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Unexpected seasonality in quantity and composition of Amazon rainforest air rea...

The hydroxyl radical (OH) removes most atmospheric pollutants from air. The loss frequency of OH radicals due to the combined effect of all gas-phase OH reactive species is a measureable quantity termed total OH reactivity. Here we present total OH reactivity observations in pristine Amazon rainforest air, as a function of season, time-of-day and height (0-80 m). Total OH reactivity is low during wet (10s-1) an...

The Amazon Tall Tower Observatory (ATTO): Overview of pilot measurements on eco...

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...

Dry and hot: The hydraulic consequences of a climate change–type drought for Am...

How plants respond physiologically to leaf warming and low water availability may determine how they will perform under future climate change. In 2015 – 2016, an unprecedented drought occurred across Amazonia with record-breaking high temperatures and low soil moisture, offering a unique opportunity to evaluate the performances of Amazonian trees to a severe climatic event. We quantified the responses of leaf w...

Climate control of terrestrial carbon exchange across biomes and continents

Understanding the relationships between climate and carbon exchange by terrestrial ecosystems is critical to predict future levels of atmospheric carbon dioxide because of the potential accelerating effects of positive climate-carbon cycle feedbacks. However, directly observed relationships between climate and terrestrial CO2exchange with the atmosphere across biomes and continents are lacking. Here we present ...

Understanding nighttime methane signals at the Amazon Tall Tower Observatory (A...

Methane (CH4) atmospheric mixing ratio measurements are analyzed for the period between June 2013 and November 2018 at the Amazon Tall Tower Observatory (ATTO). We describe the seasonal and diurnal patterns of nighttime events in which CH4 mixing ratios at the uppermost (79ma.g.l.) inlet are significantly higher than the lowermost inlet (4ma.g.l.) by 8ppb or more. These nighttime events were found to be associa...

Acridicon-chuva campaign: Studying tropical deep convective clouds and precipit...

Comprehensive 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.

The pantropical response of soil moisture to El Niño

Nighttime wind and scalar variability within and above an Amazonian canopy

Nocturnal turbulent kinetic energy (TKE) and fluxes of energy, CO2 and O3 between the Amazon forest and the atmosphere are evaluated for a 20-day campaign at the Amazon Tall Tower Observatory (ATTO) site. The distinction of these quantities between fully turbulent (weakly stable) and intermittent (very stable) nights is discussed. Spectral analysis indicates that low-frequency, nonturbulent fluctuations are res...

COo2 fluxes in oil palm plantation in eastern Amazonia

Terrestrial ecosystems are important for the CO2 exchange between surface and atmosphere. This work presents the atmospheric conditions and CO2 measurements in interspecific hybrid of oil palm in eastern Amazonia, during El Niño year. The experiment was carried out in Moju-Pará, where a micrometeorological tower was installed to obtain meteorological and CO2 data during the period from january to december 2015....

Aerosol measurement methods to quantify spore emissions from fungi and cryptoga...

Bioaerosols are considered to play a relevant role in atmospheric processes, but their sources, properties, and spatiotemporal distribution in the atmosphere are not yet well characterized. In the Amazon Basin, primary biological aerosol particles (PBAPs) account for a large fraction of coarse particulate matter, and fungal spores are among the most abundant PBAPs in this area as well as in other vegetated cont...