Temporal coverage: 8 May 2012 - present
The AIRS Prata SO2 Index Day/Night layer indicates Sulfur Dioxide column amounts in the atmosphere, measured in Dobson Units (DU).
Sulfur Dioxide (SO2), is a colorless gas with a pungent, suffocating odor that is water soluble to produce the acid, H2SO3. SO2 is one of the US Environmental Protection Agency's (EPA) six major regulated criteria pollutants (Tropospheric Ozone, Nitrogen dioxide, Sulfur dioxide, Lead, PM2.5 and PM10 particulates). It irritates the eyes, nose, and lungs. High concentrations of SO2 can result in temporary breathing impairment. It is produced by combustion of coal, fuel oil, and gasoline, since these fuels contain sulfur in the combustion, and in the oxidation of naturally occurring sulfur gases. It is a precursor to sulfuric acid, which is a major constituent of acid rain. SO2 is injected into the stratosphere by volcanic eruptions. SO2 also is a major precursor to PM2.5 (Particulate Matter up to 2.5 micrometers in size), which is a significant health concern, and a main contributor to poor visibility. These data are used by the Volcanic Ash Advisory Centers in advisories to airlines for operational decisions.
The AIRS Sulfur Dioxide Index Prata algorithm was authored by Fred Prata from the Norwegian Institute for Air Research.
The Atmospheric Infrared Sounder (AIRS) is an instrument on board the Aqua satellite. The AIRS Prata SO2 Index science parameter is a derived parameter from the Level 1B Near-Real Time Infrared (IR) geolocated and calibrated radiances, (AIRIBRAD_NRT). The imagery resolution is 2 km and sensor resolution is 45 km. The temporal resolution is daily.
References: GES DISC - AIRIBRAD_NRT: AIRS/Aqua L1B Near Real Time (NRT) Infrared (IR) geolocated and calibrated radiances V005; GES DISC - Near Real-Time Data