Aerosol optical properties calculated from size distributions, filter samples and absorption photometer data at Dome C, Antarctica, and their relationships with seasonal cycles of sources

• Published in: Atmospheric Chemistry and Physics
• Main Authors: A. Virkkula, H. Grythe, J. Backman, T. Petäjä, M. Busetto, C. Lanconelli, A. Lupi, S. Becagli, R. Traversi, M. Severi, V. Vitale, P. Sheridan, E. Andrews
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2022
• Subjects: Physics; QC1-999; Chemistry; QD1-999; Antarctic; Austral; Neumayer; South Pole; Antarc*; Antarctica; South pole
• Online Access: https://doi.org/10.5194/acp-22-5033-2022; https://doaj.org/article/fa5c4ad32faf4cd09e2ffa86fb43d1e2

Optical properties of surface aerosols at Dome C, Antarctica, in 2007–2013 and their potential source areas are presented. Scattering coefficients ( σ sp ) were calculated from measured particle number size distributions with a Mie code and from filter samples using mass scattering efficiencies. Absorption coefficients ( σ ap ) were determined with a three-wavelength Particle Soot Absorption Photometer (PSAP) and corrected for scattering by using two different algorithms. The scattering coefficients were also compared with σ sp measured with a nephelometer at the South Pole Station (SPO). The minimum σ ap was observed in the austral autumn and the maximum in the austral spring, similar to other Antarctic sites. The darkest aerosol, i.e., the lowest single-scattering albedo ω o ≈0.91 , was observed in September and October and the highest ω o ≈0.99 in February and March. The uncertainty of the absorption Ångström exponent α ap is high. The lowest α ap monthly medians were observed in March and the highest in August–October. The equivalent black carbon (eBC) mass concentrations were compared with eBC measured at three other Antarctic sites: the SPO and two coastal sites, Neumayer and Syowa. The maximum monthly median eBC concentrations are almost the same ( <math xmlns="http://www.w3.org/1998/Math/MathML" id="M9" display="inline" overflow="scroll" dspmath="mathml"><mrow><mo>∼</mo><mn mathvariant="normal">3</mn><mo>±</mo><mn mathvariant="normal">1</mn></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="36pt" height="10pt" class="svg-formula" dspmath="mathimg" md5hash="6442f66d659a0105dc28ae4509c7c5b1"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-22-5033-2022-ie00001.svg" width="36pt" height="10pt" src="acp-22-5033-2022-ie00001.png"/></svg:svg> ng m −3 ) at all these sites in October–November. This suggests that there is no significant difference in eBC concentrations between the ...