AIRS/Aqua Observations of Volcanic Emissions

This data repository provides access to observations of volcanic emissions of the Atmospheric Infrared Sounder (AIRS) aboard NASA's Aqua satellite. Volcanic emissions can be detected from AIRS measurements by means of brightness temperature difference (BTD) methods. Emissions of volcanic sulfur dioxide (SO2) are detected by analyzing a spectral feature in the 7.3 micron waveband. The AIRS channels selected for the detection are most sensitive to SO2 in the upper troposphere and lower stratosphere. Volcanic ash is detected based on the reverse absorption feature at 8.1 and 9.2 microns. This technique allows to effectively discriminate between ash particles and ice, but cannot be used to discriminate between volcanic ash and desert dust. Aqua was launched in May 2002 and is still operating near continuously.