Ship-Based Black-Carbon Observations Over the South Atlantic and Southern Ocean

Ship-based observations of black-carbon aerosol were made in the South Atlantic and Southern Ocean during the SANAE54 scientific and relief cruise of the R/V S.A. Agulhas II, during the austral summer of 2014-2015. An aethalometer was installed in the crow's nest and a stainless steel inlet tube was run to the top of the ship's mast. Relative wind speed and direction were measure with a co-located sonic anemometer. Data are filtered based on ship speed (measured by GPS), and relative wind. In general averaged BC mass concentrations are close to zero, however on two days consistent values around 25 ng.m^-3 were observed at latitudes between 40 and 50 degrees South. Back-trajectory analysis is performed on these days to attempt to determine the source region.