Landfast sea ice in the Bothnian Bay (Baltic Sea) as a temporary storage compartment for greenhouse gases

Although studies of biogeochemical processes in polar sea ice have been increasing, similar research on relatively warm low-salinity remains sparse. In this study, we investigated properties the landfast cover brackish Bothnian Bay (Northern Baltic Sea) and possible role mediating exchange greenhouse gases, including carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O) across water column–sea ice–atmosphere interface. Observations total alkalinity dissolved inorganic both column suggest that carbonate system is mainly driven by salinity. While high CH4 N2O concentrations were observed (up to 14.3 17.5 nmol L–1, respectively) 143.6 22.4 respectively), these gases appear be enriched compared column. This enrichment may attributable formation process, which concentrates impurities within brine. As temperature brine volume decrease, gas solubility decreases as well, promoting bubbles. Gas bubbles originating from underlying sediments also incorporated contribute ice. The fate merits further research, storage seasonal temporary.