A 80-Year Long Coral-Based Temperature Reconstruction for the Last Interglacial from Northern Hispaniola
Abstract
The Last Interglacial (LIG; 117-128 ka), when sea level was 6 m higher than today, can serve as an analog for future climate scenarios, yet minimal paleoclimatic information exists with seasonal to decadal resolution. The island of Hispaniola is a particularly desirable site for producing sea surface temperature (SST) reconstructions, as it displays significant correlations with SST and precipitation anomalies for much of the tropical and North Atlantic Ocean, and Hispaniola is located in the northern sector of the Atlantic Warm Pool (AWP), a primary moisture source for precipitation in the Americas. Here we present an early LIG (128,626 ±438 (2σ) years) monthly-resolved coral Sr/Ca-SST reconstruction from a well-preserved Siderastrea siderea subfossil coral spanning 80 years from the northern coast of Hispaniola (19.913°N, 70.925°W). We compare our LIG SST reconstruction with coral Sr/Ca-SST from three modern coral microatolls of the same species, the longest spanning 80 years, recovered near Port-au Prince, Haiti (18.479070°N, 72.668659°W) after the 2010 Haiti earthquake, as well as a 125 ka LIG model simulation spanning 300 years. We find similar mean SST for the LIG (27.4°C) and modern corals (27.9°C) that is consistent with MIS 5e reconstructions in the tropical oceans (27.3-29.6°C); however, these reconstructions are warmer than the LIG model mean SST for our study site (25.6°C). Seasonal variability is similar (1.5°C LIG, 1.0-1.7°C modern) consistent with the findings of LIG coral reconstructions using the tropical Atlantic coral Diploria strigosa and with climate model simulations suggesting orbital insolation changes driving LIG seasonality. However, our LIG coral contains decadal variability (1.7-3.1°C) not evident in the shorter LIG coral reconstructions or modern SST records and coral reconstructions yet are present in the LIG model simulation for our study site. This decadal variability may reflect variations in the northern extent of the AWP on decadal time scales, which may vary trade wind strength, westward moisture transport to the Americas, and precipitation in the Atlantic.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFMPP23D..03D
- Keywords:
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- 4914 Continental climate records;
- PALEOCEANOGRAPHYDE: 4924 Geochemical tracers;
- PALEOCEANOGRAPHYDE: 4928 Global climate models;
- PALEOCEANOGRAPHYDE: 4934 Insolation forcing;
- PALEOCEANOGRAPHY