Cloud Formation Suppressed by Biogenic Organic Emissions

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Researchers have found evidence that near-ground biogenic emissions of organics suppress cloud formation in cool-temperate forests in autumn, providing clues to how global warming will affect cloud formation and the overall climate.

Researchers have found evidence that near-ground biogenic emissions of organics suppress cloud formation in cool-temperate forests in autumn, providing clues to how global warming will affect cloud formation and the overall climate.

Submicron atmospheric aerosols, although they are not so visible, play a pivotal role in the climate system. They cause temperature variations by scattering or absorbing sunlight, while they also act as cloud condensation nuclei (CCN). Consequently, they can impact cloud cover and the precipitation process. Organic matter, which constitutes up to 90 percent of aerosols, is often attributable to biogenic sources.

Many questions, however, remain as to how differences in variation and quantity of biogenic organics affect aerosols and cloud formation in a cool temperate forest which has vegetation highly susceptible to climate change.

At the Tomakomai Experimental Forest, a cool temperate forest in northern Japan, the researchers of Hokkaido University collected submicron atmospheric aerosols one week at a time for each sample for around two years, resulting in 52 samples. They then analyzed the chemical compositions and CCN activities of the aerosol samples.

Read more at Hokkaido University

Image: Hokkaido University's Tomakomai Experimental Forest in Autumn with Mt. Tarumae (left) and Mt. Fuppushi (right) in the background. (Credit: Hokkaido University)