دورية أكاديمية

Aircraft-based observations of isoprene-epoxydiol-derived secondary organic aerosol (IEPOX-SOA) in the tropical upper troposphere over the Amazon region

التفاصيل البيبلوغرافية
العنوان: Aircraft-based observations of isoprene-epoxydiol-derived secondary organic aerosol (IEPOX-SOA) in the tropical upper troposphere over the Amazon region
المؤلفون: C. Schulz, J. Schneider, B. Amorim Holanda, O. Appel, A. Costa, S. S. de Sá, V. Dreiling, D. Fütterer, T. Jurkat-Witschas, T. Klimach, C. Knote, M. Krämer, S. T. Martin, S. Mertes, M. L. Pöhlker, D. Sauer, C. Voigt, A. Walser, B. Weinzierl, H. Ziereis, M. Zöger, M. O. Andreae, P. Artaxo, L. A. T. Machado, U. Pöschl, M. Wendisch, S. Borrmann
المصدر: Atmospheric Chemistry and Physics, Vol 18, Pp 14979-15001 (2018)
بيانات النشر: Copernicus Publications, 2018.
سنة النشر: 2018
المجموعة: LCC:Physics
LCC:Chemistry
مصطلحات موضوعية: Physics, QC1-999, Chemistry, QD1-999
الوصف: During the ACRIDICON-CHUVA field project (September–October 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 (BL) 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 (UT), leading to increased organic aerosol mass concentrations above 10 km altitude. The median organic mass concentrations in the UT above 10 km range between 1.0 and 2.5 µg m−3 (referring to standard temperature and pressure; STP) with interquartile ranges of 0.6 to 3.2 µg m−3 (STP), representing 78 % of the total submicron non-refractory aerosol particle mass. The presence of isoprene-epoxydiol-derived 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 UT 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 preexisting particles leads to IEPOX-SOA formation and subsequently increasing organic mass in the UT. This organic mass increase was accompanied by an increase in the nitrate mass concentrations, most likely due to NOx production by lightning. Analysis of the ion ratio of NO+ to NO2+ indicated that nitrate in the UT 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 UT either on acidic nitrate particles forming organic nitrates derived from IEPOX or on already neutralized organic nitrate aerosol particles.
نوع الوثيقة: article
وصف الملف: electronic resource
اللغة: English
تدمد: 1680-7316
1680-7324
Relation: https://www.atmos-chem-phys.net/18/14979/2018/acp-18-14979-2018.pdf; https://doaj.org/toc/1680-7316; https://doaj.org/toc/1680-7324
DOI: 10.5194/acp-18-14979-2018
URL الوصول: https://doaj.org/article/14327237ef1f4c60a054857cf1b705e6
رقم الأكسشن: edsdoj.14327237ef1f4c60a054857cf1b705e6
قاعدة البيانات: Directory of Open Access Journals
الوصف
تدمد:16807316
16807324
DOI:10.5194/acp-18-14979-2018