Dominant frazil ice production in the Cape Darnley polynya leading to Antarctic Bottom Water formation

• DOI: 10.1126/sciadv.adc9174
• Publication Date: 2022-10-19T17:57:23Z
• Authors: Kay I. Ohshima; Yasushi Fukamachi; Masato Ito; Kazuki Nakata; Daisuke Simizu; Kazuya Ono; Daiki Nomura; Gen Hashida; Takeshi Tamura
• Keywords: Antarctic Bottom Water; Lead (geology)

Antarctic Bottom Water (AABW) occupies the abyssal layer of world ocean and contributes to global overturning circulation. It originates from dense shelf water, which forms brine rejection during sea ice production. An important region AABW formation has been identified off Cape Darnley polynya. However, it remains unclear why how high production leads formation. Using moored acoustic measurements a satellite microwave algorithm, we reveal that underwater frazil dominates in This prevents heat-insulating surface-cover forming, thereby enabling efficient The nearshore longer residence times create high-salinity source water for AABW. Underwater occurs as long strong winds continue occasionally penetrates depths at least 80 m. Deep-penetrating is particularly prominent this polynya, while also other coastal polynyas.