Black carbon measurements from Ireland's Atmospheric Composition and Climate Change (AC3) network

In 2016 Magee Scientific AE33 Aethalometers, capable of measuring both black carbon (BC) and the contribution of biomass burning (BB), were installed at three sites in Ireland as part of the Atmospheric Composition and Climate Change (AC3) Network. The three sites (Mace Head, Malin Head, and Carnsore Point) are coastal locations on opposing sides of the country ideally located to assess typical northern hemispheric background concentrations as well as local, regional, and transboundary pollution events. The first results of the BC measurements from these stations combined with concurrent in-situ observations (meteorological parameters, carbon monoxide (CO), and particulate matter (PM1)) are presented here. Instrument validation was conducted and a sample dryer was found to be necessary in low-pollution environments with high relative humidity. Carnsore Point receives 33% of BC from outside Ireland, despite winds only coming from the East 14% of the time, and Malin Head BC/CO ratios indicate local traffic influence. Analysis of BC and PM1 showed the highest concentrations to the southeast of Malin Head, yet the lowest contribution of BC to PM1. The AE33's BB source apportionment measurements show distinct seasonal variation associated with winter-time heating, but also help differentiate between local and regional pollution. •Describes the inception and validation of Ireland's black carbon network.•Elucidates frequency distribution and compares seasonal wind sectoring across the network.•Contrasts time series of biomass burning with national emission inventory submission.