32-year record-high surface melt in 2019/2020 on north George VI Ice Shelf, Antarctic Peninsula ...

• Main Authors: Banwell, Alison F., Datta, Rajashree Tri, Dell, Rebecca L., Moussavi, Mahsa, Brucker, Ludovic, Picard, Ghislain, Shuman, Christopher A., Stevens, Laura A.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Copernicus Publications 2020
• Subjects: Antarctic; Antarctic Peninsula; Austral; George VI Ice Shelf; Antarc*; Ice Shelf; Ice Shelves
• Online Access: https://dx.doi.org/10.13016/m2bexc-c2i0; http://mdsoar.org/handle/11603/20119

In the 2019/2020 austral summer, the surface melt duration and extent on the northern George VI Ice Shelf (GVIIS) was exceptional compared to the 31 previous summers of dramatically lower melt. This finding is based on analysis of near-continuous 41-year satellite microwave radiometer (and scatterometer) data, which are sensitive to meltwater on the ice-shelf surface and in the near-surface snow. Using optical satellite imagery from Landsat 8 (since 2013) and Sentinel-2 (since 2017), record volumes of surface meltwater ponding are also observed on north GVIIS in 2019/2020, with 23 % of the surface area covered by 0.62 km3 of meltwater on January 19. These exceptional melt and surface ponding conditions in 2019/2020 were driven by sustained air temperatures ≥ 0 °C for anomalously long periods (55–90 hours) from late November onwards, likely driven by warmer northwesterly and northeasterly low-speed winds. Increased surface ponding on ice shelves may threaten their stability through increased potential for ...