Anthropogenic changes of CO2, CH4, N2O, CFCl3, CF2Cl2, CCl2FCClF2, CHCl3, CH3CCl3, CCl4, SF6 and SF5CF3 mixing ratios in the atmosphere over southern Poland

An overview of long-term, systematic observations of trace gas composition of the atmosphere over southern Poland is given. Three major greenhouse gases (CO2, CH4, N2O) and selected halocarbons (freons F-11, F-12 and F-113; chloroform; 1,1,1-trichloroetane; carbon tetrachloride; sulphur hexafluoride and trifluoromethyl sulphur pentafuoride) were monitored. Measurements were performed at two locations of contrasting characteristics: (1) the high-mountain site Kasprowy Wierch, High Tatras, representing atmospheric conditions relatively free of local influences, and (2) two sites located in the Krakow agglomeration, representing a typical urban atmosphere. The data available for Krakow and Kasprowy Wierch were compared with the Mace Head data, representing a marine regional background. The impact of continental sources for some of the measured gases is clearly seen in the Krakow and Kasprowy Wierch records. The mean offset between CH4 concentrations recorded at Kasprowy Wierch and at Mace Head for the period 1998-2012 is 20.7 ppb and stems from continental emissions of this gas originating mainly from anthropogenic activities (leaks of natural gas distribution networks, landfills, livestock). For N2O, a similar offset of ca. 1 ppb for the period 2009-2012 was observed. Although the long-term concentration trends of selected halogenated compounds measured in Krakow coincide in general with the respective trends in Mace Head data, the Krakow records contain numerous spikes and periods of enhanced concentrations, reflecting the impact of local sources of these compounds. The impact of a legislative framework enforced in Poland in July 2002, regulating the trade, storage and disposal of ozone-depleting substances, is visible in the Krakow record of halogenated compounds.