Coupled-isotope characterizes the upwelling of dissolved inorganic carbon from deep water in Kongsfjorden, Svalbard

To investigate the complex carbonate system in Kongsfjorden under climate change, we analyzed carbon isotopes in dissolved inorganic carbon (DIC), as well as previous published carbon isotopes from dissolved organic carbon (DOC), δ18O, and CTD measurements. The absence of a significant difference in average Δ¹⁴C-DIC values between surface waters (+14 ± 3‰) and deep waters (+17 ± 2‰) suggests rapid mixing of water masses. Strong correlations among DIC concentration, Δ¹⁴C-DIC values, and salinity indicate that freshwater dilution and meltwater input introduce aged carbon into the fjord.