An upcoming field campaign supported by the U.S. Department of Energy (DOE) will study surface-atmosphere interactions around Baltimore, Maryland, to see how they influence the city’s climate.
Ken Davis, professor of atmospheric and climate science at Penn State, is the principal investigator for this new campaign, called the Coast-Urban-Rural Atmospheric Gradient Experiment (CoURAGE). Campaign operations are expected to start as early as October 2024 and run through September 2025.
Joining Davis and five additional Penn State investigators on the CoURAGE science team are 23 co-investigators from Brookhaven National Laboratory; City College of the City University of New York; Columbia University; Howard University; Johns Hopkins University; Morgan State University; NOAA’s Earth System Research Laboratory; Princeton University; University at Albany; University of Maryland, Baltimore County; University of Maryland, College Park; and University of Texas at Austin.
DOE’s Atmospheric Radiation Measurement (ARM) user facility will provide instruments and infrastructure for CoURAGE. For more than 30 years, ARM has collected atmospheric data in under-sampled regions worldwide. Scientists around the world can freely download and use ARM data.
DOE selected CoURAGE from a fall 2022 call seeking proposals for ARM field campaigns that would support the DOE Biological and Environmental Research (BER) program’s interest in urban climate systems. CoURAGE scientists will study urban-coastal-rural interactions and their impacts on the atmospheric boundary layer (the lowest level of the atmosphere), aerosol particles and atmospheric composition, clouds, radiation, and precipitation.
Exploring Baltimore’s climate challenges
CoURAGE will contribute to the Baltimore Social-Environmental Collaborative (BSEC), one of four recently funded DOE Urban Integrated Field Laboratories. BSEC and the three other urban laboratories, located in Arizona, Texas, and Illinois, will expand the understanding of climate and weather events and their impact on urban systems.
Davis is the principal investigator for Penn State’s portion of the multi-institutional BSEC laboratory, which is being led by Johns Hopkins University. The CoURAGE science team includes BSEC’s principal investigator, Johns Hopkins professor Benjamin Zaitchik, and nine BSEC co-investigators.
In 2022, DOE announced it would support the BSEC laboratory to study Baltimore, the 30th-largest city in the United States with a population of more than 585,000 people as of the 2020 Census.
With its aging infrastructure, growing susceptibility to heat and flooding, and ongoing issues with air and water pollution, Baltimore is characteristic of many large industrial cities in the Eastern United States. This was a motivating factor in deciding to propose an urban laboratory in Baltimore, said Davis.
“It’s a city that needs to adapt to thrive in a changing climate,” he said. “The city also needs sound evidence regarding options for climate change mitigation—options like urban greening. We also need to partner to generate climate science that addresses the priorities of people and neighborhoods in the city that historically have been neglected. Many of our cities face these challenges.”
Nodes of CoURAGE
BSEC will collect long-term data on the urban atmosphere and land-atmosphere interactions. However, it does not have enough resources to observe all the important variables within the city, nor can it cover “the neighbors,” as Davis put it—the atmospheric environments upwind of Baltimore that affect the city’s climate.
During CoURAGE, ARM instruments will help provide coverage where BSEC cannot, forming much of what the campaign’s science team calls “a four-node regional atmospheric observatory network.”
CoURAGE is expected to include three ARM nodes.
The primary node is planned to be in Baltimore at Morgan State’s Clifton Park site, where ARM will operate a portable observatory consisting of instruments, shelters, and data and communications systems. ARM instruments operate 24 hours a day, seven days a week, with onsite technicians monitoring the observatory around the clock. These data will greatly expand the breadth of measurements that BSEC investigators will collect during their five-year study.
ARM’s other two nodes will be smaller observational arrays located at key sites outside the city. One will be in a rural area northwest of Baltimore, on land typical of the plains found between the coast and the foothills of the Appalachian Mountains. This rural atmosphere is often carried into Baltimore by the prevailing winds. The other site will be on an island to sample atmospheric conditions representative of Chesapeake Bay, the southeastern boundary of the Baltimore metropolitan area.
The fourth node of the CoURAGE network will be an existing long-term observatory operated in Beltsville, Maryland, by Howard University and the Maryland Department of the Environment. Located north of Washington D.C., the observatory will measure the air that is carried into Baltimore when the winds come from the southwest, traveling across the nation’s capital.
With data from multiple sites, CoURAGE will be able to document the degree to which different surface conditions around the region can change Baltimore’s atmospheric environment.
“The CoURAGE campaign will be an important contribution to BER’s urban initiative,” said DOE ARM Program Manager Sally McFarlane. “The ARM observations will help improve understanding of atmospheric processes in urban regions, the surface and environmental conditions that drive them, and how our models of urban systems need to be improved.”
CoURAGE will aim to answer the following science questions:
- What is the dependence of Baltimore’s atmospheric environment (thermodynamics, cloud properties, surface radiation, aerosols and atmospheric composition, winds, precipitation) on the surrounding surface-atmosphere interactions and atmospheric environments?
- What processes govern the differences in surface-atmosphere interactions that lead to significant gradients in atmospheric properties in the multiple environments surrounding Baltimore?
- How well can our current numerical modeling systems reproduce these gradients and associated processes? Can we improve earth system models to simulate the Baltimore atmospheric environment with more fidelity?
To get to the answers, the team will collect what it calls impact and process measurements.
Impact measurements are tied to conditions that directly affect residents, such as microclimate, air quality, or street flooding in a particular area. “Those are the properties we want to get right in order to understand the environment people live in,” said Davis.
Most of ARM’s data will be process measurements, he said. These measurements will help scientists determine whether they are getting the right answers in models for the right reasons.
Davis said his BSEC colleagues have found that wealthier neighborhoods have more existing climate and air quality measurements, so they are focused on putting instruments in lower-income parts of Baltimore. The plan could evolve as the BSEC team hears more from stakeholders in the city.
The project’s community engagement team, led by professors Tonya Sanders Thach and Samia Kirchner (Morgan State), Genee Smith (Johns Hopkins), and Lisa Iulo (Penn State), has gathered a steering committee that includes a broad array of community members and representatives of city government to guide the scientific effort. The steering committee, in turn, connects BSEC, and now CoURAGE, with a diverse cross-section of Baltimore residents to engage in knowledge co-generation, citizen science activities, and educational programs.
Other Penn State faculty who are part of CoURAGE are Kelly Lombardo, Natasha Miles, Ying Pan, John Peters, and Scott Richardson.
ARM’s last urban campaign, the TRacking Aerosol Convection interactions ExpeRiment (TRACER), took place around Houston, Texas, from October 2021 through September 2022. Led by Penn State alum Michael Jensen, a meteorologist at Brookhaven Lab in New York, TRACER studied the effects of aerosols on storms in the Houston area. Jensen is now a co-investigator for CoURAGE.