@Article{SchulzSHACSDFJKKMMPSVWZZAAMPWB:2018:AiObIs,
               author = "Schulz, Christiane and Schneider, Johannes and Holanda, Bruna 
                         Amorim and Appel, Oliver and Costa, Anja and S{\'a}, Suzane S. de 
                         and Dreiling, Volker and F{\"u}tterer, Daniel and 
                         Jurkat-Witschas, Tina and Klimach, Thomas and Kr{\"a}mer, Martina 
                         and Martin, Scot T. and Mertes, Stephan and P{\"o}hlker, Mira L. 
                         and Sauer, Daniel and Voigt, Christiane and Weinzierl, Bernadett 
                         and Ziereis, Helmut and Z{\"o}ger, Martin and Andreae, Meinrat O. 
                         and Artaxo, Paulo and Machado, Luiz Augusto Toledo and 
                         P{\"o}schl, Ulrich and Wendisch, Manfred and Borrmann, Stephan",
          affiliation = "{Max Planck Institute for Chemistry} and {Max Planck Institute for 
                         Chemistry} and {Max Planck Institute for Chemistry} and {Max 
                         Planck Institute for Chemistry} and {Institut f{\"u}r Energie- 
                         und Klimaforschung (IEK7)} and {Harvard University} and {German 
                         Aerospace Center (Deutsches Zentrum f{\"u}r Luft- und Raumfahrt)} 
                         and {German Aerospace Center (Deutsches Zentrum f{\"u}r Luft- und 
                         Raumfahrt)} and {German Aerospace Center (Deutsches Zentrum 
                         f{\"u}r Luft- und Raumfahrt)} and {Max Planck Institute for 
                         Chemistry} and {Institut f{\"u}r Energie- und Klimaforschung 
                         (IEK7)} and {Harvard University} and {Leibniz Institute for 
                         Tropospheric Research} and {Max Planck Institute for Chemistry} 
                         and {German Aerospace Center (Deutsches Zentrum f{\"u}r Luft- und 
                         Raumfahrt)} and {German Aerospace Center (Deutsches Zentrum 
                         f{\"u}r Luft- und Raumfahrt)} and {German Aerospace Center 
                         (Deutsches Zentrum f{\"u}r Luft- und Raumfahrt)} and {German 
                         Aerospace Center (Deutsches Zentrum f{\"u}r Luft- und Raumfahrt)} 
                         and {German Aerospace Center (Deutsches Zentrum f{\"u}r Luft- und 
                         Raumfahrt)} and {Max Planck Institute for Chemistry} and 
                         {Universidade de S{\~a}o Paulo (USP)} and {Instituto Nacional de 
                         Pesquisas Espaciais (INPE)} and {Max Planck Institute for 
                         Chemistry} and {University of Leipzig} and {Max Planck Institute 
                         for Chemistry}",
                title = "Aircraft-based observations of isoprene epoxydiol-derived 
                         secondary organic aerosol (IEPOX-SOA) in the tropical upper 
                         troposphere over the Amazon region",
              journal = "Atmospheric Chemistry and Physics Discussion",
                 year = "2018",
               volume = "2018",
               number = "232",
             abstract = "During the ACRIDICON-CHUVA field project (SeptemberOctober 2014; 
                         based in Manaus, Brazil) aircraft-based in-situ measurements of 
                         aerosol chemical composition were conducted in the tropical 
                         troposphere over the Amazon using the High Altitude and Long Range 
                         Research Aircraft (HALO), covering altitudes from the boundary 
                         layer height up to 14.4\ km. The submicron non-refractory 
                         aerosol was characterized by flash-vaporization/electron 
                         impact-ionization aerosol particle mass spectrometry. The results 
                         show that significant secondary organic aerosol (SOA) formation by 
                         isoprene oxidation products occurs in the upper troposphere, 
                         leading to increased organic aerosol mass concentrations above 
                         10\ km altitude. The median organic mass concentrations in 
                         the upper troposphere above 10\ km range between 1.0 and 
                         2.1\ \μg\ m\−3 (referring to standard 
                         temperature and pressure; STP) with interquartile ranges of 0.6 to 
                         3.0\ \μg\ m\−3 (STP), representing 
                         70\ % of the total submicron non-refractory aerosol 
                         particle mass. The presence of isoprene epoxydiol-derived isoprene 
                         secondary organic aerosol (IEPOX-SOA) was confirmed by marker 
                         peaks in the mass spectra. We estimate the contribution of 
                         IEPOX-SOA to the total organic aerosol in the upper troposphere to 
                         be about 20\ %. After isoprene emission from vegetation, 
                         oxidation processes occur at low altitudes and/or during transport 
                         to higher altitudes, which may lead to the formation of IEPOX (one 
                         oxidation product of isoprene). Reactive uptake or condensation of 
                         IEPOX on pre-existing particles leads to IEPOX-SOA formation and 
                         subsequently increasing organic mass in the upper troposphere. 
                         This organic mass increase was accompanied by an increase of the 
                         nitrate mass concentrations, most likely due to NOx production by 
                         lightning. We further found that the ammonium contained in the 
                         aerosol particles is not sufficient to neutralize the particulate 
                         sulfate and nitrate. Analysis of the ion ratio of NO+ to NO2+ 
                         indicated that nitrate in the upper troposphere exists mainly in 
                         the form of organic nitrate. IEPOX-SOA and organic nitrates are 
                         coincident with each other, indicating that IEPOX-SOA forms in the 
                         upper troposphere either on acidic nitrate particles forming 
                         organic nitrates derived from IEPOX or on already neutralized 
                         organic nitrate aerosol particles.",
                  doi = "10.5194/acp-2018-232",
                  url = "http://dx.doi.org/10.5194/acp-2018-232",
                 issn = "1680-7367",
             language = "en",
           targetfile = "schulz_aircraft.pdf",
        urlaccessdate = "25 abr. 2024"
}