Global data set of biogenic VOC emissions calculated by the MEGAN model over the last 30 years
- 1UPMC Univ. Paris 06; Université Versailles St-Quentin; CNRS/INSU; LATMOS-IPSL, Paris, France
- 2Department of Meteorology and Environment Protection, Faculty of Mathematics and Physics, Charles University in Prague, Prague, Czech Republic
- 3Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado, USA
- 4NOAA Earth System Research Laboratory, Chemical Sciences Division, Boulder, CO, USA
- 5Max Planck Institute for Meteorology, Hamburg, Germany
- 6Pacific Northwest National Laboratory, Atmospheric Sciences and Global Change Division, Richland, WA, USA
- 7National Center for Atmospheric Research, Boulder, USA
- 8Belgian Institute for Space Aeronomy, Brussels, Belgium
- 9Biogeochemistry Department, Max Planck Institute for Chemistry, Mainz, Germany
- 10University of Tuscia, Department of Forest Science and Environment, Viterbo, Italy
- 11Department of Physical Geography and Ecosystem Science, Lund University, Lund, Sweden
- *now at: Multiphase Chemistry Department, Max Planck Institute for Chemistry, Mainz, Germany
Abstract. The Model of Emissions of Gases and Aerosols from Nature (MEGANv2.1) together with the Modern-Era Retrospective Analysis for Research and Applications (MERRA) meteorological fields were used to create a global emission data set of biogenic volatile organic compounds (BVOC) available on a monthly basis for the time period of 1980–2010. This data set, developed under the Monitoring Atmospheric Composition and Climate project (MACC), is called MEGAN–MACC. The model estimated mean annual total BVOC emission of 760 Tg (C) yr−1 consisting of isoprene (70%), monoterpenes (11%), methanol (6%), acetone (3%), sesquiterpenes (2.5%) and other BVOC species each contributing less than 2%.
Several sensitivity model runs were performed to study the impact of different model input and model settings on isoprene estimates and resulted in differences of up to ±17% of the reference isoprene total. A greater impact was observed for a sensitivity run applying parameterization of soil moisture deficit that led to a 50% reduction of isoprene emissions on a global scale, most significantly in specific regions of Africa, South America and Australia.
MEGAN–MACC estimates are comparable to results of previous studies. More detailed comparison with other isoprene inventories indicated significant spatial and temporal differences between the data sets especially for Australia, Southeast Asia and South America. MEGAN–MACC estimates of isoprene, α-pinene and group of monoterpenes showed a reasonable agreement with surface flux measurements at sites located in tropical forests in the Amazon and Malaysia. The model was able to capture the seasonal variation of isoprene emissions in the Amazon forest.