A new publication on trends and future projections of Antarctic Sea Ice has just been published on the Portal.

Click here to access the Information Summary.

This summary is the third article in a series on Antarctic Sea Ice. Read Antarctic Sea Ice #1 and Antarctic Sea Ice #2 here.

Since reliable and continuous satellite records began in 1979, there have been strong regionally- and seasonally-varying patterns of change and variability in sea-ice extent around Antarctica (Fig. 1) – in contrast to a largely uniform loss of sea ice across the Arctic. Notably, the region west of the Antarctic Peninsula to the eastern Ross Sea has experienced significant sea ice loss in concert with a strengthening of the Amundsen Sea Low and increased warm northerly winds. On the western Peninsula, the sea ice loss and associated regional warming has led to dramatic and complex ecosystem change (see Antarctic Sea Ice #2) and has also been implicated in major ice-shelf disintegration events on the Peninsula (see Antarctic Sea Ice #1). Elsewhere, sea-ice coverage has expanded but with substantial interannual variability. The sum of these differing regional and seasonal contributions is a slight increasing trend in overall sea-ice coverage of 1.0 ± 0.5% per decade (or about 11,300 km² per year) for 1979–2018 (Fig. 1a).

Since 2012, sea ice in the Antarctic has undergone rapid and unanticipated swings in its net overall coverage, to first record high (2013-2015) then record low (2016-2022) coverage. Determining the drivers and effects of these abrupt shifts, together with differing seasonal and regional contributions, is a major focus of current research. This represents a substantial challenge given the complex processes involved in ice-ocean-atmosphere interactions and feedbacks. But better understanding of these interactions and feedbacks is crucial to improving the representation and simulation of sea-ice coverage and seasonality in climate and Earth System models. This is pivotal to improving near-term forecasting and long-term projections of Antarctic sea ice and the effects of sea ice change on the coupled climate-ocean-biosphere system in the coming decades.

“Antarctic Sea Ice #3: Trends and Future Projections” was written by Kyle Clem, Rob Massom, Sharon Stammerjohn and Phillip Reid.
Doi: https://doi.org/10.48361/4d9d-1g64

“Antarctic Sea Ice #2: Biological Importance” has just been published on the Antarctic Environments Portal.

Click here to access the Information Summary.

This Information Summary is part of a series. Read Antarctic Sea Ice #1 and Antarctic Sea Ice #3 here.

Antarctic sea ice, in the form of immobile coastal “fast ice” and the more extensive moving pack ice (see Antarctic Sea Ice #1), supports one of the most extensive and productive ecosystems on Earth and is crucial to the structure and function of Southern Ocean marine ecosystems that are highly attuned to its presence and seasonal rhythms.

Changes in Antarctic sea-ice coverage and seasonality, thickness (and snow cover depth) and properties have wide-ranging consequences with cascading effects across food chains. These effects include:

• change in the phenology of phytoplankton and ice algal blooms;
• shifts in species composition, distribution and abundance, leading to trophic mismatches in both time and space that impact ecosystem structure and function;
• changes in the breeding and foraging distribution of sea ice-obligate predators such as Adélie penguins; and
• the incursion of sub-Antarctic and/or invasive warmer-climate marine species.

Looking to the future, sea-ice coverage is predicted to significantly decrease by the end of this century in response to anthropogenic warming (see Antarctic Sea Ice #3), leading to significant reductions in ice-associated primary production and sea ice-dependent species – including Antarctic krill, Antarctic Silverfish, Adélie and Emperor penguins, Weddell and other pack-ice seals, and southern minke and other whale species.

“Antarctic Sea Ice #2: Biological Importance” was written by Kyle Clem, Rob Massom, Sharon Stammerjohn and Phillip Reid.
Doi: https://doi.org/10.48361/8tky-2793

We have just published a new Information Summary on the physical role and function of Antarctic Sea Ice.

Click here to access the Information Summary.

This summary is the first article in a series on Antarctic Sea Ice. Antarctic Sea Ice #2 and Antarctic Sea Ice #3 has also been published on the Portal.

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.

“Antarctic Sea Ice #1: Physical Role and Function” was written by Kyle Clem, Rob Massom, Sharon Stammerjohn and Phillip Reid.
Doi: https://doi.org/10.48361/2cpq-8t02

© Ryan Reisinger

A new Information Summary on ten main scientific messages on risks and opportunities for life in the Antarctic has just been published.

Click here to access the Information Summary.

The summary was initiated by the SCAR scientific research programme “Antarctic Thresholds – Ecosystem Resilience and Adaptation” (AnT-ERA, 2013-2021). 26 experts synthesized knowledge on impacts and risks of climate-change on biological processes and ecosystem functions in the Antarctic.

The ten main scientific messages that emerged addressed (1) accelerating marine and terrestrial biogeochemical cycles, (2) response to ocean acidification, (3) ecological changes in climate change hot spots, (4) unexpected dynamism of marine seafloor communities, (5) biodiversity shifts, (6) low temperature limitation of protein synthesis, (7) life intrinsically linked to changing sea ice conditions, (8) pollution, (9) genetically distinct terrestrial populations under threat, and (10) newly discovered habitats.

“Ten scientific messages on risks and opportunities for life in the Antarctic” was written by Julian Gutt, Enrique Isla, José C. Xavier, Byron J. Adams, In-Young Ahn, C.-H. Christina Cheng, Claudia Colesie, Vonda J. Cummings, Huw Griffiths, Ian Hogg, Trevor McIntyre, Klaus M. Meiners, David A. Pearce, Lloyd Peck, Dieter Piepenburg, Ryan R. Reisinger, Grace K. Saba, Irene R. Schloss, Camila N. Signori, Craig R. Smith, Marino Vacchi, Cinzia Verde and Diana H. Wall
Doi: https://doi.org/10.48361/2cpq-8t02

A new Information Summary on Leopard seals has been published. “Leopard seal (Hydrurga leptonyx)” was written by Tracey L. Rogers, Jaume Forcada and Douglas J. Krause.

The publication gives an overview of the range, habitat and ecology, management and challenges of the species.

Click here to access the Information Summary.

Brief Overview:

• The IUCN Red List conservation status of the leopard seal is ‘Least Concern’. Nonetheless, sea-ice habitat loss, reduced krill stocks and increased fishing may combine to impact the species.
• The last surveys of this species were in 1999/2000.
• The leopard seal is the only animal among the Pinnipeds to hunt large vertebrate prey and yet also filter feed to eat small invertebrate prey.