Postdoctoral Fellowship: OCE-PRF: Northern Hemisphere ocean and ice sheet variability throughout continuous mean-state changes in the climate system in the early Pleistocene

The United States has high population densities and strong economic interests in coastal cities such as New York City, Miami, and those surrounding the Gulf Coast. However, flooding is becoming an increasingly pressing issue for coastal communities and infrastructure nationwide. The melting of the polar ice caps contributes to rising sea levels and enhances the rate and frequency of coastal flooding. This project will use deep-sea sediment cores to investigate how changes in Earth’s orbit and shifts in climate influenced iceberg discharge events and ocean circulation in the past. The results will provide key insights into the future of the nation’s coastlines in relation to flooding and rising sea levels. The project supports an early career scientist as principal investigator and supports undergraduates who will carry out independent research projects.

A marine sediment core drilling expedition was conducted in the North Atlantic in 2023, near Iceland and Greenland, which collected a substantial amount of data on ocean and ice cap variability. Over 100 meters of sediments from that highly successful scientific ocean drilling expedition will be utilized for this project which aims to answer outstanding questions regarding ocean circulation and ice sheet changes during a critical period of mean-state changes in the climate system in the early Pleistocene (2.5 to 1.7 Ma). An important focus is how the high latitudes changed from a largely ice-free northern hemisphere into the most recent ice-dominant regime. The three main goals of this project are to 1) Build a highly resolved timeline of the sediment drill core by matching chemical signals in the cores to well-known global patterns of the ice ages, 2) Characterize the nature of ocean circulation changes throughout this period, and 3) Quantify the timing and amplitude of iceberg discharge events to understand their correlation to ocean circulation changes. To achieve these goals, approximately 800 newly collected drill core samples will be measured using stable isotope mass spectrometry and microscopic techniques. This multi-faceted project will provide a high-resolution and long-term record of North Atlantic Ocean and iceberg variability during a critical time in Earth’s history, bridging a gap in the current understanding of the natural processes that have driven past changes in the Earth’s ice and ocean.

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.

Award Number: 2513617
Principal Investigator: Claire Jasper
Funds Obligated: $335,736
State: CA