Positive PDO in the North Pacific results in either increased (blue) or decreased (red) winter precipitation in North America. Barron and Anderson (2011) show that this relationship characterizes the last 4,000 years.
This project uses marine, estuarine, and lacustrine sediment cores along the Pacific coast of the US to reconstruct climate variability during the last 15,000 years, with a special emphasis placed on high resolution studies of the past 2,000 years. We aim to determine the natural variability of climate (such as sea surface temperatures) in marine records off the western US on annual to millennial time scales during the past 15,000 years, extracting cycles such as the Pacific Decadal Oscillation (PDO). Diatoms, foraminifers, silicoflagellates, pollen, geochemistry and other proxies are used and compared with proxy precipitation records in the western US. Records of climate variability in North Pacific estuaries and lakes during the past 15,000 years will also be developed to determine ecosystem changes and to assess regional trends. These records will be compared with published climate records in the West in order to assess (on a regional basis) the links between extensive drought and offshore sea surface temperatures. These records will also be used to understand the variability of surface processes in the West.
Why is this research important?
Modern climate of the Pacific coastal states and much of the western US is largely dictated by the sea surface temperatures and atmospheric conditions in the eastern North Pacific (El Nino/La Nina, PDO). Distinguishing natural climate variability from anthropogenic change is critical. In the West, water availability is the issue of greatest concern both presently and in projected future (global warming) climate scenarios.