Paleoenvironmental Reconstruction Using Coral Microatolls (Sp. Siderastrea siderea) From the Gulf of Gon�ve, Haiti

Abstract

Natural and anthropogenic climate changes present unique and serious risks to society. In order to plan and implement adaptation and mitigation strategies successfully, regional manifestations of broad-scale climate changes must be understood robustly. The Caribbean region contains part of the Western Hemisphere Warm Pool (WHWP), a major sea surface temperature (SST) feature that plays a key role in North Atlantic climate. Climate variability in the Caribbean is captured poorly by climate models, due in part to a lack of continuous, multidecadal instrumental climate records from the region. I explored three research questions in this dissertation: Does non-systematic bias exist in global gridded interpolated SST products and could that result in erroneous coral SST proxy calibrations and reconstructions? How has WHWP extent varied over the past century? How has Saharan dust transport by northeasterly trade winds varied? To address the first research question, bias in global interpolated gridded SST products was quantified using high-resolution satellite SST, additionally, those interpolated SST products were used to calibrate idealized pseudocoral Sr/Ca modeled at multiple marine proxy sites to assess the impact of biases on climate reconstructions. To address the second research question, SST in the Northern Caribbean was reconstructed using trace element ratios (Sr/Ca) in three coral microatolls from the west coast of Haiti collected after the 2010 Léogâne earthquake. To address the third research question, rare earth element (REE) concentrations in Haitian microatolls were examined as a dust proxy. Examining error and bias among globally gridded interpolated SST products reveals non-systematic bias. Reconstructed SST reveals WHWP extension to Haiti prior to the 1940s followed by a reduction in Haitian WHWP conditions between the early 1950s and mid-1960s. REE analysis resulted in a novel Saharan dust proxy that demonstrates the capability of capturing rapid dust transport events in the Caribbean region.