BORTAS overview paper published

The overview paper for the BORTAS project has just been published. It introduces the background and setup to the BORTAS consortium, which aims to "Quantify the impact of BOReal forest fires on Tropospheric oxidants over the North Atlantic using Aircraft and Satellite". The paper is open access and currently in the open review and discussion stage in the BORTAS special issue of the journal Atmospheric Chemistry and Physics (Discussions) (ACP(D)), and interested colleagues are invited to comment.

ACP, like the other journals published by Copernicus on behalf of the European Geosciences Union (EGU), has a two-stage open review system in which submitted papers are published quickly as discussion papers before they are sent out to reviewers. The reviewers' comments will also be published, but in addition to the designated reviewers all other interested researchers also have the opportunity to read and comment on the paper. The editor will then take all comments into account when deciding about the publication of the final version.

The paper is written by Paul Palmer, the principal investigator of the BORTAS project, together with all colleagues who contributed significantly to the project. To quote the abstract, the article describes "the design and execution of the BORTAS (Quantifying the impact of BOReal forest fires on Tropospheric oxidants using Aircraft and Satellites) experiment, which has the overarching objective of understanding the chemical aging of airmasses that contain the emission products from seasonal boreal wildfires and how these airmasses subsequently impact downwind atmospheric composition. The central focus of the experiment was a two-week deployment of the UK BAe-146-301 Atmospheric Research Aircraft (ARA) over eastern Canada. The planned July 2010 deployment of the ARA was postponed by 12 months because of activities related to the dispersal of material emitted by the Eyjafjallajökull volcano. However, most other planned model and measurement activities, including ground-based measurements at the Dalhousie University Ground Station (DGS), enhanced ozonesonde launches, and measurements at the Pico Atmospheric Observatory in the Azores, went ahead and constituted phase A of the experiment. Phase B of BORTAS in July 2011 included the same measurements, but included the ARA, special satellite observations and a more comprehensive measurement suite at the DGS. The high-frequency aircraft data provided a comprehensive snapshot of the pyrogenic plumes from wildfires. The coordinated ground-based and sonde data provided detailed but spatially-limited information that put the aircraft data into context of the longer burning season. We coordinated aircraft vertical profiles and overpasses of the NASA Tropospheric Emission Spectrometer and the Canadian Atmospheric Chemistry Experiment. These space-borne data, while less precise than other data, helped to relate the two-week measurement campaign to larger geographical and longer temporal scales. We interpret these data using a range of chemistry models: from a near-explicit gas-phase chemical mechanism, which tests out understanding of the underlying chemical mechanism, to regional and global 3-D models of atmospheric transport and lumped chemistry, which helps to assess the performance of the simplified chemical mechanism and effectively act as intermediaries between different measurement types. We also present an overview of some of the new science that has originated from this project from the mission planning and execution to the analysis of the ground-based, aircraft, and space-borne data."