NOAA/WDS Paleoclimatology - Northeastern Gulf of Mexico, Geochemical Proxies and Tropical Cyclone Event Reconstructions during the last 5500 years

Response of tropical cyclone (TC) frequency to future climate change has important implications for society but remains poorly understood due to a lack of long-term reliable observational records. Here, we use high-resolution organic geochemical proxies (OGPs) with robust chronological control from two coastal lakes, >150 km apart, to reconstruct past TC activities in the northeastern Gulf of Mexico (GOM). Results show multi-decadal-to-centennial-scale fluctuations in TC frequency over the last 5500 years. We found that TC frequency either exceeded or was comparable to modern observations during a prolonged interval (~1500-720 cal yr BP) that encompasses the Medieval Warm Period. We also found a nearly 90% reduction in TC activity, relative to modern, during an exceptionally quiescent period (650-280 cal yr BP) that overlaps the Little Ice Age. Warmer temperatures in the North Atlantic did not always support increased TC frequency in this region. We show, for the first time, that increased TC activities in the northeastern GOM track increased solar irradiance. High TC frequency is also coupled to periods of increased sea surface temperatures in the northern GOM, enhanced El Ni˜no-Southern Oscillation, and positive phases of the Atlantic Multi-Decadal Oscillation. Our results highlight the importance of natural variability in climate and solar activity in modulating TC frequency.