German China

Pollution and Climate Industrial Snow: Factories Trigger Local Snowfall by Freezing Clouds

Source: Estonian Research Council 2 min Reading Time

Related Vendor

A study from the University of Tartu reveals how industrial emissions influence cloud dynamics and snowfall downwind of global industrial hotspots, offering fresh insights into the complex interplay between pollution and climate.

The weather radar image shows a plume of snow downwind of the Rouyn-Noranda copper smelter in Canada. The weather radar is located near Landrienne, Canada.(Source:  V. Toll, et al)
The weather radar image shows a plume of snow downwind of the Rouyn-Noranda copper smelter in Canada. The weather radar is located near Landrienne, Canada.
(Source: V. Toll, et al)

Anthropogenic aerosols, tiny solid and liquid air pollution particles, have masked a fraction of global warming caused by anthropogenic greenhouse gases. Climate researchers have known for decades that anthropogenic aerosols perturb liquid clouds by enabling the formation of a larger number of cloud droplets, making clouds brighter. A new landmark study led by the University of Tartu suggests that anthropogenic aerosols may also influence clouds by converting cloud droplets to ice at temperatures below zero degrees Celsius.

Using satellite observations, climate researchers discovered unique plumes of ice clouds and reduced cloud cover downwind of industrial hot spots in North America, Europe and Asia. Moreover, ground-based precipitation radar data revealed plumes of snowfall in the same areas where reduced cloud cover was observed in satellite images. Combining satellite and ground-based radar observations, researchers traced the physical processes from the formation of ice to snowfall to reduced cloud cover downwind of industrial hot spots. The lead author of the study, Assoc Prof V. Toll from the University of Tartu, highlighted that collaboration among researchers with diverse expertise was essential for developing the physical understanding of the identified anthropogenic snowfall events.

Gallery

Water freezes at 0 °C, right? In fact, cloud droplets can stay liquid down to temperatures as low as about -40 °C, known as the supercooling of water. This is because suitable aerosol particles are needed to convert cloud droplets to ice at temperatures between zero and -40 °C. The study suggests that industries such as metallurgical and cement factories, coal-fired power plants, and oil refineries emit aerosol particles that cause freezing of supercooled liquid clouds, leading to snowfall. However, it is important to note that heat and water vapour emitted by industries may also play a role in the freezing of supercooled liquid clouds.

The discovered plumes of reduced cloud cover are local phenomena, and it remains unclear if anthropogenic aerosols induce ice formation in clouds at larger spatial scales. Further research is needed to understand the ability of various types of anthropogenic aerosols to initiate the formation of ice.

Original Article: Glaciation of Liquid Clouds, Snowfall, and Reduced Cloud Cover at Industrial Aerosol Hot Spots; Science; DOI:10.1126/science.adl0303

(ID:50240100)

Subscribe to the newsletter now

Don't Miss out on Our Best Content

By clicking on „Subscribe to Newsletter“ I agree to the processing and use of my data according to the consent form (please expand for details) and accept the Terms of Use. For more information, please see our Privacy Policy. The consent declaration relates, among other things, to the sending of editorial newsletters by email and to data matching for marketing purposes with selected advertising partners (e.g., LinkedIn, Google, Meta)

Unfold for details of your consent