Why the Ozone Hole?
Why did the ozone hole develop over Antarctica, and not over Detroit or some other manufacturing center where chlorofluorocarbons, or CFCs, are released prodigiously? The reasons are explained by Rebecca L. Johnson, who participated in NSF’s Antarctic Artists and Writers Program in 1991, 1994, and 1997. In winter, the stratosphere above the Antarctic continent gets colder than it does anywhere else on Earth. Temperatures frequently drop below -112ºF. Antarctica is also one of the windiest places on Earth. In May and June, strong winds in the stratosphere begin to blow clockwise around the continent. These howling stratospheric winds gradually form an enormous ring of moving air, called the Antarctic polar vortex, that swirls around and around, far above the frozen land . During the winter, temperatures inside the Antarctic polar vortex fall so low that water vapor and several other types of molecules in the stratosphere condense into extremely small icy particles. These icy particles,
