Volcanic ash may have a bigger impact on the climate than we thought

by University of Colorado at Boulder, Sep 11, 2020 in ScienceDaily

“They saw some large particles floating around in the atmosphere a month after the eruption,” Zhu said. “It looked like ash.”

She explained that scientists have long known that volcanic eruptions can take a toll on the planet’s climate. These events blast huge amounts of sulfur-rich particles high into Earth’s atmosphere where they can block sunlight from reaching the ground.

Researchers haven’t thought, however, that ash could play much of a role in that cooling effect. These chunks of rocky debris, scientists reasoned, are so heavy that most of them likely fall out of volcanic clouds not long after an eruption.

Zhu’s team wanted to find out why that wasn’t the case with Kelut. Drawing on aircraft and satellite observations of the unfolding disaster, the group discovered that the volcano’s plume seemed to be rife with small and lightweight particles of ash — tiny particles that were likely capable of floating in the air for long periods of time, much like dandelion fluff.

Journal Reference:

  1. Yunqian Zhu, Owen B. Toon, Eric J. Jensen, Charles G. Bardeen, Michael J. Mills, Margaret A. Tolbert, Pengfei Yu, Sarah Woods. Persisting volcanic ash particles impact stratospheric SO2 lifetime and aerosol optical properties. Nature Communications, 2020; 11 (1) DOI: 10.1038/s41467-020-18352-5