Benjamin S. Felzer
I am a research associate at The Ecosystems Center, part of the Marine Biological Laboratory in Woods Hole, MA. I am working with the Terrestrial Ecosystems Model (TEM), a biogeochemical model of the carbon, nitrogen, and water cycles. We are using this model to understand the effects of the land surface, particularly vegetation, on the global carbon cycle. For example, global warming is caused by emissions of greenhouse gases, such as carbon dioxide (CO2), but not all the CO2 we emit into the atmosphere remains there because of absorption by the ocean and land surface. Several important questions include a) can we account for the land component of the 'carbon sink? b) how do changes in vegetation cover affect atmospheric CO2 and the resulting climate? c) how does the ability of vegetation to remove CO2 from the atmosphere change with a warmer climate? d) how will vegetation migrate with shifting climates, and e) how does air pollution affect vegetation productivity?
I have been looking at the effects of ozone pollution on vegetation productivity and carbon sequestration. Ground-level ozone has been observed to inhibit photosynthesis by direct cellular damage. I have incorporated a simple empirical equation (based on Ollinger et al., 1997 and Reich, 1987) derived for deciduous and coniferous forest and crops to the TEM model. This equation inversely relates gross primary productivity (GPP) to accumulated hourly ozone levels. The ozone values are based on the AOT40 index, which is a measure of hourly-accumulated ozone above a threshold of 40 ppb. In order to apply the equation to TEM, I have developed a gridded map of AOT40 for the U.S. developed from the EPA CASTNET and AIRS datasets, and a globally, gridded map of AOT40 values based on the MIT Integrated Global System Model (IGSM) and MATCH models. Results for the U.S. observed dataset are published in Tellus (article) and at MIT (MIT reprint series) while the global economic implications of future ozone pollution are published at "MIT report 103" and also are currently under review at climatic change.
During 2000/2001 I helped coordinate NOAA's Office of Global Programs (OGP)'s GCIP/GAPP (GEWEX Continental-scale International Project/GEWEX Americas Prediction Project, where GEWEX is the Global Energy and Water Cycle Experiment) program. Previous to that, I served as the climate scenarios coodinator for the U.S. National Assessment of the potential consequences of climate variability and change (details ), following my postdoctoral research at the National Center for Atmospheric Research (details ). Please see my CV for list of publications and graduate research.