This project uses an infrared (IR) interferometer to monitor some of the trace constituents of the atmosphere above South Pole and McMurdo, Antarctica. The measurements will be made in two modes: An absorption mode, using the sun as an infrared source of IR radiation shining through the atmosphere. This technique will allow very sensitive measurements of a number of trace constituents, especially during the local springtime, when the antarctic ozone hole is forming. An emission mode, using radiation emitted by the atmospheric gases themselves. This technique is much less sensitive than the absorption mode, but does allow critical measurements during the long, dark polar night, when the chemistry which sets the stage for the springtime ozone depletion is taking place. The compounds which will be measured include: hydrogen chloride, nitric acid, chlorofluorocarbon 11 and 12, nitrous oxide, methane, ozone and chlorine nitrate. These gases all play a role in the ozone hole and several of them are also important greenhouse gases. This project is a precursor to the establishment of an antarctic Network for the Detection of Stratospheric Change (NDSC) station. When the NDSC station is established, presumably at Dome C, then Murcray will begin to make similar measurements there. This project is jointly funded by NSF's Office of Polar Programs and Division of Atmospheric Sciences and also by NASA's Office of Earth Sciences and Applications.