Friday, June 29, 2012
Every day, through the National Oceanic and Atmospheric Administration, 102 sites in the United States, Caribbean and the Pacific launch a large, white balloon into the air. There’s a device, called a radiosonde, attached to the balloon; it’s a battery-powered instrument, and its sensors measure and transmit profiles of air pressure, temperature and relative humidity from the Earth’s surface up to approximately 20 miles into the sky. It also obtains data for wind direction and speed.
One of the launch sites is the Bismarck National Weather Service, located near the airport. Weather personnel there have been launching these balloons since about 1939.
At first, they only launched the balloon at night, but after two years, they started to launch two balloons, one at night and one at noon. Just imagine: a hot summer day, an endless blue sky, a field of wheat swaying in the breeze, and a white balloon floating upwards high overhead.
Eventually, though, the radiosondes drop back to the earth. And on this date in 1941, North Dakotans were on the hunt for the fallen equipment. After all, if they found it, and sent the machine back to Washington, they would receive a $1 recovery reward. This was a good payout for the time and effort, and it proved fruitful especially to those up to 150 miles southeast of Bismarck, though the instruments sometimes travelled even farther – one was found 225 miles away in Watertown, South Dakota.
F. J. Bavendick was director of the Bismarck Weather Service, and he estimated that with this bounty for the radiosondes, about 90 percent of the 700 some instruments the Bismarck station had launched were found and returned.
Today, the Bismarck Weather Service still launches the balloons, but the radiosondes are considered expendable, and fewer than 20 percent are returned. There’s no longer a reward, but their return is still welcomed, as the National Weather Service will recondition and re-use them.
Dakota Datebook written by Sarah Walker
The Bismarck Tribune, Monday, June 29, 1941