They are in fact remote-controlled floating weather and atmosphere data monitors. These controlled meteorological balloons, or CMETs, are light enough to drift with the wind, tracking how fast and in which direction pollution drifts in the lower levels of the atmosphere. For the first time, they survived ice-laden clouds for a total of 80 flight hours when they were launched from Svalbard this month in an ongoing project to measure pollution in the Arctic. Read More
