm Ise Kogyo revealed its concept for preventing typhoons by using a fleet of submarines to pump cold water up to the surface.