Spatial variability and regional trends of Antarctic ice shelf surface melt duration over 1979–2020 derived from passive microwave data

• Published in: Journal of Glaciology
• Main Authors: Andrew Johnson, Regine Hock, Mark Fahnestock
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press 2022
• Subjects: Environmental sciences; GE1-350; Meteorology. Climatology; QC851-999; Antarctic; The Antarctic; Antarctic Peninsula; Austral; Dronning Maud Land; West Antarctica; Bellingshausen Sea; Ross Ice Shelf; Wilkes Land; Antarc*; Antarctica; Ice Shelf; Ice Shelves; Journal of Glaciology
• Online Access: https://doi.org/10.1017/jog.2021.112; https://doaj.org/article/c8e9953466a94aa8964791fdf4b48228

Passive microwave satellite observations are used to identify the presence of surface meltwater across Antarctica at daily intervals from July 1979 to June 2020, with a focus on ice shelves. Antarctic Peninsula ice shelves have the highest number of annual days of melt, with a maximum of 89 days. Over the entire time period, there are few significant linear trends in days of melt per year. High melt years can be split into two distinct categories, those with high melt days in Dronning Maud Land and Wilkes Land, and those with high melt days in the Antarctic Peninsula and the Bellingshausen Sea sector of West Antarctica. The first pattern coincides with significant negative correlations between melt days and spring and summer Southern Annular Mode. Both patterns also form the primary modes of spatial and annual variability in the dataset observed by Principal Component Analysis. Areas experiencing extended melt for the first time in years tend to show large decreases in subsequent winter microwave emissions due to structural changes in the firn. We use this to identify the impact of novel melt events, particularly over the austral summers of 1991/92 and 2015/16 on the Ross Ice Shelf.