Cloud formation affected by human activity, study says

September 12, 2006

University of Toronto researchers and their collaborators have discovered that solid ammonium sulphate aerosol – an airborne particle more prevalent in continental areas - can act as a catalyst to the formation of ice clouds, suggesting that cloud formation is another aspect of the global climate system that can be affected by human presence. The findings were published last week in Science.

With European climate scientists and cloud physicists, U of T atmospheric chemists Jon Abbatt and Zamin Kanji investigated whether ammonium sulphate aerosol in its crystal form could act as the ice nuclei to form cirrus clouds, the thin, wispy ice clouds that cover one quarter of the globe at any given time.

Cirrus clouds are important to the climate system because they scatter incoming sunlight, trap outgoing heat radiation and control the amount of water vapour in the upper troposphere. “Water vapour is a greenhouse gas, so any change in the ratio of ice cloud to water vapour affects the overall system,” says Abbatt. “So knowing how ice clouds form helps us better understand the system, and put together a better climate model.”

Studies of cirrus formation in different parts of the world have found that the clouds form more efficiently in the moderately polluted air of the Northern hemisphere than in the clean oceanic air of the Southern hemisphere. Abbatt’s team found a correlation between the amount of sulphate aerosol in the air and the efficiency of cloud formation in the regions. Because atmospheric ammonia now mainly comes from livestock and nitrogen-based fertilizer, the study provides evidence that human agricultural practices impact how and what kind of clouds form in the sky.

Source: University of Toronto

Explore further: Since Katrina: NASA advances storm models, science

Related Stories

Since Katrina: NASA advances storm models, science

August 21, 2015

On Aug. 28, 2005, the National Hurricane Center issued a public notice warning people in New Orleans of "devastating damage expected...power outages will last for weeks...persons...pets...and livestock left exposed to the ...

ESO image: Sibling stars

August 19, 2015

Open star clusters like the one seen here are not just perfect subjects for pretty pictures. Most stars form within clusters and these clusters can be used by astronomers as laboratories to study how stars evolve and die. ...

Solar System formation don't mean a thing without that spin

August 18, 2015

New work from Carnegie's Alan Boss and Sandra Keiser provides surprising new details about the trigger that may have started the earliest phases of planet formation in our solar system. It is published by The Astrophysical ...

Oxymoronic black hole RGG 118 provides clues to growth

August 12, 2015

Astronomers using NASA's Chandra X-ray Observatory and the 6.5-meter Clay Telescope in Chile have identified the smallest supermassive black hole ever detected in the center of a galaxy, as described in our latest press release. ...

What is the Oort Cloud?

August 11, 2015

For thousands of years, astronomers have watched comets travel close to Earth and light up the night sky. In time, these observations led to a number of paradoxes. For instance, where were these comets all coming from? And ...

Recommended for you

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.