Sea Ice Production in the 2016 and 2017 Maud Rise Polynyas

Abstract

Polynyas are regions of low sea ice concentration (SIC) or thickness where the comparatively warm ocean is exposed to the cold atmosphere. Coastal polynyas are mainly driven by katabatic winds, while sensible heat convection results in open-ocean/offshore polynyas (Morales Maqueda et al., 2004). Morales Maqueda et al. ( 2004) (and references therein) summarized that air-ice-ocean interactions in polynyas could impact: (a) the moisture and heat exchange between atmosphere and ocean and, therefore, the local wind dynamics; (b) the upper ocean properties and vertical flows of dense saline water through brine rejection and buoyancy loss; (c) the biogeochemical fluxes, for example, acting as the sinks of atmospheric CO 2 , between air and sea; and (d) the local ecosystems with extra phytoplankton and zooplankton, serving as "oases" in a polar ocean desert. In the Southern Ocean, open-ocean polynyas rarely occur but can reach a large extent. Such an open-ocean polynya, the Maud Rise polynya, opened in the vicinity of the Maud Rise seamount (centered on 64°S and 3°E)

Recent Decline in Antarctic Sea Ice Cover From 2016 to 2022: Insights From Satellite Observations, Argo Floats, and Model Reanalysis

“…Furthermore, when heat loss to the atmosphere increases, these polynyas are also characterized by large amounts of sea ice production due to the restratification of fresh water to the surface (Dufour et al, 2017;Ohshima et al, 2013). The Maud Rise polynya in 2017 produced ~200 km 3 of new sea ice (Zhou et al, 2023).…”

Closing the loops on Southern Ocean dynamics: From the circumpolar current to ice shelves and from bottom mixing to surface waves

“…In winter, they are "sea ice factories", in which ≈ 10% of Antarctic sea ice is producted and with the Ross Sea polynya by far the most prolific (Tamura et al, 2008;Ohshima et al, 2016;Zhou et al, 2023). A contemporary review of polynyas is given in § § 4.2.2-4.2.3, rather than in § 3.2, due to their important influence on turbulent convection.…”

Polar Lows and Their Effects on Sea Ice and the Upper Ocean in the Iceland, Greenland, and Labrador Seas

“…Sea ice growth was not stored as an output variable, so we calculated potential ice production in polynyas from model output (Gutjahr et al., 2016; Zhou et al., 2023). The conductive heat flux through the ice ( F c ) is assumed to be balanced by the net surface heat flux Q : $$${F}_{c}={F}_{sw}+{F}_{lw}+{F}_{sh}+{F}_{lh}=Q,$$$ …”

“…We then computed the daily ice volume growth within a polynya (sea ice concentration <60%), as follows (Cheng et al., 2017; Zhou et al., 2023): $$$V=tA(1-SIC)\frac{\partial h}{\partial t},$$$ …”