Seminar

Abstract

We will discuss recently purported trends in Arctic ozone loss extremes (related to the dubious claim that "the coldest winters are getting colder"), and show that they are largely a result of internal climate variability, and not increased greenhouse gases. We will then demonstrate that such Arctic ozone loss extremes are able to produce robust anomalies in tropospheric winds, and surface temperature and precipitation in April and May over large portions of the Northern Hemisphere, owning to elevated levels of ozone depleting substances. Coupling between chemistry and dynamics is therefore essential for a complete representation of surface climate variability and climate change in the Arctic.

---

Lorenzo Polvani is a professor of Applied Mathematics and of Earth & Environmental Sciences at Columbia University. His research interests include atmospheric and climate dynamics, geophysical fluid dynamics, numerics for weather and climate modeling, and planetary atmospheres.