New Publication: Footprint region of ATTO

Christopher Pöhlker and co-authors published an extensive new paper, characterizing the footprint region of ATTO. They hope that fellow researchers in the Amazon region can use this publication as resource and reference work to embed ATTO observations into a larger context of Amazonian deforestation and land use change. Pöhlker et al. published the paper Open Access in Atmospheric Chemistry and Physics Volume 19.

In their study, they used backward trajectories to first define the ATTO footprint region. With this modeling approach, you can trace air masses in the atmosphere back along their presumed transport path to ATTO. Because the source regions of observed trace gases and aerosols might be thousands of kilometers away, they did not necessarily trace it all the way back.

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New Publication: Human influence on particulate matter in the Amazon

We hear a lot about particulate matter these days, mostly in the context of air pollution in inner cities. But what about particulate matter in the Amazon rainforest? Well, the short answer is that particulate matter is present in the air above the Amazon, too. And although its concentrations are lower than those in large cities, urbanization and deforestation fires have a significant impact. To find out what that impact exactly is, was the aim of a new study by Suzane de Sá and co-authors.

They analyzed the concentration, composition and properties of particulate matter in the central Amazon. As part of the GoAmazon campaign, they collected data during the dry season, when burning events are most frequent.… Continue reading

New Publication: biodiversity of microorganisms within aerosols of the Amazon rainforest

It is well established that aerosols are relevant for the climate, for example, because they contribute to cloud formation. However, natural, biological aerosols emitted by plants serve another important purpose. They help disperse living microorganisms across the globe, affecting their distribution. Yet little is known about those bioaerosols emitted by pristine forests such as the Amazon. And even less about the diversity of the microorganisms in the aerosols.

Felipe Souza and co-authors now collected bioaerosols at our ATTO site. Then they extracted and analyzed the DNA to determine the communities present. This is the first study which described the community of microorganisms within aerosols in the Amazon.

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New Publication: Inertial Sublayer over the Amazon Rainforest?

The Amazon rainforest interacts with the atmosphere by exchanging many substances. Many of these, such as carbon dioxide, methane, ozone, and organic compounds, are produced by the vegetation. They are very influential in both the regional and global climates. Until now, the estimates of their emission and absorption rates are based on classical theories. But those were developed over relatively short vegetation and are valid for the so-called the “inertial sublayer.”

Cléo Quaresma Dias‐Júnior and co-authors now checked if such an inertial sublayer even exists over the Amazon, where trees grow much higher. With an average tree height of some 40 meters, they expected it at around 100 meter above the forest floor.

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New Publication: rainforest VOC emissions change in El Nino years

OH reactivity (as a measure for VOCs) in the lower part of the graph indicated by the black (2012) and red (2015) lines show maxima at noon and around sunset, respectivelyScience is a lot like life: Things don’t always turn out the way you thought they would.

Recently, Eva Pfannerstill and her team wanted to find out how Amazonian plants react to ecological stresses, such as heat and drought. They wondered if they release more VOCs in such a situation. To do that, they compared data from November 2012 and 2015. 2012 was a pretty “normal” year without any significant temperature or precipitation anomaly. 2015, on the other hand, was influenced by a particularly strong El Nino. It brought extremely hot temperatures and severe drought to the region. However, the scientists were surprised to find that overall emissions were pretty much the same in the two years.Continue reading