The authors used «fingerprints» of the ozone changes with season and altitude to attribute the ozone's recovery to the continuing decline of atmospheric chlorine originating from chlorofluorocarbons (CFCs). (sciencedaily.com)
They further found that this decline matched the model's predictions, and that more than half the shrinkage was due solely to the reduction in atmospheric chlorine. (sciencedaily.com)
Those techniques have led to everything from the development of catalysts that remove poisonous carbon monoxide from car exhaust to the understanding of how ice crystals in stratospheric clouds supercharge atmospheric chlorine's ability to destroy the planet's protective ozone layer. (sciencemag.org)