Swiss halocarbon emissions for 2019 to 2020 assessed from regional atmospheric observations

Abstract. Halocarbons contribute to global warming and stratospheric ozone depletion. They are emitted the atmosphere by various anthropogenic activities. To determine Swiss national halocarbon emissions, we applied top-down methods, which rely on atmospheric concentration observations sensitive targeted emissions. We present 12 months (September 2019 August 2020) of continuous 28 halocarbons from a measurement campaign at Beromünster tall tower in Switzerland. The site is Plateau, most densely populated area Therefore, measurements well suited derive Emissions were calculated two different i.e. tracer ratio method (TRM), with carbon monoxide (CO) as independent tracer, Bayesian inversion (BI), based transport simulations using FLEXPART–COSMO. results compared previously reported emission estimates, high-Alpine Jungfraujoch, bottom-up greenhouse gas (GHG) inventory, annually United Nations Framework Convention Climate Change (UNFCCC). observed moderately elevated concentrations chlorofluorocarbons (CFCs) hydrochlorofluorocarbons (HCFCs), both banned production consumption Europe. corresponding emissions likely related ongoing outgassing older foams refrigerators confirm widespread historical use these substances. For major hydrofluorocarbons (HFCs), HFC-125 (CHF2CF3) HFC-32 (CH2F2), our 100 ± 34 45 14 Mg yr−1 good agreement numbers whereas, for HFC-134a (CH2FCF3), result 280 89 more than 30 % lower inventory. HFC-152a (CH3CHF2), 21 5 significantly higher number other investigated HFCs, perfluorocarbons (PFCs), SF6 NF3, small Finally, first country-based estimates three recently phased-in, unregulated hydrofluoroolefins (HFOs), HFO-1234yf (CF3CF=CH2), HFO-1234ze(E) ((E)-CF3CH=CHF), HCFO-1233zd(E) ((E)-CF3CH=CHCl). HFOs, 15 4, 14, 7 1 yr−1, respectively.