International Polar Year conference

From June 8–12 this year about 2300 scientists, policy-makers, teachers and students attended some 1800 presentations during the International Polar Year-Oslo Science Conference (IPY-OSC) in Oslo, Norway. The conference was the first opportunity for participants in the IPY (2007–09) — an internationally coordinated scientific campaign in the Arctic and Antarctic — to reunite and to celebrate and publish early results. Here’s what two of our Antarctic scientists had to say about the meeting.

Dr Tas van Ommen — ice core and climate scientist

Participating in the five days of the IPY–OSC, with some 2300 others was both impressive and invigorating. It was also a challenging exercise to select from the 1800 presentations in, at times, 17 parallel sessions.

The science reported included some real highlights of the IPY generally and updates on the latest developments. From an Australian perspective it was fascinating to see the view beneath the ice sheet that is emerging from the IPY AGAP project (‘Antarctica’s Gamburtsev Province’). Australia made a significant contribution to the operation of AGAP and is involved in the closely related IPY ICECAP project (‘Investigating the Cryospheric Evolution of the Central Antarctic Plate’). Together, these results are reshaping our view of what lies beneath East Antarctica. From AGAP, we see a much more detailed view of the Gamburtsev Mountains. It shows rugged peaks and deep valleys that somewhat resemble a modern-day alpine landscape that has been preserved beneath the ice for millions of years.

Another IPY project of special interest to the Australian program is the IPICS initiative (‘Ice Core Partnerships in Ice Core Sciences’). Australia is a leading participant in IPICS and we presented new results from the Law Dome ice core at the meeting. These results show how Antarctic climate records at the end of the last ice age can be synchronised with those from Greenland to reveal a see-saw behaviour: at times when Greenland is cold, Antarctica warms more strongly, and when Greenland has rapid warming, Antarctica cools. The ice age finishes with the poles taking turns to warm.

Also from the realm of ice core science, a paper presented by British Antarctic Survey researchers re-examined temperature estimates of previous warm interglacial periods (ca. 120 000 and 330 000 years ago). Current thinking indicates that central Antarctica was a few degrees warmer than it is now, but the revision would increase that estimate to as high as six degrees warmer.

Of course a final highlight of any meeting this size is the unparalleled opportunity to discuss present and future science plans and the meeting itself has no doubt stimulated the post-IPY polar research agenda.

Dr Andrew Klekociuk — atmospheric scientist

I was involved in a specific IPY study related to ozone depletion above Antarctica (Australian Antarctic Magazine 12: 12–13, 2007) and through this became involved in convening a special session at the IPY conference on climate processes in the polar lower atmosphere. From this and earlier work I had developed an awareness of the roles played by the Arctic and Antarctic in climate forcing and reacting to various important climate processes. But what surprised me at the conference was hearing how far- reaching and significant these roles really are.

For me, the most significant revelation at the meeting was just how uncertain we are about the future of summer sea ice in the Arctic. Modelling suggests rapid change due to feedbacks from circulation changes in the oceans and atmosphere, but the predictions appear to be underestimating the rate and magnitude of change. The disappearance of the summer sea ice is having a far-reaching impact on ecosystem processes, as well as human society at high latitudes. This change is also significantly influencing Arctic atmospheric temperatures and circulation, which are positively reinforcing sea ice decline. The Arctic issues are teaching us new lessons about the feedbacks between the atmosphere and cryosphere, which are now being applied to the Antarctic.

An interesting new insight came from Lorenzo Polvani (Columbia University, USA). He reported that new climate model results suggest that a significant amount of change in the summer atmospheric circulation in the Southern Hemisphere has likely been forced by the springtime Antarctic ozone hole. This work is part of a growing body of evidence showing the importance of the Antarctic stratosphere (about 15–55km above Earth) in influencing trends and variability across southern mid- and high-latitudes over the past 30 years. We also heard further about trends and variability in surface temperatures and sea ice in West Antarctica. The general pattern of change is not fully consistent with dominant forcing from stratospheric ozone changes, but the modelling work that has led to this view has yet to benefit from recent developments in coupling the dynamical and chemical components of the atmosphere.

Overall, the meeting reinforced to me just how important, vibrant and dynamic polar research currently is. It will be fascinating to watch the results from the IPY emerge over the next few years as scientists and policy-makers explore the wealth of information that has been gleaned.

Sophistication in information-gathering

The umbrella provided by IPY has fostered a unique collaborative environment in which polar processes have been freshly examined from many angles in an effort to capture salient information on environmental change. IPY research has been timely in two respects. Firstly, data gathering has significantly benefitted from recently established infrastructure, such as the train of satellites in NASA’s Earth Observing System, the worldwide array of Argo ocean sensors and improved networks of automatic weather stations. Secondly, state-of-the-art climate models have recently reached a sufficient level of maturity to benefit from the new observations for model validation and process studies.

An example of the current level of sophistication in marrying modelling and observations is demonstrated in the ‘POLARCAT’ program which produced new measurements of trace gases in the Arctic. POLARCAT involved several airborne and ground-based campaigns to characterise the components and transport of Arctic pollution. The level of sophistication in small-scale weather forecasting now allows aircraft to repeatedly ‘sniff’ the same small parcels of air over several days as they meander around the Arctic region. This type of work is important in helping to quantify the dispersal of pollutants such as black carbon and sulphate aerosols, which are having a measured impact on the coupling of solar energy to the Arctic surface.

Andrew Klekociuk