The Amazon rainforest is the largest source region of VOCs to the Earth´s atmosphere. Thousands of reactive compounds are released into the air each day though photosynthesis and respiration. We monitor which species are released and how they are oxidized to a multitude of products in the atmosphere. Our group has been active in characterizing this source in terms of individual VOCs (including isoprene, monoterpenes, and oxygenates). In parallel, we measured the reactivity presented by all gas phase species to the atmosphere´s primary oxidant OH. This quantity is termed total OH reactivity. Our measurements from at the ATTO site characterized VOC and total OH reactivity as a function of time of day, height, and season. Recently we have also characterized chiral monoterpenes and sesquiterpenes in the rainforest. This was part of the EU project Ultrachiral.(http://ultrachiral.iesl.forth.gr/). We operate several instruments at the Amazon Tall Tower (ATTO) which allows VOC measurements up to 325m in the middle of the Amazon rainforest. In addition we take VOC measurements from aircraft flying low over the rainforest.
E. Y. Pfannerstill, A. C. Nölscher, A. M. Yáñez-Serrano, E. Bourtsoukidis, S. Keßel, R. H. H. Janssen, A. Tsokankunku, S. Wolff, M. Sörgel, M. O. Sá, A. Araújo, D. Walter, J. V. Lavrič, C. Quaresma Dias-Júnior, J. Kesselmeier, J. Williams. Total OH reactivity changes over the Amazon rainforest during an El Nino event. Frontiers in Forests and Global Change, section Forests and the Atmosphere, Front. For. Glob. Change, 18 December 2018 | https://doi.org/10.3389/ffgc.2018.00012.
E. Bourtsoukidis, T. Behrendt, A. M. Yañez-Serrano, H. Hellén, E. Diamantopoulos, E. Catão, K. Ashworth, A. Pozzer, C. A. Quesada, D. L. Martins, M. Sá, A. Araujo, J. Brito, P. Artaxo, J. Kesselmeier, J. Lelieveld & J. Williams. Strong sesquiterpene emissions from Amazonian soils. Nature Communications, 9, Article number: 2226, 2018. (https://www.nature.com/articles/s41467-018-04658-y)
J. Williams, S. U. Keßel, A. C. Nölscher, Y- Yang, Y. Lee, A. M. Yáñez-Serrano, S. Wolff, J. Kesselmeier, T. Klüpfel, J. Lelieveld, Min Shao. Opposite OH reactivity and ozone cycles in the Amazon rainforest and megacity Beijing: Subversion of biospheric oxidant control by anthropogenic emissions. Atmos. Environ. Volume 125, Part A, January 2016, Pages 112–118 (https://www.sciencedirect.com/science/article/pii/S1352231015305161)
A.C. Nölscher, A.M. Yañez-Serrano, S. Wolff, A.C. de Araujo, J.V. Lavrič, J. Kesselmeier, J. Williams Unexpected seasonality in quantity and composition of Amazon rainforest air reactivity. Nature Communications. 2016 Jan 22;7:10383. doi: 10.1038/ncomms10383. (https://www.nature.com/articles/ncomms10383)
M. O. Andreae, O. C. Acevedo, A. Araùjo, P. Artaxo, C. G. G. Barbosa, H. M. J. Barbosa, J. Brito, S. Carbone, X. Chi, B. B. L. Cintra, N. F. da Silva, N. L. Dias, C. Q. Dias-Júnior, F. Ditas, R. Ditz, A. F. L. Godoi, R. H. M. Godoi, M. Heimann, T. Hoffmann, J. Kesselmeier, T. Könemann, M. L. Krüger, J. V. Lavric, A. O. Manzi, D. Moran-Zuloaga, A. C. Nölscher, D. Santos Nogueira, M. T. F. Piedade, C. Pöhlker, U. Pöschl, L. V. Rizzo, C.-U. Ro, N. Ruckteschler, L. D. A. Sá, M. D. O. Sá, C. B. Sales, R. M. N. D. Santos, J. Saturno, J. Schöngart, M. Sörgel, C. M. de Souza, R. A. F. de Souza, H. Su, N. Targhetta, J. Tóta, I. Trebs, S. Trumbore, A. van Eijck, D. Walter, Z. Wang, B. Weber, J. Williams, J. Winderlich, F. Wittmann, S. Wolff, and A. M. Yáñez-Serrano. The Amazon Tall Tower Observatory (ATTO) in the remote Amazon Basin: Overview of first results from ecosystem ecology, meteorology, trace gas, and aerosol measurements. Atmos. Chem. Phys., 15, 10723-10776, 2015 (https://www.atmos-chem-phys.net/15/10723/2015/)