Huge Icelandic volcano eruption exposes cool affect of aerosols

A groundbreaking new study has identified the extent to which tiny particles in the air form clouds, helping significantly improve climate modelling and predictions. 

Research into clouds and aerosols led by the University of Exeter has increased scientific understanding of how tiny particles in the air, including those created by human activities, helps keep global temperatures below where they should be based on the warming effects of greenhouse gases. 

Up until now, the cooling impact of increased cloud cover due to aerosols has been difficult to measure. However, by using data from the 2014 Icelandic volcano eruption, experts now have a much greater grasp on the relationship between temperatures, clouds, and aerosols. 

‘This massive aerosol plume in an otherwise near-pristine environment provided an ideal natural experiment to quantify cloud responses to aerosol changes, namely the aerosol’s fingerprint on clouds,’ said lead author Dr Ying Chen. ‘Our analysis shows that aerosols from the eruption increased cloud cover by approximately 10%.

‘Based on these findings, we can see that more than 60% of the climate cooling effect of cloud-aerosol interactions is caused by increased cloud cover. Volcanic aerosols also brightened clouds by reducing water droplet size, but this had a significantly smaller impact than cloud-cover changes in reflecting solar radiation,’ she continued. 

20 years of satellite images were used, taken from two different sources, allowing in-depth comparisons of atmospheric conditions before and after the eruption. This has provided observational evidence of the climate impact of aerosols, which will allow for more accurate modelling and predictions for how the climate will change in the coming years. 

Revisit Air Quality News‘ feature on the impact of volcanic eruptions on the atmosphere. 

Image credit: Yosh Ginsu