Delphine Farmer - 6th year Graduate Student

B.Sc. Chemistry 2000, McGill University, Montreal, QC, CA

M.S. Environmental Science, Policy and Management, 2001, UC Berkeley,

Research Interests -

I. Biosphere-atmosphere exchange of NOy-

I am interested in how forest ecosystems interact with the atmosphere and exchange nitrogen. In the last few decades, human activity has lead to dramatic increases in atmospheric nitrogen and thus N deposition into forest ecosystems. As nitrogen is often a limiting nutrient, these increases have far-reaching consequences on forest health, water quality, air quality, and the carbon cycle and global climate change. However, there have been few studies on the biosphere-atmosphere fluxes of these compounds, and little is known about the magnitude and mechanisms of the exchange. I am using thermal dissociation-laser induced fluorescence (TD-LIF) to make some of the first eddy covariance fluxes of NO2, sum peroxy nitrates, sum alkyl nitrates, nitric acid, and NOy at a Ponderosa pine plantation in the mid-elevation Sierra Nevada in California. I am using these data to identify not only the magnitude of the ecosystem-scale fluxes, but also in combination with laboratory and modelling studies to identify the role of ecological, chemical and micrometeorological processes in controlling the flux.

Publications -

Silver, W. L., A. E. Lugo, and D. Farmer. 2002. Soil organic carbon in tropical forests of the U. S. Pages 363-382 in J. Kimble, R. Birdsey, L. Heath, R. Follett, and R. Ratan (eds). The Potential of U.S. Forest Soils to Sequester Carbon and Mitigate the Greenhouse Effect.

Presentations -

Farmer, D.K., Wooldridge, P.J., and Cohen R.C., A novel Approach to Eddy Covariance Fluxes of NO2, S Peroxy nitrates, S Alkyl Nitrates and HNO3, AGU Fall 2004, San Francisco, CA. Poster (pdf)