Volcanic SO2, BrO and plume height estimations using GOME-2 satellite measurements during the eruption of Eyjafjallajokull in May 2010

The eruption of the Eyjafjallajokull volcano, Iceland, in April and May 2010 caused unprecedented disruptions of European air traffic showing that timely monitoring of volcanic ash and SO2 dispersion as well as the corresponding plume heights are important for aviation safety. This paper describes the observations of SO2 and BrO columns in the eruption plume and the determination of the SO2 plume height using the GOME-2 satellite instrument. During the eruptive period in May 2010, SO2 total columns of up to similar to 20 DU and BrO columns of similar to 7.7 x 10(13) molec/cm(2) were detected. The BrO/SO2 ratio estimated from the GOME-2 observations of the Eyjafjallajokull eruption varies from 1.1 x 10(-4) to 2.1 x 10(-4). The SO2 plume heights estimated from the GOME-2 observations on 5 May range from 8-13 km and mostly agree within 1-3 km with visual observations, radar data and modeling results. Furthermore, the GOME-2 SO2 observations are compared with in situ measurements of the DLR Falcon aircraft on 17 and 18 May 2010 and with Brewer instruments at Valentia, Ireland and Hohenpeissenberg, Germany. The SO2 columns derived from the Falcon profile measurements range from 0.6-4.7 DU and the comparison with the GOME-2 measurements shows a good agreement, mainly within 1 DU. The Brewer observations at Hohenpeissenberg also agree well with the GOME-2 measurements with a daily average SO2 column of similar to 1.3 DU during the overpass of the SO2 cloud on 18 May, whereas the Brewer instrument at Valentia shows up to 50% higher SO2 columns (similar to 8 DU) on 11 May.