Collaborative Research: Patterns and processes of abrupt Arctic warming based on paleoclimate observations and models

The rate at which the Arctic has warmed during the past 50 years is likely faster than anytime during the past 7 millennia, and temperatures will likely continue to rise during the coming centuries. This research uses geological evidence and model simulations to study the Arctic system’s response to past warming events that had similar rate and duration to that of modern warming. This project provides detailed insights into the temperature and ocean-atmosphere circulation changes associated with abrupt warming events in the Arctic, thus providing a better understanding of the potential response to future warming. Through outreach efforts, this project connects K–12 students in underserved communities to higher-education opportunities and supports multiple early career researchers, including graduate and undergraduate students. Finally, the database and model output generated from this project will be made publicly available in community-standard formats and archives, thus accelerating advances in Arctic science beyond the life of this project. This study focuses on the feedbacks and processes that determine the interactions of multiple components of the Arctic system as they have undergone rapid warming during the recent deglacial period: sea ice, coupled ocean and atmosphere, and terrestrial Arctic climate. This project tests the hypothesis that during past abrupt warming events, Arctic temperature and moisture changes exhibit a common spatial pattern, strongly controlled by proximity to sea-ice changes and paths of moisture transport. The researchers employ a three-pronged approach: (1) Quantify the climate response to three periods of abrupt warming (14,500; 11,700; and 8,000 years ago) by generating new paleoclimate data — specifically new hydroclimate inferences based on compound-specific isotopes and more accurate chronological control based on a large number of new radiocarbon ages — using existing lake sediment cores from sites that fill major data gaps; (2) Reconstruct the spatiotemporal pattern associated with these abrupt warming events using an updated Arctic-wide paleoclimate database; and (3) Compare the paleoclimate database with existing and new global climate simulations, including those using state-of-the-art isotope-enabled models to assess mechanistic links between components of the Arctic and global climate system during abrupt warming. 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.