Watch the explosive demise of a weather balloon

Meteorologists worldwide send hundreds of weather balloons skyward every day, but it’s not often that people get to see them burst—something that usually happens dozens of kilometers overhead. Problem solved, thanks to the images captured by a GoPro camera dangling a few meters beneath one such balloon recently lofted near Boulder, Colorado. Typically about 1.5 meters in diameter when they’re released and about 10 meters across when they burst 90 minutes or so later, the instrument-laden balloons fail at a weak spot and then shred to pieces as fissures race to a point opposite the blowout. The burst unfolds in less than one-tenth of a second, the researchers report this week in the Bulletin of the American Meteorological Society. The cloud left in the wake of the burst is a powder that prevents the inside surface of the balloon from sticking together before it’s inflated. More than 90% of weather balloons burst between the altitudes of 29 and 32 kilometers (and between temperatures of –40°C to –75°C, respectively), the researchers note. In dry regions prone to static electricity, the scientists fill their balloons with nonburning helium. But in humid areas where sparks are much less common, they’ll inflate the balloons with flammable hydrogen, which is about half as weighty and allows for faster ascents.