Interest in hurricane mitigation has peaked since Hurricane Katrina devastated New Orleans in 2005, and any means of limiting the damage wrought by these huge storms would be welcomed by governments and vulnerable populations alike.

Now an Israeli team says it has developed a way to take the sting out of the storms. Their new patent application says seeding hurricanes with smoke particles could lower wind speeds enough to mitigate their destructive potential.

A hurricane's destructive potential is proportionally related to the strongest winds inside it, and only a small reduction in wind speed is needed to dramatically reduce the damage it causes.

Hurricanes derive their immense power from warm waters on the surface of the sea. As the water evaporates, it rises into the hurricane and eventually condenses and falls as rain, releasing its latent heat energy as it does so - a process known as "heat cycling".

Daniel Rosenfeld and colleagues at the Hebrew University of Jerusalem say injecting smoke into the lower parts of a hurricane causes water vapour to condense at a lower altitude than usual, and form droplets that are too small to fall as rain.

Instead these are swept into higher and more peripheral regions of the storm, eventually reaching a point where they freeze. This provides an injection of energy on the edges of the storm that destabilises its destructive centre and causes a lowering of windspeeds.

At least, it works that way in Rosenfeld's computer-simulated hurricanes. The team has not tried the idea in the wild yet.

They have, though, calculated how much smoke might be needed to pull off their trick: about 10 cargo aircraft could carry enough material to generate the smoke particles needed to seed a single hurricane.


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