Deposition fluxes of oxygenated volatile organic compounds (OVOCs) above FLONA Tapajós in central Amazon rainforest, Brazil.

Tuesday, 16 December 2014
Jeong-Hoo Park, National Center for Atmospheric Research, Boulder, CO, United States, Eliane Gomes Alves, INPA National Institute of Amazonian Research, Climate and Environment Department, Manaus, Brazil, Sarah Suely Alves Batalha, Federal University of West Para, Society, Nature and Development, Santarem, PA, Brazil, Roger Seco, University of California Irvine, Department of Earth System Science, Irvine, CA, United States, Julio Tota, Federal University of West Para, Institute of Engineering and Geoscience, Santarem, PA, Brazil, Rodrigo Augusto Ferreira de Souza, Universidade do Estado do Amazonas, Manaus, AM, Brazil, Alex B Guenther, Pacific Northwest National Laboratory, Richland, WA, United States, Saewung Kim, University of California Irvine, Irvine, CA, United States and James N Smith, NCAR, Boulder, CO, United States
Understanding of VOC deposition is highly uncertain due to a lack of direct flux measurements, but this loss process has been inferred to dominate the removal of VOC from the atmosphere. A recent study on ecosystem scale BVOC fluxes over Amazonian rainforest showed that some oxygenated volatile organic compounds (OVOCs), which are photochemically produced above the canopy, were depositing measurably into the forest. However, that study was limited to only a few compounds due to the technical difficulties. Very recently (June and July 2014), we deployed a PTR-TOF-MS (Proton Transfer Reaction – Time of Flight – Mass Spectrometer) to apply eddy covariance flux measurements of volatile organic compounds (VOC) above the FLONA Tapajós (Floresta Nacional do Tapajós) in the central Amazon rainforest in Brazil. The main goal of this study is to quantify emissions and depositions of a wide range of VOCs and their oxidation products formed above and below canopy. In this presentation, data analysis will be focused on some depositing OVOCs into the forest. From preliminary results for the first 3 days of eddy covariance flux measurement, m/z 31 (CH2OH+), m/z 45 (C2H4OH+), m/z 61 (C2H4O2H+), m/z 71 (C4H6OH+), and m/z 113 (C5H4O3H+) were observed as uniformly depositing compounds during the daytime.