"Some global observations seemed to indicate that the direct effect of aerosols on solar radiation hardly exists, suggesting that aerosols only indirectly - by contributing to cloud formation - reduce warming," says lead-author Tobias Vetter from the Potsdam Institute for Climate Impact Research. Co-author Frank Wechsung: "Our analysis of the outstandingly continuous now confirmed previous assumptions about the aerosol effect - so this effect is correctly represented in current climate models."
In the second half of the past century, power generation from lignite-fueled power plants emitted a lot of particulate matter into the air. After the collapse of the East German socialist state, the "German Democratic Republic", these emissions rapidly reduced. The amount of solar radiation getting to the ground in Potsdam changed accordingly. "Only measurements that run unchanged for at least several decades allow retrospective analyses like the one we did, so obviously we'd wish for a continuation of these long-term Potsdam measurements," says Wechsung. Some of the local observation series started as early as 1893.
Weblink to the article: http://onlinelibrary.wiley.com/doi/10.1002/2015JD023669/abstract
Weblink to the Potsdam longterm measurements: https://www.pik-potsdam.de/services/infodesk/telegraphenberg/suering-haus/long-term-meteorological-station
