On the settling depth of meltwater escaping from beneath Antarctic ice shelves
Name
[15200485 - Journal of Physical Oceanography] On the Settling Depth of Meltwater Escaping from beneath Antarctic Ice Shelves.pdf
Description
Published version
Size
2.39 MB
Format
Unknown
Checksum (MD5)
6b1ec3ae61d284986635813fda23c28d
Author(s)
Arnscheidt, Constantin W
Marshall, John
Dutrieux, Pierre
Rye, Craig D
Ramadhan, Ali
Date Issued
June 2021
Journal
Journal of Physical Oceanography
Publisher
American Meteorological Society
Version
Final published version
Abstract
AbstractAntarctic glacial meltwater is thought to play an important role in determining large-scale Southern Ocean climate trends, yet recent modeling efforts have proceeded without a good understanding of how its vertical distribution in the water column is set. To rectify this, here we conduct new large-eddy simulations of the ascent of a buoyant meltwater plume after its escape from beneath an Antarctic ice shelf. We find that the meltwater’s settling depth is primarily a function of the buoyancy forcing per unit width of the source and the ambient stratification, consistent with the classical theory of turbulent buoyant plumes and in contrast to previous work that suggested an important role for centrifugal instability. Our results further highlight the significant role played by localized variability in stratification; this helps explain observed interannual variability in the vertical meltwater distribution near Pine Island Glacier. Because of the vast heterogeneity in mass loss rates and ambient conditions at different Antarctic ice shelves, a dynamic parameterization of meltwater settling depth may be crucial for accurately simulating high-latitude climate in a warming world; we discuss how this may be developed following this work, and where the remaining challenges lie.
MIT Department
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1175/JPO-D-20-0286.1
