Featured Research

from universities, journals, and other organizations

Understanding critical nucleus in haze formation

Date:
June 17, 2010
Source:
Texas A&M University
Summary:
Haze -- scientifically known as atmospheric aerosols, microscopic particles suspended in the Earth's atmosphere -- represents a major environmental problem because it degrades visibility, affects human health and influences the climate. Despite its profound impacts, how the haze is formed is not fully understood.

Professor Renyi Zhang.
Credit: Image courtesy of Texas A&M University

Haze -- scientifically known as atmospheric aerosols, microscopic particles suspended in the Earth's atmosphere -- represents a major environmental problem because it degrades visibility, affects human health and influences the climate. Despite its profound impacts, how the haze is formed is not fully understood, says a Texas A&M University professor of atmospheric sciences and chemistry who has studied air chemistry for more than 20 years.

Professor Renyi Zhang published his work in the June 11 issue of Science magazine, summarizing recent findings and new research directions that could pave the way for a better understanding of aerosol formation.

"Aerosols, also referred to as haze, influence climate by absorbing and reflecting solar radiation and modifying cloud formation," he explains. "A better understanding of how aerosols form in the atmosphere will greatly improve climate models.

"But, formation of aerosols in the atmosphere is not fully understood, particularly at the molecular level, creating one of the largest sources of uncertainty in climate predictions," he adds.

For aerosols to form, the bonding particles must cross an energy threshold, which the scientists call nucleation barrier. Once the barrier is crossed, aerosol formation can happen spontaneously, he notes.

The interaction between organic acids and sulfuric acid can facilitate the crossing of the barrier by creating a critical nucleus, the Texas A&M professor says in the Science article.

Large amounts of organic gases are emitted to the atmosphere by plants, industry and automobiles and form organic acids; sulfur dioxide, on the other hand, are produced by human activities, such as burning coals, and then form sulfuric acid.

To better understand aerosol formation, scientists need to predict the nucleation rate based on knowledge of the composition of the critical nucleus, Zhang explains.

This knowledge can be obtained by combining theoretical approaches with "measurements of the size and chemical composition of freshly nucleated nanoparticles in the laboratory and in the field," Zhang notes.

Understanding and eventually controlling aerosol formation may help the environment, benefit human health and improve climate prediction, he says.


Story Source:

The above story is based on materials provided by Texas A&M University. Note: Materials may be edited for content and length.


Journal Reference:

  1. R. Zhang. Getting to the Critical Nucleus of Aerosol Formation. Science, 2010; 328 (5984): 1366 DOI: 10.1126/science.1189732

Cite This Page:

Texas A&M University. "Understanding critical nucleus in haze formation." ScienceDaily. ScienceDaily, 17 June 2010. <www.sciencedaily.com/releases/2010/06/100616161211.htm>.
Texas A&M University. (2010, June 17). Understanding critical nucleus in haze formation. ScienceDaily. Retrieved September 19, 2014 from www.sciencedaily.com/releases/2010/06/100616161211.htm
Texas A&M University. "Understanding critical nucleus in haze formation." ScienceDaily. www.sciencedaily.com/releases/2010/06/100616161211.htm (accessed September 19, 2014).

Share This



More Earth & Climate News

Friday, September 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Wildfires in CA Burn Forest Asunder

Raw: Wildfires in CA Burn Forest Asunder

AP (Sep. 18, 2014) — An out-of-control Northern California wildfire has nearly 2,800 people from their homes as it continues to grow, authorities said Thursday. Authorities said a man has been arrested on suspicion of arson for starting the fire on Saturday. (Sept. 18) Video provided by AP
Powered by NewsLook.com
Raw: Elephant Undergoes Surgery in Tbilisi Zoo

Raw: Elephant Undergoes Surgery in Tbilisi Zoo

AP (Sep. 18, 2014) — Grand the elephant has successfully undergone surgery to remove a portion of infected tusk at Tbilisi Zoo in Georgia. British veterinary surgeons used an electric drill to extract the infected piece. (Sept. 18) Video provided by AP
Powered by NewsLook.com
Raw: Scientists Examine Colossal Squid

Raw: Scientists Examine Colossal Squid

AP (Sep. 16, 2014) — Squid experts in New Zealand thawed and examined an unusual catch on Tuesday: a colossal squid. It was captured in Antarctica's remote Ross Sea in December last year and has been frozen for eight months. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Man Floats for 31 Hours in Gulf Waters

Man Floats for 31 Hours in Gulf Waters

AP (Sep. 16, 2014) — A Texas man is lucky to be alive after he and three others floated for more than a day in the Gulf of Mexico when their boat sank during a fishing trip. (Sept. 16) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins