Hurricane and climate interactions over the past two millennia: Insights from sediment cores and climate models
Speaker: Dr. Elizabeth Wallace, Old Dominion University
Title: Hurricane and climate interactions over the past two millennia: Insights from sediment cores and climate models
Host: Xiaojing Du
Time: Wed, 8 Oct, 1:30pm
Location: Horizon Hall, Room 4014 or via Zoom (for Zoom link, email xdu5@gmu.edu)
Abstract: Atlantic hurricanes threaten growing coastal populations along the U.S. coastline and in the Caribbean islands. Unfortunately, little is known about the forces that alter hurricane activity on multi-decadal to centennial timescales. This talk will explore results from sediment cores collected from coastal basins from in the Bahamas to constrain the spatiotemporal variability in hurricane activity in the North Atlantic over the past millennium. I will present annually resolved archives of storm activity stretching over the past 1000 to 1500 years derived from sediment cores from blue holes on three islands in the Bahama Archipelago. All three paleorecords capture multi-decadal and longer periods of elevated hurricane activity over the past millennium. Adding our new records to the North Atlantic network of paleohurricane sites demonstrates a dipole pattern in coherent storm landfalls with persistent intervals of increased (decreased) occurrence along the eastern US concurrent with inverse activity in the southwest Caribbean and Gulf of Mexico, associated with basin-scale redistributions of storm tracks. Sampling biases in sediment proxies make it difficult to ascertain whether signals in paleohurricane records are related to climate variability or just stochasticity. I will also explore large sets of synthetic storms forced with different past millennium climate simulations (Max Planck Institute (MPI), Community Earth System Model (CESM), Last Millennium Reanalysis (LMR)). Comparing proxies and models, I find strong agreement between compiled reconstructions from sedimentary paleohurricane records and statistical models of hurricane activity. The TC landfall dipole pattern also emerges in modelled climate which provides context and support for its presence within proxy-reconstructions. This work lays the foundation for creating high-resolution paleohurricane records from coastal karst basins and using hurricane models to inform our interpretations of these records.
