Observations of oxidation products above a forest imply biogenic emissions of very reactive compounds
- 1Department of Environmental Science, Policy, and Management (ESPM), Division of Ecosystem Sciences, University of California, Berkeley, California, 94720-3110, USA
- 2Atmospheric Science Program, Department of Land, Air, and Water Resources, University of California, Davis, California, 95616-8717, USA
Abstract. Vertical gradients of mixing ratios of volatile organic compounds have been measured in a Ponderosa pine forest in Central California (38.90° N, 120.63° W, 1315m). These measurements reveal large quantities of previously unreported oxidation products of short lived biogenic precursors. The emission of biogenic precursors must be in the range of 13-66µmol m-2h-1 to produce the observed oxidation products. That is 6-30 times the emissions of total monoterpenes observed above the forest canopy on a molar basis. These reactive precursors constitute a large fraction of biogenic emissions at this site, and are not included in current emission inventories. When oxidized by ozone they should efficiently produce secondary aerosol and hydroxyl radicals.