Increased aerosols content in the atmosphere over Ukraine during summer 2010

Abstract. In this paper we assess the influence of one of the most important sources of aerosols in the atmosphere, biomass burning, during summer 2010 on the abundance, dynamics, and properties of aerosols over Ukraine, also considering influences and effects over neighboring countries: ETR, Estonia, Belarus, Poland, Moldova, and Romania. MODIS satellite instrument data were used to study fires distribution. Ground-based remote measurements from the international sun photometers network AERONET and MODIS and CALIOP satellite instruments data were used to determine aerosols content and optical properties in the atmosphere over East Europe. HYSPLIT model was used to further investigate atmospheric dynamics and to simulate pathways of particles transport. We found that the highest air pollution was observed over Moscow in the first half of August 2010, apparently due to the proximity of the most active combustion centers. Significant temporal dynamics of the aerosols content with pronounced pollution peaks during August 7–17 was observed at Ukrainian (Kyiv, Sevastopol), Belarusian (Minsk), Estonian (Toravere) and Romanian (Bucharest) AERONET sites. Aerosols spatio-temporal distribution over Ukraine were constructed and analyzed using MODIS AOD 550 nm data validated by Kyiv AERONET site sunphotometer measurements, and CALIOP AOD 532 nm validated by MODIS AOD data. Vertical distribution of aerosols extinction at 532 nm, retrieved from the measurements by CALIOP, were constructed for the territory of Ukraine at locations where high AOD values were observed during intense wildfires. The influence of the fires on the optical and microphysical properties of aerosol particles, such as size distribution, spectral single-scattering albedo and refractive indices, was analyzed and estimated using Kyiv AERONET measurements, performed during summer 2010. In this study we show that the highest aerosols pollution over Ukraine recorded on summer 2010 was caused by particles transported from the forest fires in Russia. These fires caused the highest AOD 440 nm over Kyiv site, which for August 2010 exceeded the mean value for the same month for the entire observational period by factor of two. Also, the influence of fires resulted in a change of particles microphysical properties in the regions, where pollution was the highest.