High Performance Computing-Enabled Ice Sheet Response Analysis under Oceanic Forcing

Abstract:

Ocean warming has been accelerating both tidewater glacier submarine melting and ice shelf basal melting. However, sufficient physical representation of key process within ice shelf cavity or glacier-fjord system requires high resolution simulation, thus large computational resources. Current semi-empirical methods or parameterizations can reduce simulation complexity, yet they are based on simplifications and are poorly constrained due to sparse observational data and short periods covered.

This study aims to capture the response of both Greenland and Antarctica under oceanic forcing via semi-empirical method based on model emulation. Major glaciers in Greenland and major ice shelves in Antarctica are modeled and studied. The melting response functions are generalized by forcing glacier-plume model and ice shelf cavity model – Potsdam Ice-shelf Cavity mOdel (PICO) (Reese et al., 2018) – with unit ocean temperature rise. Subglacial discharge is estimated from Regional Climate Model (RCM) for each glacier catchment in Greenland. Various sources of Conductivity, Temperature and Depth (CTD) measurements and ocean data are utilized to formulate oceanic forcing. Time series is constructed by adding present-day and future warming trend generated by Atmosphere-Ocean General Circulation Model (AOGCM). This study identifies the responses of ice sheet glacier and ice shelf under ocean warming and provides a framework of deriving ocean induced melting.

Reference

Reese, R., Albrecht, T., Mengel, M., Asay-Davis, X., & Winkelmann, R. (2018). Antarctic sub-shelf melt rates via PICO. The Cryosphere, 12(6), 1969–1985. https://doi.org/10.5194/tc-12-1969-2018