SO2 as a possible proxy for volcanic ash in aviation hazard avoidance

T. M. Sears, G. E. Thomas, E. Carboni, A. J. A. Smith, R. G. Grainger
2013 Journal of Geophysical Research - Atmospheres  
1] Airborne volcanic ash poses a significant danger to aircraft, but is difficult to quantify accurately using satellite data, while sulphur dioxide is much easier to detect accurately, but is much less of a direct hazard to aviation. This paper investigates the reliability of using SO 2 as a proxy for the location of volcanic ash, using an SO 2 retrieval from the Infrared Atmospheric Sounding Interferometer (IASI) and ash detections from IASI and the Advanced Along Track Scanning Radiometer
more » ... TSR). Using a numerical "missed ash fraction" applied to the eruptions of Eyjafjallajökull in 2010 and Puyehue-Cordón Caulle in 2011 reveals that the SO 2 flag typically misses 30% of the detectable ash. Furthermore, the missed ash fraction is found to be highly variable, both between the two eruptions and over the course of each eruption, with values of over 80% found on some days. The detection threshold of the AATSR ash flag is also investigated using radiative transfer calculations, allowing the threshold of the IASI flag to be inferred, and these are related to the ash contamination levels.
doi:10.1002/jgrd.50505 fatcat:ni3wtmnxjbhnjeqs3ddqeb2p7m