Grant: Research Tools and Instruments - Category 1 (<$150,000)

A microscope and a microwave digester will be acquired to accelerate the processing of palynological samples used to study abrupt climatic changes. My entire research program is based on reconstructions of sea surface conditions (temperature, salinity) that is based on palynological proxy data, more specifically dinoflagellate cysts. These cysts can only be counted in sediment samples that have been digested in acids. The microwave digester will be used to remove organics and silica from the sediment samples, allow seeing the dinoflagellate and counting them. A microscope with excellent quality optics will allow more precise cyst identification and facilitate the analysis. The equipment requested is essential to process the large number of samples necessary to meet the objectives of my research program. The last few years have seen increased interest in abrupt climatic changes because evidence accumulated worldwide that they occurred on a millennial time scale during the Holocene and because of their potentially serious impacts on human society. Of special concern is that fact their exact frequency and amplitude are unknown, because high resolution paleoclimatic records are insufficient at the moment, which hinders the determination of their causes and mechanisms. It is also difficult to separate the effects of the natural climatic variability from that of increased freshwater releases to the oceans, an expected consequence from global warming. Past events are used to model the impacts on climate of increased freshwater inputs to the oceans. However, there are still uncertainties about the exact entry points and path of large amounts of freshwater to North Atlantic Ocean during the deglaciation. My research program will address these problems by reconstructing sea surface conditions from high resolution records from the Eastern Canadian Margin. I will clarify the entry points and path of large meltwater releases to the oceans, document the natural climatic variability and provide valuable paleoclimatic data to test existing numerical climatic models used to predict future climate change.