Ocean-ice data from an Antarctic ice shelf water plume flowing beneath land-fast sea ice

Date 2015-10
Temporal extent 2015-10-21 -2015-11-04
Author(s) Stevens CraigORCID1, 2, Robinson NatalieORCID1, O'Connor GabbyORCID1, 2, Grant BrettORCID3
Affiliation(s) 1 : National Institute of Water and Atmospheric Research, Greta Point, Wellington, New Zealand
2 : University of Auckland, New Zealand
3 : National Institute of Water and Atmospheric Research, Dunedin, New Zealand
DOI 10.17882/90432
Publisher SEANOE
Keyword(s) Antarctica, ice shelf water plume, under ice boundary layer, turbulent boundary layer, frazil, fast ice, ice shelf, supercooled, shear microstructure
Abstract

Data from a measurement campaign examining the oceanic connection between an ice shelf cavity and sea ice. Here we present data from the ocean boundary-layer in an Ice Shelf Water outflow region from the Ross/McMurdo Ice Shelves. From a fast ice field camp during the Spring of 2015, we captured the kinematics of free-floating relatively large (in some cases 10s of mm in scale) ice crystals that were advecting and then settling upwards in a depositional layer on the sea ice underside (SIPL, sub-ice platelet layer). Simultaneously, we measured the background oceanic temperature, salinity, currents and turbulence structure. At the camp location the total water depth was 536 m, with the uppermost 50 m of the water column being in-situ super-cooled. Tidal flow speeds had an amplitude of around 0.1 m s-1 with dissipation rates in the under-ice boundary layer measured to be up to e=10-6 W kg-1. Acoustic sampling (200 kHz) identified backscatter from large, individually identifiable suspended crystals associated with crystal sizes larger than normally described as frazil. Crystal sizes in the SIPL were also measured.

Licence CC-BY
Acknowledgements We would like to acknowledge Professor Pat Langhorne for her leadership on the wider topic. Tim Haskell is thanked for his development of the K131 infrastructure program. We are grateful to Inga Smith, Pat Wongpan, Cecilia Bitz, Greg Leonard and Andrew Pauling for their assistance and insight. Antarctica New Zealand provided field support. Funding was provided by the Royal Society of New Zealand Marsden Fund, NIWA Strategic Science Investment Funding, N.Z. Antarctic Research Institute, the Deep South National Science Challenge, and the New Zealand Ministry of Business, Innovation and Employment through the Antarctic Science Platform (ANTA1801).
Sensor metadata

Data

Format

Where

Acoustic

EK60.sav – ASCII files with timestamp in first line

Echo-data folder

CTD

Ascii cnv format with header information embedded.

Ctd-data folder

Mooring timeseries

Various ascii files

Mooring-data folder

Platelet data

csv

Platelet-data folder

VMP turbulence

Ascii processed files (raw files available on request). .dat files are dissipation rate estimations, P.dat are temperature and conductivity profiles.

VMP-data folder

Data
File Size Format Processing Access
CTD, microstructure, crystal size, acho sounder data 1 GB TEXTE Quality controlled data Open access
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How to cite 

Stevens Craig, Robinson Natalie, O'Connor Gabby, Grant Brett (2015). Ocean-ice data from an Antarctic ice shelf water plume flowing beneath land-fast sea ice. SEANOE. https://doi.org/10.17882/90432