The William Bankhead National Forest in Alabama is set to host sophisticated scientific instruments as part of a U.S. Department of Energy (DOE) research facility aimed at studying the connections between the forest and atmosphere. The DOE’s Atmospheric Radiation Measurement (ARM) user facility will ensure these instruments' precision and accuracy before installation.
At the Center for Aerosol Measurement Science (CAMS) at DOE’s Brookhaven National Laboratory, scientists are calibrating aerosol instrumentation with standard samples of aerosols. These tiny particles suspended in the atmosphere can trigger cloud formation.
Maria Zawadowicz, a scientist in Brookhaven Lab's Environmental and Climate Sciences Department, is working with interns on an intercomparison study of aerosol mass spectrometers, one of which will be deployed to Bankhead. “What I’m very interested in is how biological aerosols influence climate and ecosystems,” Zawadowicz stated.
She explained that aerosols come from both natural and human-made sources: “Aerosols can be emitted from car tailpipes directly or formed from pollutants in the atmosphere,” she said. Trees and other plants also emit gaseous compounds that convert to aerosols through chemical reactions.
Due to Alabama's high vegetation, Zawadowicz anticipates many natural aerosols like pollen, spores, and bacteria influencing the local climate. The spectrometer will be part of ARM’s Bankhead National Forest atmospheric observatory, which aims to provide high-quality data for studying plant interactions with clouds and aerosols.
Brookhaven scientists led site selection and developed a science plan for the observatory. Argonne National Laboratory oversees instrument installation within and outside the forest while managing site operations slated to open this fall.
Many aerosol instruments will be housed in retrofitted shipping containers known as Aerosol Observing Systems (AOS). Each AOS has an inlet drawing outside air into conductive tubing directing ambient samples for analysis by individual instruments.
Zawadowicz's team is fine-tuning four mass spectrometers destined for different ARM-managed sites across Alaska, Oklahoma, Maryland, and Alabama. Ensuring comparable performance among these instruments involves generating common reference particles for calibration.
Pamela Acevedo, a graduate student at the University of Puerto Rico at Río Piedras, analyzes bioaerosols like pollen from plants and spores from fungi using specialized coarse-mode instruments such as Wideband Integrated Bioaerosol Sensors (WIBS).
Intern Jackson Normandin from Northeastern University studies aerosol particles coated with substances like volatile organic compounds emitted by industry or burning vegetation. He simulates how these coatings form in a lab setting to understand their properties over time better.
The reliability of scientific instruments is crucial for long-term data collection at Bankhead observatory. Chongai Kuang from Brookhaven’s Environmental and Climate Sciences Department emphasized that well-performing instruments are essential for discerning variations due to seasonality or local processes rather than irregularities in measurements.
Zawadowicz will soon travel to Alabama to install the calibrated mass spectrometer in an AOS container: “As an ‘instrument mentor,’ I calibrate the instruments...install them...and make sure that they provide quality-controlled data,” she said.
Trustworthy science requires trustworthy data derived from reliable instruments.
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