Fast Ice Thickness Distribution in the Western Ross Sea in Late Spring

• Published in: Journal of Geophysical Research: Oceans
• Main Authors: Langhorne, Pat, Haas, Christian, Price, Daniel, Rack, Wolfgang, Leonard, G H, Brett, G M, Urbini, Stefano
• Other Authors: #PLACEHOLDER_PARENT_METADATA_VALUE#, Istituto Nazionale di Geofisica e Vulcanologia (INGV), Sezione Roma2, Roma, Italia
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley-Agu 2023
• Subjects: Annual maximum fast ice and sub-ice platelet layer thickness distributions are surveyed by airborne electromagnetics over 700 km of Ross Sea; Deformed against the coast; 50% of transect volume was rough first-year fast ice (mode 3.3 m thick); that was thicker than nearby pack ice; Sub-ice platelet layers over 0.5 m thick underlay level ice over large parts of four embayments; revealing land ice-fast ice interaction; Adare; Cape Adare; Granite Harbor; Hells Gate; McMurdo Sound; Moubray Bay; New Harbor; Ross Sea; Silverfish Bay; Ice Shelf
• Online Access: http://hdl.handle.net/2122/16684; https://doi.org/10.1029/2022JC019459

We present a 700 km airborne electromagnetic survey of late-spring fast ice and sub-ice platelet layer (SIPL) thickness distributions from McMurdo Sound to Cape Adare, providing a first-time inventory of fast ice thickness close to its annual maximum. The overall mode of the consolidated ice (including snow) thickness was 1.9 m, less than its mean of 2.6 ± 1.0 m. Our survey was partitioned into level and rough ice, and SIPL thickness was estimated under level ice. Although level ice, with a mode of 2.0 m and mean of 2.0 ± 0.6 m, was prevalent, rough ice occupied 41% of the transect by length, 50% by volume, and had a mode of 3.3 m and mean of 3.2 ± 1.2 m. The thickest 10% of rough ice was almost 6 m on average, inclusive of a 2 km segment thicker than 8 m in Moubray Bay. The thickest ice occurred predominantly along the northwestern Ross Sea, due to compaction against the coast. The adjacent pack ice was thinner (by ∼1 m) than the first-year fast ice. In Silverfish Bay, offshore Hells Gate Ice Shelf, New Harbor, and Granite Harbor, the SIPL transect volume was a significant fraction (0.30) of the consolidated ice volume. The thickest 10% of SIPLs averaged nearly 3 m thick, and near Hells Gate Ice Shelf the SIPL was almost 10 m thick, implying vigorous heat loss to the ocean (∼90 W m −2). We conclude that polynya-induced ice deformation and interaction with continental ice influence fast ice thickness in the western Ross Sea. Published e2022JC019459 OSA2: Evoluzione climatica: effetti e loro mitigazione JCR Journal