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

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

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

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

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

New Publication: Aerosol composition and cloud dynamics

The properties and dynamics of clouds are strongly dependent on the types and amounts of aerosol particles in the atmosphere. They act as so-called cloud condensation nuclei as they initiate the formation of cloud droplets. Therefore, it is crucial to gain a sound understanding of the emission patterns, properties, and seasonal variability of aerosols in relation to the cloud life cycles. In order to achieve this goal, our aerosol group was able to record such data at ATTO. Over the course of a full year, they continuously measured aerosols and their properties in the atmosphere at the 80 m tower.… Continue reading