10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
Equivalent Black Carbon (EBC) Measurement at a Regional Background Site in Central Europe Using a Multiple Wavelength Aethalometer: Variability and Source Apportionment
SALIOU MBENGUE, Norbert Serfozo, Jaroslav Schwarz, Nadežda Zíková, Adéla Holubová Šmejkalová, Ivan Holoubek, Global Change Research Institute, CAS, Brno 60300, CZ
Abstract Number: 1217 Working Group: Carbonaceous Aerosol
Abstract Equivalent Black carbon (EBC) is a primary carbonaceous aerosol emitted from a variety of combustion related sources. It is recognized to play an important role on adverse public health and in the Earth’s climate system. Although measurements at background areas are important for better characterizing and understanding the influence of anthropogenic emissions on climate forcing and health effect, scarce studies have been reported in Eastern Central Europe using real-time EBC measurements. This study focuses on the seasonal, diurnal and weekly trends of EBC at a regional background site in Central Europe. Our aim is to identify the potential sources of EBC, especially the influence of fossil fuel and biomass burning.
The EBC in PM10 was monitored at NAOK (National Atmospheric Observatory Košetice, 49°35ʹN, 15°05ʹE), central Czech Republic. Measurements were performed from 2012 to 2017 at ground base (4 m) with a 5 min time resolution using a seven wavelength aethalometer (Model AE31, Magee Scientific). The EBC data have been corrected for loading effect, and Delta-C variable (EBC370nm-EBC880nm) was calculated.
Preliminary results show that concentrations of EBC are higher in winter than in summer, which could be related to the variability in sources intensities and meteorological conditions. The wavelength dependence of light absorption by collected aerosols will be investigated to identify the potential sources of EBC at the rural site. The diurnal cycles of EBC in the near-ultraviolet (370 nm) and in the near-infrared (880 nm) spectral regions are compared for winter and summer. The diurnal cycles are stronger in winter than in summer with lower concentrations observed at noon time when the mixing height reaches a peak (i.e. higher dispersion of pollutants). In summer, EBC emission could be mostly attributed to fossil fuel combustion, which is consistent with the smaller difference between diurnal profiles of λ1 and λ6. Delta-C values, a proxy for biomass burning is more pronounced in winter, which is consistent with the increased emissions from wood burning.
Furthermore, correlations will be examined between EBC and other parallel measurements of atmospheric pollutants (OC/EC, CO, NO2, SO2) at NAOK. The influence of fossil fuel and biomass burning will be investigated deeper using Ångström absorption exponent and Delta-C.