U.S. scientists say they have developed a technique to measure atmospheric levels of pollution, including soot, with satellite technology even when skies are cloud-covered. While clouds typically impair a remote-sensing
satellite’s ability to detect pollution levels closer to the ground, University of Iowa scientists say their new technique enables them to calculate particle concentrations by measuring the degree to which those pollutants affect the properties of the clouds above them. After calculating the number of droplets in the clouds using satellite data, they say, researchers assimilate those results with a numerical model that estimates particle concentrations by describing the interaction between the aerosols and the clouds. “This technique can directly improve predictions of near-surface, fine-mode aerosols — such as coal-fired electric generating plants and wood-fueled cooking stoves — responsible for human health impacts” and low-cloud solar heating, said Greg Carmichael, lead author of the study published in the Proceedings of the National Academy of Sciences.