Subject: C5e) Why don't we try to destroy tropical cyclones by cooling the surface waters with icebergs or deep ocean water ?
Contributed by Neal Dorst
Since hurricanes draw their energy from warm ocean water, some proposals have been put forward to tow icebergs from the arctic zones to the tropics to cool the sea surface temperatures. Others have suggested pumping cold bottom water in pipes to the surface, or releasing bags of cold freshwater from near the bottom to do this.
Consider the scale of what we are talking about. The critical region in the hurricane for energy transfer would be under or near the eyewall region. If the eyewall was thirty miles (48 kilometer) in diameter, that means an area of nearly 2000 square miles (4550 square kilometers). Now if the hurricane is moving at 10 miles an hour (16 km/hr) it will sweep over 7200 square miles (18,650 square kilometers) of ocean. That's a lot of icebergs for just 24 hours of the cyclone's life.
Now add in the uncertainty in the track, which is currently 100 miles (160 km) at 24 hours and you have to increase your cool patch by 24,000 sq mi (38,000 sq km). For the iceberg towing method you would have to increase your lead time even more (and hence the uncertainty and area cooled) or risk your fleet of tugboats getting caught by the storm.
For the bag/pipe method you would have to preposition your system across all possible approaches for hurricanes. Just for the US mainland from Cape Hatteras to Brownsville would mean covering 528,000 sq mi (850,000 sq km) of ocean floor with devices.
Lastly, consider the creatures of the sea. If you suddenly cool the surface layer of the ocean (and even turn it temporarily fresh), you would alter the ecology of that area and probably kill most of the sea life contained therein. A hurricane would be devastating enough on them without our adding to the mayhem.
Last updated August 13, 2004
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