U.S. Department of Energy Office of Biological and Environmental Research

BER Research Highlights

Fungal Spores are a Primary Source of Sodium Salt Particles in Amazon Air
Published: November 19, 2018
Posted: February 20, 2019

For the first time, an international team of scientists discovers the true origin of sodium salt in the pristine Amazon air.

The Science
Tiny particles of sodium salt float in the air over the pristine Amazon basin. Why? The only explanation before now has been that winds blow marine particles hundreds of miles inland from the Atlantic Ocean. An international team of scientists used chemical imaging and atmospheric models to prove otherwise. They discovered that, during the wet season, fungal spores make up as much as 69 percent of the airborne sodium salt particles in the central Amazon basin.

The Impact
Particles in the air act as nuclei to form ice and clouds. Never have fungal spores been considered a significant source of these particles over the Amazon. By understanding where and when sodium salt particles will be present and in what quantities, scientists can better predict cloud formation and the effect of changes in the terrestrial ecosystem on long-term climate patterns.

Scientists from EMSL partnered with colleagues at Pacific Northwest National Laboratory, Lawrence Berkeley National Laboratory (LBNL), University of California at Berkeley, Purdue University, China’s Xiamen University, Germany’s Max Planck Institute for Chemistry, and Brazil’s Federal University of São Paulo, University of São Paulo, and Federal University of Para on a project to determine the source of sodium salt particles in the Amazon. The team collected samples of airborne particles during the beginning of the wet season from a pristine rainforest site in the Amazon region. They then applied a variety of chemical imaging techniques such as EMSL’s scanning electron microscope and secondary ion mass spectrometry, and LBNL’s scanning transmission X-ray microscope in the Advanced Light Source to analyze particle size and composition. Results showed that locally emitted fungal spores contributed considerably to sodium salt particles, which were previously solely attributed to oceanic emissions. To evaluate the geographic distribution and frequency of high fungal spores over the Amazon basin, they conducted simulations using the Community Earth System Model. Modeling results suggested that fungal spores account for approximately 69 percent of the total sodium mass during the wet season and that their fractional contribution increases during the night. The work offers new insights into the composition of Amazon air and suggests areas for further study.

Contacts Program Managers
Shaima Nasiri and Paul Bayer
Department of Energy, Office of Science, Biological and Environmental Research, Atmospheric System Research

Principal Investigator
Alex Laskin
Purdue University

This work was supported by the U.S. Department of Energy’s Office of Science (Office of Biological and Environmental Research) through the Atmospheric System Research Program, and including support of the Environmental Molecular Sciences Laboratory (EMSL), a DOE Office of Science User Facility. Additional support came from the Chemical Imaging Initiative at Pacific Northwest National Laboratory, the Advanced Light Source at Lawrence Berkeley National Laboratory, and the National Science Foundation.

China, S., S.M. Burrows, B. Wang, T.H. Harder, J. Weis, M. Tanarhte, L.V. Rizzo, J. Brito, G.G. Cirino, P.-L. Ma, J. Cliff, P. Artaxo, M.K. Gilles, and A. Laskin. “Fungal spores as a source of sodium salt particles in the Amazon basin.” Nature Communications 9 Article 4793 (2018). [DOI: 10.1038/s41467-018-07066-4]

Topic Areas:

  • Research Area: Atmospheric System Research

Division: SC-23 BER


BER supports basic research and scientific user facilities to advance DOE missions in energy and environment. More about BER

Recent Highlights

Aug 24, 2019
New Approach for Studying How Microbes Influence Their Environment
A diverse group of scientists suggests a common framework and targeting of known microbial processes [more...]

Aug 08, 2019
Nutrient-Hungry Peatland Microbes Reduce Carbon Loss Under Warmer Conditions
Enzyme production in peatlands reduces carbon lost to respiration under future high temperatures. [more...]

Aug 05, 2019
Amazon Forest Response to CO2 Fertilization Dependent on Plant Phosphorus Acquisition
AmazonFACE Model Intercomparison. The Science Plant growth is dependent on the availabi [more...]

Jul 29, 2019
A Slippery Slope: Soil Carbon Destabilization
Carbon gain or loss depends on the balance between competing biological, chemical, and physical reac [more...]

Jul 15, 2019
Field Evaluation of Gas Analyzers for Measuring Ecosystem Fluxes
How gas analyzer type and correction method impact measured fluxes. The Science A side- [more...]

List all highlights (possible long download time)