SAGE I
in scheme: projects
definition: Scientific Objectives: The Stratospheric Aerosol and Gas Experiment I instrument, a Sun photometer, aboard the Applications Explorer Mission-2 (AEM-2) satellite began collecting data in October 1979. The scientific objective was to develop a global stratospheric aerosol, ozone, and nitrogen dioxide database that could be used for the investigation of the spatial and temporal variations of these species caused by seasonal and short-term meteorological variations, atmospheric chemistry, microphysics, and transient phenomena such as volcanic eruptions. The database could also be used for the study of trends, atmospheric dynamics and transport, and potential climatic effects. The SAGE I sensor was designed to measure the attenuation of solar radiation resulting from atmospheric aerosol, ozone, and nitrogen dioxide at four spectral regions through the Earth's atmosphere during each spacecraft sunrise and sunset. Project Description: The AEM-2 satellite was placed in an orbit of approximately 600 kilometers at an inclination of 56 degrees to extend the latitudinal coverage for the solar occultation measurements from 79 degrees South to 79 degrees North. The SAGE I instrument consists of four spectral channels centered at wavelengths of 1000, 600, 450, and 385 nanometers for measuring global data concerning aerosol vertical extinction profiles, ozone vertical concentrations profiles, and nitrogen dioxide vertical concentrations profiles during spacecraft sunrise and sunset. The solar wavelengths of 1000 and 450 nanometers are used to generate altitude profiles of ozone and nitrogen dioxide concentration. The SAGE I aerosol data were validated by comparison with correlative lidar and dustsonde in situ measurements, the ozone data were validated by comparison with balloon ECC ozonesonde and rocket measurements, and the nitrogen dioxide measurements were compared with climatology. The operation of the instrument, during each sunrise and sunset measurement, was totally automat…
type: Concept

S - U
type: Concept