Contrasting the Transient and Equilibrium Responses of Atlantic Tropical Cyclones to Pacific Sea Surface Temperature Patterns

Tropical cyclones are significant natural hazards that cause economic losses and loss of life through extreme winds and flooding, as evidenced most recently by the impacts of Hurricane Helene in 2024. While it is well-known that El Niño, a transient warming of the Pacific Ocean relative to other areas on Earth, typically suppresses Atlantic hurricane activity, it remains unclear if a long-term warming of the Pacific Ocean, relative to other areas on Earth, will have the same effect. This project seeks to bridge that knowledge gap and provide critical insights that will improve long-term hazard preparedness and risk management for impacted coastal communities. The project will also contribute to workforce development through graduate training and ensure broad accessibility of findings through open-source tools and collaboration with risk management stakeholders, advancing national resilience. The primary technical objective of this research is to investigate how Atlantic tropical cyclone (TC) activity responds to reductions in the equatorial Pacific zonal sea-surface-temperature (SST) gradient across different timescales. The project focuses on disentangling the differences between the transient and equilibrium responses of Atlantic TCs to Pacific SST patterns. The research utilizes a hierarchical modeling approach to identify the specific physical mechanisms at play, ranging from single-column models and idealized general circulation models (GCMs) to the high-resolution physics-based downscaling of comprehensive Earth system models. By bridging these theoretical and applied frameworks, the study aims to determine whether the suppression of hurricanes observed during short-term El Niño events holds true for longer-term, forced SST shifts. These activities will provide a rigorous physical framework for understanding large-scale atmospheric controls on hurricane variability, leading to more accurate projections of TC activity in a changing climate. 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. NSF Award ID: 2536062 | Program: 01002627DB NSF RESEARCH & RELATED ACTIVIT | Principal Investigator: Jonathan Lin | Institution: Cornell University, ITHACA, NY | Award Amount: $541,181 View on NSF Award Search: https://www.nsf.gov/awardsearch/show-award/?AWD_ID=2536062 View on Research.gov: https://www.research.gov/awardapi-service/v1/awards/2536062.html