Collaborative Research: Quantifying East African hydroclimate seasonal variability for humid intervals during the last 200 kyrs, Omo-Turkana Basin

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The proposed project will examine the ways in which monsoon variability shapes ecosystems by studying samples from Omo-Turkana in eastern Africa. This project will use a variety of tools to examine seasonal rainfall variability and test whether increased seasonality is strongly correlated with wet intervals. Fossil data and chemical analyses will be used to understand past environments and help determine how this sensitive, water-limited region will respond to a modern and future world shaped by anthropogenic climate change. International collaboration will include training opportunities for the next generation of geoscientists, with a focus on supporting undergraduates from both the US and Ethiopia. Both PIs are based at Primarily Undergraduate Institutions and will develop a learning community through pre-fieldwork programming, collaborative fieldwork, and regular project team meetings. The project has the potential to recruit, engage and retain students from historically underserved communities in STEM to continue as leaders in the geosciences. This project will test the hypothesis that solar insolation maxima increased the strength of the East African monsoon, resulting in enhanced seasonality in eastern Africa during humid periods. Understanding the extremes of seasonality is essential to constrain the terrestrial paleoclimatic and thus paleoenvironmental conditions and resource availability in eastern Africa where early hominins and modern humans evolved. Specifically, the project will 1) establish a single valve ostracod carbon and oxygen isotope proxy record of the eastern African seasonality during wet phases over the last 200 kyrs, 2) develop complementary ostracod-based proxy records of seasonality using trace elements and ostracod-paleoecology, and 3) use modern water isotope records to develop and calibrate a model of paleo-hydroclimate for key intervals over the past 200 kyrs. Given the sensitivity of the study site to significant atmospheric phenomena such as the Intertropical Convergence Zone (ITCZ) and walker circulation, the outcome of this study will improve understanding of the degree of seasonality in humid intervals over the last 200 kyrs.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.