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

Optical properties of surface aerosols at Dome C, Antarctica in 2007-2013 and their potential source areas are presented. Scattering coefficients (σsp) were calculated from measured particle number size distributions with a Mie code and from filter samples using mass scattering efficiencies. Absorption coefficients (σap) were determined with a 3-wavelength Particle Soot Absorption Photometer (PSAP) and corrected for scattering by using two different algorithms. The scattering coefficients were also compared with σsp measured with a nephelometer at the South Pole Station (SPO). The minimum \sigma_{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 \omega_o ≈ 0.91 was observed in September and October and the highest \omega_o ≈ 0.99 in February and March. The uncertainty of the absorption Ångström exponent \sigma_{ap} is high. The lowest \sigma_{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 (~3 ± 1 ng m-3 ) at all these sites in October-November. This suggests that there is no significant difference in eBC between the coastal and plateau sites.

VIRKKULA A;  GRYTHE Henrik;  BACKMAN John;  PETÄJÄ Tuukka;  BUSETTO Maurizio;  LANCONELLI Christian;  LUPI Angelo;  BECAGLI Silvia;  TRAVERSI Rita;  SEVERI Mirko;  VITALE Vito;  SHERIDAN Patrick;  ANDREWS Elisabeth; 

2022-12-01

COPERNICUS GESELLSCHAFT MBH

JRC126609

1680-7316 (online),   

https://acp.copernicus.org/articles/22/5033/2022/,    https://publications.jrc.ec.europa.eu/repository/handle/JRC126609,   

10.5194/acp-22-5033-2022 (online),