Weber and Mayer
NSERC funding
1. High-Resolution Marine Paleoclimate Time-Series: M.E. Weber and L. A. Mayer
As the Canadian contribution to the international IMAGES program, we have joined the NSERC-sponsored Climate System History and Dynamics project aimed at bringing together climate modelers and paleoclimate data collectors to gain a better understanding of the nature of climate change. Our contribution to this program has been to collect long undisturbed deep-sea cores and to develop ways to use automated, near continuous measurements of physical properties collected with a Multi-Sensor Core Logger and optical properties collected with a Minolta spectrometer to produce very high-resolution records of paleoclimate indicators. We now explore the nature of variability in these time series to gain insight into the forcing factors and earth's response to climate change. We also begin to predict the variation of important climate proxies such as stable oxygen isotopes, carbonate and organic carbon from logging data.
As part of this effort, we have developed an interactive 3-D visualization of the role that orbital forcing (Milankovitch forcing) plays in controlling insulation. We have also developed tools for interactively exploring multidimensional spectra of these time series (evolutionary spectra) that help in understanding the interplay of factors responsible for long-term climate evolution.
2. Quaternary Climate Evolution in the Eastern Equatorial Pacific: M.E. Weber
During several ship expeditions we collected paleoceanographic data from piston cores and from sites drilled by the Ocean Drilling Program (ODP) in the Eastern Equatorial Pacific. High-resolution downcore log measurements of physical and optical properties allow, for the first time, the extraction of carbonate and opal records at unprecedented temporal resolution (approximately 1000 years for the last 1.3 million years). We collected additional paleoclimatic and paleoceanographic proxy data from sediment cores (sea-surface temperature records derived from alkenones, organic carbon, and stable isotopes) to explore both the spatial and temporal evolution of climate with respect to the forcing factors across the equatorial zone of high productivity.
Deep-sea carbonate responds primarily to orbital variations on the 100,000-year cycle of eccentricity as well as to insulation changes on the 21,000-year band. Carbonate contents and carbonate accumulation rates were highest during the transition from cold to warm climate, whereas dissolution was strong on the transition from warm to cold climate. Productivity in surface waters was clearly enhanced during peak cold times, when sea-surface temperatures were lowest.
For further information: http://www.omg.unb.ca/~mweber/Projects.htm