HUNTSVILLE, Alabama -- When severe thunderstorms roll in, residents are urged to head indoors, if they're outside, or stay indoors.
However, a group of scientists and students from the University of Alabama in Huntsville jump in their "car" and drive up to New Market to get up close and personal with the nasty weather.
"That's what we do here," said Larry Carey, an associate professor of atmospheric science at UAH.
Carey is among more than 100 researchers from the National Center for Atmospheric Research, NASA and other agencies and universities including Penn State and Colorado State who are studying thunderstorms in North Alabama, Colorado and the Texas-Oklahoma panhandle to discover what happens when clouds suck air up from the Earth's surface high into the atmosphere.
Called the Deep Convective Clouds and Chemistry Project, or DC3, the study began this spring and continues through June 30.
The research will measure how thunderstorms transport, produce and process chemicals that form harmful ozone, according to the National Oceanic and Atmospheric Administration. The study will explore what happens in air just beneath the stratosphere, a little-explored region that influences the Earth's climate and weather patterns, NOAA said in a statement.
North Alabama, Colorado and Oklahoma were chosen partly because of their differences, including types of storms that form over them and the different types of industrial and vehicle pollution, researchers said.
Chemicals from industry and vehicles are sucked high into storms, where they are involved in the production of ozone. Researchers want to compare how the process occurs in all three states, and how pollution is carried by the storms.
The DC3 project includes aircraft: The National Science Foundation/NCAR's Gulfstream V, a NASA DC-8 and a Dassault Falcon 20E, operated by the German aerospace agency.
The Gulfstream research aircraft will undertake the bulk of the high-altitude measurements; the DC-8 will fly as low as 1,000 feet above the ground, measuring air flowing into the cloud bases as well as the chemistry of the surrounding air; the Falcon is joining the project for three weeks and flying especially close to storm cores at high altitudes.
There also are ground-based instruments including dual-Doppler research radars, lightning mapping arrays and balloon launches to measure the state of the atmosphere from the ground to the stratosphere.
"We use advanced radar, ARMOR with WHNT and radar on the truck," Carey said.
So, why are they setting up in New Market?
"Trees, mountains and hills are not friends of radar," Carey said. "We found the area in New Market and send staff and students up there."
He said the UAH group is part of the ground component of the study, which he says is as much a chemistry experiment as a meteorological study.
"Our goal is to provide a context of what thunderstorms are doing to redistribute chemicals - you can call this pollution," he said.
DC3 explores how thunderstorms change the chemical makeup of the atmosphere, forming upper-atmosphere ozone, a greenhouse gas that has a particularly strong warming effect high in the atmosphere.
"When thunderstorms form, air near the ground has nowhere to go but up," said NCAR scientist Mary Barth, a principal investigator on the project. "Suddenly you have an air mass at high altitude that's full of chemicals that can produce ozone."
Ozone in the upper atmosphere plays an important role in climate change by trapping significant amounts of energy from the sun. However, ozone is difficult to track because, unlike most greenhouse gases, it is not directly emitted by either pollution sources or natural processes. Instead, sunlight triggers interactions between pollutants such as nitrogen oxides and other gases, and those reactions create ozone.
These interactions are understood at the Earth's surface, but they have not been measured at the top of the troposphere, the lowest layer of the atmosphere, which is just below the stratosphere.
"Lightning produces nitric oxide which helps ozone production," he said.
Ozone, itself, is beneficial at some altitudes and also damaging at others, Carey said.
"Ozone is important to protect us from ultraviolet rays," he said. "But it's also a greenhouse gas at certain levels."
That's the keystone of the study.
"We are pretty sure lightning is the largest natural source of nitric oxide," said NOAA National Severe Storms Laboratory scientist Don MacGorman. "It is important to know the naturally occurring contribution."
Carey said when storms come in, it gets hectic with the aircraft aloft collaborating with staff in the field and those in the office (the DC3 control room for North Alabama is at the National Space Science and Technology Center at UAH).
"On any given day, we have 10 to 15 people running stuff, not counting the people behind the scenes," he said. "It's literally a three-ring circus with Colorado, Texas-Oklahoma and Huntsville all doing the same thing - for seven weeks straight."
But, Carey said the work is "fun."
"We're in awe of (the storms) and try to understand it," he said. "It's a lot of fun that keeps us busy till the end of the month."