Stratospheric Ozone and Climate Change This averaging procedure provides an ensemble-mean visualization of flow structures responsible for erosion “events”. Preliminary evidence indicates that surface stress peaks are associated with the passage of inclined, high-momentum regions flanked by adjacent low-momentum regions.   . The Environmental Fluid Dynamics Lecture Series Presents a Seminar Stratospheric Ozone and Climate Change Prof. Lorenzo Polvani Professor Applied Mathematics and Earth & Environmental Sciences Columbia University New York Tuesday, August 30, 2016 216 DeBartolo Hall 11 am-12 noon Unlike well-mixed greenhouse gases, the radiative forcing of climate due to observed stratospheric ozone loss in the second half of the 20th Century is relatively small. In spite of this, much new evidence has emerged in the last decade showing that the formation of the ozone hole has caused profound changes in the entire Southern Hemisphere climate system, starting from the observed poleward shift of the mid-latitude jet in the summertime. This has been linked to changes in tropospheric and surface temperatures, clouds and cloud radiative effects, precipitation at both middle and low latitudes, as well as temperature and circulation changes in the ocean, and possibly the cryosphere. Similarly, the projected closing of the ozone hole will figure prominently in future climate change. Professor Lorenzo Polvani Is a Professor of Applied Mathematics and Earth & Environmental Sciences at Columbia University. He has been teaching at Columbia for 25 years. His research is focused mostly on atmospheric and climate dynamics, but occasionally he dabbles in oceanography, planetary science and applied mathematics. Dr. Polvani received his B.Sc. degree in Physics at McGill University in 1981, and his Ph.D. in Oceanography at M.I.T. in 1988.