BAR HARBOR — From weather forecasting to climate change research, many scientific endeavors depend on data collected by instruments carried high into the atmosphere by balloons and launched from sites around the world.
The person in charge of launching a key instrument at six of those locations is Bar Harbor resident Donna Holdridge. She is in the Environmental Science Division of Argonne National Laboratory, which is part of the U.S. Department of Energy.
She is responsible for an instrument called a radiosonde, which measures air temperature, humidity, barometric pressure, wind speed and direction, solar radiation and aerosols, which are tiny particles in the atmosphere. As the balloon rises, the radiosonde takes measurements at various levels in the atmosphere and transmits that information to a receiver on the ground.
The program that Holdridge is part of has three fixed launch sites: near Billings, Okla.; in Barrow, Alaska, and on an island in the Azores off the coast of Portugal. There also are three mobile launch facilities that can be taken virtually anywhere in the world.
Starting in September, one of them will be on an icebreaker in the Arctic Ocean that will freeze into the ice and then move along with it for 13 months. The balloon launches will be part of the Multidisciplinary Drifting Observatory for the Study of Arctic Climate.
Occasionally, those launching weather balloons can encounter challenges that have nothing to do with weather or technology. In 2012, launching had to be suspended on the island of Gan in the Maldives because of civil unrest.
Scientists can apply to use any of the balloon launch facilities and to have the instruments that are carried aloft collect data for their specific research purposes. The data is often used in creating weather forecasting or climate research models.
Holdridge said one reason scientists find it so useful is that the balloon-borne radiosondes take measurements in the atmosphere as they rise through it.
“There are radars and lasers that look up and satellites that look down,” she said. “But we get a data point every 30 feet in the atmosphere. Radiosonde data is extremely important because of its unique characteristic, [providing] high resolution data in the vertical.
“We also use radiosonde data to verify the earth-based remote sensing that looks up and the satellites looking down. Scientists can use that data to help tweak those [other] measurements.”
Holdridge said most of the scientists she works with are doing research related to climate change.
“They’re looking for specifics and trying to pinpoint items that drive climate change, like methane gas, greenhouse gases, water vapor and aerosols,” she said. “There are all kinds of research. It’s a huge field and it’s extremely important.”
As part of overseeing balloon launch sites, “I go between the scientists and the field operations to make sure the scientists are getting what they want,” Holdridge said. “We want to be sure that everything is working smoothly and the data is getting out.”
The six balloon launch facilities have a total of 12 launch systems. Eleven are operated manually; the one in Barrow is robotic.
“It launches weather balloons by itself; we just have to put them in,” she said.
Holdridge, who holds a master’s degree in atmospheric science from the University of Illinois, said she has always been interested in meteorology.
“I used to track the weather when I was a kid.”
Her employer, Argonne National Laboratory, is in Lemont, Ill., a suburb of Chicago. Since moving from there to Bar Harbor a couple of years ago, she has been doing much of her work from home.