THE POLAR OZONE AND AEROSOL MEASUREMENT INSTRUMENT

The second Polar Ozone and Aerosol Measurement instrument (FOAM II) is a spaceborne experiment designed to measure the vertical profiles of ozone, water vapor, nitrogen dioxide, aerosol extinction, and temperat ure in the polar stratosphere and upper troposphere with a vertical re solution of about 1 km. Measurements are made by the solar occultation technique. The instrument package, which has a mass of less than 25 k g, is carried on the Satellite Pour l'Observation de la Terre (SPOT) 3 spacecraft and has a design lifetime of 3-5 years. FOAM II has provid ed data on the south polar ozone hole, north and south polar ozone phe nomena, the spatial and temporal variability of stratospheric aerosols and polar stratospheric clouds, and has detected polar mesospheric cl ouds.