Modeling the breakup of tabular icebergs

Mark R England; Till J W Wagner; Ian Eisenman

doi:10.1126/sciadv.abd1273

Modeling the breakup of tabular icebergs

Sci Adv. 2020 Dec 16;6(51):eabd1273. doi: 10.1126/sciadv.abd1273. Print 2020 Dec.

Authors

Mark R England^{1

2}, Till J W Wagner³, Ian Eisenman²

Affiliations

¹ Department of Physics and Physical Oceanography, University of North Carolina Wilmington, Wilmington, NC, USA. mengland@ucsd.edu.
² Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA.
³ Department of Physics and Physical Oceanography, University of North Carolina Wilmington, Wilmington, NC, USA.

Abstract

Nearly half of the freshwater flux from the Antarctic Ice Sheet into the Southern Ocean occurs in the form of large tabular icebergs that calve off the continent's ice shelves. However, because of difficulties in adequately simulating their breakup, large Antarctic icebergs to date have either not been represented in models or represented but with no breakup scheme such that they consistently survive too long and travel too far compared with observations. Here, we introduce a representation of iceberg fracturing using a breakup scheme based on the "footloose mechanism." We optimize the parameters of this breakup scheme by forcing the iceberg model with an ocean state estimate and comparing the modeled iceberg trajectories and areas with the Antarctic Iceberg Tracking Database. We show that including large icebergs and a representation of their breakup substantially affects the iceberg meltwater distribution, with implications for the circulation and stratification of the Southern Ocean.

Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).