Space-based Measurement of Gaseous and Aerosol Pollutants (Invited Presentation)

Systematic measurements of atmospheric gases and aerosols from space started with the launch of NASA’s Nimbus-7 satellite in October 1978. The early measurements were largely focussed on the stratosphere amid growing concerns about the health and environmental impact of ozone depletion. Tropospheric measurements were largely confined to aerosols, which could only be measured over water until the mid 90s when a UV sensor first demonstrated the capability to track UV-absorbing aerosols, such as smoke, desert dust  and volcanic ash, over both land and water, as well as over clouds and snow. These data were retrospectively processed starting in 1979. This field has seen rapid growth in the past two decades with variety of sensors routinely providing estimates of five of six criteria pollutants defined by EPA that include particulate matter (PM), ozone, SO₂, NO₂ and CO. Other boundary layer trace gases that have been measured include BrO, formaldehyde, glyoxal, and ammonia. More recently the space-based capability of measuring column CO₂ and CH₄ has emerged. I will provide a broad overview of the techniques that have been deployed to make these measurements and how are these data being utilized by the scientific and environmental communities. Finally, I will discuss the prospects of continuing and improving these measurements to better meet the emerging scientific needs.