RESEARCH HIGHLIGHT

The Applied Physics Laboratory Ice Station 2007 (APLIS07)

• IARC Led Project: SEDNA Sea ice experiment, dynamic nature of the Arctic.
• BIPREX Biologically mediated Processes in OASIS Exchange (led by Monica Modigh - Stazione Zoologica A., Naples, Italy).
• SNACS-mercury Study of the Northern Alaska Coastal System (led by Bill Simpson, UAF).
• RIDGE Representations of Ice Deformation and Growth Experiment (led by Max Coon, North West Research Associates, Seattle).

website: http://aplis07.iarc.uaf.edu/

January 26, 2007

In one of the first major science campaigns of the 4th International Polar Year, the National Science Foundation is supporting a 2 week ice camp in the Beaufort Sea in April 2007. The camp will utilize infrastructure setup for a US Navy field exercise, and will host up to 30 scientists (from Italy, Iceland, Germany, UK, and USA) studying sea ice, microbial activity and mercury cycling in the Arctic.

The Beaufort Sea has experienced remarkable change in sea ice cover over the last 5 years. The recent summer minimum of sea ice extent has receded approximately 200km north compared to the 1979-2000 mean summer minimum ice extent. Climate models suggest that Arctic sea ice could decline dramatically this century. Are the changes being observed in the Beaufort Sea a precursor of these predicted conditions, or will the system revert back to 1970's state? How might such a reduction in sea ice cover affect the Arctic system as a whole? Participants at the APLIS07 ice camp will be working to answer these questions.

The SEDNA team, an international collaboration (coordinated between Jenny Hutchings, Jackie Richter-Menge, Cathy Geiger (USA), Peter Wadhams (UK), Christian Haas (Germany), and Inga Jonsdottir (Iceland)), are investigating how well current models of sea ice drift and deformation represent the response of sea ice to storms. SEDNA will investigate the dynamic response of sea ice to changes in Arctic sea ice drift patterns, changes in storm tracks, and how a seasonal ice pack of reduced thickness influences regional sea ice mass balance. This will allow the researchers to determine whether feedbacks between sea ice deformation processes and climate change will dampen or amplify the response of sea ice to global climate change. The RIDGE project, led by Max Coon, will be performing field experiments to validate an entirely new model of sea ice dynamics. This model includes physically realistic description of ice deformation processes, assuming ice is a discontinuous cover on the Arctic Ocean. SEDNA and RIDGE will lead to improved representation of how sea ice controls energy exchange between ocean and atmosphere and the role of sea ice in ocean circulation; resulting in more realistic models of future climate.

The Arctic ecosystems, sea ice, snow and pollutants are tightly intertwined. Dramatic changes in the state of Arctic sea ice and snow cover are expected to lead to dramatic changes in Arctic-wide food webs and to dramatic changes in some pollutant pathways in the Arctic. Mercury concentrates in the Arctic due to unique polar chemistry. The SNACS-mercury project, led by Bill Simpson, will study how sea salts become reactive in the Arctic spring, leading to mercury deposition. Our knowledge of microbial biodiversity and, in particular, microbial activities throughout the Beaufort Sea and Arctic is very limited indeed. The BIPREX project, led by Monica Modigh, is investigating the composition and metabolic activities of microbial communities in the Arctic. BIPREX and SNACS-mercury are coordinating their efforts as microbiota may play a role in transforming sea salts and in mercury absorption/re-emission. Microbes, bacteria and algae, in snow, ice and water mediate exchanges with the atmosphere. They are significant players in regulating the biosphere and are the main drivers of biogeochemical cycles and the major producers and consumers of carbon dioxide and other greenhouse gases. BIPREX's field work and modeling studies will improve understanding of how temperature shifts and changes in Arctic sea ice and snow influence microbiota and related feedbacks in the future climate. SNACS-mercury will determine the dependency of mercury deposition on Arctic sea ice and snow cover. Global climate models that predict future sea ice state can then be used to extrapolate future Arctic mercury deposition intensity and access impact on human health.

Other APLIS07 projects include two NSF-supported special IPY Education and Outreach projects. Middle and high school teachers will be working with the researchers, and sharing blogs, images and lesson plans online with students and educators across America as part of the PolarTREC project. A video crew from POLAR-PALOOZA will be on hand creating podcasts and video clips for use in a national tour of science centers and natural history museums starting in Fall 2007.

The APLIS07 researchers are seeking to reduce uncertainty in projections of the consequences of future climate change. Further information about APLIS07 and projects hosted by the camp can be found at http://aplis07.iarc.uaf.edu/.