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. Instead, they defined the region on the South American continent over which the atmosphere interacts most intensely with the land surface below. Such interactions might be the exchange of gases, taking up water vapor or releasing it through precipitation, or altering the aerosol content (e.g. washing out of aerosols with rain or taking up new aerosols that are dispersed into the atmosphere).
Biogenic volatile organic compounds remove OH from the atmosphere through chemical reactions, which affects processes such as cloud formation. In a new study, Pfannerstill et al. reveal the important contributions of previously not-considered BVOCs species and underestimated OVOCs to the total OH reactivity.
Although located in the tropics, the Amazon sporadically experiences incursions of cold waves called friagem events. They significantly impact the weather patterns during the time they occur, causing for example a temperature drop and increased cloudiness. Guilherme Camarinha-Neto and his colleagues now found that they also affect atmospheric chemistry.
The majority of global precipitation is formed through the pathway of ice nucleation, but we’re facing large knowledge gaps that include the distribution, seasonal variations and sources of ice-nucleating particles. To fill some of those knowledge gaps, Jann Schrod and his co-authors produced a record of long-term measurements of INPs. They collected data for nearly two years at four different locations. One of those sites was ATTO.
Convective storms often occur in the tropics and have the potential to disturb the lower part of the atmosphere. They might even improve the venting of trace gases out of the forest canopy into the atmosphere above. To better understand these processes, Maurício Oliveira and co-authors used the infrastructure at ATTO to study storm outflows during nighttime. They published the results in a new paper in the Open Access Journal Atmospheric Chemistry and Physics.
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 “inertial sublayer.”
Aquino et al. published a new study in Agricultural and Forest Meteorology about the characteristics of turbulence within the forest canopy at two Amazonian sites. They found that the air layer close to ground is largly decouples from the air layer in the upper canopy and above.