12 documents found, page 1 of 2
Molecular composition of organic aerosols in central Amazonia: An ultra-high-re...
Kourtchev, Ivan N.; Godoi, Ricardo Henrique Moreton; Connors, Sarah; Levine, James G.; Archibald, Alexander Thomas; Godoi, Ana Flávia LocateliThe Amazon Basin plays key role in atmospheric chemistry, biodiversity and climate change. In this study we applied nanoelectrospray (nanoESI) ultra-high-resolution mass spectrometry (UHRMS) for the analysis of the organic fraction of PM2.5 aerosol samples collected during dry and wet seasons at a site in central Amazonia receiving background air masses, biomass burning and urban pollution. Comprehensive mass s...
Dimethyl sulfide in the Amazon rain forest
Jardine, Kolby J.; Yáñez-Serrano, Ana Maria; Williams, Jonathan C.; Kunert, Norbert; Jardine, Angela B.; Taylor, Tyeen C.; Abrell, Leif; Artaxo, PauloSurface-to-atmosphere emissions of dimethyl sulfide (DMS) may impact global climate through the formation of gaseous sulfuric acid, which can yield secondary sulfate aerosols and contribute to new particle formation. While oceans are generally considered the dominant sources of DMS, a shortage of ecosystem observations prevents an accurate analysis of terrestrial DMS sources. Using mass spectrometry, we quantif...
Leaf phenology as one important driver of seasonal changes in isoprene emission...
Alves, Eliane Gomes; Tóta, Júlio; Turnipseed, Andrew A.; Guenther, Alex B.; Vega Bustillos, José Oscar W.; Santana, Raoni Aquino Silva deIsoprene fluxes vary seasonally with changes in environmental factors (e.g., solar radiation and temperature) and biological factors (e.g., leaf phenology). However, our understanding of the seasonal patterns of isoprene fluxes and the associated mechanistic controls is still limited, especially in Amazonian evergreen forests. In this paper, we aim to connect intensive, field-based measurements of canopy isopre...
Seasonality of isoprenoid emissions from a primary rainforest in central Amazonia
Alves, Eliane Gomes; Jardine, Kolby J.; Tóta, Júlio; Jardine, Angela B.; Yáñez-Serrano, Ana Maria; Karl, Thomas G.; Tavares, Julia ValentimTropical rainforests are an important source of isoprenoid and other volatile organic compound (VOC) emissions to the atmosphere. The seasonal variation of these compounds is however still poorly understood. In this study, vertical profiles of mixing ratios of isoprene, total monoterpenes and total sesquiterpenes, were measured within and above the canopy, in a primary rainforest in central Amazonia, using a pr...
Intermediate-scale horizontal isoprene concentrations in the near-canopy forest...
Batista, Carla E.; Ye, Jianhuai; Ribeiro, Igor Oliveira; Guimarães, Patrícia Costa; Medeiros, Adan Sady S.; Barbosa, Rafael G.; Oliveira, Rafael L.The emissions, deposition, and chemistry of volatile organic compounds (VOCs) are thought to be influenced by underlying landscape heterogeneity at intermediate horizontal scales of several hundred meters across different forest subtypes within a tropical forest. Quantitative observations and scientific understanding at these scales, however, remain lacking, in large part due to a historical absence of canopy a...
Introduction: Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5)
Martin, Scot T.; Artaxo, Paulo; Machado, Luiz Augusto Toledo; Manzi, Antônio Ocimar; Souza, Rodrigo Augusto Ferreira de; Schumacher, Courtney J.The Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5) Experiment was carried out in the environs of Manaus, Brazil, in the central region of the Amazon basin for 2 years from 1 January 2014 through 31 December 2015. The experiment focused on the complex interactions among vegetation, atmospheric chemistry, and aerosol production on the one hand and their connections to aerosols, clouds, and p...
Airborne observations reveal elevational gradient in tropical forest isoprene e...
Gu, Dasa; Guenther, Alex B.; Shilling, John E.; Yu, Haofei; Huang, Maoyi; Zhao, Chun; Yang, Qing; Martin, Scot T.; Artaxo, Paulo; Kim, SaewungIsoprene dominates global non-methane volatile organic compound emissions, and impacts tropospheric chemistry by influencing oxidants and aerosols. Isoprene emission rates vary over several orders of magnitude for different plants, and characterizing this immense biological chemodiversity is a challenge for estimating isoprene emission from tropical forests. Here we present the isoprene emission estimates from ...
An overview of the Amazonian Aerosol Characterization Experiment 2008 (AMAZE-08)
Martin, Scot T.; Andreae, Meinrat O.; Althausen, Dietrich; Artaxo, Paulo; Baars, Holger; Borrmann, Stephan H.; Chen, Qi; Farmer, Delphine K.The Amazon Basin provides an excellent environment for studying the sources, transformations, and properties of natural aerosol particles and the resulting links between biological processes and climate. With this framework in mind, the Amazonian Aerosol Characterization Experiment (AMAZE-08), carried out from 7 February to 14 March 2008 during the wet season in the central Amazon Basin, sought to understand th...
Isoprene photochemistry over the Amazon rainforest
Liu, Yingjun; Brito, Joel F.; Dorris, Matthew R.; Rivera-Ríos, Jean C.; Seco, Roger; Bates, Kelvin H.; Artaxo, Paulo; Duvoisin, Sérgio JrIsoprene photooxidation is a major driver of atmospheric chemistry over forested regions. Isoprene reacts with hydroxyl radicals (OH) and molecular oxygen to produce isoprene peroxy radicals (ISOPOO). These radicals can react with hydroperoxyl radicals (HO2) to dominantly produce hydroxyhydroperoxides (ISOPOOH). They can also react with nitric oxide (NO) to largely produce methyl vinyl ketone (MVK) and methacro...
Urban pollution greatly enhances formation of natural aerosols over the Amazon ...
Shrivastava, Manish K.; Andreae, Meinrat O.; Artaxo, Paulo; Barbosa, H. M. J.; Berg, Larry K.; Brito, Joel F.; Ching, Joseph; Easter, Richard C.One of the least understood aspects in atmospheric chemistry is how urban emissions influence the formation of natural organic aerosols, which affect Earth’s energy budget. The Amazon rainforest, during its wet season, is one of the few remaining places on Earth where atmospheric chemistry transitions between preindustrial and urban-influenced conditions. Here, we integrate insights from several laboratory meas...