In early to mid nineteen hundreds, the US engaged in a few tests to modify the path and strength of hurricanes by using dry ice. The most known case of using dry ice to modify hurricanes was in 1947. This dry ice experiment was conducted by the United States Weather Bureau as part of Project Cirrus.
Project Cirrus
Project Cirrus was the first attempt for the United States Weather Bureau to modify a hurricane. On October 13, 1947 a B-17 bomber dropped 180 pounds of crushed dry ice in to the storm. The Boeing B-17 took off at MacDill Field in Florida on the 13th. When the B-17 reached the hurricane it climbed to 500 feet above the hurricane and dropped the dry ice.
Before the dry ice was dropped, the hurricane was traveling northeast away from land. After the dry ice was dropped in to the hurricane, the hurricane turned and started heading west toward Savannah, Georgia. The hurricane made landfall on October 15th near Savannah. The hurricane did over $23 million in damage.
The public was outraged and immediately blamed the seeding of dry ice with the hurricane changing its path. Many lawsuits were threatened and Project Cirrus was cancelled.
Seeding With Dry Ice
Seeding with dry ice is nothing new. It has been practiced for many years. Most of the time it is not used for hurricane alteration. Cloud seeding with dry ice is practiced as a way to get clouds to rain. This is done very similarly, where dry ice is flown above the clouds and dropped in. This extremely cold temperature of the dry ice is supposed to condense particles and cause rain to fall.