Speaker: Prof. Julian Sachs (University of Washington)
Abstract: The Little Ice Age (LIA, 1400-1800 A.D.) was a time of harsh winters and glacier advances in the Northern Hemisphere that coincided with three extended sunspot minima and heightened volcanic activity. While some evidence exists for contemporaneous climate extremes in the tropics and the Southern Hemisphere there is no consensus yet on whether the LIA was global in extent. We will present data from lake sediments on islands across the northern tropical Pacific, mollusks from the coast of Peru, and corals from the southwest tropical Pacific that indicate (1) the Intertropical Convergence Zone (ITCZ) was closer to the equator by about 5° of latitude, (2) the South Pacific Convergence Zone (SPCZ) was weaker and/or located closer to the equator, (3) ENSO variability was diminished, and (4) the mean annual SST and seasonal SST range were diminished along the coast of Peru during the LIA relative to today.
Speaker's website: http://faculty.washington.edu/jsachs/