Decline in Surface Melt Duration on Larsen C Ice Shelf Revealed by The Advanced Scatterometer (ASCAT)

Bevan, Suzanne Louise, Luckman, Adrian John, Munneke, Peter Kuipers, Hubbard, Bryn, Kulessa, Bernd and Ashmore, David William ORCID: 0000-0003-4829-7854 (2018) Decline in Surface Melt Duration on Larsen C Ice Shelf Revealed by The Advanced Scatterometer (ASCAT). EARTH AND SPACE SCIENCE, 5 (10). pp. 578-591.

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Official URL: http://dx.doi.org/10.1029/2018ea000421

Abstract

<jats:p>Surface melting has been contributing to the surface lowering and loss of firn air content on Larsen C Ice Shelf since at least the mid‐1990s. Where the amount of melting and refreezing is significant, the firn can become impermeable and begin to support ponds of surface meltwater such as have been implicated in ice shelf collapse. Although meteorological station data indicated an increase in melt on the Antarctic Peninsula over the second half of the 20th century, the existing Ku‐band Quick Scatterometer (QuikSCAT) time series is too short (1999–2009) to detect any significant 21st century trends. Here we investigate a longer 21st century period by extending the time series to 2017 using the C‐band Advanced Scatterometer (ASCAT). We validate our recent observations with in situ weather station data and, using a firn percolation model, explore the sensitivity of scatterometry to water at varying depths in the firn. We find that active microwave C‐band (5.6‐cm wavelength) instruments can detect water at depths of up to 0.75 m below a frozen firn layer. Our longer scatterometry time series reveals that Larsen C Ice Shelf has experienced a decrease in melt season length of 1–2 days per year over the past 18 years consistent with decreasing summer air temperatures. Only in western inlets, where föhn winds drive melt, has the annual melt duration increased during this period.</jats:p>

Item Type:	Article
Uncontrolled Keywords:	13 Climate Action
Depositing User:	Symplectic Admin
Date Deposited:	09 Oct 2018 08:35
Last Modified:	17 Mar 2024 00:37
DOI:	10.1029/2018EA000421
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3027277