astronomy(The science concerned with celestial bodies and the observation and interpretation of the radiation received in the vicinity of the earth from the component parts of the universe)
atmospheric aerosol(Particulate matter suspended in the air. The particulate matter may be in the form of dusts, fumes, or mist. Aerosols in the atmosphere are the form in which pollutants such as smoke are dispersed)
atmospheric chemistry(The study of the production, transport, modification, and removal of atmospheric constituents in the troposphere and stratosphere)