Insights into spatial sensitivities of ice mass response to environmental change from the SeaRISE ice sheet modeling project II: Greenland

Abstract

[1] The Sea-level Response to Ice Sheet Evolution (SeaRISE) effort explores the sensitivity of the current generation of ice sheet models to external forcing to gain insight into the potential future contribution to sea level from the Greenland and Antarctic ice sheets. All participating models simulated the ice sheet response to three types of external forcings: a change in oceanic condition, a warmer atmospheric environment, and enhanced basal lubrication. Here an analysis of the spatial response of the Greenland ice sheet is presented, and the impact of model physics and spin-up on the projections is explored. Although the modeled responses are not always homogeneous, consistent spatial trends emerge from the ensemble analysis, indicating distinct vulnerabilities of the Greenland ice sheet. There are clear response patterns associated with each forcing, and a similar mass loss at the full ice sheet scale will result in different mass losses at the regional scale, as well as distinct thickness changes over the ice sheet. All forcings lead to an increased mass loss for the coming centuries, with increased basal lubrication and warmer ocean conditions affecting mainly outlet glaciers, while the impacts of atmospheric forcings affect the whole ice sheet.Citation: Nowicki, S., et al. (2013), Insights into spatial sensitivities of ice mass response to environmental change from the SeaRISE ice sheet modeling project II: Greenland,

Ice Sheet Model Intercomparison Project (ISMIP6) contribution to CMIP6

“…In addition, ISMIP6 collaborates with the CMIP6-Endorsed Paleoclimate Model Intercomparison effort (PMIP4, Kageyama et al, 2016) and builds on the CMIP6-Endorsed ScenarioMIP (O'Neill et al, 2016) that focuses on future climate experiments for CMIP6. For a selected number of AGCM/AOGCM Figure 1.…”

“…ISMIP6 collaborates with PMIP4 for experiment lig127k, a simulated time slice of the Last Interglacial (LIG): the warm period from 129 000 to 116 000 years ago when global mean sea level was 5-10 m higher than present (Masson-Delmott et al, 2013). The future in CMIP6 falls under the guidance of ScenarioMIP (O'Neill et al, 2016); IS-MIP6 will focus on the high-emission scenario ssp585 that produces a radiative forcing of 8.5 W m −2 in 2100 and its extension to 2300, to evaluate climate and ice-sheet changes in response to a large forcing. If time permits, lower-emission mitigation scenarios will also be included in the ISMIP6 standalone ice-sheet framework.…”

Self-affine subglacial roughness: consequences for radar scattering and basal water discrimination in northern Greenland

“…Price et al, 2011;Seroussi et al, 2013;Nowicki et al, 2013;Shannon et al, 2013;Sergienko et al, 2014;Ritz et al, 2015;Cornford et al, 2015). Notably, the basal traction parameterisation -which encapsulates the thermal state, basal roughness, and lithology -is potentially the largest single geophysical uncertainty in projections of the response of ice sheets to climate change (Ritz et al, 2015).…”

Progress in Numerical Modeling of Antarctic Ice-Sheet Dynamics

“…A few years ago, the first international initiative to produce multi-model average projections of the contribution of Greenland and Antarctica to SLR, SeaRISE, was launched [18,88]. Based on the premise that the combined results are more robust than the evaluation of a single model, it estimated that the contribution of the Antarctic ice sheet to future SLR during the next century will likely be within -20 to +185 mm.…”