Research Abstracts Online
January 2010 - March 2011
University of Minnesota Twin Cities
College of Food, Agricultural, and Natural Resource Sciences
of Soil, Water, and Climate
PI: Dylan B. Millet
Constraints on Global Biogenic Hydrocarbon Emissions and Chemistry From Synthesis of Aura Satellite Observations
This research will advance scientific understanding of the emissions and atmospheric chemistry of isoprene and methanol, the two most important biogenic volatile organic compounds (VOCs). The work involves three-dimensional chemical transport model simulations (GEOS-Chem CTM) and analysis of satellite (TES, OMI) and in-situ observations. Research will be guided by the following overarching questions: 1) What is the distribution of biogenic VOC (BVOC) fluxes to the global atmosphere? 2) How do emissions vary with season and environmental forcing? and 3) What is the resulting seasonal impact on tropospheric chemistry via photochemical production of key carbonyls and CO?
Atmospheric VOCs play a critical role in tropospheric chemistry as precursors of tropospheric ozone, carbon monoxide, formaldehyde, and secondary organic aerosol. The global biosphere is the dominant source of VOCs to the atmosphere, with emissions of isoprene and methanol each estimated to be greater than those of all anthropogenic VOCs combined. These compounds raise several fundamental issues to be resolved: bottom-up BVOC inventories are based on extrapolation of localized measurements and are highly uncertain; data is lacking about how to constrain BVOC fluxes over large parts of the globe, and to quantify how emissions depend on environmental drivers and season; and the impact of BVOCs on tropospheric composition is poorly known due to uncertainties in the emission fluxes and in their chemistry. This project will advance the resolution of these key issues.
Nicholas Boeke, Graduate Student
Su Youn Kim, Research Associate
Wes Reinhart, Undergraduate Student
Kelley Wells, Research Associate