Observations of the Wave-One Ozone Maximum during the LASIC Field Campaign at Ascension Island

During August and September of 2017, ozone profiles were taken at Ascension Island, UK during the LASIC and CLARIFY field campaigns. The ozone measurements help in understanding the contributions from biomass burning and lightning sources from South America and Southern Africa. Ozonesonde Launches were timed to examine plumes of biomass burning reaching Ascension Island from Southern Africa. The altitude and timing of elevated ozone mixing ratios coincide with biomass burning aerosols in the lower to middle troposphere. Ozone concentrations in the middle/upper troposphere were subject to considerably more variability, with HYSPLIT trajectories suggestive of Africa and potentially lightning as the primary source of ozone. The co-location of biomass burning aerosols and high ozone mixing ratios suggest that surface warming is enhanced through longwave forcing over the South Atlantic Ocean.