The data set reports on long term atmospheric observations (chemical composition and physical properties of the aerosol, surface ozone, and particle concentration) at the Air Chemistry Observatory of the German Antarctic station Neumayer III during the year 2021, measured about 7 m above ground. Particle number concentrations and surface ozone mixing ratios are typically available in 60 sec resolution while the chemical composition of the aerosol (ionic composition) is in the majority of cases available in daily resolution.