Title:	Total OH reactivity changes over the Amazon rainforest during an El Niño event.
Authors:	PFANNERSTILL, E. Y. NÖLSCHER, A. C. YÁÑEZ-SERRANO, A. M. BOURTSOUKIDIS, E. KEBEL, S. JANSSEN, R. H. H. TSOKANKUNKU, A. WOLFF, S. SÖRGEL, M. SÁ, M. O. ARAUJO, A. C. de WALTER, D. LAVRIC, J. DIAS-JUNIOR, C. Q. KESSELMEIER, J. WILLIAMS, J.
Affiliation:	Eva Y. Pfannerstill, Max Planck Institute for Chemistry Anke C. Nölscher, Max Planck Institute for Chemistry Ana M. Yáñez-Serrano, Max Planck Institute for Chemistry Efstratios Bourtsoukidis, Max Planck Institute for Chemistry Stephan Keßel, Max Planck Institute for Chemistry Ruud H. H. Janssen, Massachusetts Institute of Technology Anywhere Tsokankunku, Max Planck Institute for Chemistry Stefan Wolff, Max Planck Institute for Chemistry Matthias Sörgel, Max Planck Institute for Chemistry Marta O. Sá, INPA ALESSANDRO CARIOCA DE ARAUJO, CPATU David Walter, Max Planck Institute for Chemistry Jošt Lavric, Max Planck Institute for Chemistry Cléo Q. Dias-Júnior, IFPA Jürgen Kesselmeier, Max Planck Institute for Chemistry Jonathan Williams, Max Planck Institute for Chemistry.
Date Issued:	2018
Citation:	Frontiers in Forests and Global Change, v. 1, Article 12, Dec. 2018.
Description:	The 2015/16 El Niño event caused unprecedented drought and warming in the Amazon basin. How tropical forests react to such extreme events in terms of volatile organic compound (VOC) emissions is of interest as the frequency of these events is predicted to increase through climate change. The diverse VOCs emitted can be significant for plants' carbon budgets, influence ozone and particle production, and through their reactivity impact OH concentrations. Total OH reactivity is a directly measureable quantity that gives the reaction frequency of OH radicals with all reactive species in the atmosphere in s?1. Here we present a comparison of the OH reactivity diel cycle from November 2015, i.e., extreme drought and elevated temperatures associated with strong El Niño conditions, with November 2012, a ?normal? El Niño Southern Oscillation (ENSO)-neutral period. Interestingly, the diel maximum of OH reactivity during the El Niño event occurred at sunset instead of, under normal conditions, early afternoon. The absolute total diel OH reactivity, however, did not change significantly. Daytime OH reactivity averages were 24.3 ± 14.5 s?1 in 2012 and 24.6 ± 11.9 s?1 in 2015, respectively. Our findings suggest that a combination of stronger turbulent transport above the canopy with stress-related monoterpene and, possibly, other biogenic volatile organic compound (BVOC) emissions were responsible for the increased reactivity at sunset.
NAL Thesaurus:	El Nino Amazonia
DOI:	10.3389/ffgc.2018.00012
Type of Material:	Artigo de periódico
Access:	openAccess
Appears in Collections:	Artigo em periódico indexado (CPATU)