Simulating Multi-Season Past Droughts
Abstract

Abstract Author: Robert Burgman

Abstract Title: The role of tropical Pacific SSTs in forcing Medieval hydroclimate

Abstract: The possible role that tropical Pacific SSTs played in driving medieval hydroclimate is addressed. Fossil coral records from Palmyra Atoll are used to derive tropical Pacific SSTs for the period from 1320 to 1462 A.D. These boundary conditions describe La Niña like mean state conditions in the tropical Pacific with inter-annual and decadal variability about that altered state. The reconstructed SSTs are used to force a 16 member ensemble of atmospheric general circulation model simulations, each with different initial conditions, coupled to a one layer ocean model outside of the tropical Pacific. Model results are compared with modern climate simulations and reproduce many aspects of medieval hydroclimate found in paleo-proxy records from around the globe, suggesting that tropical Pacific SSTs played an active role in driving medieval hydroclimate, though other oceans also played a role.