Category: Publications

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.

… Continue reading
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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

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New Publication: Comparing air pollution in Manaus and at ATTO by identifying aerosols

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You have probably heard a lot about air pollution recently, comparing air pollution in Manaus and in the Amazon rainforest by analyzing what aerosols are present. Edited after Wu et al. (2018)be it because of the massive wildfires in California, smog in India or the diesel emission scandal in Germany. So let’s look into air pollution in the Amazon. Most air pollutants are actually aerosols. Identifying these aerosols and their chemical composition can help us understand where they come from and to what extent certain regions are affected by air pollutions. That is exactly what Li Wu and co-authors did in their new study in the Amazon rainforest.

They collected and analyzed aerosols in two locations: the city of Manaus, a large urban area in Brazil, and the ATTO site in the heart of the forest.… Continue reading

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New Publication: Air turbulence characteristics in and above the Amazon rainforest canopy

One of our major goals at ATTO is understanding how the Amazon rainforest interacts with the atmosphere above. This includes studying how the characteristics of the air change within and above the tree canopy in terms of atmospheric turbulence. The strength of the wind and the thickness of the canopy determine, among other things, how well the air can mix and to what degree gases from the atmosphere may reach the forest floor and vice versa.

In a new study, the scientists were looking into these processes at two Amazon sites, including ATTO. They found that the lowermost air-layer from the forest floor to about half the tree height is largely decoupled from the air in the upper part of the canopy and above.… Continue reading

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New Publication: Variability of black and brown carbon concentrations

We are currently in the middle of the dry season in the central Amazon basin, where ATTO is located. This time of year is always characterized by lots of biomass burnings, both natural and anthropogenic. Fires produce aerosols, such as black and brown carbon. But the situation isn’t the same every year.

Our researchers studied the concentration of light-absorbing aerosol particles at ATTO over a 5-year period from 2012 to 2017. They found that the aerosol concentration increased significantly during the El Niño of 2015-2016. During that time, the dry season lasted longer than normal and forest and agricultural fires occurred much more frequently compared to other years.… Continue reading

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