B43F-0614
Observed and Modeled Isoprene Fluxes at a Remote Michigan Forest Site
Thursday, 17 December 2015
Poster Hall (Moscone South)
Miao Wen1, Shelley N Pressley2, Dasa Gu3, Haofei Yu4, Alex B Guenther3 and Timothy M VanReken1, (1)Washington State University, Pullman, WA, United States, (2)Washington State Univ, Pullman, WA, United States, (3)University of California Irvine, Irvine, CA, United States, (4)Pacific Northwest National Laboratory, Richland, WA, United States
Abstract:
Biogenic volatile organic compounds (BVOCs) constitute a major part of global VOC emissions and can affect regional or global climate by influencing tropospheric chemistry and forming secondary organic aerosols. Isoprene is the most abundant species in global BVOC budget. The Model of Emissions of Gases and Aerosols from Nature (MEGAN) 2.1 (Guenther et al., 2006, 2012) is a state-of-art emission model that simulates BVOC emissions by considering major environmental activity factors (e.g. temperature, solar radiation). Here we compare measurements of isoprene emissions in a mixed hardwood forest at the University of Michigan Biological Station (UMBS) during 1999-2005 growing seasons (Pressley et al., 2004, 2005) with MEGAN model simulations. We investigated the seasonal variations of isoprene emissions by considering the impacts from meteorological conditions, as well as correlations between sensible heat flux, latent heat flux and isoprene flux for a model uncertainty analysis. Model simulations are in good agreement with observations during leaf full expansion periods, but the values are 3-4 times higher than observations before full leaf development and after leaf senescence periods. There are significant correlations between the variations of isoprene emissions and precipitation.
