Towards Quantifying Multi-model Uncertainty in Antarctic Basal Melt Rate using High-resolution Regional Ocean Modeling
Abstract
Global sea level rise (SLR) of several meters is thought to be possible within a century or two, with serious implications for coastal protection in the future. The largest uncertainty in global SLR is the contribution from Antarctic land ice.
This uncertainty is partly due to the fact that state-of-the-art global climate models 1) are limited to resolutions too coarse to explicitly represent the small-scale ocean processes in the shallow seas around Antarctica and in the ice-shelf cavities where melt is occurring, and 2) differ in their projected ocean and atmospheric conditions. We present a study aiming to quantify the multi-model uncertainty in future Antarctic basal melt rate. A regional circum-Antarctic ocean model (5km horizontal resolution ROMS) with static ice-shelf cavities is forced by conditions derived from a climate model, to simulate the sub-ice-shelf melt. As an example, we examine the melt rates produced over the historical period when the high-resolution regional model is forced by ocean and dynamically-downscaled atmospheric boundary conditions from the ACCESS 1.3 climate model. These results are a first step to relate large-scale atmospheric and ocean conditions from global climate models to melt rates occurring underneath ice shelves, in both historical and future projections. This study will be extended to include a suite of such simulations, each driven by distinct boundary conditions derived from a given state-of-the-art (CMIP5) climate model. By providing a better representation of ocean processes, and relying on a range of climate forcings (rather than a single CMIP5 model), this effort will contribute to quantifying uncertainties in SLR, and pave the way for better projections to inform strategic adaptation decisions.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFMOS13F1552B
- Keywords:
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- 0726 Ice sheets;
- CRYOSPHEREDE: 4207 Arctic and Antarctic oceanography;
- OCEANOGRAPHY: GENERALDE: 4215 Climate and interannual variability;
- OCEANOGRAPHY: GENERALDE: 4255 Numerical modeling;
- OCEANOGRAPHY: GENERAL