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Antarctic sea ice #1: physical role and function


Clem, K and Massom, R and Stammerjohn, S and Reid, P, Antarctic sea ice #1: physical role and function, Antarctic Environments Portal, 02 August pp. 1-9. (2022) [Professional, Refereed Article]

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DOI: doi:10.48361/tqhw-c793


Sea ice – comprising frozen seawater in the form of both moving pack ice and stationary coastal landfast ice (fast ice) – is of major climatic, ecological and societal importance in that it:

  • forms a bright surface that strongly reflects incoming solar radiation (the albedo effect) to moderate the equator-to-pole temperature gradient, which in turn influences large-scale atmospheric and oceanic circulation;
  • strongly influences ocean-atmosphere interactions by forming an insulative substrate and physical barrier that reduces and/or modifies air-sea exchanges of heat and water vapour and the transfer of momentum (wind energy) to mix the upper ocean;
  • is a major contributor to global ocean (thermohaline) circulation through the production of dense (cold and salty) water during its formation, leading in places to the generation of Antarctic Bottom Water;
  • modulates the ocean freshwater budget, and regulates the properties and structure of the atmosphere and ocean (including upper-ocean stratification and deep-ocean ventilation);
  • interacts with floating ice-sheet margins (including ice shelves) and influences ice-shelf basal melt and stability and iceberg calving;
  • is a major habitat and crucial component of the marine ecosystem (see Antarctic Sea Ice #2); and
  • forms a biogeochemically-active substrate that plays a key role in the atmosphere-ocean exchange, storage and cycling of climate-relevant gases, including carbon dioxide (CO2), dimethyl sulphide (DMS) and methane (CH4) (see Antarctic Sea Ice #2).

Each year around Antarctica, sea ice transforms a vast area of the surface of the Southern Ocean, covering up to 19-20 million km2 at its maximum extent in September (~4% of Earth’s surface) before diminishing to 2-4 million km2 in February. This remarkable annual cycle has an immense influence on the Southern Ocean environment and beyond. The sea ice also accumulates snowfall, which substantially influences its physical and optical properties, its growth and decay, and its interactions with other parts of the ice-ocean-atmosphere system.

Improved knowledge of Antarctic sea ice characteristics and ice-ocean-atmosphere-biosphere processes, interactions, and feedbacks is required to develop and improve Earth System models. Such knowledge is crucial to reducing current uncertainties in those models and to improve confidence in projections of the Antarctic sea-ice system over the coming decades and beyond (see Antarctic Sea Ice #3), including its impacts and coupled feedbacks. Improved sea-ice forecasting capability is also required to support safe and efficient shipping and logistical activities around the Antarctic continent.

Item Details

Item Type:Professional, Refereed Article
Keywords:Antarctic, Southern Ocean, sea ice, physical
Research Division:Environmental Sciences
Research Group:Other environmental sciences
Research Field:Other environmental sciences not elsewhere classified
Objective Division:Environmental Management
Objective Group:Other environmental management
Objective Field:Other environmental management not elsewhere classified
UTAS Author:Massom, R (Dr Robert Massom)
UTAS Author:Reid, P (Dr Phillip Reid)
ID Code:154020
Year Published:2022
Deposited By:Australian Antarctic Program Partnership
Deposited On:2022-10-24
Last Modified:2022-10-24

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