Continuous snow fall and accumulation over the Earth’s ice sheets and glaciers preserve a history of the evolving atmospheric environment and of the dynamic climate. My environmental chemistry research uses ice cores from these ice bodies that provide chronological proxy records of the atmospheric environment for hundreds of thousands of years. Fresh snow and aerosol samples serve as indicators of the current atmospheric conditions. Chemical analyses of these samples in the laboratory yield vital environmental information, such as the large scale atmospheric pollution by human activities, and the relationship between global climatic changes and the atmospheric chemical composition and biogeochemical cycles. These are important topics in global environmental change research.

    Ice core chemistry data are archives of the atmospheric composition from a few hundred years to thousands years. For example, I have used chronologically dated ice core records to reconstruct a continuous history of explosive volcanic eruptions which have played an important role in global climate fluctuations.

    Most of my research projects involve traveling to locations in Antarctica (e.g., the South Pole) to drill ice cores and to collect snow and aerosol samples. This and preparing samples for analysis require working in the cold. Field work in Antarctica is exciting but demanding. Making sure that everything (including your body) functions at !30EC requires more than luck, and the 24-hour Antarctic daylight can make your work day longer than anyone’s. However, everyone I know would like another opportunity to go "south" again.

    The concentrations of natural and pollutant chemical species in Antarctic snow and ice samples are typically at the parts-per-billion level or lower. I use ultra-sensitive analytical techniques (GC/MS, HPLC, ICP-MS) to determine and measure inorganic and organic compounds in these samples. An important part of my research is to develop new techniques and methodologies often needed to detect and quantify ultra-trace amounts of the compounds. A current challenge is to develop analytical techniques for direct measurements on frozen ice cores.

    In addition to natural variations, the atmospheric environment has been changing in response to large scale human activities beginning in the nineteenth century. Evidence of pollution can be found even in the most remote areas of the world, such as Antarctica. Part of my research in ice core chemistry is to search for and identify pollutant compounds, either from the few human habitats on the Antarctic continent or from long range atmospheric transport. With ice cores, we can document and quantify the extent of global pollution against a natural background unperturbed by human activities. Knowledge from this type of research provides a realistic picture of our changing environment and helps us plan for the future of our home planet.