Stratospheric Anticyclones and their Interactions with the Troposphere

Cornell University, Ithaca NY

Investigators

Abstract

The project aims to advance our understanding of anticyclones or high pressure systems (clockwise/counterclockwise turning circulations in the Northern/Southern Hemisphere) in the layer of the atmosphere within 10-50 km above the earth's surface, which is called as Stratosphere. These stratospheric anticyclones, including the Aleutian High and Atlantic High of the Northern Hemisphere, and Australian High in the Southern Hemisphere, are co-evolved with the stratospheric polar vortex (low-pressure systems) over each hemisphere's winter pole as well as weather systems that produce cold-air outbreaks near the earth's surface. The outcome of the project would help reveal stratospheric processes and improve their predictions societally important and high-impact weather events, such as cold-air outbreaks and winter storms. This project supports a post-doctoral fellow and undergraduate student, contributing to the training of next generation of scientists. The project's research methods will be used in courses taught by the PI, thus introducing these methods to a larger body of students outside of those working on the project. Numerical experiments with an atmospheric model with various specially designed configurations (e.g., with/without topography) will be used to reveal the conditions under which continental scale near-surface temperature anomalies would occur, acting alone or in concert with the stratospheric processes that disturb the polar vortex. Numerical experiments will also be used to disclose the patterns of stratospheric temperature anomalies that lead to near-surface cold-air outbreaks in different geographical regions. The project will yield fundamental new insights into stratospheric circulation systems and their coupling with the weather at the earth's surface, including new knowledge about near-surface cold-air outbreaks and their regulation by stratospheric processes. 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.