Department Seminar: Funing Li

Title: Physics, Projections, and Origins of Midlatitude Weather Extremes

Abstract: Heating and convection are fundamental atmospheric processes responsible for a wide range of high-impact weather hazards, including heatwaves, wildfires, droughts, floods, thunderstorms, and tornadoes. Yet fundamental questions regarding why they form and how they evolve remain challenging, particularly in the midlatitudes, where conventional theories such as the quasi-equilibrium assumption often fail and multifaceted interactions among land, ocean, atmosphere, and human activity add further complexity.

This talk focuses on near-surface moist heat and severe convective storms, which frequently co-occur across midlatitude land regions due to the stored-energy nature of midlatitude convection. I will present an inversion-constraint theory showing that their maximum intensities are tightly constrained by preexisting low-level thermal inversions, which helps better interpret their projected intensification as the planet warms. Specifically, I will show that emerging future hotspots of moist heat and convection extremes over northeastern Asia and eastern North America arise from amplified warming over upstream highlands, which strengthens downstream inversions. This result highlights orographically elevated heating as a key geographic control of extreme weather changes, and more broadly, it points to a fundamental role of geographic factors in determining the origins of extreme weather patterns on Earth. I will show an example of how large-scale surface roughness, an overlooked geographic driver, contributes to forming the world’s tornado capital in the U.S. (a.k.a. Tornado Alley). I will close by discussing implications for severe weather risk solution and for understanding weather activities beyond Earth and its current and future climate.