LAKE SEDIMENT RECORDS OF HOLOCENE HYDROCLIMATE VARIABILITY ACROSS THE NORTHERN TROPICAL AMERICAS (Invited Presentation)

Lake sediment records from the tropical Americas provide a unique perspective of Holocene hydroclimate variability. Here, we present a synthesis of lake-level and stable isotope records along a transect from the tropical Americas with a focus on newly developed datasets from the circum-Caribbean region. There is dissimilar spatio-temporal variability in paleoclimate records across the lowland northern tropics, with some indicating a wet-dry-wet pattern, and others a dry-wet-dry pattern during the early, middle, and late Holocene. On a larger scale, hydroclimate records from the southern outer tropics appear to covary with the northern outer tropics, while lake level records of moisture-balance changes from the inner tropics from both hemispheres are generally synchronous. Thus, the available records indicate a complex, spatially-variable pattern that we argue cannot be explained as a direct response to orbital-driven solar forcing. Instead, hydroclimate variability during the Holocene is likely more of a response to non-linear responses to orbital forcing, such as regional shifts in sea-surface temperatures, ocean-atmospheric processes, and monsoon dynamics. For the last millennium, we focus on high-resolution stable isotope records and evaluate the northern tropical hydroclimate responses to the North Atlantic Oscillation (NAO) and the El Niño Southern Oscillation (ENSO).