Alex Guenther, University of California, Irvine
Biogenic volatile organic compounds (BVOCs) emitted by plants and microbes within terrestrial ecosystems drive atmospheric distributions of ozone, particles and other constituents relevant for air quality and climate. BVOC emissions can vary over more than an order of magnitude on spatial scales of meters to kilometers and time scales of minutes to years. Estimating emissions of these compounds is also challenging due to biological diversity, ecosystem spatial heterogeneity on multiple scales, potentially rapid changes in driving variables, and complex responses to environmental stress. Recent studies have revealed both the importance of BVOCs for atmospheric chemistry and the inadequacy of our current understanding of BVOC sources, sinks and transformations. While there have been advances in BVOC emission modeling over the past several decades, the remaining gaps limit the predictability of BVOC emission inputs for CTMs. Recent progress towards reconciling model predictions with observations will be discussed along with findings that demonstrate a lack of progress in some aspects. New approaches for improving the current major BVOC emission uncertainties on local, regional and global scales will be presented. The latest version of the Model of Emission of Gases and Aerosols from Nature (MEGAN3.1) will be described along with a summary of the remaining gaps and priorities for future progress in biogenic VOC emission modeling.