air quality

A watershed year for 911�� sustainability data

Jennifer Pocock — Mon, 30 Jun 2025 16:14:43 +0000

A watershed year for 911�� sustainability data Jennifer Pocock Mon, 06/30/2025 - 12:14

In This Story

An intercollegiate study, in partnership with 911��'s Facilities, analyzes the effects of campus events and weather on local air and water quality.

Maryam Zavareh tests a water sample from the Fairfax Campus. Photo provided.

Major events at 911��, like graduation ceremonies, basketball games, and Mason Day are high-water events in student life. But how do they affect the campus ecosystem?

For the past year, with support from the Institute for a Sustainable Earth (ISE), groups of undergraduate and graduate engineering students have worked with university Facilities to sample air and water quality measurements at eight spots across campus. They are studying how human-centered activities like special events and campus construction projects, along with natural events like heavy rainstorms, affect the urban campus environment.

“Fairfax is a very active campus in terms of construction,” said Maryam Zavareh, an expert in environmental engineering who earned her PhD from 911�� in 2021. “They’re always building something or something is always going on for students.”

Weather is also a factor, she pointed out, and so are projects like rain gardens (also called best management practices or BMPs). “Rain can affect a stream’s turbidity and its dissolved oxygen in a negative way, while BMPs can help quality.”

As part of her PhD program, Zavareh started taking measurements around Mason Pond and campus streams. She wanted to use machine learning to predict water quality patterns in conjunction with the Maggioni Research Group, a lab run on campus by water resources engineering expert Viviana Maggioni, an associate professor in the Sid and Reva Dewberry Department of Civil, Environmental, and Infrastructure Engineering, and air quality expert Lucas Henneman, an assistant professor in the department. With this ISE grant, Maggioni called Zavareh back to run the project as a consultant.

Starting in May 2024, a new group of students each semester have learned to gather data in the field, work with the instruments, and calibrate them for accurate readings.

“One of the advantages of this project is that students get to go into the field and take measurements,” said Dinesh Neupane, a PhD candidate in civil and environmental engineering and student leader for the project. “That was lacking in my previous programs—students stayed in the labs.”

Neupane is excited for the opportunity to measure air quality—something that hasn’t been done yet on campus—in addition to water. “We want to calibrate the ground data we measure with satellite imagery to see if we can get the imaging to accurately take the readings for us,” he said.

So far, Neupane said that campus events do not have a major effect on water quality. “We think big gatherings will have an effect on air quality, but we don’t have that data yet. We’re still in the process of setting those instruments up.”

This year’s work by Zavareh, Neupane, and their student teams lays the groundwork for future students to analyze their data and carry the research forward. They are proving that ISE’s Mason as a Living Lab program offers great insights.

Topics

Mason as a Living Lab

Institute for a Sustainable Earth (ISE)

Department of Civil Environmental and Infrastructure Engineering (CEIE)

environmental engineering

civil engineering; stormwater infrastructure; climate variability

water resource engineering; civil and infrastructure engineering

International Space Station experiment may improve climate science predictions

tdonnel — Wed, 05 Mar 2025 20:33:24 +0000

International Space Station experiment may improve climate science predictions tdonnel Wed, 03/05/2025 - 15:33

The earth’s atmosphere is full of aerosols, both from natural events such as volcanic eruptions and human activity such as burning fossil fuels. The Department of Mechanical Engineering’s Jeffrey Moran is planning an experiment on the International Space Station (ISS) to better understand what factors drive aerosols from place to place, which could enable climate scientists to predict the overall effect of aerosols on climate with less uncertainty.

“Aerosols can exacerbate or alleviate climate change, depending on what they’re made of,” said Moran. “For example, carbon soot aerosols can intensify warming by absorbing sunlight that would otherwise be reflected back into space. Other aerosols, such as sulfates, can reduce warming by increasing solar reflection.”

Aerosols’ location also matters—for example, many aerosols can act as nuclei for clouds to form, and this can exert an overall warming or cooling effect in different locations. “The overall effect aerosols will have on the climate is hard to predict, partly because we don’t have a full understanding of what factors cause them to migrate from one place to another,” said Moran.

Jeff Moran. Photo by Evan Cantwell/Office of University Branding

The experiment is specifically examining whether and how temperature gradients influence the movement of certain aerosols through the atmosphere. Moran’s team, along with his collaborator, David Warsinger of Purdue University, and a team of undergraduate students there, are designing an apparatus inside of which aerosols of a certain size can be observed across a temperature gradient. They recently completed a fit check to confirm that the apparatus both fits in the ISS microscope’s enclosure and that the aerosol container, or cuvette, is transparent enough for observation.

Moran said the experiment could help climate researchers understand how temperature differences, which are common in the atmosphere, cause particles to move through the air.

“If the effect of the temperature gradient is significant, it could give us a clearer indication of how aerosols will affect the climate in the future. It could also inform geoengineering proposals, which would seek to mitigate climate change by intentionally injecting aerosols into the atmosphere, since we would have a better sense of where they will go, and thus what their overall effect will be,” said Moran. “It could also offer a way to control aerosols on the ground, for example, by using thermophoresis to collect virus-laden aerosols from the HVAC systems of hospitals.”

The team’s apparatus includes a 3D-printed stage with hot and cold fixtures on either end. A prototype cuvette is mounted between them in the enclosure of the microscope. Crucially, the apparatus fits snugly inside the microscope enclosure, which is necessary for the experiment to be carried out in microgravity.

Crystals of the NaCl sample (see Figure 2), imaged using the 2x objective on the Keyence BZ-X810 microscope (nearly identical to the one on the ISS).

“The capstone team did a wonderful job,” Moran added.

The team tested the cuvette’s transparency by placing sodium chloride, table salt, inside it and taking images with the microscope. To verify airtightness, the team placed the salt-filled cuvette in a beaker of water and observed that the salt (which is soluble in water) remained in its solid form, indicating no water had leaked into the cuvette.

“We obviously don’t want to pose an inhalation hazard to the ISS crew, so it’s important that the particle samples be packaged on the ground in containers that are as close to airtight as possible,” said Moran.

“These images are a promising first step, as they demonstrate that aerosols in the range of sizes we are considering (10-100 µm) can be clearly imaged through the prototype cuvettes using a microscope nearly identical to the one currently on the ISS,” said Moran.

From here, Moran, Warsinger, and a new team of students will work to improve the cuvette fabrication and polishing procedures. They will also test alternative cuvette materials such as quartz, which may be thinner and more transparent, thereby allowing them to take clearer images at a higher magnification. This would enable them to examine even smaller aerosol particles. The team is also refining the design of the cuvettes to improve optical transparency and minimize the thickness of the windows.

“We want to make the cuvettes smaller, bringing the hot and cold surfaces as close together as we can get them, because it's not really clear how steep of a temperature gradient we're going to need to induce motion,” Moran explained.

In addition, the team is finalizing their choice of aerosol materials to send to the ISS. They are currently set on using carbon soot, sodium chloride, and silica due to their relevance in atmospheric aerosols and climate science.

“Carbon soot is one of the most important materials in terms of climate, because it is known to intensify warming,” Moran said, adding that sodium chloride enters the atmosphere as sea spray and can drift to faraway locations, such as the North Pole, intensifying the warming that is already happening at a rapid pace there. Silica is a common ingredient in sand and thus a common material in the atmosphere as well. Overall, the team aims to strike a balance between having materials that can be studied safely on the ISS while also yielding insights into aerosol dynamics in the atmosphere.

The College of Engineering and Computing will cover Moran’s progress leading up to the experiment in space, scheduled for fall 2025 or spring 2026.

In This Story

Jeffrey Moran

Topics

mechanical engineering

Space experiment could teach us how aerosols move in the atmosphere

tdonnel — Mon, 05 Aug 2024 19:45:22 +0000

Space experiment could teach us how aerosols move in the atmosphere tdonnel Mon, 08/05/2024 - 15:45

As a child, Jeffrey Moran was fascinated by outer space. Now, he is designing an experiment to be carried out on the International Space Station (ISS) in 2025.

"I was obsessed with space as a kid,” said the mechanical engineering assistant professor. “The house I grew up in is still filled with drawings of Space Shuttles. Airplanes and spacecraft were a major reason I chose engineering when I got to college."

Jeffrey Moran. Photo by Office of University Branding

When the National Science Foundation issued a call for proposals to conduct research projects on the ISS to benefit life on earth, Moran jumped at the chance and wrote a proposal that was successfully funded. His grant-winning experiment will examine the extent to which aerosols (small particles suspended in air) move through air in response to a temperature difference (meaning the air on one side is hotter than on the other). This phenomenon—migration of particles in response to temperature gradients—is known as thermophoresis.

“It all started with a brainstorming session I had with a collaborator,” said Moran, describing the conversation he had with Purdue University colleague David Warsinger, who is a co-investigator on the NSF-funded project. “In contrast to most of my projects, which consider particles that move through liquids, we considered a simple question: what mechanisms could we use propel small particles through air?”

“My lab focuses on developing self-propelled particles for applications like water treatment or drug delivery," said Moran. "It’s a new and exciting field, but it’s so far been restricted entirely to water environments. No one has tried to develop a swimmer that moves in air. That ties into climate change, because aerosols are everywhere in the atmosphere—both because of human activity, like burning fossil fuels, and because of natural events like volcanic eruptions—and we don’t have a solid understanding of the net effect aerosols will have on the climate.”

Thermophoresis occurs in both liquids and gases, but it’s difficult to study in gases on earth because of the influence of gravity. Another challenge with studying particle migration in temperature gradients on earth is that the heated air tends to rise (for the same reason that hot air balloons rise), making it difficult to know exactly why the particles are moving. Doing the experiment in space allows scientists to run their tests with a minimal influence of gravity, to purely examine the effect of temperature on aerosols without creating air currents, which inevitably form when one tries to create a temperature difference in air because hot air tends to rise (which is the reason hot air balloons rise).

“We’re going to send various aerosol samples into space, each in a specially designed cuvette, for the astronauts to test,” Moran explained. “There’s a microscope on the ISS, and the astronauts will place our cuvettes into an apparatus we’ve designed that applies heat and cold to opposite walls of the cuvette. The astronauts will then use the microscope to determine how fast the particles move towards hot or towards cold. We expect that aerosols made from different materials will respond differently to the temperature gradient, but nobody knows how. That’s what’s exciting about this experiment – no one has made these types of measurements before.”

“For the last part of the project, we’re going to see whether some particles with asymmetric properties might generate the propulsive temperature difference on their own,” Moran continued. “These particles will have half of their surface coated in a metal. The other side is an insulating material,” Moran explained. “When we shine a light on them, the metal side efficiently absorbs the light and heats up relative to the insulating side. The hot hemisphere heats the air near it, and that creates a temperature difference in the surrounding air. This could help us understand whether odd-shaped aerosols in the atmosphere move on their own, without the need for a temperature difference.”

Before the experiment can be carried out, Moran and his team need to determine the experiment’s parameters as well as the materials required.

“This is very much a work in progress,” said Moran. “We're figuring out exactly which particles we want to send to the space station [based on] which materials matter the most to climate scientists [and] what the biggest question marks are.”

He mentioned, among other examples, the possibility of experimenting with carbon soot.

“Carbon soot is produced by burning fossil fuels, and it’s known to be harmful to the environment because it absorbs sunlight efficiently,” he said. “Another source of carbon soot, increasingly common in this era, is from rocket launches.”

“It’s pretty well established that carbon soot overall intensifies warming,” he said. “It's black, so it tends to absorb sunlight efficiently. This leads to a net warming effect on the atmosphere, but it's not clear how much it moves in thermophoresis (how much it moves in temperature differences).”

Moran looks forward to working with the National Aeronautics and Space Administration (NASA) to refine the plan. An early step in this project will be for Moran and his team to travel to Texas to examine a replica of the equipment available to scientists on the International Space Station.

The College of Engineering and Computing will cover Moran’s progress as the project moves forward.

In This Story

Jeffrey Moran

Learn more about 911��'s College of Engineering and Computing

Topics

mechanical engineering

College of Engineering and Computing

What to know about air quality alerts

Mary Cunningham — Thu, 08 Jun 2023 18:59:19 +0000

What to know about air quality alerts Mary Cunningham Thu, 06/08/2023 - 14:59

In This Story

Amira Roess, PhD, MPH

Air quality alerts are currently raised higher than usual along the eastern United States due to traveling smoke from Canadian wildfires. Epidemiologist and professor in Mason’s College of Public Health Amira Roess discusses what you need to know about air quality alerts and how it affects your health.

Why are wildfires in Canada affecting the air in northern Virginia?

The wildfires that are raging in Northeast Canada approximately 800 miles from those of us in the DMV (D.C.-Maryland-Virginia) are generating tremendous amounts of smoke and pollutants. Satellite imagery shows smoke blanketing our area and many other parts of the United States.

These fires are the worst that Canada has seen and are being fueled by a lingering high-pressure system over Canada for weeks now that has led to high temperatures and low precipitation. In addition to the high-pressure system, there is another low-pressure system in the northeast. Together these two systems are creating something like a pathway for smoke to move along over parts of the U.S.

How do I know what the air quality is?

There are many weather apps that now include air quality. The air quality scale most in use in the U.S. ranges from 0 to 300 and colors are assigned to the different ranges. The colors to look out for are:

Orange (101-150) is considered unhealthy for some populations and individuals who are vulnerable should avoid being outdoors.
Red is considered unhealthy (151-200) for all individuals, and everyone should limit their time outdoors, avoid strenuous activity, and wear a good quality N95 or K95 mask.
Purple (201-300) is considered very unhealthy for all groups and, in addition to the precautions taken under a red alert, everyone should stay indoors when purple alerts are issued.
Maroon (301) is considered hazardous, and we rarely see this.

Due to the smoke that is being generated by the Canadian wildfires currently, we are seeing red and purple alerts during much of the day. You can learn more about what these alerts mean from the U.S. Air Quality Index.

What can you do to protect yourself?

When air quality is suboptimal (orange), certain individuals should avoid being outdoors. Those with underlying conditions, especially respiratory and heart conditions, the elderly and young children should avoid being outdoors because they are at risk for the worst health impacts from poor air quality. When air quality is poor (red) or very poor (purple), which is what we are seeing right now, then all individuals should avoid being outdoors.

If you must be outdoors when air quality is poor or very poor, limit your time and you should wear an N95 or a KN95 mask. Remember that we want to make sure we use clean masks. These masks cannot be washed and once they are wet or dirty, they are a lot less effective, so discard them. Wearing scarves or bandanas is not at all effective at protecting you. It's very important to limit your time outdoors.

If you have pets that need to go out, take them out for short bathroom breaks only. Do not take them on long walks or have them do any strenuous activities. Remember that pets cannot wear masks as this can cause them to panic and can hinder their breathing. Late in the evening air quality tends to improve.

If you start to develop respiratory or other symptoms due to spending time outdoors, you should contact a health care provider immediately.

In addition to not going outside, what can you do to stay safe on a red or purple air quality day?

Limit how much outdoor air comes into your home.

Keep your doors and windows closed while air quality is poor or very poor.

When you are home, you can do small things to keep the indoor air quality good, such as not lighting candles and not using gas stoves, if you can avoid it.

Make sure your HVAC system is working efficiently. This means making sure that you change the filters as the manufacturer recommends and that you stick to your HVAC service schedule.

If you have neighbors or loved ones that are immune compromised or in the vulnerable groups mentioned above, check up on them and help them avoid being outdoors. You can do small things like taking their garbage out or walking their pets.

Are we going to see more of these situations?

In general, as we've seen a shift towards higher temperatures in our hemisphere, we are going to see more wildfires and other climate change-related disasters.

Topics

College of Public Health

air quality

A watershed year for 911�� sustainability data

In This Story

Topics

International Space Station experiment may improve climate science predictions

In This Story

Related Stories

Topics

Space experiment could teach us how aerosols move in the atmosphere

In This Story

Related Stories

Topics

What to know about air quality alerts

In This Story

Topics

air quality

A watershed year for 911���� sustainability data

In This Story

Topics

International Space Station experiment may improve climate science predictions

In This Story

Related Stories

Topics

Space experiment could teach us how aerosols move in the atmosphere

In This Story

Related Stories

Topics

What to know about air quality alerts

In This Story

Topics

A watershed year for 911�� sustainability data