Planning, Coordinating and Communicating: The Science Behind Winter Storm Chasing Experiments

by Abby Graf

As the snowstorm headed through New York on February 24, one professor at Stony Brook University in Stony Brook, New York spent the hours leading up to it preparing his students to head right into the storm.

Brian Colle, atmospheric science professor at Stony Brook University, is part of many operations in NASA’s Investigation of Microphysics and Precipitation for Atlantic Coast-Threatening Snowstorms (IMPACTS).

Whether it’s preparing a team to operate radars and mobile trucks, launching weather balloons, or flying in the cockpit of one of two aircraft used in the experiment, Colle’s job deals with the fun of coordinating and communicating, and the heart of the mission: science. IMPACTS aims to understand the precipitation mechanisms within snowstorms. The campaign uses two aircraft, ground-based radars, weather balloons, computer simulations, and airborne instruments to help answer questions about how snowstorms form and develop, and how to better predict them.

“One of my jobs is serving as the liaison between the teams,” said Colle. “We start with a briefing the morning of, then I’m making sure I know the plan of the day. I’m coordinating, sending emails, making sure the radar truck is ready. As the mission goes along, I’m in contact with the teams the whole time, making sure we’re collecting data. The job isn’t finished until the storm is over.”

Using Mobile Radar Trucks at Key Locations to Capture Data 

Colle sent teams of students out midday on February 24 to prepare for the overnight storm. One of the teams operates the mobile radar truck that has a Skyler-2 radar on it, which sends out pulse signals every few seconds to collect observations about the atmosphere from lower altitudes, providing high-resolution data from the large geographic regions it samples. “This is the next generation of radars; [helping us] understand rapid storm evolution,” said Colle.

Radar truck parked in a snowy lot with instruments on the back.
The Stony Brook University radar truck deployed during a storm. The instruments on the back of the truck provide data from the Skyler-2 radar, snow size particle sizes from the Parsivel instrument, as well as pressure, temperature, humidity, wind direction, and wind speed of the storms they sample. Photo courtesy of Brian Colle.

The truck is also outfitted with a Parsivel instrument, which is a vertically pointed radar that samples the sizes of snowflakes or raindrops, along with a standardized weather instrument package including thermometers, gauges, pressure sensors, and more. Some of the team headed up to the storm hours before it began to find a location with good visibility in all directions. The goal is to have an area where trees and buildings are not blocking the sensing instruments. While collecting data would’ve begun around 1 a.m., internet issues prevented the team from getting the experiment running, but they have collected a great amount of data from past storms. 

Launching Weather Balloons in the Depths of the Storm

Back at Stony Brook University, Colle organized a group of students to launch weather balloons on campus to measure temperature, pressure, and humidity at different altitudes. An instrument package is attached to the balloon and can “communicate” with a computer on the ground, sending data back as the balloon rises in the air.

A group of students prepares to launch a weather balloon from a snowy field.
A group of Stony Brook students getting the weather balloons ready for a past storm on January 28, 2022. The instruments are tied to strings attached to the balloons, including a parachute and GPS system that provides the location of the balloon. Around 8 kilometers (5 miles), the communication drops off and contact is lost with the system. Photo Courtesy of Brian Colle.

These balloons are launched from a radar truck, which is also equipped with instruments to measure snowflake characteristics. The team started collecting data hours before the two aircraft reached the storms. The P-3 aircraft flies directly into the storm, with instruments aboard to collect data and images from various altitudes. This gives scientists a deeper look at the microphysical properties of the storm, while the ER-2 aircraft flies at roughly 65,000 feet, capturing data with six remote-sensing instruments from above the clouds. The ER-2 arrived at the storm around 4:30 a.m., but the P-3 faced mechanical issues that delayed its launch until the morning of February 25.

The Full Flight Experience

Though not on the P-3 flight this time around, Colle has had the opportunity to fly in the cockpit of the aircraft a few times the past two months, including the February 17 snowstorm in the Chicago area. This falls under his one of many roles but is one of the reasons he joined this mission early on. Interested in studying snowstorms for years, being in the cockpit of the plane during these storms is a lot of fun for Colle. He’s the mission scientist when on the plane, helping interpret the data collected, modify flight tracks, communicate any changes to the pilots, and helping with coordinating the instruments on the plane to make sure everything is functioning and communicating. 

One of the lessons he’s learned is how the pilots navigate the busy airspaces. In populated areas like Chicago or New York, there are a lot of planes taking off, flying, and landing, requiring the pilots to coordinate where the aircraft is headed. It requires a team effort to figure out how to best orient the aircraft. 

With a radar snapshot showing the storm being sampled by the P-3 aircraft, Colle snaps a selfie in the cockpit of the plane. Photo Courtesy of Brian Colle.
With a radar snapshot showing the storm being sampled by the P-3 aircraft, Colle snaps a selfie in the cockpit of the plane. Photo Courtesy of Brian Colle.

“It’s awesome to be a part of the mission. For many years we didn’t have these opportunities. In the past, I’d take measurements on the ground, collecting snowfall and looking under a microscope at the crystal shapes and habits. Looking at data in real-time, looking out the window, and then interacting with the pilots and hearing what they have to deal with…it’s a continuous science experiment and participating in regions we haven’t sampled before has been very exciting,” said Colle.

As IMPACTS winds down its science experiments this winter, Colle and the rest of the team are looking forward to their opportunities next time around. Winter storms aren’t always the easiest to sample, and the scientists are constantly learning. But the instances in which challenges and difficulties occur only make Colle more confident that the data collected this year will give them better opportunities for improvement next year.

Storm Chasing Scientists Fly Into the Clouds to Understand Winter Snowstorms

By Abby Graf

Imagine the feeling of flying on an airplane. Smooth sailing, clear skies, not a cloud in sight. It’s a relaxing ride that many take for work or recreational travel. Now imagine flying through clouds, with the turbulence of different intensities. While some sink and hold onto their seats, others view it like a rollercoaster ride with their adrenaline pumping. Christian Nairy and Jennifer Moore know a thing or two about that.

Nairy and Moore, two atmospheric science graduate students at the University of North Dakota, are part of NASA’s Investigation of Microphysics and Precipitation for Atlantic Coast-Threatening Snowstorms (IMPACTS). Their job is to operate probes on one of two aircraft used in the experiments. The P-3 aircraft that houses their airborne office flies directly into the snowstorms, allowing the instruments Nairy and Moore operate to measure snow particles and atmospheric properties within the storm clouds.

The P-3 aircraft on the tarmac at NASA Wallops.
The P-3 aircraft at NASA Wallops on February 3 before a science flight. Credit: Vidal Salazar

IMPACTS is the first comprehensive study of snowstorms in the Northeastern United States in 30 years. The campaign combines satellite data, ground-based radars, weather balloon launches, computer simulations, and airborne instruments to understand snowstorms. The goal is to develop greater comprehension of winter storm formation and development by using several instruments that examine the microphysical characteristics of snow particles at various temperatures and altitudes. The data collected during the multi-year IMPACTS campaign can help advance the future of snowstorm forecasting and predictions.

“If we understand the microphysics of the clouds, what we’re seeing, when we’re seeing them, and how we’re seeing them, it gives scientists in other disciplines a better understanding of what they’re studying,” said Nairy. The IMPACTS experiments will provide robust datasets about winter snowstorms for scientists to analyze and incorporate into their own research.   

Nairy and Moore have spent the last few months based at NASA’s Wallops Flight Facility in Virginia, spending their days troubleshooting problems and revamping the nine probes that are on each flight. When a storm is in the forecast, it’s go time. They arrive at the hangar to prepare the probes, computers, and flash drives that will accompany their research in the air. An hour before the plane takes off, they board the P-3 and continue prepping the cloud probes.

All but one of the probes hangs off the tips of the plane’s wings, away from the propellers, each having its own job: taking high-definition photos of ice particles, measuring the total amount of water (both in liquid and ice form),  measuring the size of full and partial snow particles, and sampling shattered particles. These data-collecting tools can sample over 30 million particles in a single eight-hour flight alone.


Close-up images of snow particles captured by one of the probes on the P3.
A few of several particle images that the probes captured. Dependent upon the temperature and humidity at which they’re formed, some are “Bullet Rosettes” which are star-patterned, near the top of cold clouds; There are also hexagon-shaped particles, a pencil-shaped particle with hexagons at each side, a conglomeration of “plates” that are connected and more. Photos courtesy of Christian Nairy taken on the PHIPS Instrument.

“The whole point is to measure as much as we can when it comes to particles, concentration, sizes and particle habits,” says Moore. “We want to further our understanding of these storms and why they dump snow over the Northeast.”

Probes hanging off the wing of the plane.
The left wing of the P-3 aircraft. The probes capture data in different ways, some particles entering directly into their openings, some read by lasers, and more. Photo Credit: Christian Nairy
Probes hanging off the wing of the P3.
The right wing of the P-3 aircraft with its probes. Credit: Christian Nairy

Once the plane takes off, the team settles in for eight hours of flying and collecting data. Flying through the clouds isn’t always smooth sailing, though. Sometimes there’s turbulence and sometimes the storm quickly changes from snowflakes one minute to liquid water droplets the next. The transitions are quick, but the technology that captures these changes furthers the researchers’ understanding of how snowstorms work. While much of the flight involves looking at data in real-time, there are downtimes where conversation and collaboration can happen. The team chats with other researchers onboard, cracks jokes, takes notes of what they’re seeing and communicates with the IMPACTS HQ ground team at NASA Wallops.

IMPACTS Principal investigator Lynn McMurdie is on the ground at NASA Wallops as the flights take place. While the planes cruise at 300 mph at various altitudes within the storm, she’s constantly communicating with the teams, directing them to sample certain parts of the storm – like snow bands and when to make in-flight adjustments.

Snow bands are narrow structures in the atmosphere that are created by the storm itself. These banded structures tend to cause heavy snowfall. Not all storms produce these bands, however, and sometimes the bands don’t dump lots of snow, which furthers the importance of understanding just why, how, and when they do or don’t form. 

“We decide where to fly based on forecasts of our storm of interest,” McMurdie shares. “We tend to draw a line or box of where we want to do our sampling, usually going across any banded structures from one side to the other. Going across the snow bands gives us variability in and outside of the band.” 

Sampling snow bands with variability offers researchers’ an improved understanding of how the distribution of snow varies from storm to storm. It’s dependent upon two factors: storm strength and location. There are times when snow bands will drop many inches of snow within a short period of time, but other times when there’s only a light dusting of snow.  Sampling from within and outside of the band, and at different altitudes, helps the team see the whole picture of precipitation and snow production.

Christian Nairy and Jennifer Moore seated at their in-flight computers in the P3 aircraft.
Jennifer Moore (left) and Christian Nairy (right) are seen here operating the monitors and looking at data that their nine cloud probes produce. Photo Courtesy of Christian Nairy.

“The more data we can get, the better we can predict and understand. It’s so important to try and fly in every storm we possibly can,” Moore says. “[The snow storms] can be really impactful, even if it’s an inch or two. You think you understand them, but then you actually get into the science of it. You learn so much more when you’re actually experiencing it.”

As the eight-hour flight prepares to land, Nairy and Moore’s work isn’t done. As soon as the P-3 touches down, the probes are shut off and covered, the data is downloaded to computers, and a post-flight briefing occurs. The two graduate students update and maintain the probes to ensure they’re ready for their next storm-chasing flight. And then it’s time to call it a day.

Up, up and away: Launching Balloons in a Blizzard

by Sofie Bates

Andrew Janiszeski and Troy Zaremba blow up a weather balloon in a dark hotel lobby. The weather was calm last night when they drove into Plymouth, Massachusetts, but this morning a blizzard is raging outside. Snow is piling up in the hotel parking lot, wind gusts are near 70mph, and the power is out – but they have a job to do.

Janiszeski and Zaremba, two graduate students at the University of Illinois at Urbana-Champaign, are one of several teams deployed throughout the northeastern United States to launch weather balloons during the approaching snowstorm. While the teams launch weather balloons from the ground, two NASA aircraft will fly overhead to study the storm from a different vantage. The experiments are part of NASA’s multi-year Investigation of Microphysics and Precipitation for Atlantic Coast-Threatening Storms (IMPACTS) mission, which is the first comprehensive study of snowstorms across the Eastern United States in 30 years. 

Satellite image of snowfall over the northeastern U.S.
The nor’easter dumped snow on the northeastern United States on January 28-29 and brought hurricane force winds and blizzard conditions to some states. Image by NASA Earth Observatory / Lauren Dauphin using MODIS data from NASA’s Aqua satellite.

Janiszeski and Zaremba bundle up and step out into the blizzard to prepare for the first balloon launch of the day. They bury a communications antenna in a snowbank next to their van and attach a small device, called a radiosonde, to the balloon with tape and zip ties. If all goes well, the radiosonde will measure the balloon’s position as well as the temperature, pressure and humidity at different altitudes as the balloon rises into the sky. This data will help the scientists understand the atmospheric conditions of the storm and how they change with altitude.

Andrew Janiszeski prepares to launch a weather balloon in a winter snowstorm.
Andrew Janiszeski prepares to launch a weather balloon near Geneseo, New York on a previous deployment for IMPACTS. Hanging below the weather balloon is the radiosonde, which will collect data as the balloon rises and then parachute back down once the balloon pops. Photo courtesy of Troy Zaremba.

They walk the balloon out of the hotel lobby. Double check that the communications antenna and radiosonde are working. Then they let the balloon go.

“It went fifteen feet up, caught a gust of wind, did a loop, dove down, almost hit a car, rag dolled around a tree, went over a gas station, and popped,” said Janiszeski. They tried again with another balloon. Same thing – pop! Hesitant to sacrifice more balloons to the winds, Janiszeski and Zaremba called the IMPACTS Headquarters team to report that they couldn’t launch.

Snow piles up in the hotel parking lot in Plymouth, Massachusetts where Janiszeski and Zaremba are launching weather balloons. Photo courtesy of Andrew Janiszeski.
Snow piles up in the hotel parking lot in Plymouth, Massachusetts where Janiszeski and Zaremba are launching weather balloons. Photo courtesy of Andrew Janiszeski.

Meanwhile at IMPACTS Headquarters, based at NASA’s Wallops Flight Facility located on the eastern shore of Virginia, scientists monitored the weather and coordinated with the various teams on the ground and in the air. Their goal is to fly the two aircraft – the ER-2 aircraft that flies above the storm clouds and the P-3 aircraft that flies within them – in a stacked formation, one above the other, providing a look at the storm from different perspectives. The team also plans the flights so that the aircraft pass over the teams launching weather balloons and the teams using ground-based radars. 

“We’re trying to coordinate all of the equipment to get a nice cross section of the storm. But the storm doesn’t sit still for us, so sometimes we have to adjust our plans,” said Bob Rauber, Director of School of Earth, Society and Environment at the University of Illinois at Urbana-Champaign and one of the assistant flight planners for IMPACTS. There are a lot of factors to consider, though: clearance from the Federal Aviation Administration (FAA), weather forecasts, where the storm is moving and points of interest in its path, and last-minute changes for the aircraft and ground teams – including problematic weather balloon launches.

The NASA P-3 Orion aircraft preparing to take off from NASA’s Wallops Flight Facility.
The NASA P-3 Orion aircraft preparing to take off from NASA’s Wallops Flight Facility. Photo courtesy of Andrien Liem.

By early afternoon the winds had subsided to around 40 mile per hour gusts at the balloon launch site in Plymouth, said Janiszeski, so he and Zaremba decided to attempt another launch. They tied the radiosonde to the weather balloon, adding extra zip ties and duct tape for good measure. Then they walked it out of the hotel lobby, took a breath, and let it go.

As soon as it was released, the balloon was taken by the wind. It flipped once, twice, three times, and Janiszeski’s hope plummeted. But then the balloon righted itself and kept rising, and rising, until it was impossible to see. 

“It was a miracle,” said Janiszeski. “I really thought we were going to get a whopping zero balloons up at the beginning of the day.” But from there on out, the balloon launches were largely successful, he said. The duo got five successful balloon launches before the storm moved away from Plymouth. 

“This was, without the remotest doubt, the most severe conditions we’ve experienced during IMPACTS,” said Janiszeski. “I was getting a little pessimistic, but five radiosondes in a storm like that… We’ll take it as a win.” 

Mission (almost) Impossible: SHARC

Part of the SHARC team–including members from MARS (Mobile Aerospace Reconnaissance Systems), JAXA, SCIFLI, RSD and ESPO – in front of a NASA Gulfstream, G-III, aircraft at Adelaide Airport, South Australia, in the early morning hours following the team’s overnight dress rehearsal flights.

Richard von Riesen, Ron Dantowitz, Michael Legato, Brent Johnson, Joe Sanchez, Jr., David Zimmermann, Christian Lockwood, Nick Newman, Satoshi Nomura, Mac O’Conor, Hideyuki Tanno, David Hudson, Shunsuke Noguchi, Brian Lula, Yiannis Karavas, James Scott, Carey Scott, Jr., Rob Conn, Jennifer Inman, Zev Hoover, John Bombaro, Jr., Jhony Zavaleta, Caitlin Murphy. Not pictured: Bill Ehrenstrom, Kurt Blankenship, Katelyn Gunderson, Johnny Scott, Jr., David Fuller, Taylor Thorson, Matt Elder, Kevin Shelton, Rob White, Ken Cissel. Credit: NASA

By Katrina Wesencraft

As project manager for NASA’s Scientifically Calibrated In-flight Imagery (SCIFLI) group, Dr. Jennifer Inman is used to managing complicated logistics and solving problems ahead of her team’s deployments. Someone needs a new laptop? No problem. A research plane needs new window panels? OK!

The SCIFLI team – which specializes in in-flight imaging – collects data used to predict the aerodynamics of spacecraft launches, flights, parachute deployments, and atmospheric re-entries. In November 2020, they were due to put their skills to work in Australia, observing JAXA’s Hayabusa2 sample return capsule, with pieces of asteroid Ryugu on board. The international mission was called the SCIFLI Hayabusa2 Airborne Re-entry Observation Campaign, or SHARC.

Dr. Inman’s team would image the return capsule – one of the fastest human-made objects to ever fly through Earth’s atmosphere – while flying high above the landing site, Woomera in South Australia, nearly 300 miles north of Adelaide. It was her responsibility to get the SCIFLY team, and all their scientific instruments, to the site.

But the COVID-19 pandemic has a way of putting a wrench into even the most meticulous plans. As countries closed their borders and travel came to a screeching halt, Dr. Inman found herself in a tangled web of changing regulations both at home in the U.S. and abroad.

“It was like Whac-A-Mole, solving one problem at a time,” she said. “And the bad days were days where moles that I’d already whacked, popped their heads back up.”

The SHARC team selected an airliner-style plane, the NASA DC-8 based out of Armstrong Flight Research Center, to carry out their observations. But there was a major problem – the DC-8 was due to have an engine replaced before their trip. However, the maintenance facility was shut down because of the pandemic. The aircraft wasn’t going to be ready in time for the mission.

“We ended up scrambling. And where we settled was that we were going to use two of NASA’s Gulfstream III aircrafts,” Inman said. “But it meant we had to redo everything. All of our plans, all the engineering and analysis.”

The Gulfstream III is much smaller than the DC-8. The gimbals – specially engineered mounts used to secure scientific instruments in the aircraft – didn’t fit the smaller cabins and had to be completely redesigned and rebuilt. The mission computers were also too big. Dr. Inman had to order NASA-approved laptops – a relatively small purchase, but one that can take months to be approved.

Making matters worse, the scientific instruments used to observe the sample return capsule couldn’t ‘see’ through the Gulfstream III jets’ windows – no UV light could pass through them, and their multiple panes would have resulted in images with multiple reflections.

“We ended up borrowing some aircraft windows and window frames, like the actual hardware that got epoxied into the airframes,” said Inman. “We borrowed those from Armstrong, some of them, and had to fabricate additional windows and frames using Armstrong’s design.”

SHARC scientists Ron Dantowitz (left) and Zev Hoover (right) of MARS, Scientific, Inc., prepare an optical window for integration with one of the NASA Gulfstream G-III aircraft prior to deployment to South Australia. Credit: NASA

Pandemic restrictions were difficult for collaborators from Japan, too. During normal times, JAXA colleagues would have come to the U.S. to integrate their scientific instruments into the aircraft and perform system checks on their equipment. They ended up having to ship their equipment to Johnson Space Center, in Houston, where they entrusted a NASA team with those tasks. The next time JAXA scientists got to see their equipment again would be in Australia.

And all of this happened before even leaving the U.S. Getting the research planes and essential personnel to Australia in time for the mission were also huge hurdles.

In addition to visa requirements, the team needed special authorization to enter Australia and to travel across internal, police-controlled borders. The rapidly changing situation meant that travel regulations weren’t well-defined, particularly for the NASA aircraft that needed to make several international fuel stops along their route to Australia. Initially, the team didn’t know what types of COVID-19 tests would be accepted or where they could obtain them.

Jhony Zavaleta, mission support specialist from the Ames Earth Science Project Office (ESPO) was concerned that the team wouldn’t be able to provide their test results within a set time frame. “Some of our guys were getting tests, and sometimes it would be 48 hours or maybe a week until results came back,” he said. “There was a lot of uncertainty.”

NASA Ames’ ESPO (Earth Science Project Office) team, Caitlin Murphy and Jhony Zavaleta, welcome N992NA, one of the two Gulfstream G-III mission aircraft, upon its arrival from Johnson Space Center to Adelaide, South Australia. This aircraft carried several imaging instruments from JAXA and NASA. Credit: NASA

For the personnel not traveling on the NASA planes, getting to Australia wasn’t any easier. The team faced the prospect of a 42-hour journey, via Qatar, where there were more requirements to provide negative tests and additional documentation. There were also very few flights scheduled – and many of those were being canceled.

As the clock ran down, the team was running out of options. Zavaleta had to charter an aircraft to carry the key personnel to Australia.

Dr. Jay Grinstead, SHARC’s principal investigator from NASA Ames, was impressed by the last-minute efforts: “People were really interested in seeing this mission succeed. So they made concessions and made funding available.”

The team conducts a final pre-flight briefing just prior to the observation flight. From left to right: Joe Sanchez, Jr., Caitlin Murphy, Michael Legato, Katelyn Gunderson, Jennifer Inman, Brent Johnson, Hideyuki Tanno, Carey Scott, Jr. Credit: NASA
The team conducts a final pre-flight briefing just prior to the observation flight. From left to right: Joe Sanchez, Jr., Caitlin Murphy, Michael Legato, Katelyn Gunderson, Jennifer Inman, Brent Johnson, Hideyuki Tanno, Carey Scott, Jr. Credit: NASA

Zavaleta and a colleague from ESPO made it to Australia ten days early to allow them to set up ahead of the full team’s arrival. “Nobody from our team had been to Australia before to plan,” he said. “We didn’t know what the situation on the ground was.”

Normally, key details like where to buy supplies and the team’s transportation would be sorted six months in advance. But now, the team didn’t know what restrictions would be in place by the time they arrived, who would be supporting them, or even what hangars their planes would be in. The instruments also needed to be calibrated, and Zavaleta had to make sure the hangar operators were aware of the team’s needs and willing to work off-hours. It was an incredibly tight turnaround.

Despite the numerous setbacks, the mission was a huge success, largely due to the collaboration between Dr. Inman’s team, the aircraft organizations at both Langley Research Center and Johnson Space Center, ESPO, NASA Headquarters, JAXA, the Australian Space Agency, and other Australian officials. Dr.Grinstead said, “We really could not have pulled this off without our international partners.”