DSSS: The Close Links Between Biology and Atmospheric Chemistry in Amazonia2 min read

• Who: Paulo Artaxo, Ph.D., University of São Paulo
• What:   Download the Flyer (pdf)
• Where: Building 66 Auditorium, hosted by Peter Nico
• When: 10:30 am to 12:00 noon, July 11, 2014
• Why: About the Distinguished Scientist Seminar Series

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Paulo Artaxo is professor of physics at the University of São Paulo, and has been an active researcher in Amazonia since 1980.  He has studied aerosol-clouds interactions in Amazonia as well as the effects of climate change on tropical ecosystems. He's been the chairman of the Large Scale Biosphere Atmosphere Experiment in Amazonia (LBA) Science Steering Committee for the last 8 years, and one of the leaders in Amazonian and climate change research in Brazil. He's a member of the IPCC AR4 and AR5 WG1 teams, and is one of the most widely cited Brazilian Researchers.

Abstract

mazonia is a place where the biology of the forest and atmospheric chemistry of trace gases and aerosols are very well coupled. Feedbacks are very strong between ecosystem functioning, trace gases and aerosol emissions and deposition. Cloud cover, precipitation, radiation balance and nutrient cycling are also linked to forest processes. In the wet season, a large portion of the Amazon region constitutes one of the most pristine continental areas, with very low concentrations of atmospheric trace gases and aerosol particles. However, land use change modifies the biosphere-atmosphere interactions in such a way that key processes that maintain the functioning of Amazonia are substantially altered. This study presents long term aerosol and trace gases observations at a preserved forest site in Central Amazonia, with observations from 2008 to 2014. Amazonian aerosols were characterized in detail, including aerosol size distributions, aerosol light absorption and scattering, optical depth and aerosol inorganic and organic composition, among others properties. Trace gases analyzed includes VOCs, O3, CO₂ and CO. Organic aerosol accounts to 81% to the non-refractory PM1 aerosol loading. There are significant changes in the radiation balance due to smoke aerosols that increases the diffuse radiation flux, with an increase of Net Ecosystem Exchange (NEE) of 18-29%.  From this analysis, it is clear that land use change in Amazonia shows alterations of many atmospheric properties, and these changes are affecting the functioning of the Amazonian ecosystem in significant ways.