有机气体有助于云的形成

Clouds. They’re fluffy, white, and full of mystery. [Song lyric: I really don’t know clouds at all.] Although scientists may have a better handle on clouds, even they don’t know it all. Because a new study shows that atmospheric gases can help clouds form in a way no one had ever considered. That’s according to a report in the Proceedings of the National Academy of Sciences. [Neha Sareen et al., Surfactants from the gas phase may promote cloud droplet formation]

Clouds form when water vapor condenses around dust particles in the atmosphere. But there’s more to the sky than just water and dust. The atmosphere is loaded with trace amounts of a variety of carbon-containing gases.

To see how these organic gases might affect cloud formation, scientists mixed them with aerosolized particles, and then loaded the particles into an experimental cloud chamber. And they found that the gases coat the particles and make them more “soapy,” which enhances their ability to form cloud droplets.

Because clouds reflect incoming sunlight, the findings could lead to better climate models. And maybe another look at clouds. [Song lyric: I’ve looked at clouds from both sides now.]

—Karen Hopkin