Volcanic aerosol impact on cirrus clouds and climate

The overarching goal of this project is to improve the representation of volcanic impact on cirrus clouds and gain better estimates of volcanic influence on climate.

Explosive volcanic eruptions can cool the climate by increasing the amount of light attenuating aerosol particles in the stratosphere. This project aims at determining how cirrus clouds are impacted by volcanic aerosol descending from the stratosphere. In a recent paper, the main applicant reports hemispheric asymmetry in cirrus response to volcanic aerosol.

We will investigate possible causes for this asymmetry by using existing aircraft data of aerosol particles, clouds, and meteorological conditions from several different research projects.

Results from this analysis will be used to improve the representation of volcanic impact on cirrus clouds in an Earth System Model.The first two years of the project will be devoted to gathering and analyzing aircraft data and the modelling work will be performed during the last two years.The climatic effects of volcanically induced changes in cirrus clouds could enforce or offset the cooling caused by the particles themselves and the resulting impact on climate has high uncertainty.

It´s important to understand these natural climate drives to correctly simulate our past, present and future climate.

Quantifying volcanic impact on cirrus clouds is furthermore essential considering the ongoing discussions of deliberate climate manipulation via stratospheric aerosol emissions.