【讲座题目】Ice core studies of climate and environment changes: What we did and what is the perspective in Canada?
【主 讲 人】Jiancheng (James) Zheng, Department of Earth and Environmental Sciences, University of Ottawa, Geological Survey Canada, Natural Resources Canada
Jiancheng (James) Zheng is a research scientist (cold regions chemistry) with Geological Survey Canada (GSC), Natural Resources Canada (NRCan) based in Ottawa. He completed his undergraduate program in chemistry in Wuhan University, China, his master program in geosciences with Ottawa University, Canada and his PhD program in Environmental Geochemistry in Heidelberg University, Germany. He is an adjunct professor with the Department of Earth and Environmental Sciences, University of Ottawa.
In his early research career, James worked on marine fouling organism corrosion for a Chinese oceanography institute located in Xiamen, China. James came to Canada to carry out his 2-year scholarship awarded by the Department of Education, China in 1983, working on marine CO2, at the Institute of Ocean Sciences (IOS), Department of Fisheries and Oceans (DFO) in Victoria, BC, under supervision of Dr. C. S. Wong, director of Ocean Chemistry Division. James was later invited to join the ice core research project by Dr. Shier Berman, director of Measurement Sciences at National Research Canada (NRC), Canada. James has been worked with GSC, NRCan since 1999.
James is interested in climate changes and anthropogenic contaminants via studying snow/ice cores and environmental waters. His major research areas include archive reconstruction of inorganic trace metals and paleoclimate variations as well as monitoring of current climate trends with ice and snow in the Canadian High Arctic. James developed his GSC version of ultra clean protocol for snow/ice sampling, processing and sample storage/protection for studies of trace elements with ultra low concentrations. James is also interested in development of methodologies and quality control protocols for practical operation in laboratory and in the filed. He has recently set up a laboratory for tangential flow filtration systems for studying mobility and fate of trace elements in environment waters. James’ interest also extends to other contaminants, both inorganic and organic, contaminant source apportionment, the linkage of archives between ice cores and other records as well as ice core drilling in Canadian High Arctic ice caps.
James has published over 60 peer reviewed papers in international scientific journals, more than 50 other publications, book chapters and reports. James is currently reviewers for 9 scientific journals and editors for 3 journals. He was interviewed by Canadian media, including radio, journals and newspapers. He received an international award for foreign specialists from Japan (1998) and a Marie Curie Action Fund for Incoming Scientists from European Commission (2006), 3 sector awards (Earth Science), one department award (Natural Resources Canada) and one Federal government Treasury Board award (Award of Excellence).
To retrieve information of climate changes many thousands of years ago and to retrospect to contamination history in pre-instrument times, many natural archives, such as lake sediments, peat bogs, tree rings and ice cores could be suitable. Ice/snow in Polar Regions and alpine glaciers, however are specifically valuable because 1). Glaciers are remotely located with only atmospheric inputs; 2). Snow/ice accumulation rate can be much higher than other natural archives, therefore, a higher resolution; and 3). Once accumulated, ice/snow stays in place in the frozen matrix with little disturbance. Therefore, ice core is a media, currently best available and reliable for reconstructing pre-instrument contamination history.
Since the first deep ice core was drilled at Site 2 in NW Greenland in 1956, many deep ice cores have been recovered from Antarctica and Greenland. The “oldest” one so far was dated as old as 890,000 years from EPICA Dome C. During last IPY years, an ice coring project aiming for the last interglacial and beyond has been accomplished in the northwest Greenland (NEEM-The North Greenland Eemian Ice Drilling). Hopefully a few years, a coring project for a 1.2 million year record of climate and atmospheric gases will start in Antarctica.
In Canadian High Arctic, several dozens of ice cores have been drilled for studies of climate and environment. Most of the cores were drilled on Devon, Agassiz, Prince of Wales and Penny Ice Caps as well as Mt. Logan. Among those ice cores, about a dozen of them spanned a time interval of over 100,000 years. Those ice cores provide us important information on climate and variation of atmospheric compositions.
How do we drill ice cores from Canadian High Arctic? What can those cores be used for? And where is the drill facility and ice core archives now? This talk will briefly address those issues.