Journal cover Journal topic
The Cryosphere An interactive open-access journal of the European Geosciences Union
https://doi.org/10.5194/tc-2017-155
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 4.0 License.
Research article
08 Aug 2017
Review status
This discussion paper is a preprint. A revision of this manuscript was accepted for the journal The Cryosphere (TC) and is expected to appear here in due course.
Frazil-ice growth rate and dynamics in mixed layers and sub-ice-shelf plumes
David W. Rees Jones1,2 and Andrew J. Wells1 1Atmospheric, Oceanic and Planetary Physics, Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, UK
2Department of Earth Sciences, University of Oxford, South Parks Road, Oxford, OX1 3AN, UK
Abstract. The growth of frazil or granular ice is an important mode of ice formation in the cryosphere. Recent advances have improved our understanding of the microphysical processes that control the rate of ice-crystal growth when water is cooled beneath its freezing temperature. These advances suggest that crystals grow much faster than previously thought. In this paper, we consider models of a population of ice crystals with different sizes to provide insight into the treatment of frazil ice in large-scale models. We consider the role of crystal growth alongside the other physical processes that determine the dynamics of frazil ice. We apply our model to a simple mixed layer (such as at the surface of the ocean) and to a buoyant plume under a floating ice shelf. We provide numerical calculations and scaling arguments to predict the occurrence of frazil-ice explosions, which we show are controlled by crystal growth, nucleation and, gravitational removal. Faster crystal growth, higher secondary nucleation and slower gravitational removal make frazil-ice explosions more likely. We identify steady-state crystal size distributions, which are largely insensitive to crystal growth rate but are affected by the relative importance of secondary nucleation to gravitational removal. Finally, we show that the fate of plumes underneath ice shelves is dramatically affected by frazil-ice dynamics. Differences in the parameterization of crystal growth and nucleation give rise to radically different predictions of basal accretion and plume dynamics; and can even impact whether a plume reaches the end of the ice shelf or intrudes at depth.

Citation: Rees Jones, D. W. and Wells, A. J.: Frazil-ice growth rate and dynamics in mixed layers and sub-ice-shelf plumes, The Cryosphere Discuss., https://doi.org/10.5194/tc-2017-155, in review, 2017.
David W. Rees Jones and Andrew J. Wells
Interactive discussionStatus: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version      Supplement - Supplement
 
RC1: 'Frazil-ice growth rate and dynamics in mixed layers and sub-ice-shelf plumes', Anonymous Referee #1, 06 Sep 2017 Printer-friendly Version 
 
RC2: 'Anonymous review', Anonymous Referee #2, 03 Oct 2017 Printer-friendly Version 
 
AC1: 'Author response to Referees' comments', David Rees Jones, 06 Nov 2017 Printer-friendly Version Supplement 
David W. Rees Jones and Andrew J. Wells

Model code and software

Frazil-dynamics code
D. W. Rees Jones
https://doi.org/10.5281/zenodo.836794
David W. Rees Jones and Andrew J. Wells

Viewed

Total article views: 318 (including HTML, PDF, and XML)

HTML PDF XML Total BibTeX EndNote
240 72 6 318 6 9

Views and downloads (calculated since 08 Aug 2017)

Cumulative views and downloads (calculated since 08 Aug 2017)

Viewed (geographical distribution)

Total article views: 318 (including HTML, PDF, and XML)

Thereof 317 with geography defined and 1 with unknown origin.

Country # Views %
  • 1

Saved

Discussed

Latest update: 22 Nov 2017
Publications Copernicus
Download
Short summary
Frazil or granular ice grows rapidly from turbulent water cooled beneath its freezing temperature. We analyze numerical models of a population of ice crystals to provide insight into the treatment of frazil ice in large-scale models and hence in the environment. We determine critical conditions for explosively rapid frazil growth. We show that frazil-ice processes impact whether a plume of ice shelf water beneath an Antarctic ice shelf intrudes at depth or reaches the end of the shelf.
Frazil or granular ice grows rapidly from turbulent water cooled beneath its freezing...
Share