Encontrados 35 documentos, a visualizar página 1 de 4
The Amazon Tall Tower Observatory (ATTO): Overview of pilot measurements on eco...
Andreae, Meinrat O.; Acevedo, Otávio C.; Araüjo, Alessandro Carioca de; Artaxo, Paulo; Barbosa, Cybelli G.G.; Barbosa, H. M. J.; Brito, Joel F.The Amazon Basin plays key roles in the carbon and water cycles, climate change, atmospheric chemistry, and biodiversity. It has already been changed significantly by human activities, and more pervasive change is expected to occur in the coming decades. It is therefore essential to establish long-term measurement sites that provide a baseline record of present-day climatic, biogeochemical, and atmospheric cond...
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...
Linking meteorology, turbulence, and air chemistry in the amazon rain forest
Fuentes, José D.; Chamecki, Marcelo; dos Santos, Rosa Maria Nascimento; Von Randow, Celso; Stoy, Paul C.; Katul, Gabriel George; Fitzjarrald, David RoyA field campaign reveals that the Amazon rain forest produces enough chemical species to undergo oxidation and generate aerosols, which can activate into cloud condensation nuclei and potentially influence cloud formation. © 2016 American Meteorological Society.
Planetary boundary layer evolution over the Amazon rainforest in episodes of de...
Oliveira, Maurício I.; Acevedo, Otávio C.; Sörgel, Matthias; Lima Nascimento, Ernani de; Manzi, Antônio Ocimar; Oliveira, Pablo E.S.In this study, high-frequency, multilevel measurements, performed from late October to mid-November of 2015 at a 80m tall tower of the Amazon Tall Tower Observatory (ATTO) project in the central state of Amazonas, Brazil, were used to diagnose the evolution of thermodynamic and kinematic variables as well as scalar fluxes during the passage of outflows generated by deep moist convection (DMC). Outflow associate...
Variability of carbon and water fluxes following climate extremes over a tropic...
Zeri, Marcelo; Sá, Leonardo Deane Abreu; Manzi, Antônio Ocimar; Araú, Alessandro C.; Aguiar, Renata Gonçalves; Von Randow, CelsoThe carbon and water cycles for a southwestern Amazonian forest site were investigated using the longest time series of fluxes of CO2 and water vapor ever reported for this site. The period from 2004 to 2010 included two severe droughts (2005 and 2010) and a flooding year (2009). The effects of such climate extremes were detected in annual sums of fluxes as well as in other components of the carbon and water cy...
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...
Soil CO2 efflux in central Amazonia: environmental and methodological effects
Zanchi, Fabrício Berton; Waterloo, Maarten J.; Kruijt, Bart J.; Kesselmeier, Jürgen; Luizão, Flávio Jesus; Manzi, Antônio Ocimar; Dolman, Albertus J.Respiração do solo possui um importante papel no ciclo do carbono em florestas tropicais Amazônicas. Entretanto poucas medidas de respiração do solo foram feitas. Neste estudo são apontados os efeitos na metodologia de instalação dos anéis no solo, bem como os efeitos da precipitação e a distribuição espacial da emissão de CO2 na Amazônia central. Os efeitos da inserção de anéis no solo aumentaram de 13 a 20% p...
Acridicon-chuva campaign: Studying tropical deep convective clouds and precipit...
Wendisch, Manfred; Pöschl, Ulrich; Andreae, Meinrat O.; Machado, Luiz Augusto Toledo; Albrecht, Rachel I.; Schlager, Hans; Rosenfeld, DanielComprehensive in situ and remote sensing observations of deep convective clouds using the new German research jet aircraft HALO have been performed over Amazonia to study the influence of anthropogenic aerosols on the cloud life cycle and precipitation formation processes. © 2016 American Meteorological Society.
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...
Highly reactive light-dependent monoterpenes in the Amazon
Jardine, Angela B.; Jardine, Kolby J.; Fuentes, José D.; Martin, Scot T.; Martins, Giordane Augusto; Durgante, Flávia MachadoDespite orders of magnitude difference in atmospheric reactivity and great diversity in biological functioning, little is known about monoterpene speciation in tropical forests. Here we report vertically resolved ambient air mixing ratios for 12 monoterpenes in a central Amazon rainforest including observations of the highly reactive cis-β-ocimene (160 ppt), trans-β-ocimene (79 ppt), and terpinolene (32 ppt) wh...