Discussing an extreme mock/what-if scenario over the antarctic peninsula: the effect of intense melt on surface mass balance

• Main Authors: Glaude, Quentin, Dethinne, Thomas, Lambin, Clara, Fettweis, Xavier
• Other Authors: SPHERES - ULiège BE
• Format: Article in Journal/Newspaper
• Language: English
• Published: Société Geographique de Liege 2023
• Subjects: Physical; chemical; mathematical & earth Sciences; Earth sciences & physical geography; Physique; chimie; mathématiques & sciences de la terre; Sciences de la terre & géographie physique; Antarc*; Antarctic; Antarctic Peninsula; Greenland; Ice Shelves
• Online Access: https://orbi.uliege.be/handle/2268/311172; https://orbi.uliege.be/bitstream/2268/311172/1/glaude.pdf

peer reviewed This discussion paper interprets the findings of a recent study comparing melt estimates from the regional atmospheric model MAR, those derived from Automatic Weather Stations (AWS), and microwave remote sensing images over the Antarctic Peninsula from 2019 to 2021. Our interpretation reveals a paradox: MAR overestimates melt when compared to AWS-based melt estimates, yet underestimates melt when compared to satellite imagery. This discrepancy underscores a fundamental gap in our understanding of surface processes. To illustrate the potential implications of this gap, we present a fictional (“what-if”) scenario that explores an extreme case of melting, based on parametrizations from Kittel et al., 2022, and the outliers of Dethinne et al., 2023. We examine the potential impact on the ice sheet's surface mass balance (SMB), drawing parallels with the situation in Greenland during the 1990s, where increased melt production had cascading effects on SMB. Moreover, we highlight that the presence of liquid water at the surface of the snowpack can be a precursor to significant destabilization processes over ice shelves, although this aspect is not the focus of our current paper. By opening a debate on the accuracy and interpretation of melt modeling, we aim to draw attention to the potential consequences of extreme melting events on the Antarctic Ice Sheet's SMB and stability.