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Day 2 - Sea ice

Title: Sea Ice Physics and Ecosystems Experiment 2 – An update

Presenter: Klaus Meiners

Australian Antarctic Division, Kingston, Channel Highway, Kingston 7050, Tasmania, Australia

Authors: Klaus Meiners1,2, Guy Williams2, Jan Lieser2, Petra Heil1,2, Rob Massom1,2, Adam Steer2, Karen Westwood1, Jessica Melbourne-Thomas1,2 and the SIPEX 2 team

1 - Australian Antarctic Division, Kingston, Channel Highway, Kingston 7050, Tasmania, Australia,,,,,

2 - Antarctic Climate and Ecosystems Cooperative Research Centre, University of Tasmania, Hobart, Private Bag 80, Hobart 7000, Tasmania, Australia,,,


The Sea Ice Physics and Ecosystems eXperiment 2 (SIPEX 2) project was a large marine science project conducted during the Australian Antarctic program’s 2012/13 season. This multi-disciplinary study was specifically designed to address major knowledge gaps in Antarctic sea ice zone processes as identified by national and international end-users. The study was conducted using RSV Aurora Australis in the region of 100-120°E off East Antarctica during September – November 2012, and brought together over 50 scientists from 9 nations. The team measured the physical and biological properties of sea ice on small-to-regional scales using classical methods and state-of-the-art technology, including ice coring surveys, remotely-operated and autonomous underwater vehicles, drifting buoys and instrumented helicopters. Data currently being processed will enhance our understanding of the role of sea ice in Antarctic climate and ecosystem processes. These data will also be utilised in the validation of satellite-derived products and the parameterisation of sea ice processes in climate and ecosystem models. This presentation will give an overview of the voyage and will provide initial scientific results from the project.

Title: First deployments of under-ice floats through winter on the Antarctic continental shelf

Presenter: Esmee van Wijk

CSIRO Marine and Atmospheric Research

Authors: Esmee van Wijk1, Steve Rintoul2, Breck Owens3

1 - CSIRO Marine and Atmospheric Research

2 - Wealth from Oceans National Research Flagship, CSIRO Marine and Atmospheric Research, Centre for Australian Weather and Climate Research, Antarctic Climate and Ecosystems Cooperative Research Centre, University of Tasmania, Hobart

3 - Woods Hole Oceanographic Institute


The high latitudes play a vital role in setting the rate and nature of global climate variability through their moderation of the earth’s heat, freshwater and carbon budgets. Some of the most rapid climate change signals are already underway in the polar regions. Observations of the high latitudes however are sparse and in particular few observations exist beneath the winter sea ice. Technical advances in float design now give us the capability to deploy profiling floats in the seasonal ice zone. Floats are usually deployed in water depths greater than 2000m, drifting with the ocean currents and providing a profile every ten days. Here we describe the first results from a pilot program of three ice-capable SOLO floats deployed in January 2012. These floats are the first to be deployed on the continental shelf within the Mertz polynya and were deliberately grounded between profiles in order to increase their residence time in a poorly observed area. We see evidence of super-cooled temperature plumes and observe a full annual cycle of salinification of the water column through winter formation of sea ice and brine rejection.

Title: Sea ice freeboard in McMurdo Sound 2003-2009 derived by ICESat

Presenter: Daniel Price

Gateway Antarctica, University of Canterbury, Christchurch, New Zealand

Authors: D Price1, W Rack1, C Haas2, P Langhorne3, J Beckers4, V Helm5

1 - Gateway Antarctica, University of Canterbury, Christchurch, New Zealand

2 - Department of Earth, Space Science and Engineering, York University, Toronto, Canada

3 - Department of Physics, University of Otago, Dunedin, New Zealand

4 - Department of Earth & Atmospheric Sciences, University of Alberta, Edmonton, Canada

5 - Alfred Wegener Institute, Bremerhaven, Germany


This investigation employs the use of ICESat to derive freeboard of sea ice in McMurdo Sound from 2003-2009. Two techniques for freeboard retrieval are compared. The primary method follows those previously presented in the literature using the lowest elevations to construct an estimate of sea surface height. However the lack of open leads in the study area motivated the development of a secondary method which utilizes tide models. Each year is divided into two investigation periods from September-December and February-June. Using Envisat Advanced Synthetic Aperture Radar imagery these investigations were further segmented by sea ice type, firstyear and multiyear. Both applied methods reveal a statistically significant linear increase in multiyear sea ice freeboard. For the primary method the mean freeboard increased over the study period from 0.53 m to 1.00 m and for the secondary from 0.46 m to 0.95 m. Evidence is presented that the multiyear sea ice freeboard increase is strongly linked to the attachment and incorporation of the sub-ice platelet layer. No statistically significant trends were observed for first year sea ice in either investigation period. ICESat derived freeboards in 2009 compare within one standard deviation of airborne measured freeboard in November of the same year. We attempt to extend this time series of satellite derived freeboard in the region using
CryoSat-2 data which is complemented by an extensive sea ice fieldwork campaign in November 2011 involving helicopter-borne electromagnetic induction (HEM) surveys and in situ measurements of sea ice freeboard, thickness and snow depth.

Title: Modelling wave-ice interactions in the marginal ice zone

Presenter and Author: Luke Bennetts

University of Adelaide, Adelaide, SA 5005,


Sea ice models contain no information about floe sizes at present, although they play an important role in the dynamical and thermodynamical properties of the ice cover in the marginal ice zone (MIZ). Floe sizes in the MIZ are controlled by the presence of ocean waves, which fracture the ice into relatively small floes. A wave-ice interaction model that predicts the width of the MIZ and floe sizes within it, as functions of the properties of the ice cover and incident wave field, is being developed. The model is motivated by the need for improved forecasts of the ice and wave conditions in the Arctic MIZ for offshore engineering activities there. I will describe the wave-ice interaction model, and how they will be used to introduce floe sizes into climate models, with particular emphasis in improving the model of the Antarctic MIZ.

Title: Change and variability in the seasonality of East Antarctic sea ice, 1979/80-2009/10

Presenter: Philip Reid

Australian Bureau of Meteorology, Centre for Australian Weather and Climate Research

Authors: Robert A Massom1,2, Philip Reid3, Sharon Stammerjohn4, Ben Raymond1,2, Alexander D Fraser2, Shuki Ushio5

1 - Australian Antarctic Division, Kingston, Channel Highway, Kingston 7050, Tasmania, Australia,,

2 - Antarctic Climate & Ecosystems Cooperative Research Centre, University of Tasmania, Sandy Bay, Tasmania 7001, Australia,

3 - Australian Bureau of Meteorology, Centre for Australian Weather and Climate Research, GPO Box 727, Hobart, Tasmania, Australia,

4 - Institute of Arctic and Alpine Research, University of Colorado, Boulder, Colorado, USA,

5 - National Institute of Polar Research, Tachikawa, Tokyo, Japan,


Although widely-reported, the trend towards increasing overall Antarctic sea-ice extent since 1979 masks significant regional change that has occurred in the seasonality of sea-ice coverage i.e., the timing of annual advance and retreat and resultant duration. As reported in scientific studies based on the West Antarctic Peninsula/Bellingshausen Sea sector, shortening of the sea-ice season (lengthening of the open-water period) by over 3 months there has had dramatic physical and biological impacts. At the same time, sea ice duration has increased by ~2.6 months in the western Ross Sea. Here, we present new results from the first detailed analysis of East Antarctic sea-ice seasonality (using satellite data), and compare them with results from elsewhere around Antarctica and also the Arctic. Patterns of change across East Antarctica are more complex, in that they comprise mixed signals on regional-to-local scales. Indeed, pockets of strongly positive and negative trends in ice-season duration (of ±2-3 days per year) occur in near juxtaposition in certain regions e.g., Prydz Bay. Areas of negative trend in sea-ice duration (of -1 to -3 days per year) occur in fairly isolated areas in the outer pack from ~95–110°E, and in various near-coastal regions (notably between the Amery and West Ice Shelves). Areas of positive trend in ice season duration include an extensive zone from
160-170°E, and along the near-coastal zone between 40 and 100°E. Patterns of variability reflect variability in the different elements of the marine “icescape” e.g. fast ice, polynyas and the marginal ice zone.

Title: What can we learn about the “health” of an ice shelf from sea ice records?

Presenter: Pat Langhorne

University of Otago, Dunedin, New Zealand

Authors: P.J. Langhorne1, A.J. Gough1, M.J.M. Williams2, C.L. Stevens2, I.J. Smith1, N.J. Robinson1,2,
W. Rack3, C.R. Purdie1, D. Price, A.R. Mahoney1,4, G.H. Leonard1, K. Hughes1, T.G. Haskell5, C. Haas6,
D.E. Dempsey1

1 - University of Otago, Dunedin, New Zealand

2 - NIWA, Wellington, New Zealand

3 - Gateway Antarctica, University of Canterbury, Christchurch, New Zealand

4 - Geophysical Institute, University of Alaska, Fairbanks, USA

5 - Callaghan Innovation, Lower Hutt, New Zealand

6 - York University, Toronto, Canada


Despite the important role of the ocean in the mass balance of an ice shelf, direct observations of long-term trends in ice shelf basal melting/freezing have been severely limited by accessibility. However, observations on sea ice just beyond an ice shelf are more common. If we understand how sea ice is affected by basal ice shelf processes, modern and historical observations may indicate how sub-ice shelf conditions have varied over longer timescales.

Close to an ice shelf, sea ice often grows in water that has been supercooled by interacting with the ice shelf at depth. The sea ice therefore not only loses heat to the atmosphere, but also to the ocean. This ocean heat flux modifies sea ice growth, leaving its signature. The thermal deficit also produces crystals in the water column that accumulate and grow under the sea ice or attached to objects suspended in the ocean. Over the past decade we have used sea ice and oceanographic observations and modeling to help us understand this ice-ocean interaction.

Here we combine data from a range of sources to construct a proxy record of oceanic heat flux in sea ice around the Ross and McMurdo ice shelves. Data include crystallographic sea ice records, observations of ice crystals on objects and in the near-surface ocean, measurements of the thickness of the layer of crystals that accumulates under the sea ice, and near-surface oceanography. These multiple sources of data will enable indices of the ice shelf “health” to be constructed.

Latest news

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    27 Jun 2013

    The Strategic Science in Antarctica conference concluded yesterday and two days of workshops have commenced. Congratulations to those who were awarded prizes for their contributions to the conference.

  • Watch the welcome message from Australia's Environment Minister
    24 Jun 2013

    In a welcome message via video from Canberra, Australia’s Environment Minister, Tony Burke, reflected on the foresight of earlier decision-makers who agreed to set aside an entire continent for scientific research.

  • Last minute information for attendees
    20 Jun 2013

    There's not too long to wait until the start of the Strategic Science in Antarctica conference, and we hope you’re as excited as we are! Read on for more information about the final program, registration, Twitter, presenters, posters and social functions.

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Key dates

  • 11th June 2013
    Registrations close
  • 21st June 2013
    Registrations at the AAD open for staff
  • 24th June 2013
    Registrations at the venue open
  • 24th June 2013
    Conference commences
  • 26th June 2013
    Conference concludes

More key dates…

This page was last modified on 6 June 2013.