Dr. Sebastian Eastham
Massachusetts Institute of Technology
Air quality is typically thought of as a local problem, but understanding its influences can require a global perspective. At these scales, stratospheric chemistry or upper tropospheric dynamics can be crucial to understanding why a county in the US cannot meet its ozone targets. In this seminar, I'll be describing the approaches I have taken to better understand the global nature of air quality problems, focusing on the example of how aircraft emissions affect public health. The seminar will include an in- depth analysis of the chemical mechanisms linking cruise-altitude emissions to premature mortality, in addition to the ways in which cutting-edge atmospheric models are underestimating the effect of intercontinental sources of pollution - and why they are likely to continue to do so. Finally, I will introduce the recently-developed GEOS-Chem High Performance (GCHP) model, which provides a new, scalable platform on which to study atmospheric composition, its drivers, and its likely evolution.
Dr. Sebastian Eastham is a research scientist at Massachusetts Institute of Technology, working on a wide variety of problems related to aviation, air quality, and atmospheric modeling. His work spans modeling of stratospheric chemistry, air quality impact evaluation for policy and technology choices, development and integration of cutting-edge atmospheric modeling techniques in offline and online global models, and process-level modeling of contrail formation, persistence, and interactions. His most recent focus has been on intercontinental pollution, engaging both the question of the mechanisms underlying long-range impacts of cruise altitude aviation on air quality, and the problem of reproducing the fine, filamented structure of atmospheric plumes which are observed to carry harmful chemicals over synoptic-scale distances. Prior to his current work he spent two years working under Daniel Jacob at Harvard University through a double fellowship from the NOAA Climate and Global Change Program and from the Harvard University Center for the Environment. Dr. Eastham received his B.A. and M. Eng. in aerospace and aerothermal engineering from the University of Cambridge in 2011, and his Ph. D. in aeronautical and astronautical engineering in 2015 from the Massachusetts Institute of Technology.