NSF Award
2402100
The Pliocene, from ~5.3 to 2.6 million years ago (Ma), is the last epoch when Earth’s mean temperature was ~3°C warmer than today and CO2 concentrations were sustained at high levels. Global temperatures resembling those of the Pliocene may prevail during the 21st century, making this epoch a valuable opportunity to test our understanding of how the hydrological cycle functions in a warm climate. However, there is insufficient information about rainfall patterns during this time, limiting our ability to assess the mechanisms governing rainfall regimes during times of sustained warmth that could help making predictions about the near-future. This project aims to understand tropical rainfall patterns in northern South America during the Pliocene and across the Pliocene-Pleistocene boundary. To achieve this goal, measurements of chemical signals of rainfall preserved in a sediment core from the Bogotá basin at ~4°N will be made. The proposed research will provide an insight into tropical rainfall and water resources that could help regional water managers prepare for the future. This project supports a female, non-native English speaker, Latina postdoctoral researcher as a PI. It will also support the resources for designing and implementing, in both English and Spanish, the following activities: 1) climate literacy lesson plans for elementary school students, teachers, and caregivers and 2) disseminating the results of the project in social media platforms that are culturally relevant to Latin Americans. Developing climate literacy and outreach content in both languages will help cross language barriers and accelerate access to educational materials. <br/> <br/>Specifically, this project aims to test the hypotheses about the mechanisms that governed, and may govern in the future, rainfall regimes during the late Pliocene to early-mid Pleistocene in northern South America. This research will generate and interpret a new record of hydrogen isotopic composition of precipitation from plant wax (Dwax), both with n-alkanes and n-alkanoic acids, preserved in the Funza-II core from the Bogotá Basin to detect paleohydrological changes between ~1.5 to 4 Ma. It is also proposed to generate a modern dataset of stable isotope composition of daily rainfall and back-trajectory analysis of rain-bearing air masses to improve the understanding of the regional hydroclimate patterns and variability. δDwax data of the Funza-II will be compared against model outputs and existing hydroclimate and sea surface temperature information to test critical hypotheses about the mechanisms that governed rainfall regimes during the Plio-Pleistocene. It is anticipated that project outcomes will provide fundamental insights into the mechanisms governing the hydrological cycle under these boundary conditions across the Americas.<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.
