We operate a multi angle absorption photometer MAAP (Model 5012, Thermo Electron Corp.) in the Aerosol and Trace Gas Observatory at Neumayer III Station since March 2006 ongoing. This instrument measures the atmospheric aerosol light absorption coefficient (mainly caused by black carbon, BC) by sampling ambient aerosol glass fiber filter tape. The intake of the aerosol inlet can be found on top of the observatory at approx. 5-7 m above ground. The measured absorption coefficients abs(637) refer to a wavelength of 637 nm. Raw data were originally sampled in one-minute resolution. Finally, hourly averaged MAAP data are presented here. We also provide BC concentrations (ng/m³) derived from the absorption coefficients using the specific BC mass absoption coefficient of 6.6 m²/g.

Important notice: BC concentrations are extremely low at Neumayer, typically lower than the instrumental noise level referring to 1 hour averages (between 0.04 and 0.05 Mm-1). Notwithstanding, we archived hourly averages, but one has to be aware that negative values may not be removed when smoothing the data or when calculating averages with lower temporal resolution, otherwise the results would exhibit a substantial positive bias!