Significant methane undersaturation during austral summer in the Ross Sea (Southern Ocean)

Methane (CH4) is a climate-relevant trace gas that emitted from the open and coastal oceans in considerable amounts. However, its distribution remote oceanic areas largely unknown. To fill this knowledge gap, dissolved CH4 was measured at nine stations 75°S Ross Sea during austral summer January 2020. undersaturation (mean: 82 ± 20%) found throughout water column. In subsurface waters, of mainly resulted mixing masses situ consumption, whereas concentrations surface mixed layer were driven by air–sea exchange diapycnal diffusion between layers, as well consumption CH4. With mean flux density −0.44 0.34 μmol m−2 d−1, substantial sink for atmospheric summer, which contrast with most regions, are known sources.