Seminar: Gary Lackmann – NCSU Department of Marine, Earth, and Atmospheric Sciences

UNC-CH’s Department of Marine Sciences is proud to host a seminar by Gary Lackmann. This event is scheduled for Wednesday, November 6th, at 12:30 pm in room G201 on the ground floor of Murray/Venable Hall at the University of North Carolina at Chapel Hill. This seminar will also be broadcast live to seminar room 222 at the Institute of Marine Sciences (IMS) in Morehead City, NC and online via Zoom (Meeting ID: 222-273-711).

Presenter Affiliation: Editor in Chief, Weather and Forecasting; Professor, North Carolina State University; Department of Marine, Earth, and Atmospheric Sciences

Title: The Extratropical Transition of Tropical Cyclones in a Changing Climate

Abstract: Tropical cyclones that undergo transformation into strong extratropical cyclones are capable of major societal impacts. How will these “extratropical transition” (ET) events change in frequency, location, intensity, and impact in a changing climate? While the question of how climate change will affect tropical cyclones has been studied extensively, much less work has been conducted to date on how climate change could affect ET. In this talk, I will present results from two different approaches to this problem, drawing on the recent work of graduate students Allison Michaelis, Chunyong Jung, and Ana Torres-Vazquez. First, I will present a “pseudo-global warming” case study in order to assess environmental influences on a single event, Hurricane Irene (2011). For this event, we identified greater ET intensity and an extended ET duration in a warmer climate relative to present-day conditions. In order to generalize these findings and to avoid limitations in the PGW approach, I will also share results of a set of high-resolution “tropical-cyclone allowing” global model simulations. Results of both approaches consistently reveal the potential for greater ET intensity and impacts in a warmer climate. Specifically, the global model results demonstrate changes in the geographical location of ET events, and illustrate that the changes are highly basin-dependent. In a warmer climate, tropical cyclones retain their tropical characteristics to higher latitudes. The western North Atlantic showed the greatest geographical ET change in our global model simulations, with increases in ET in the northern portion of the Atlantic basin. Projected warming leads to stronger winds and increases in precipitation that exceed the rate of water vapor change.