High concentrations of tiny pollution particles near the Sierra Nevada Mountains in the western United States invigorate cloud formation and boost snowfall on the mountains, according to a new study by scientists at the Department of Energy's Pacific Northwest National Laboratory and their collaborators at Colorado State University.

That happens because the particles lead to the creation of many more shallow clouds in the California Central Valley and foothills, changing local air circulation. Latent heat is given off when the cloud droplet forms, which strengthens the transport of moisture to the windward slope.

The newly discovered phenomenon by PNNL scientist Jiwen Fan and colleagues offers insights for other mountainous regions of the planet that are polluted, such as in China and India.

More details about the work, which was published recently in Atmospheric Chemistry & Physics, are available in this article.