Surface and basal boundary conditions at the Southern McMurdo and Ross Ice Shelves, Antarctica

We derive the surface and basal radar reflectance and backscatter coefficients of the southern McMurdo Ice Shelf (SMIS) and part of the nearby Ross Ice Shelf (RIS), Antarctica, from radar statistical reconnaissance using a 60-MHZ airborne survey. The surface coefficients are further inverted in term...

Full description

Bibliographic Details
Published in:Journal of Glaciology
Main Authors: C. GRIMA, I. KOCH, J. S. GREENBAUM, K. M. SODERLUND, D. D. BLANKENSHIP, D. A. YOUNG, D. M. SCHROEDER, S. FITZSIMONS
Format: Article in Journal/Newspaper
Language:English
Published: Cambridge University Press 2019
Subjects:
basal
ice shelf
processes
radar
roughness
surface
Environmental sciences
GE1-350
Meteorology. Climatology
QC851-999
Ross Ice Shelf
McMurdo Ice Shelf
Antarc*
Antarctica
Ice Shelf
Ice Shelves
Journal of Glaciology
Online Access:https://doi.org/10.1017/jog.2019.44
https://doaj.org/article/5da463d1217d48f8899a07af8814fa8a
Description
Summary:We derive the surface and basal radar reflectance and backscatter coefficients of the southern McMurdo Ice Shelf (SMIS) and part of the nearby Ross Ice Shelf (RIS), Antarctica, from radar statistical reconnaissance using a 60-MHZ airborne survey. The surface coefficients are further inverted in terms of snow density and roughness, providing a spatial distribution of the processes contributing to the surface boundary conditions. We disentangle the basal coefficients from surface transmission losses, and we provide the basal coherent content, an indicator of the boundary geometric disorder that is also self-corrected from englacial attenuation. The basal radar properties exhibit sharp gradients along specific iso-depths, suggesting an abrupt modification of the ice composition and geometric structure. We interpret this behavior as locations where the pressure-melting point is reached, outlining fields of freezing and melting ice. Basal steps are observed at both SMIS and RIS, suggesting a common geometric expression of widespread basal processes. This technique offers a simultaneous view of both the surface and basal boundary conditions to help investigate the ice-shelf stability, while its application to airborne data significantly improves coverage of the difficult-to-observe ice–ocean boundary. It also provides constraints on thermohaline circulation in ice shelves cavities, which are analogs for ice-covered ocean worlds.

Similar Items