Pollution Prevents Thunderstorms but it also Makes Them Worse


Image credit: MontyPython/Flickr

The formation of thunderhead clouds, which reflect solar radiation out of the atmosphere and return evaporated water to the ground, form an integral part of the planet's climate system. Aerosol particles, a pollutant sent into the atmosphere by burning fuel, industrial processes, and other sources, have a significant impact on cloud formation.

The influence of pollutants on clouds, however, is a complex and little-understood phenomena but new research has offered one explanation.Thunderstorms are created by convection processes during which the warmer air of lower altitudes is pulled up into a higher, larger, cloud mass. Wind shear, a phenomenon in which horizontal wind speed and direction varies at different altitudes, often occurs at the front of such storms. When these irregular winds interact with pollution particles, researchers found, they can have a significant dampening effect on storm's convection.

Aerosol particles from pollution, a study found, cause water to condense as droplets that affix to them. This process releases heat which fuels the convection process, increasing the size and severity of the storm.

When wind shear is present, however, these condensed droplets quickly evaporate, cooling the air in the cloud mass and stopping the convection process. This effectively kills the thunderstorm before it has a chance to fully form.

Jiwen Fan, an atmospheric scientist at the Department of Energy's Pacific Northwest National Laboratory, commented that this is "an important factor regulating how aerosols change storms and precipitation."

Her findings provide new insights into how to better incorporate these variables into models, which may lead to more accurate climate modeling in the future.

Read more about the effects of pollution:
Canadian Study Shows Air Pollution May Trigger Appendicitis
A Picture is Worth... Air Pollution in China
Pollution in China is Worse Than Ever, Citizens Say

Tags: Pollution