We operate a 7-wavelength aethalometer (Model AE33, Magee Scientific) which is in operation since 23 January 2019 ongoing. The Aethalometer model AE33 collects aerosol particles continuously by drawing the aerosol-laden air stream through a spot on the filter tape. It analyzes the aerosol by measuring the transmission of light through one portion of the filter tape containing the sample, versus the transmission through an unloaded portion of the filter tape acting as a reference area. This analysis is done at seven optical wavelengths spanning the range from the near-infrared to the near-ultraviolet. The Aethalometer calculates the instantaneous concentration of optically-absorbing aerosols from the rate of change of the attenuation of light transmitted through the particle-laden filter.

This file comprises continuous measurements of a 7-wavelength Aethalometern (Modell AE33, Magee Sci.) between 01 January 2021 00:00 and 31 December 2021 24:00. This instrument measures atmospheric light absorption by aerosol (mainly caused by black carbon, BC) at 7 different wavelength between 370 nm and 950 nm. Raw data were originally sampled in one-minute resolution. Finally, hourly averaged data are presented here.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!