Coupled simulations of Greenland Ice Sheet and climate change up to A.D. 2300

Abstract

Recent observations indicate a high sensitivity of the Greenland Ice Sheet (GrIS) to climate change. We examine the coupling between the GrIS surface mass balance, elevation, and dynamical flow with one of the few coupled GrIS and atmosphere-ocean general circulation models. Bidirectional coupling from the early Holocene reveals a growing present-day GrIS in the absence of anthropogenic forcing. We identify atmospheric sources of biases in the simulated present-day GrIS and assess the GrIS sensitivity to future greenhouse gas forcing through three Representative Concentration Pathways and their extensions and to climate variability. The elevation-surface mass balance feedback contributes to future GrIS mass loss with 8-11% (by 2100), depending on the forcing scenario, and 24-31% (by 2300). Climate variability causes a 2.5 times spread in the magnitude of the simulated present-day GrIS mass trends in a three-member ensemble. Our results represent a first step toward more advanced higher resolution coupled modeling of GrIS and climate evolution.

Projections of Future Sea Level Contributions from the Greenland and Antarctic Ice Sheets: Challenges Beyond Dynamical Ice Sheet Modeling

“…Simulations in which ice sheets fully interact with the atmosphere in climate models show promising results and demonstrate the importance of ice sheets as an interactive component of climate models. For example, allowing for elevation-SMB feedback increases the surface runoff at lower elevations and thus the contribution of the Greenland Ice Sheet to sea level rise (Vizcaino et al, 2015).…”

Grand Challenges in Cryospheric Sciences: Toward Better Predictability of Glaciers, Snow and Sea Ice

“…However, currently most ice-sheet models are stand-alone models without two-way coupling (Vizcaino, 2014;Vizcaino et al, 2015). The necessary large computational resources are an additional barrier to progress in fully coupled modeling.…”

Assessment of the Greenland ice sheet – atmosphere feedbacks for the next century with a regional atmospheric model fully coupled to an ice sheet model

“…GrIS changes can also disrupt the atmospheric circulation over Greenland caused by changes in topography thermal contrast between ice sheet surface and atmosphere layers, surface albedo and ice sheet area, as shown by Vizcaino et al (2015), Vizcaíno 10 et al (2008) and Lunt et al (2004). Quantifying the balance between these different processes and feedbacks is required to understand and predict more confidently the evolution of the GrIS under current and future global warming.…”

“…Although numerous studies highlighted the importance of correctly representing the interactions between the GrIS topography changes and the atmosphere (Vizcaino et al, 2015;Edwards et al, 2014a;Alley and Joughin, 2012;Huybrechts et al, 2002), only few global or regional models have taken the GrIS topography changes into account to compute the future evolution of 15 the SMB, ST and energy budget over the GrIS. The climate models usually represent the ice sheet component with a fixed and constant topography, even under a warm transient climate forcing.…”

“…The climate models usually represent the ice sheet component with a fixed and constant topography, even under a warm transient climate forcing. Recently, Vizcaino et al (2015) used an atmosphereocean general circulation model (AOGCM) coupled with an ice sheet model (ISM) to explore topography feedbacks on ice mass loss. They found an ice mass loss amplification of 8-11 % (by 2100) and of 24-31 % (by 2300).…”