This project aims to use a new interdisciplinary toolbox to resolve inter-site uncertainties by synthesizing existing lake sediment cores records with existing global climate models to simulate atmospheric moisture transport, build proxy-system models, and ultimately improve the understanding of tropical precipitation variability and change.<br/><br/>The largest single cause, globally, in interannual precipitation variability is associated with the El Nino-Southern Oscillation (ENSO) phenomenon. Large uncertainties remain regarding the magnitude and direction of the projected precipitation response with ENSO. Numerous lake sediment paleoclimate reconstructions have been developed from the Amazon, Andes, and Galapagos Archipelago with the goal of understanding the response of ENSO and tropical hydroclimate (i.e., precipitation amount, intensity, and seasonality) to past climate changes. Disagreement between these records, however, complicates the ability to prepare for climate risks and hydroclimate extremes.<br/><br/>This project specifically aims to: (i) improve the interpretation of tropical lake sediment archives and facilitate proxy-model comparisons using high-resolution moisture tracking simulations with a comprehensive climate model; (ii) constrain the sensitivity of tropical paleo-climate records from the early-Holocene to present; and (iii) synthesize climate reconstructions from lakes with climate model simulations to understand tropical hydroclimate variability across spatial and temporal scales.<br/><br/>The potential Broader Impacts include improved understanding of the magnitude, timing, and drivers of tropical hydroclimate variability over the Holocene. The project will also provide support for two early-career researchers, a postdoctoral fellow, two graduate students, and undergraduate students.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.