NASA's Stratospheric Aerosol and Gas Experiment II (SAGE II) determines the spatial distributions of stratospheric aerosols, ozone, nitrogen dioxide, water vapor, and cloud occurrence by mapping vertical profiles and calculating monthly averages of each. 

The SAGE II instrument, a Sun Photometer, was launched into a 57-degree inclination orbit aboard the Earth Radiation Budget Satellite (ERBS) in October 1984 and operated through August 2005. SAGE II data includes Aerosols, NO₂, O_3, and water vapor profiles.