Atmospheric System Research

A Pennsylvania researcher builds and tests a novel device for measuring the precursor gases in seed-particle formation

It has been said that the Earth has two oceans. One is combined from the expansive salty seas that cover 70% of the planet. The other ocean is the atmosphere, where vast decks, wisps, and puffs of clouds are the chief visible signs of Earth’s water cycle—a continuous surface-to-sky-to-surface exchange of water in the form of vapor, liquid, and ice.

All the clouds rolling and folding above us contain a big fraction of the atmosphere’s water. So, it is useful to ask how clouds are made.

Welcome to the research world of Coty Jen, an associate professor of chemical engineering at Carnegie Mellon University in Pittsburgh, Pennsylvania. Among other things, she is interested in precursor gases that evolve (“nucleate”) into the seed-like particles needed for cloud droplet formation. Worldwide, this process of atmospheric nucleation generates 50% of the particles that condense into clouds.

However, the chemical and physical mechanisms of how new particles become aerosols remain an uncertainty in models that simulate a changing climate. Aerosols are tiny atmospheric particles (hybrids of gases, solids, and water) that make clouds and precipitation possible.

Some clouds gather in decks thousands of miles wide. But the gases from which they grow are tiny—as little as 1 angstrom across. That’s the width of an atom.

Most precursor gases, says Jen, are a little larger, though still “as small as two molecules huddled together.”

Spotlighting Sulfuric Acid

Jen’s primary research target is sulfuric acid, the most prominent of the precursor gases that initiate cloud-forming particles. Challengingly, nucleation reactions take place at very low concentrations of precursor gases—so low that sometimes they are only measurable in parts per quadrillion. (Carbon dioxide, an atmospheric gas everyone has heard of, is measured in parts per million.)

At the same time, other gases either enhance or suppress sulfuric acid nucleation. These compounds are so diverse (water, amino acids, oxidized organics, and more) that they further complicate attempts to model nucleation. (Jen has even studied the role of compounds like ammonia from penguin “emissions” in the Southern Ocean.)

She leads a Carnegie Mellon laboratory group looking for ways to observe, measure, and model atmospheric nucleation driven by sulfuric acid.

To this end, Jen is principal investigator in a 2021-2025 project funded by the Atmospheric System Research (ASR) program at the U.S. Department of Energy (DOE).

In the Field

The field portion of Jen’s ASR investigation, in May and June 2024, was a small ARM campaign called Vertically Resolved Nucleation Precursors at SGP (VRNPS).

For VRNPS, she made two basic decisions. One was to conduct the work at the Central Facility of the Southern Great Plains (SGP) atmospheric observatory in Lamont, Oklahoma. SGP has 50 core surface instruments operated by Atmospheric Radiation Measurement (ARM), a DOE Office of Science user facility.

The other decision was to deploy some custom instrumentation aboard an ARM tethered balloon system (TBS). Tethered balloons were an ideal platform for Jen’s mission to sample the gas precursors of particle nucleation. Such balloons, strung with small instruments like paper lanterns, operate at altitudes up to about 1,000 meters (3280 feet). That’s high enough to examine atmospheric conditions at the base of some clouds.

The operational limitations of TBS (instruments must be light and compact) fit right in with one of Jen’s key ASR ambitions—to develop a device for measuring atmospheric sulfuric acid that is compact, research-grade, medium-cost, and easy to power up.

At SGP in 2023, one member of Jen’s group, chemical engineering PhD student and National Science Foundation (NSF) Graduate Fellow Dominic Casalnuovo, briefly tried out a prototype of the novel measurement technique aboard a TBS. Jen called it “a very low-stakes deployment” that revealed a few problems.

Her team tried again (with better success) in June 2024, when the final prototype went aloft.

Counting Particles

The custom instrument from Jen’s lab is a reactive condensation particle counter. It’s about the size of a lunchbox, with a thermos-shaped nucleation flow reactor that measures concentrations of sulfuric acid. The counter is designed to minimize the effects of high relative humidity, which can suppress particle formation.

Chongai Kuang, an atmospheric scientist and aerosols researcher at Brookhaven National Laboratory, helped develop the particle counter for TBS flights and was at SGP to conduct complementary measurements of freshly formed particles aloft.

In the GIF (guest-instrument facility) at SGP, Jen’s team set up larger instruments for measuring particle sizes and characterizing gas and particle chemistry.

Back home in Pennsylvania, the team is using their SGP data to test a nucleation potential model designed to predict nucleation rates even in the world’s chemically complex atmospheric systems. The model addresses one big challenge: Sulfuric acid combines with many other compounds linked to different rates of nucleation, all of which vary regionally across the world.

A Utility Knife, Please

Jen grew up in suburban Wisconsin, captivated early on by the idea of building things. At age 4, she remembers asking her father for a utility knife. All the better to make house dioramas and three-dimensional (3D) models of all kinds.

By middle school, “I was super into 3D modeling and CNC (computer numerical control) milling,” as well as working with wood, says Jen. Later, during a collaborative product design class in high school, she did all the model work and machining.

Given such interests, naturally, one early dream was to become an architect—and even today “every so often I would still like to do that,” says Jen.

Instead, before applying to colleges, she embraced the idea of engineering, her father’s profession. “It’s very broad,” says Jen, with plenty of opportunities for building things.

By the time Jen enrolled at Columbia University (B.S. Chemical Engineering, 2010), she had acquired a newfound fascination with the chemistry of long-chain polymers. Undergraduates are expected to join a research team, but Jen hit a dead end with the polymer chemistry faculty.

“No one wrote me back,” she says.

But then the magic happened: V. Faye McNeill, a new faculty member starting an atmospheric chemistry laboratory from scratch, needed a student who was a woodworker, too.

Bingo.

“I got to build all this stuff,” says Jen, “and learn about cool instrument principles.”

As for switching to atmospheric science, “no one had to persuade me,” she says. “I am fortunate enough to find almost everything interesting.”

Locked into Aerosols

At the University of Minnesota-Twin Cities (M.S. Chemical Engineering, 2013; PhD Mechanical Engineering, 2015), Jen joined an aerosol group when her doctoral work began. Her dissertation contained the seeds of the research she loves to do now: a mass spectrometry investigation of sulfuric acid and links to nucleation processes in the atmosphere.

In 2015, Jen joined the University of California, Berkeley, as an NSF postdoctoral research fellow, digging into speciating organic aerosols in the Amazon Rainforest and characterizing fresh and aged emissions from biomass burning events. (The evolution of aerosols in the atmosphere is called “aging.”)

At the time, Jen briefly considered shifting away from research on aerosols, “but I’m locked in now,” she says. “It worked out well.”

As a faculty member at Carnegie Mellon, which she joined in 2018, Jen brings a shade of her younger, build-happy self.

Her group often focuses on making instruments robust enough for field deployments in rugged places and sensitive enough “to understand the (atmospheric) processes happening there,” says Jen.

She credits her husband, a climate modeler, with inspiring much of her own instrument design. For that, she has to counter the hard realities of most laboratory instruments: They are large, expensive, “and crazy power-intense,” says Jen, who has tried to leverage her ASR project to develop a small, battery-powered, field-ready device for measuring sulfuric acid and its behavior in the upper boundary layer.

Meanwhile, “I don’t know if I’m helping the planet,” says Jen. “But I like to think we are understanding how it’s changing in some way, creating knowledge to adapt, and developing technology to address problems.”

Those planetary changes rely on the fine details of precursor gases, particle nucleation, and other data to explain what happens in the atmosphere.

“How can we come up with effective engineering technologies for climate change,” Jen asks, “if we don’t understand the fundamental ways the atmosphere is behaving?”

Three representative ARM small field campaigns investigate aerosol formation, ship exhaust, and evolving albedo

Compared to their larger counterparts in atmospheric research, small field campaigns involve fewer people, smaller budgets, and tighter schedules. However, these time- and money-constrained efforts still take on big scientific questions.

Small campaigns are regularly supported by the U.S. Department of Energy’s (DOE’s) Atmospheric Radiation Measurement (ARM) user facility. ARM operates three fixed and three mobile atmospheric observatories in climate-critical regions of the world.

By ARM’s definition, small campaigns cost no more than $300,000. Funding covers only the use of ARM facilities, instruments, and expertise, not the research itself.

Mike Ritsche at Argonne National Laboratory in Illinois refers to small campaigns as “short-term campaigns” because they typically require just weeks or a few months to complete. (However, ARM does have several multiple yearlong small campaigns.)

Ritsche is a member of ARM’s Infrastructure Management Board (IMB), which reviews small-campaign proposals from scientists worldwide. ARM accepts proposals for small campaigns throughout the year.

What ‘Small’ Means

In addition to their short-term nature, ARM small campaigns often:

• generate data complementary to ARM’s instruments
• involve early career researchers
• require only a few people, unlike typical large-scale ARM campaigns
• field-test instruments still under development.

Over the years, ARM has supported deployments of guest instruments developed by both academic researchers and by small businesses funded by DOE’s Small Business Innovation Research program.

Small campaigns are popular among new and veteran ARM users, says Ritsche.

Since 2014, ARM has conducted 314 campaigns, according to the ARM Data Center at Oak Ridge National Laboratory in Tennessee. Most are small. In fiscal year 2024, the IMB approved 25 small campaigns for ARM’s three fixed-location observatories: 19 in Oklahoma, four in Alaska, and two in the Azores. Here’s a look at three of those campaigns.

The Chemistry of New Particle Formation

In May and June 2024, Coty Jen, an associate professor of chemical engineering at Carnegie Mellon University in Pennsylvania, used surface and balloon-mounted instruments at ARM’s Southern Great Plains (SGP) atmospheric observatory in Oklahoma to measure gases that lead to new particle formation.

The chemical and physical mechanisms of how new particles become aerosols remain an uncertainty in models that simulate a changing climate. Aerosols are tiny atmospheric particles—hybrids of gases, solids, and water—that make clouds and precipitation possible.

During a small campaign called Vertically Resolved Nucleation Precursors at SGP (VRNPS), Jen and three Carnegie Mellon PhD students deployed a prototype reactive condensation particle counter on ARM’s tethered balloon platform. About the size of a lunchbox, the counter measures concentrations of sulfuric acid that “nucleate,” or initiate, cloud-forming particles.

The SGP’s Guest Instrument Facility also housed Jen’s larger project instruments. They measured the concentration and size of atmospheric aerosol particles and characterized gas chemistry. The group’s main measurement targets were sulfuric acid, related precursor gases, and newly formed particles.

Precursor gases react to form seed-like particles for making cloud droplets. But they start out very tiny—some “as small as two molecules huddled together,” says Jen, whose work was funded by DOE’s Atmospheric System Research (ASR) program.

Tiny but mighty: Worldwide, atmospheric nucleation generates 50% of the seed particles that help form cloud droplets.

Such nucleation begins with gases, primarily sulfuric acid, which initiate particles in ways Jen is trying to observe, measure, and model. One challenge is that sulfuric acid combines with many other compounds. That results in dramatically different particle formation rates, which vary with changes in region and altitude.

Another challenge is that nucleation reactions take place at very low concentrations, sometimes only measurable in parts per quadrillion.

Still, tethered balloons were an ideal platform for Jen’s science mission. They have controlled rates of ascent and can pause at given altitudes. Their operational range, up to a kilometer (about 3,280 feet), is high enough in the atmosphere’s boundary layer to investigate how the vertical distribution of precursor nucleation gases changes with meteorological conditions.

Tethered balloons restrict the size and weight of instruments. But that fit nicely with Jen’s goal of developing a small research-grade device that makes it affordable to measure atmospheric sulfuric acid in the field. Her prototype cost about $20,000, a fraction of the cost of larger, more complex laboratory instruments.

Jen’s team also used the SGP opportunity to test a nucleation potential model. It’s designed to predict nucleation rates even chemically complex atmospheric systems across the world.

Tracking Ship Tracks

Historically, ships zigzagging across the world’s oceans have burned dirty, high-sulfur diesel fuel. The resulting emissions of sulfur, other gases, and carbonaceous aerosols created a lot of air pollution in the open ocean. But the same emissions also generated cloud-like ship tracks whose brightness and reflectivity had a global cooling effect.

In 2020, the U.N. International Maritime Organization implemented new global fuel standards to address (or help reduce) sulfur pollution in the open ocean.

Since then, scientists have been studying how these regulations are changing the levels of sulfur in the atmosphere; how those changes affect marine clouds and their radiative properties; and how changes in shipping emissions are linked to observed increases in temperatures over the ocean.

Among them was a pair of British scientists that tapped DOE resources.

Plymouth Marine Laboratory chemical oceanographer Mingxi Yang and University of Manchester atmospheric composition professor Hugh Coe led a small ARM field campaign called Impact of Changing Ship Emissions (ACRUISE) that began in 2019 and wrapped up in mid-October 2023.

They collected data from ARM’s Eastern North Atlantic (ENA) atmospheric observatory in the Azores as part of a wider European-American inquiry into the impacts of new regulations on the sulfur content of ship fuels.

ACRUISE is also the acronym for Atmospheric Composition and Radiative forcing changes due to UN International Ship Emissions regulations, a 2019–2024 project funded by the U.K.’s Natural Environment Research Council (NERC). Yang and Coe have related but separate NERC funding awards.

“The ENA site provided a very useful platform,” wrote Yang in an email, in part because its remoteness makes it a handy place to measure the evolution of atmospheric sulfur levels in the open ocean. “We also benefited from the well-established cloud and radiation measurements.”

Starting in March 2019, “with wonderful support from the ENA team,” wrote Yang, the ARM portion of ACRUISE installed a high-volume aerosol sampler to collect 24-hour samples once a week. Local staff replaced filters and air-mailed frozen filters periodically to England for analysis of ions, sulfur isotopes, and changes in total sulfate concentrations, post-regulation.

Because of pandemic-related interruptions and changes in personnel, chemical analyses were “substantially delayed but are now underway,” he added.

Data from the ARM fraction of ACRUISE—destined to be included in a future paper, wrote Yang—will be combined with measurement sources from the larger, NERC-funded project. Those include surface sites, research aircraft, and satellites.

Also ahead, he added, are large-scale and high-resolution ACRUISE-informed models of aerosol-cloud interactions and the impact of ship emissions on clouds and their radiative properties.

More broadly, Yang sees ACRUISE as one element in unraveling “highly complex and nonlinear” aerosol-cloud interactions, he wrote, which are “the largest uncertainty in our understanding of the Earth’s radiative balance and in any future climate projections.”

SALVO 2024: Chasing the Melt

 

Jennifer “Jen” Delamere, an associate research professor at the University of Alaska Fairbanks, recently wrapped up her lead role in the final phases of a small ARM campaign called Snow ALbedo eVOlution (SALVO). This ARM- and ASR-supported mission started in Alaska in 2019 to document the snow-to-no-snow springtime transition.

During this transition, she says, very bright surfaces no longer reflect 80% of sunlight back into the atmosphere. Instead, they become predominantly dark surfaces that absorb 80% of sunlight, which warms soils, water, and vegetation.

This springtime transition turns “the arctic world from white to dark,” says Delamere. “You can go from this very white surface to—boom!—tundra within a week.”

In April, May, and June 2024, near ARM’s North Slope of Alaska (NSA) atmospheric observatory, Delamere led the final measurement stages of SALVO.

The term “albedo” (derived from the Latin word for “white”) describes the reflectivity of Earth’s surface. Changes in albedo are amplified in the Arctic, but they affect warming trends on a global scale.

The first SALVO leg, led by Delamere’s university colleague Matthew Sturm, produced one springtime investigation of evolving albedo in 2019. Delamere served as a co-investigator on that leg before leading the final two legs of SALVO, the first in 2022 and the second in 2024. Sturm was a co-investigator on the last two legs.

For 10 days in April 2024, while there was still snow cover, members of Delamere’s team were out in the field to collect benchmark data. From May 20 through June 20, they measured changing albedo on a variety of surfaces and topography.

Delamere and her 2024 SALVO team—from five to nine people, depending on work requirements—set up three instrumented transects 200 meters by 25 meters (656 feet by 82 feet) in size. Two were on tundra and one on sea ice—complex terrain covered with snow nine months of the year, where land, ocean, and sea ice meet.

To get even more data for a library of representative landscapes, Delamere and her team laid out additional study swaths about 1,500 meters (4,900 feet) long. They measured thousands of snow depths, snapped aerial photographs, and investigated drained lakes, shallow and deep melt ponds on tundra and sea ice, and various types of tundra vegetation.

The team also studied the impacts on albedo of the distinctive polygonal land features that appear when subsurface permafrost in the Arctic is exposed by the elements.

“As the team became faster and faster with measurement sequences, we were able to chase the melt,” says Delamere.

She credits special contributions from the NSA support team based at Sandia National Laboratories in New Mexico, as well as Jimmy and Josh Ivanoff, full-time observers at the NSA who work for Ukpeaġvik Iñupiat Corporation (UIC) Science.

One SALVO paper has appeared so far, in January 2024, based on 2019 and 2022 fieldwork.

In December 2024, the team plans to present a poster on surface albedo evolution at the annual meeting of the American Geophysical Union.

Nearly 8% of genetic males and 0.5% of genetic females have some form of Color Vision Deficiency (CVD)

Editor’s note: The original version of this story by Marguerite Huber appeared on the Argonne National Laboratory website.

Imagine having to do your job, but not being able to visually process the data right in front of you. Nearly 8% of genetic males and 0.5% of genetic females have some form of color vision deficiency (CVD), or the decreased ability to discern between particular colors. CVD is commonly referred to as color blindness.

Scientists use colors to convey information. Many scientists in the weather radar community have CVD, and the use and interpretation of color is an important aspect of their work. Most colormaps don’t take into account those with CVD; for instance, the maps show green next to red.

A team led by scientists at the U.S. Department of Energy’s (DOE’s) Argonne National Laboratory recently published a paper in the Bulletin of the American Meteorological Society detailing their work to create CVD-friendly colormaps that highlight important characteristics of clouds and precipitation.

DOE’s Atmospheric Radiation Measurement (ARM) user facility supported their research.

“ARM is facilitating great science, visualizations, and tools that are open to the community,” said Scott Collis, an Argonne atmospheric scientist and co-author of the paper. ​“Without ARM, none of this would be possible, and in practicing open science, ARM data, tools and software are more impactful.”

A Dedication to Inclusivity

One type of colormap, Ze, shows radar reflectivity or storm intensity. The higher the reflectivity factor, the higher chance there is for rain, hail, and more. In general, the higher the Ze, the higher the chance of public impact. These colormaps are ones most commonly seen by the general public in local weather forecasts.

Some colormaps, like Ze, are difficult for individuals with CVD to distinguish between varying types of precipitation and convection. Convection is the transport of heat and moisture by the movement of a fluid. Thunderstorms are one form of convection. Another problem with the current colormaps is that they are not perceptually uniform. Perceptual uniformity is when changes in color (lightness or color) and data values are weighted equally and do not create artificial structure.

As the scientists interacted with the community, they realized they needed to do a better job displaying data. Their work focused on finding the right color representation that was both CVD-friendly and good for the radar community. The researchers took this knowledge and created CVD-friendly Ze and velocity colormaps using Python programming language tools. They gave everything its own color, from drizzle to rain to hail. Velocity colormaps were also tested using an existing oceanography map.

“The Python programming community aims to be inclusive,” said Collis. ​“And there was this push from users to make colormaps more accessible.”

A Longer-Term Impact

The new and existing colormaps were tested on different weather events using software that visualized the data through the eyes of an individual with CVD. Comparisons were then provided to the CVD community for their input and feedback. Overall, radar researchers in the focus group agreed that the new colormaps were more interpretable than the default colormaps currently utilized.

The new colormaps are now available in a GitHub repository that is used by a variety of open-source radar software packages found in the open radar community.

To further engage the CVD community, the authors presented their colormaps at important scientific conferences around the world. The community provided feedback, tested colormaps, and helped build the library.

“Now that we have better colormaps, we know from the community that they are relevant and inclusive,” said co-author and Argonne Systems Integration Admin Zachary Sherman. ​“People have a choice to be colorblind-friendly.”

Some of the authors have personally experienced how their colormaps have impacted those with CVD. Everyone from students to conference co-chairs have expressed their gratitude for colormaps they could finally understand. Providing these CVD-friendly colormaps allows for equitable scientific visualization and inclusivity.

Going forward, the research team plans to develop more colormaps and complete additional outreach. Their goal is to build a community practice around the world.

“Radar meteorology is a unique visual science,” said Collis. ​“Scientists can see the shape in the storm that would signal strong winds or a tornado. That is why colormaps are so important to our community.”

Eventually, members of the radar community won’t be the only ones to benefit from CVD-friendly colormaps. That’s because the landscape of future meteorologists is changing. As up-and-coming students finish their studies, they are working exclusively with radar meteorology tools that feature CVD-friendly colormaps. Those types of colormaps are the norm for the next class of meteorologists.

Then, as they take on roles at local television channels, they will start to bring inclusive colormaps to general audiences through weather reports. So, one day in the near future, the general CVD population will be able to watch the morning weather forecast and be able to see, for the first time, how a colormap was meant to be seen.

 

The Department of Energy’s (DOE) Office of Science has announced that the Office of Science Graduate Student Research (SCGSR) program is now accepting applications for the 2024 Solicitation 2. 

• Deadline: Applications are due 5:00 p.m. ET on November 6, 2024.

Detailed information about the SCGSR program, including eligibility requirements and access to the online application system, can be found at: https://science.osti.gov/wdts/scgsr/.

 The SCGSR program supports supplemental awards to outstanding U.S. graduate students to conduct part of their graduate thesis research at a DOE national laboratory in collaboration with a DOE laboratory scientist for a period of 3 to 12 consecutive months—with the goal of preparing graduate students for scientific and technical careers critically important to the DOE Office of Science mission.

The SCGSR program is open to current PhD students (U.S. citizens and lawful permanent residents) in qualified graduate programs at accredited U.S. academic institutions who are conducting their graduate thesis research in targeted areas of importance to the DOE Office of Science. A full list of the research priority areas can be found here.

The research opportunity is expected to advance the graduate students’ overall doctoral thesis/dissertation while providing access to the expertise, resources, and capabilities available at the host DOE laboratories. The supplemental award provides for additional, incremental costs for living and travel expenses directly associated with conducting the SCGSR research project at the DOE host laboratory during the award period.

The Office of Science expects to make approximately 85 awards in 2024 Solicitation 2 cycle, for project periods beginning anytime between June 9, 2025 and October 6, 2025.

Since its inception in 2014, the SCGSR program has provided support to over 1150 graduate awardees from 165 different U.S. universities to conduct thesis research at all 17 DOE national laboratories across the nation.

The SCGSR program is sponsored and managed by the DOE Office of Science’s Office of Workforce Development for Teachers and Scientists (WDTS), in collaboration with the eight Office of Science research and advanced technology program offices and the DOE national laboratories/facilities, and program administration support is provided by the Oak Ridge Institute for Science and Education (ORISE).

For any questions, please contact the SCGSR Program Manager, Dr. Igor I. Slowing, at sc.scgsr@science.doe.gov.

The new ASR-supported atmospheric observatory in Alabama is scheduled to be operational by October 1, 2024

The final push is underway to open the Bankhead National Forest (BNF) atmospheric observatory for business.

Staff from the Atmospheric Radiation Measurement (ARM) user facility are working in Alabama to have the BNF’s main and supplemental sites operating by October 1, 2024.

ARM wanted to open its newest observatory earlier in the year, but the schedule had to be revised because of delays related to weather, staffing, and receipt of some key electrical components.

After receiving those items, the team turned on power at the main site on August 7 so installation can begin.

Later in the month, instrument installation will start at the main site in the forest and three supplemental sites at Courtland, Double Springs, and Falkville. Installation is currently expected to take about a week at each supplemental site and six weeks at the main site.

After the main and supplemental sites are operational, staff will continue ongoing work to prepare and set up additional BNF sites.

In reviewing ARM’s two proposed scanning radar locations outside the forest, Alabama state and tribal historic preservation officers found that they are not historic or ancestral sites.

With those reviews complete, the BNF site operations team, led by staff at Argonne National Laboratory in Illinois, now awaits an Argonne Site Office review to ensure that the proposed radar activities comply with the National Environmental Policy Act (NEPA). The act requires federal agencies, including the U.S. Department of Energy (DOE), to consider environmental effects of their proposed actions before making decisions.

Once the final step of the NEPA review is complete, the C-Band Scanning ARM Precipitation Radar and the Ka- and X-band scanning ARM cloud radars will be made operational in preparation to deliver data to users in spring 2025.

A 140-foot (42.7-meter) walk-up tower will be installed about three-quarters of a mile (1,200 meters) west of the main site. Instruments on the tower will sample a variety of properties below, within, and above the forest canopy. The current schedule is to build the tower in November, complete site development in December, and start instrument installation after the holidays in January.

ARM plans to install the instrument field for BNF tethered balloon system flights in January or February, with flights currently set for March.

Guest Instruments and Research Funding

For scientists eager to start fieldwork at the BNF, ARM expects to be able to accommodate guest instruments soon after operations begin at the main site, likely November at the earliest.

Guest instrument deployments require an ARM field campaign proposal. Because research activities at the BNF might also need U.S. Forest Service approval, ARM encourages scientists to plan ahead and submit requests early for any potential guest instrument activities.

Appendix E of the ARM Field Campaign Guidelines includes a flowchart on Page E.3 to help scientists determine if they should propose their field research activity to ARM for coordination with the Forest Service. The flowchart also indicates the timelines that scientists should expect for proposal reviews and approvals. A full breakdown of the timelines follows the flowchart.

“We look forward to hosting as many people and campaigns as proposed,” says BNF Manager Mike Ritsche.

Funding for BNF research is now available from DOE. A new DOE funding opportunity is open for Atmospheric System Research (ASR), Earth and Environmental Systems Modeling (EESM), and Environmental System Science (ESS) program science in the Southeast United States. The announcement leverages the BNF and other recent DOE investments. Learn more about the new funding opportunity.

DOE has held funding opportunities for BNF research in past funding cycles. In July, DOE announced a set of new research projects from an ASR funding opportunity issued in October 2023. One of the principal investigators, Cleveland State University’s Thijs Heus, plans to use BNF data to study contrasts in shallow and deep convection. This is in addition to a group of BNF-focused studies announced in 2023 as part of a larger set of ASR projects.

Uncrewed Aerial System Activities

The ARM Aerial Facility conducted flights of the ArcticShark uncrewed aerial system over and around the BNF from July 24 through August 7. These science and engineering flights will help the ARM Aerial Facility determine the optimal operational parameters for future missions in the area.

The ArcticShark took off from Cullman Regional Airport and flew in small to large square and rectangular patterns 6 to 34 miles from the airport. Visual observers on the ground and a chase plane in the air tracked the ArcticShark to help ensure safe operations.

During its flights, the ArcticShark collected data on humidity, temperature, cloud composition, aerosols, trace gases, and land surface properties. Data from the flights are freely available through the ARM Data Center.

ARM plans to issue a special call this fall for ArcticShark flights in fiscal year 2025 at the BNF or Southern Great Plains observatory in Oklahoma.

Story by Leah Shaffer; this article originally appeared on the Washington University in St. Louis website on July 25, 2024.

New findings will help make climate models more accurate as massive wildfires become more common

In an actively warming world, large-scale wildfires are becoming more common. These wildfires emit black carbon to our atmosphere, one of the most potent short-lived atmospheric warming agents. This is because of its strong sunlight absorption characteristics. But scientists have yet to get a handle on the extent of atmospheric warming caused by black carbon in pyrocumulonimbus (pyroCb) clouds that develop from high-intensity wildfires.

In their most extreme form, these wildfire clouds will inject smoke into the upper troposphere and lower stratosphere, where it can linger and impact stratospheric temperatures and composition for several months. Some of the details of that impact have been investigated now thanks to new research from Washington University in St. Louis’ Center for Aerosol Science & Engineering (CASE).

The research was led by Rajan Chakrabarty, a professor at WashU’s McKelvey School of Engineering, and his former student Payton Beeler, now a Linus Pauling distinguished postdoctoral fellow at Pacific Northwest National Laboratory. The study was published in Nature Communications.

“This work addresses a key challenge in quantifying black carbon’s radiative effect on the upper atmosphere,” Chakrabarty said.

The team made airborne measurements from within the upper portion of an active pyroCb thunderstorm in Washington state as part of the 2019 NOAA/NASA Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) field campaign, he added.

“We considered the full complexity and diversity of the measured black carbon size and morphology on a per-particle basis for accurate estimation of its solar absorption. What we discovered is that a pyroCb black carbon particle absorbs visible sunlight two times as much as a nascent black carbon particle emitted from smaller fires and urban sources,” he said.

The authors uniquely combined measurements of black carbon mass and the thickness of organic coatings on individual particles in the plumes with a detailed single-particle optics model. They used a numerically exact particle-resolved model to calculate the black carbon optical properties and quantified how much light those black carbon particles are absorbing (and thus how much more heat they bring to the upper atmosphere).

In addition, the work highlights the unique light absorption properties of black carbon in pyroCbs versus black carbon from wildfires that does not end up in pyroCbs and black carbon from urban sources.

The next step in this research is to take further measurements and do a more precise study of the black carbon behavior in the stratosphere.

Black carbon injected into the lower stratosphere by recent pyroCb events in Canada and Australia have traveled around the globe, persisted for months, and altered dynamic circulation and radiative forcing across large regions, Chakrabarty said. These thunderstorms are deemed responsible for 10% to 25% of the black carbon in the present-day lower stratosphere, with impacts extending to both the Northern and Southern hemispheres. Scientists are increasingly observing how much it impacts climate, but there is more to learn.

“We need more direct measurements of pyroCb black carbon light absorption measurements to better constrain climate model predictions of stratospheric warming,” Chakrabarty said.

Paper: Beeler P,  Kumar J,  Schwarz JP, Adachi K, Fierce L, Perring AE, Katich JM, Chakrabarty RK. Light absorption enhancement of black carbon in a pyrocumulonimbus cloud. Nat Commun 15, 6243 (2024) DOI: https://doi.org/10.1038/s41467-024-50070-0

DOE awards $15.4 million to improve understanding of atmospheric processes

The U.S. Department of Energy (DOE) has announced the selection of 20 innovative research projects that will receive funding through its Atmospheric System Research (ASR) program.

Eighty-eight proposals were submitted for funding under DOE Funding Announcement DE-FOA-0003194. The ASR funding opportunity, announced in October 2023, was sponsored by the Office of Biological and Environmental Research (BER) within the DOE Office of Science. The 20 ASR-recommended projects will share cumulative funding of $15.4 million over the next three to five years.

“We want to thank everyone who took the time and did the hard work to submit proposals; it is exciting to support so many new projects,” says ASR Program Manager Jeff Stehr. “The quality of these research proposals was excellent. It was a very competitive review process, and we’re excited about the atmospheric science to come.”

Stehr also noted that the project awards include four investigators and three institutions new to ASR funding and two early-career scientists. “We are pleased to welcome these new investigators and institutions to the ASR program this year,” he says. “Their contributions will enhance ASR science and drive forward our understanding of atmospheric processes.”

The 20 university-based projects will focus on observational, data analysis, and modeling research that uses observations supported by DOE’s BER program, including the Atmospheric Radiation Measurement (ARM) user facility. Each of the projects addresses one or more of the following:

• Aerosol processes at ARM sites
• Convective cloud processes
• Aerosol and cloud processes from ARM’s Eastern Pacific Cloud Aerosol Precipitation Experiment (EPCAPE)
• Mixed-phase cloud and ice cloud processes

Stehr and ASR Program Manager Shaima Nasiri expressed gratitude to those who contributed to the review process. “We want to thank the 61 members of the scientific community who stepped up to help us review these proposals. Each contributed significant time and expertise throughout the peer-review process.”

Nasiri adds that the new projects expand ASR’s footprint in the research community. “With these awards, DOE welcomes four new principal investigators and three new institutions to ASR,” she says. “It is important that funding opportunities are equitably available to all scientists and from all universities.”

As Fiscal Year 2024 funding awards are finalized, detailed information about principal investigators, project titles, abstracts, and team members will be available on the ASR projects web page.

The 20 principal investigators and their ASR-recommended projects include:

• Christine Chiu, Colorado State University – “Discovering Macro- and Micro-Physical Relations in Precipitation Efficiency and Aerosol Wet Scavenging in Warm Clouds Using ARM Observation-Model Data Cubes and Machine Learning”
• Brenda Dolan, Colorado State University – “New Insights into Precipitation Variability and Cloud Processes Using Polarimetric Radar and Cloud System-Resolving Model Simulations”
• Joseph Galewsky, University of New Mexico – “Probing Aerosol-Cloud Interactions in EPCAPE Using Measurements of Water Vapor Isotopic Composition”
• Christopher Hennigan, University of Maryland, Baltimore County – “Aerosol Acidity Across Seasons: Unveiling Dynamic Shifts in Aerosol-Cloud Processes from Regional and Urban Atmospheres”
• Thijs Heus, Cleveland State University – “Contrasting Shallow and Deep Convection over Bankhead National Forest”
• Adele Igel, University of California, Davis – “Macrophysical and Microphysical Properties and Processes in Arctic Fog”
• Matthew Kumjian, Pennsylvania State University – “Using Machine Learning to Uncover Deep Convective Cloud Processes with TRACER Observations”
• Zachary Lebo, University of Oklahoma – “Linking Convective Environments to Microphysical Processes in Updrafts and Downdrafts Using DOE ARM Data and High-Resolution Modeling”
• Gerald Mace, University of Utah – “Using ARM Data to Explore Processes Associated with Southern Ocean Cloud Feedback Using MARCUS, AWARE, and CAPE-k Data”
• Gregory McFarquhar, University of Oklahoma – “Impacts of Cloud-Aerosol-Meteorology Relations in Mixed-Phase Clouds on Radiative Fluxes Over High Latitudes”
• Mark Miller, Rutgers University – “Connecting Aerosol-Related Cloud Brightness to Turbulence using EPCAPE Measurements”
• Christopher Nowotarski, Texas A&M University – “Determining the Importance of Initiation Mechanism and Background Environment on the Evolution of Deep Convection in Varied Regimes”
• Rachel O’Brien, University of Michigan – “Generalizing Aerosol Mixing State: Synthesis from Observations and Connection to Models”
• Mariko Oue, Stony Brook University – “Investigating Microphysical and Dynamical Processes Controlling Convective Cloud Characteristics and Lifecycle within Different Aerosol and Ambient Environments”
• Pallav Ray, Florida Institute of Technology – “Exploring the Land-Sea Breeze Circulation and its Association with Moist Static Energy Using TWP ARM Observations”
• Kerri Pratt, University of Michigan – “Pristine Southern Ocean Aerosol and Cloud Processes: Coupling Single-Particle Measurements and Modeling during CAPE-k”
• David Romps, University of California, Berkeley – “Influence of Urban Features on the Vertical Development of Cumulus Clouds During TRACER”
• Joel Thornton, University of Washington – “Elucidating the Impacts of Shallow and Deep Convective Cloud Processing on Biogenic VOC-Driven particle formation and growth”
• Wendell Walters, University of South Carolina – “From Precursors to Particles: Evaluating Chemical Formation and Sources of Aerosols in the Eastern North Atlantic”
• Christopher Williams, University of Colorado, Boulder – “Identifying and Reducing Structural Errors in Parameterized Warm Rain Processes using ARM EPCAPE and ENA Observations”