The Atmospheric effects of Southern Ocean open-ocean polynyas onto coastal polynyas in EC-Earth3

Polynyas are recurrent areas of open water or thin ice within the ice pack, which alter the local heat and moisture exchange and high-latitude atmosphere-ocean circulation interannual variability. They are differentiated as coastal (latent heat) or open-ocean (sensible heat) polynya according to their forming location. Especially, coastal polynyas are critical sources of dense water and the formation of Antarctic Bottom Water (AABW) following the brine enrichment of surface waters during sea-ice formation, and easily influenced by the local atmosphere conditions. However, few studies have examined the atmospheric response of open-ocean polynyas on the coastal polynyas given the fact that open-ocean polynyas have capability to re-adjust mesoscale atmosphere circulation. To better understand the surrounding impact of large open-ocean polynya events, output from CMIP6 historical experiment synoptic scale EC-Earth3 is adopted. Our results show an increasing coastal polynya frequency and extent accompanying with more active open-ocean polynya years in the Weddell Sea. The results are explained by near-surface wind speed differences in the coastal regions, which are found statistically significant between more and less active open-ocean polynya years. Furthermore, those intensifications of winds are found in days where easterly-dominated winds north-westerly to north-easterly and easterly to south-easterly cross the open-ocean polynya. Increased near-surface air temperatures as well as a deepening in sea level pressure are also observed during the years with more active open-ocean polynya events. The findings contribute to a better understanding of coastal polynya opening processes, as well as how we might expect to see the different type of polynya interact by their influence and dependence on surrounding atmospheric conditions.