01	Atmospheric Physics	Physical and chemical properties of the atmosphere, exclusive of considerations of weather and climate; Aeronomy, aurorae and airglow; Atmospheric structure, energetic particles and solar-terrestrial relationships. For atmospheric propagation of radio waves, See 20/14, Radiofrequency Wave Propagation. For solar terrestrial magnetic interactions, See 08/04, Geomagnetism.
02	Meteorology	Weather observations, prediction, and modification of the atmosphere; Climatology; Meteorological modelling.