USAP-DC

Convincing evidence now confirms that polar regions are changing rapidly in response to human activities. Changes in sea ice extent and thickness will have profound implications for productivity, food webs and carbon fluxes at high latitudes, since sea ice biota are a significant source of biogenic matter for the ecosystem. While sea ice is often thought to be a barrier to gas exchange between the ocean and the atmosphere, it more likely functions as a source or sink for climate-active gases such as carbon dioxide and ozone-depleting organohalogens, due in part to activities of microbes embedded in the sea ice matrix. This project brings together experienced US and Swedish investigators to examine the controls by sea-ice biota on the production and degradation of key climate-active gases in the Pacific sector of the Southern Ocean. We hypothesize that 1) the physical properties of the sea-ice environment will determine the community structure and activities of the sea ice biota; 2) the productivity, biomass, physiological state and species composition of ice algae will determine the production of specific classes of organic carbon, including organohalogens; 3) heterotrophic co-metabolism within the ice will break down these compounds to some extent, depending on the microbial community structure and productivity, and 4) the sea ice to atmosphere fluxes of CO2 and organohalogens will be inversely related. This project will build close scientific collaborations between US and Swedish researchers and also train young scientists, including members of underrepresented groups. Dissemination of results will include the scientific literature, and public outreach venues including interactions with a PolarTrec teacher.

Person	Role
Smith, Walker	Investigator
Yager, Patricia	Investigator
Dennett, Mark	Investigator

Antarctic Organisms and Ecosystems	Award # 0836144
Antarctic Organisms and Ecosystems	Award # 0836112
Antarctic Organisms and Ecosystems	Award # 0836061

YagerOSO08
NSF-ANT08-36144
NSF-ANT08-36061_1
NSF-ANT08-36112_1

None in the Database

Repository	Title (link)	Format(s)	Status
BCO-DMO	Amundsen Sea Polynya International Research Expedition (ASPIRE) data	None	exist
USAP-DC	Controls on Climate-Active Gases by Amundsen Sea Ice Biota	None	exist
USAP-DC	Controls on Climate-Active Gases by Amundsen Sea Ice Biota	None	exist

1. Mattson, E., Karlsson, A., Smith,, W. O., & Abrahamsson, K. (2012). The relationship between biophysical variables and halocarbon distributions in the waters of the Amundsen and Ross Seas, Antarctica. Marine Chemistry, 140-141, 1–9. (doi:10.1016/j.marchem.2012.07.002)
2. Granfors, A., Karlsson, A., Mattsson, E., Smith, W. O., & Abrahamsson, K. (2013). Contribution of sea ice in the Southern Ocean to the cycling of volatile halogenated organic compounds. Geophysical Research Letters, 40(15), 3950–3955. (doi:10.1002/grl.50777)