Eruption column ascent rates obtained using the Advanced Baseline Imager for the La Soufrière eruption in April 2021
Isabelle A. Taylor 1, Roy G. Grainger1, Geri Peykova1, David M. Pyle2
Affiliations: 1COMET, Atmospheric, Oceanic and Planetary Physics, University of Oxford, Oxford, UK; 2COMET, Earth Sciences, University of Oxford, Oxford, UK.
Presentation type: Talk
Presentation time: Thursday 09:30 - 09:45, Room S160
Programme No: 3.12.5
Abstract
La Soufrière, St Vincent, began erupting explosively in April 2021. The explosive eruption lasted for two weeks and consisted of at least 35 events. The eruption was observed with the Advanced Baseline Imager (ABI) onboard the Geostationary Operational Environmental Satellite (GOES)-East. For a large part of the eruption data was available every minute: providing a unique opportunity to observe the ascent of the eruption columns. The maximum overshooting top heights from three different techniques are presented: (1) estimating the neutral buoyancy height from brightness temperature measurements and working backwards from this to estimate the overshooting top heights; (2) using the position of the coldest pixel relative to the volcano and relating this to the parallax between the satellite instrument and the ash column; (3) incorporating estimates of umbrella and maximum column heights from Horvath et al. (2022; doi:10.5194/acp-22-12311-2022) who estimates the height using side angle measurements from ABI on GOES-West (10 minute resolution). Combining the estimates of the maximum heights with event onset times based on seismic data (Sparks et al., 2024; doi:10.1144/sp539-2022-286) and estimates of the time at which the column reaches its maximum height (timing of the coldest pixel) it is possible to estimate the average ascent rate of the eruption column. This approach has been applied to 18 explosive events during the La Soufrière eruption, the majority of which have an average ascent rate of 20 - 35 m/s.