Microscopic Air Pollution Particles Are Changing Earth's Weather in Dangerous Ways
We often hear lectures about air pollution around aerosol cans and their slow destruction of our ozone layer, and the effects that aerosol and other chemicals have on climate change are also documented.
Now, a new study shows that even microscopic pollution particles one-thousandth the width of a human hair can change the weather—making storms more intense, increasing cloud size and, as a result, cause more rain to fall.
"This result adds to our knowledge of the interactions between aerosols, clouds and precipitation," said study co-author Zhanging Li. "In areas where aerosols are otherwise limited, such as remote regions of the Amazon rainforest, ultrafine aerosol particles can have a surprisingly strong effect. "This finding will help us better understand the physical mechanisms of cloud development and severe storm formation, which can help us develop better storm prediction methods."
Using data gathered from the Green Ocean Amazon research campaign like ground and airborne measurements of rainforest climate and water cycling from 2014-2015, the team focused on a largely pristine, untouched area of the Amazon. This was a unique opportunity to assess the impact of pollution on atmosphere in a pre-industrial environment. It led to the conclusion that, in an area where the air is already very clean, microscopic particles make a particularly strong impact.
The researchers used computer simulations to show how this works. Though the ultrafine particles are small in size, they are large in quantity and encourage a sharp rise in water vapor that causes humidity to spike well beyond 100 percent. Because the particles draw excess water vapor from the atmosphere, they also release more heat, making powerful updrafts. Warm air is pulled into the clouds, creating a runway effect that launches more droplets and creates stronger storms.
"Our findings open a new door to understanding cloud physics, which matters to both weather forecasting and climate modeling," said Li. "In particular, cloud physicists will revisit the mechanisms of aerosol-cloud-precipitation interactions, especially for regions such as the Amazon where the environment has undergone rapid change due to urbanization and deforestation."
Toward the end of 2017's catastrophically epic year of natural disasters, NASA launched a powerful weather satellite for tracking storms. NOAA's Space Weather Prediction Center warns of an impending geomagnetic storm powerful enough to wipe out such satellites, however, along with Earth's entire power grid. Last Friday's storm was just classified as a G1, thankfully, and the most intense G5 storms only occur about four times every solar cycle.