Modeling the Greenland Ice Sheet's Committed Contribution to Sea Level During the 21st Century

Nias, Isabel J ORCID: 0000-0002-5657-8691, Nowicki, Sophie, Felikson, Denis and Loomis, Bryant (2023) Modeling the Greenland Ice Sheet's Committed Contribution to Sea Level During the 21st Century. JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE, 128 (2).

Access the full-text of this item by clicking on the Open Access link.

Official URL: http://dx.doi.org/10.1029/2022jf006914

Abstract

<jats:title>Abstract</jats:title><jats:p>Mass loss from the Greenland Ice Sheet can be partitioned between surface mass balance and discharge due to ice dynamics through its marine‐terminating outlet glaciers. A perturbation to a glacier terminus (e.g., a calving event) results in both an instantaneous response in velocity and mass loss and a diffusive response due to the evolution of ice thickness over time. This diffusive response means the total impact of a retreat event can take decades to be fully realized. Here we model the committed response of the Greenland Ice Sheet by applying perturbations to the marine‐terminating glacier termini that represent recent observed changes, and simulating the response over the 21st century, while holding the climate forcing constant. The sensitivity of the ice sheet response to model parameter uncertainty is explored within an ensemble framework, and Gravity Recovery and Climate Experiment data is used to constrain the results using a Bayesian calibration approach. We find that the Greenland Ice Sheet's committed contribution to 21st century sea level rise is at least 33.5 [17.5 52.4] mm (25th and 75th percentiles in brackets), with at least 6 mm being attributable directly to terminus retreat that occurred between 2007 and 2015. The spread in our projections is driven by uncertainty in the basal friction coefficient. Our results complement the ISMIP6 Greenland projections, which report the ice sheet response to future forcing, excluding the background response. In this way, we can obtain estimates of Greenland's total contribution to sea level rise in 2100.</jats:p>

Item Type:	Article
Uncontrolled Keywords:	sea level rise, Greenland Ice Sheet, ice sheet modeling, Bayesian calibration
Divisions:	Faculty of Science and Engineering > School of Environmental Sciences
Depositing User:	Symplectic Admin
Date Deposited:	14 May 2023 14:31
Last Modified:	23 Aug 2023 11:24
DOI:	10.1029/2022JF006914
Open Access URL:	https://doi.org/10.1029/2022JF006914
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3170333