Holocene Paleoclimate Studies with Centennial Resolution —Xxxxx Xxxxxxx Sample Clauses

Holocene Paleoclimate Studies with Centennial Resolution —Xxxxx Xxxxxxx. A full understanding of climate change over past millennia and into the coming century requires proxy data from geological samples of the ocean. The argument is simple. Instrumental observations of atmosphere and ocean properties are short; quality data are limited to the past 100 yrs at best, yet it is axiomatic that variance in climate increases with length of timescale. There are special locations on the seafloor where proxy data such as oxygen isotope ratios in carbonates can be used to reconstruct past ocean temperatures and salinities. In the nearshore environment, geologists have at their disposal mollusk shells and corals which accrete calcium carbonate in annual bands, and in the deep ocean sediment cores and solitary corals contain records of climate and ocean change on decadal to millennial timescales. This project will exploit many such locations around the North Atlantic by mapping patterns of climatic variability using geochemical techniques. It will begin by evaluating the suitability of existing samples and then continue by targeting new locations with a month long expedition at sea. One of our overriding goals will be to determine the ocean’s role in climate change on the century timescale. Recent studies of the North Atlantic Oscillation have made predictions about ocean ventilation on decadal timescales, and recent geological studies have found an opposite response on millennial timescales. It will be particularly rewarding to work at the century timescale, the very timescale on which human influence is probably occurring.