Antarctic sea ice extent is a complex and puzzling beast, not following a simple process of rapid Arctic sea ice diminishment. A new paper in Nature Geoscience argues that warm deep ocean currents are contributing to ice shelf melt and causing Antarctic sea ice expansion. While ice mass loss from Antarctica is presently at 250 Gigatonnes per year and accelerating, sea ice is also expanding slowly but to record levels. What a paradox!
The trend for a gradual increase in Antarctic Sea ice has puzzled scientists for some time. The expansion is at odds with general climate model results. I reported on the puzzle of Record Antarctic Sea Ice Growth in November 2012. In that article I explained that (Holland et al 2012) argued that atmospheric variability in the form of local winds was pushing the ice northwards creating space for new sea ice to form. While climate deniers claimed record Antarctic sea-ice was a refutation of climate change, in reality it showed they could not fathom that the cryosphere and the planet's climate are complex processes which we are still trying to understand, with some surprising processees not readily open to be modelled.
Tasmania presently hosts the Antarctic Climate and Ecosystems Co-operative Research centre (ACE CRC) , the Australian Antarctic Division, along with CSIRO's Division of Marine and Atmospheric Research. But funding for the ACE CRC will come to an end in the next year. The University of Tasmania, CSIRO and ACE CRC are currently working on a proposal for a new Antarctic research organisation.
Antarctica and the Southern Ocean influence the regional and global climate and in this period of climate change understanding the mechanisms and changes taking place will provide valuable information for climate adaptation. Temperatures are increasing at 3 times the global average on West Antarctica, ice streams are accelerating ice mass loss with the collapse of the West Antarctic Ice Sheet a real possibility in the decades and centuries ahead. The Southern ocean is warming and freshening at a much faster rate than the global ocean. The food web in the southern ocean is changing with Penguin numbers suffering with krill decline due to Global Warming
Climate change is causing the southern ocean to warm and freshen which will melt ice shelves and glacier tongues affecting glacier discharge and producing Antarctic Ice Sheet mass loss and global sea level rise. A new study shows that small temperature changes of the Southern Ocean can contribute to far-reaching changes on the Antarctic ice sheet that could lead to substantial future sea-level rise.
Related: Waking the giant: Global Warming in the Weddell Sea, West Antarctic Ice Sheet and sea level rise | Attenborough warns of ice shelf destruction in Antarctica | Global Warming in Antarctica: Thwaites and Pine Island Glaciers accelerating, West Antarctic Ice Sheet losing mass
Significant scientific research has been published in recent weeks on the impact of global warming on changing wind patterns and southern ocean currents and the flow-on impact on Antarctic ice shelves and glaciers. The most recent studies reveal the potential instability of the Filchner-Ronne Ice Shelf in the Weddell Sea area. But the real questions to be asked concern the long term stability of the West Antarctic Ice Sheet (WAIS) and how rapidly it could collapse raising global sea levels by up to 6 metres.
I highlighted in November 2011 that the Thwaites and Pine Island Glaciers accelerating, West Antarctic Ice Sheet losing mass in the Amundsen Sea area. Now climate researchers of the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association studying the opposite side of the West Antarctic Ice Sheet (WAIS) in the Weddell Sea area have discovered a mechanism which will drive warm ocean water towards the coast in the later decades of this century, allowing a higher rate of basal melting - the melting from underneath of ice shelves and glaciers by warmer ocean currents - leading to greater discharge of ice from the icesheet.
Another research team has found a large deep basin, about 20,000 square kilometres in size and up to 2 kilometres deep, underneath the ice sheet in the Weddell Sea area, which makes the ice sheet inherently unstable if pinion points for the ice shelf retreat and warmer water enters the basin.
We are stacking the climate dice against the survival of many species on planet earth. A few species may be able to ride the changes, at least temporarily. And so it is with the largest of birds, the wandering albatross, with some populations of this species able to take advantage, so far, of the changing winds of climate change. But for how long?
Global warming has caused the westerly winds in the Southern Ocean to increase in intensity and move poleward. The wandering albatross, with a three metre wing span, spends much of it's life soaring above the ocean searching for food, with the changes in the winds increasing it's foraging ability, breeding capacity and reducing it's conflict with commercial long line fishing operations.
