BORTAS was a NERC Response mode project which aims to investigate the connection between the composition and the distribution of biomass burning outflow, ozone production and loss within the outflow, and the resulting perturbation to oxidant chemistry in the troposphere. The BORTAS team will sample biomass burning outflow over the North Atlantic in summer 2011 the using FAAM BAe-146 aircraft and then describe the observed chemistry within plumes and quantify the impact of boreal fires on the North Atlantic region using a nested 3-D chemistry transport model.