Ground-based observations reveal that the amount of light-scattering aerosols in the stratosphere has been increasing substantially in the past decade, probably due to a dramatic rise in coal-fired power plants worldwide.
Aerosols in the stratosphere, the layer of the atmosphere between altitudes of about 10 kilometers and 50 kilometers, come from three main sources: major volcanic eruptions, upwelling of the lower atmosphere at tropical latitudes and the slow upward drift of aerosols created by industrial emissions worldwide. Now, a nearly two-decade-long lull in large volcanic eruptions has enabled scientists to discern that anthropogenic aerosol levels in the stratosphere are on the rise, says Michael E. Trudeau, an atmospheric scientist with NOAA’s Earth Systems Research Laboratory in Boulder, Colo. He and his colleagues report their finding in the Aug. 16 Geophysical Research Letters.
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