Particle physics experiments

The Science Behind Winter Storm Chasing Experiments – NASA Earth Expeditions

by Abby Graf

As the blizzard swept through New York on Feb. 24, a Stony Brook University professor in Stony Brook, New York, spent the hours leading up to preparing his students to head straight into the storm.

Brian Colle, a professor of atmospheric sciences at Stony Brook University, is involved in numerous operations as part of NASA’s Atlantic Coastal Snowstorm Microphysics and Precipitation Survey (IMPACTS).

Whether preparing a team to operate radar and mobile trucks, launching weather balloons, or flying in the cockpit of one of the two aircraft used in the experiment, Colle’s work focuses on the pleasure of coordinating and communicating, and the heart of the mission: science . IMPACTS aims to understand the mechanisms of precipitation in snowstorms. The campaign uses two aircraft, ground-based radar, weather balloons, computer simulations and airborne instruments to help answer questions about the formation and development of snowstorms, and how to better predict them.

“One of my jobs is to serve as a liaison between teams,” Colle said. “We start with a briefing the morning of, then I make sure I know the plan for the day. I coordinate, I send e-mails, I make sure the radar truck is ready. As the mission progresses, I am in contact with the teams all the time, making sure that we are collecting data. The job isn’t done until the storm has passed.

Use of mobile radar trucks at key locations to capture data

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

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

The truck is also equipped with a Parsivel instrument, which is a vertically pointed radar that samples the size of snowflakes or raindrops, as well as a set of standard meteorological instruments including thermometers, gauges, sensors pressure, etc. Some team members headed into the storm a few 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 do not block detection instruments. While data collection reportedly began around 1 a.m., internet glitches prevented the team from launching the experiment, but they collected a large amount of data from past storms.

Launch weather balloons into the depths of the storm

Back at Stony Brook University, Colle organized a group of students to start weather balloons on campus to measure temperature, pressure and humidity at different altitudes. A set of instruments 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 prepare to launch a weather balloon from a snowy field.
A group of Stony Brook students prepare the weather balloons for a past storm on January 28, 2022. The instruments are attached to ropes attached to the balloons, including a parachute and a GPS system that provides the location of the balloon. At around 8 kilometers (5 miles), communication breaks down 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 the characteristics of snowflakes. The team began collecting data hours before the two planes reached the storms. the P-3 plane flies directly into the storm, with instruments on board to collect data and images at different altitudes. This gives scientists deeper insight into the microphysical properties of the storm, as the ER-2 aircraft flies at about 65,000 feet, capturing data with six remote sensing instruments above the clouds. The ER-2 arrived at the storm around 4:30 a.m., but the P-3 encountered mechanical problems that delayed its launch until the morning of February 25.

The complete flight experience

Although he is not on the P-3 flight this time around, Colle has had the opportunity to fly in the plane’s cockpit a few times over the past two months, including during the snow storm. February 17 in the Chicago area. It’s his role among many others, but it’s 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 great fun for Colle. He is the mission scientist while on the plane, helping to interpret collected data, alter flight paths, communicate any changes to pilots, and coordinate the aircraft’s instruments to ensure that everything works and communicates.

One of the lessons he’s learned is how pilots navigate busy airspace. In populated areas like Chicago or New York, there are many planes taking off, flying, and landing, requiring pilots to coordinate the direction of the plane. It takes a team effort to figure out the best way to orient the plane.

With a radar snapshot showing the storm sampled by the P-3 plane, Colle takes a selfie in the plane's cockpit.  Photo courtesy of Brian Colle.
With a radar snapshot showing the storm sampled by the P-3 plane, Colle takes a selfie in the plane’s cockpit. Photo courtesy of Brian Colle.

“It’s great to be part of the mission. For many years we did not have these opportunities. In the past, I took measurements on the ground, collecting snowfall and observing under a microscope the shapes and habits of the crystals. Watching the data in real time, looking out the window and then interacting with the pilots and hearing what they have to deal with…it’s an ongoing science experiment and participating in regions we haven’t sampled before has been very exciting,” Colle said.

As IMPACTS wraps up her science experiments this winter, Colle and the rest of the team look forward to their opportunities next time. Winter storms aren’t always the easiest to sample, and scientists are constantly learning. But the instances where challenges and difficulties arise only make Colle more confident that the data gathered this year will give them better opportunities for improvement next year.