Long-term black carbon variation in the South-Eastern Baltic Region in2008–2015

Özet

Long-term continuous measurement data of equivalent black carbon (eBC) concentration over a period of 8 years(2008–2015) from the coastal–background site in Preila, Lithuania, have been analysed. The analysis performedwith Preila data has shown that the average mean of eBC concentration was 750 ng/m3. A seasonal pattern wasalso observed with the highest eBC values (1170 ng/m3) in winter gradually declining to the minimum con-centration (380 ng/m3) in summer. The frequency distribution of the data wasfitted with lognormal modes. Coldand warm seasons were parameterised with three and two modes, respectively. Both the parametric and non-parametric trend analysis methods were applied in this research. A positive annual linear trend for the wholeperiod was estimated to range from +1.97% to +5.35% per year. However, the second order trend had amaximum in 2013 and was declining during the last years of the analysed period, or, according to thet-test, hadany statistically significant trend. Regional and long-range emissions of coal and biomass combustion are themain sources of the observed eBC in the Preila station during the cold seasons. This study presents the currentsituation of black carbon trends in the Baltic Sea region and will be helpful for assessing the policies of blackcarbon emissions in Europe.