Imaging air volume fraction in sea ice using non-destructive X-ray tomography

Crabeck, Odile, Galley, Ryan, Delille, Bruno, Else, Brent, Geilfus, Nicolas Xavier, Lemes, Marcos, Roches, Mathieu Des, Francus, Pierre, Tison, Jean Louis and Rysgaard, Søren (2016) Imaging air volume fraction in sea ice using non-destructive X-ray tomography. Cryosphere, 10 (3). pp. 1125-1145. ISSN 1994-0416

[img]
Preview
PDF (Published_Version) - Published Version
Available under License Creative Commons Attribution.

Download (4MB) | Preview

Abstract

Although the presence of a gas phase in sea ice creates the potential for gas exchange with the atmosphere, the distribution of gas bubbles and transport of gases within the sea ice are still poorly understood. Currently no straightforward technique exists to measure the vertical distribution of air volume fraction in sea ice. Here, we present a new fast and non-destructive X-ray computed tomography technique to quantify the air volume fraction and produce separate images of air volume inclusions in sea ice. The technique was performed on relatively thin (4&ndash;22cm) sea ice collected from an experimental ice tank. While most of the internal layers showed air volume fractions < 2 %, the ice-air interface (top 2 cm) systematically showed values up to 5 %. We suggest that the air volume fraction is a function of both the bulk ice gas saturation factor and the brine volume fraction. We differentiate micro bubbles (Ø < 1 mm), large bubbles (1 mm < Ø < 5 mm) and macro bubbles (Ø > 5 mm). While micro bubbles were the most abundant type of gas bubbles, most of the air porosity observed resulted from the presence of large and macro bubbles. The ice texture (granular and columnar) as well as the permeability state of ice are important factors controlling the air volume fraction. The technique developed is suited for studies related to gas transport and bubble migration.

Item Type: Article
Uncontrolled Keywords: water science and technology,earth-surface processes ,/dk/atira/pure/subjectarea/asjc/2300/2312
Related URLs:
Depositing User: LivePure Connector
Date Deposited: 05 Apr 2019 08:30
Last Modified: 03 Jun 2020 23:54
URI: https://ueaeprints.uea.ac.uk/id/eprint/70486
DOI: 10.5194/tc-10-1125-2016

Actions (login required)

View Item View Item