Research data supporting "Low-level urban anthropogenic sources contribute to strong aerosol light-absorption on the South African Highveld" - Tables SD1, SD2, SD3

This dataset supports the article “Low-level urban anthropogenic sources contribute to strong aerosol light-absorption on the South African Highveld” by Baldo et al. (2025), accepted for publication in JGR-Atmospheres. The paper presents the first apportionment of light-absorbing aerosols in the Highveld region, based on chemical and optical analysis of 42 filter samples collected during the 2021 cold/dry season at four sites in the Greater Johannesburg Area (GJA), part of the Highveld Air Quality Priority Area. The selected sites, Diepkloof (DK), Olifantsfontein (OF), Springs (SP), and Jabavu (JB), represent a range of environments, including industrial (OF), residential (SP and JB), and traffic (DK) areas.
Table SD1 contains the mass concentrations (μg·m⁻³) of measured chemical species. This includes elemental concentrations determined by X-ray fluorescence (XRF), water-soluble ionic species and organic acids determined by ion chromatography (IC), and organic carbon (OC) and elemental carbon (EC) concentrations measured by thermal-optical analysis.
Table SD2 reports the spectral aerosol absorption coefficient (βabs(λ), Mm⁻¹), measured at 375, 407, 532, 635, and 850 nm using a Multi-Wavelength Absorbance Analyzer (MWAA). Derived metrics include the mass absorption efficiency (MAE(λ), 10⁻³ m²·g⁻¹), and absorption Ångström exponent (AAE(λ)).
For both Table SD1 and Table SD2, values are presented as mean ± standard deviation for the entire measurement period, with minimum and maximum values given in brackets. Data are reported for all sites combined as well as for the different site types.
Table SD3 provides the apportionment of βabs(λ) between 375 and 532 nm into contributions from black carbon (BC), brown carbon (BrC), and mineral dust (MIN), βabs(λ) - BC, βabs(λ) - BrC, and βabs(λ) - MIN, respectively. Associated chemical tracers used in the apportionment are also included.