Nav: Home

Frequent growth events and fast growth rates of fine aerosol particles in Beijing

January 11, 2018

Serious environmental problems have arisen alongside the rapid economic development of China, such as the well-known issue of haze pollution. Not only does haze bring low atmospheric visibility, causing traffic-related problems, but it can also damage human health, and affect other aspects of the weather and climate, directly or indirectly. Secondary aerosol formation and rapid increases in aerosol particle sizes are believed to play important roles in haze formation. However, some simple but important questions remain unanswered, such as: How frequently and how fast do fine aerosol particles grow? And what affects their rates of growth?

Professor Chuanfeng ZHAO (Beijing Normal University) and his collaborators sought to answer these questions based on observations from a comprehensive experiment referred to as "AC3E" in Xianghe, Hebei, China, in June 2013. In a newly published study, they report a high frequency (~50%) of growth events of fine aerosol particles, with fast growth rates of between 2.1 and 6.5 nm/hour. The average growth rate of fine aerosol particles was around 5.1 nm/hour. A review of related studies suggested that the growth rate of fine aerosol particles is highest in megacities, followed by urban and forest regions, with rural and ocean regions having the lowest rates. Among the four contributing mechanisms of nucleation, internal coagulation, external coagulation and multi-chemical reaction, the suggestion is that nucleation--under high concentrations of NOx, SO2 and water vapor--most likely plays the dominant role.

"Although we are not sure if the fine aerosol particles are all from the new particle formation, it is clear that they often grow very fast at the size range of 10-100 nm. Within less than 20 hours, fine aerosol particles with sizes around 10 nm can grow to larger than 100 nm. This partially explains why the atmosphere can only keep clear for 1-2 days before it turns back to "dirty", resulting in haze events. This contribution is even more serious in winter due to higher relative humidity", explains Professor ZHAO.

Institute of Atmospheric Physics, Chinese Academy of Sciences

Related Climate Articles:

Believing in climate change doesn't mean you are preparing for climate change, study finds
Notre Dame researchers found that although coastal homeowners may perceive a worsening of climate change-related hazards, these attitudes are largely unrelated to a homeowner's expectations of actual home damage.
How trees could save the climate
Around 0.9 billion hectares of land worldwide would be suitable for reforestation, which could ultimately capture two thirds of human-made carbon emissions.
Climate undermined by lobbying
For all the evidence that the benefits of reducing greenhouse gases outweigh the costs of regulation, disturbingly few domestic climate change policies have been enacted around the world so far.
Climate education for kids increases climate concerns for parents
A new study from North Carolina State University finds that educating children about climate change increases their parents' concerns about climate change.
Inclusion of a crop model in a climate model to promote climate modeling
A new crop-climate model provides a good tool to investigate the relationship between crop development and climate change for global change studies.
More Climate News and Climate Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Rethinking Anger
Anger is universal and complex: it can be quiet, festering, justified, vengeful, and destructive. This hour, TED speakers explore the many sides of anger, why we need it, and who's allowed to feel it. Guests include psychologists Ryan Martin and Russell Kolts, writer Soraya Chemaly, former talk radio host Lisa Fritsch, and business professor Dan Moshavi.
Now Playing: Science for the People

#537 Science Journalism, Hold the Hype
Everyone's seen a piece of science getting over-exaggerated in the media. Most people would be quick to blame journalists and big media for getting in wrong. In many cases, you'd be right. But there's other sources of hype in science journalism. and one of them can be found in the humble, and little-known press release. We're talking with Chris Chambers about doing science about science journalism, and where the hype creeps in. Related links: The association between exaggeration in health related science news and academic press releases: retrospective observational study Claims of causality in health news: a randomised trial This...