Paris, France, 11 April 2006: A European Space Agency satellite instrument is giving scientists more information about polar stratospheric clouds according to Michael Hopfner of Germany`s Karlsruhe Scientific Research Center. Using data collected by MIPAS, Hopfner and other scientists discovered a belt of nitric acid trihydrate clouds developing in the polar night over Antarctica in 2003 – about one month after the first PSCs, which were composed of water crystals, were detected. “This has been the first evidence for the existence of nitric acid trihydrate PSCs on a large scale,” Hopfner said. The polar clouds play a role in ozone depletion.
Although much of the clouds` function remains a mystery, MIPAS — the Michelson Interferometer for Passive Atmospheric Sounding — is the first space instrument with the ability to observe polar stratospheric clouds, or PSCs, especially during the polar night, by using middle range infrared images. The scientist said NAT particles enhance the potential for chlorine activation and irreversibly remove nitrogen from the lower stratosphere, causing a process known as denitrification, which slows the return of chlorine to its inactive form and allows ozone destruction to continue. The research is explained on the Paris-based ESA`s Web site.