A - C
BPL
Short Title: RadTrace Proposal URL: http://classic.ipy.org/development/eoi/proposal-details.php?id=443 Radionuclides can serve as valuable tracers of atmospheric and terrestrial transport processes, which will be altered by changing climate patterns. This project is anchored in the existing Health Canada radiological monitoring network operated throughout Canada. The network includes seven Arctic sites equipped with high volume samplers for airborne particulates. Two of these sites are also equipped for noble gas collection and one site is equipped with a continuous gamma radiation monitor. In addition to the primary functions of supporting of the Canadian Federal Nuclear Emergency Plan and the international Comprehensive Nuclear Test Ban Treaty, the network provides regular measurements of a wide range of naturally-occurring radionuclide concentrations in air. Heavy metals and some organic compounds will also be measured in airborne particulates collected by the air samplers. An archive of air filters extending back to the early 1970s will allow the elucidation of time trends in these contaminants. The Health Canada air monitoring network covers an area extending from 55o to 83o North Latitude and 60o to 135o West Longitude, representing a large fraction of the entire land mass in the North polar region. Data from the Canadian network will supplemented with similar data collected by collaborators in other countries notably Norway, Sweden, Finland, and Germany. Ground-based sample collections will also be carried out in the Canadian north to gain a better understanding of the deposition of atmospheric contaminants and their movement through food chains leading to humans. The objectives of this project are: -Establish an international database for sharing data between monitoring networks in collaborating countries. -Develop and extend atmospheric transport models to trace the movement of radionuclides and other contaminants from sources in temperate zones to remote Arctic locations -Demonstrate changing trends in atmospheric circulation to the Arctic and within the Arctic by using these contaminants as tracers of atmospheric processes. -Document changes in soil gas emanation due to changing permafrost conditions. -Examine the link between climate change and forest fires in the north -Contribute to an understanding of ozone depletion in the stratosphere and ozone chemistry at ground level. -Assess the impact of these changes on the movement of contaminants through Arctic ecosystems and particularly in food chains leading to humans. The following ongoing and future studies will be carried out with the aid of air monitoring networks for radionuclides and other contaminants: -A study carried out in collaboration with Meteorological Services of Canada has traced the movement of iodine-129 from nuclear fuel reprocessing facilities in Siberia to remote locations in the Canadian Arctic. -Radioxenon from the reactor belt in eastern North America has been traced to Yellowknife, NWT. Measurements will be extended to include the long-lived krypton-85, a waste product from nuclear fuel reprocessing, in both the Arctic and Antarctic regions. -Cesium-137 released from wood-burning in distant forest fires has been detected at the Yellowknife location. Levoglucosan, a combustion product from forest fires, will also be measured on archived air filters to provide an historical record of forest fire effects. -Measurements of uranium, radium, lead-210, and potassium-40, and total dust loading will give information on intercontinental dust transport. -The short-lived radon and thoron decay products (lead-212, bismuth-214) are indicative of local emanations of soil gas and will be used to study changing permafrost conditions. -The beryllium isotopes (Be-7 and Be-10) are produced by cosmic irradiation of air molecules in the stratosphere. Their abundances and ratios at the earth's surface give information on exchanges of air masses between the stratosphere and troposphere, which are vulnerable to changing climate conditions. -Measurements of heavy metals (e.g., Hg, Cd) and selected organic compounds will extend the range of sources and pathways that can be studied and will aid in the understanding of atmospheric chemistry processes in the Arctic. Details are still being worked out on the ground based studies. They will include collections of precipitation, soil, lichens, and higher plants to track the deposition of airborne contaminants and their movement through the food chain.