Observationally constrained surface mass balance of Larsen C Ice Shelf, Antarctica



Kuipers Munneke, Peter ORCID: 0000-0001-5555-3831, McGrath, Daniel ORCID: 0000-0002-9462-6842, Medley, Brooke ORCID: 0000-0002-9838-3665, Luckman, Adrian ORCID: 0000-0002-9618-5905, Bevan, Suzanne ORCID: 0000-0003-2649-2982, Kulessa, Bernd ORCID: 0000-0002-4830-4949, Jansen, Daniela, Booth, Adam ORCID: 0000-0002-8166-9608, Smeets, Paul, Hubbard, Bryn ORCID: 0000-0002-3565-3875
et al (show 6 more authors) Observationally constrained surface mass balance of Larsen C Ice Shelf, Antarctica.

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Abstract

<jats:p>Abstract. Combining several geophysical techniques, we reconstruct spatial and temporal patterns of surface mass balance (SMB) over Larsen C Ice Shelf (LCIS), Antarctic Peninsula. Continuous time series of snow height at five locations allow for multi-year estimates of seasonal and annual SMB over LCIS. There is high interannual variability, with an SMB of 395 ± 61 to 413 ± 42 mm w.e. y−1 in the north and a larger SMB of up to 496 ± 50 mm w.e. y−1 farther south. This difference between north and south is corroborated by winter snow accumulation derived from an airborne radar survey from 2009, which showed an average snow thickness of 0.95 m north of 76° S, and 1.12 m south of 78°. Analysis of ground-penetrating radar from several field campaigns allows for a longer-term perspective of spatial SMB: a particularly strong and coherent reflection horizon below 25–44 m w.e. of ice and firn is observed in radargrams collected across the shelf. We propose that this horizon was formed in a single melt season over the ice shelf. Combining ground and airborne radar with SMB output from a regional climate model confirms that SMB increases from north to south, overprinted by a gradient of increasing SMB to the west. Previous observations show a strong decrease in firn air content toward the west, which we attribute to spatial patterns of melt, refreezing, and densification, rather than SMB. </jats:p>

Item Type: Article
Depositing User: Symplectic Admin
Date Deposited: 02 Mar 2020 11:25
Last Modified: 03 May 2022 00:10
DOI: 10.5194/tc-2017-44
URI: https://livrepository.liverpool.ac.uk/id/eprint/3076763