Taxonomy term

aerosol

New global volcanic emissions map debuts

Volcanoes may not always be erupting ash or lava, but that doesn’t mean they’re not venting other materials. Many, in fact, continuously spew gases like carbon dioxide and sulfur dioxide into the air. In a new study, volcanologists compiled data tracking such releases, collected by NASA’s Aura satellite, into the first global map of volcanic sulfur dioxide emissions.

13 Jul 2017

To cool the planet, volcanoes of the future will need more firepower

Explosive volcanic eruptions can spew sulfur gas into the stratosphere — the layer of the atmosphere above where most clouds and weather occur — where it forms sulfate aerosols that reflect sunlight back into space and cool the planet. Now, researchers investigating how volcanic plumes could be affected by projected anthropogenic warming have found that, as temperatures rise, it becomes more difficult for volcanic plumes to reach the stratosphere.

06 Mar 2017

Clouds can form without particles

In addition to their aesthetic and photogenic appeal, clouds play a crucial role in Earth’s climate and ecosystems, helping regulate temperatures by reflecting sunlight. All clouds — from fluffy cumulus to wispy cirrus — grow from seeds that, more often than not, are tiny particles of pollen, dust or chemical aerosols that float into the atmosphere from Earth’s surface. Sulfuric acid, a byproduct of volcanic eruptions and fossil fuel combustion, is one of the most ubiquitous precursors to atmospheric aerosols today and has long been thought to play a major role in modern cloud formation. But what about earlier in Earth’s history, before humans impacted the atmosphere as much? Three new studies, representing both experimental and field data, suggest that the planet’s plants and trees might have done just fine on their own pumping cloud-forming aerosols into the skies.

30 Sep 2016

Volcanic aerosols not enough to cause mass extinctions?

Mass extinctions — when more than half of Earth’s species disappear in a geologic instant — offer some of the planet’s most perplexing unsolved mysteries. Prolonged periods of volcanic activity have long been prime suspects for these ancient whodunits, the most recent of which finished off the last nonavian dinosaurs at the close of the Cretaceous about 66 million years ago. But scientists debate how drastic the environmental effects of such volcanism might have been, and whether other factors — like asteroid impacts, as in the end-Cretaceous extinction — played a big role as well.

25 Feb 2016

Marine microorganisms drive summer clouds over Southern Ocean

The Southern Ocean surrounding Antarctica is home to some of the most pristine air anywhere on Earth. And yet it’s also one of the cloudiest places on the planet, a seeming contradiction because water droplets require particulate matter in the air to condense into clouds. Now, a study looking at cloud droplet concentrations over the Southern Ocean is giving scientists a clearer understanding of the role played by marine microorganisms in cloud formation and climate.
 
06 Nov 2015

Secondary aerosols a primary cause of Chinese smog

Images of Chinese skylines and streetscapes blurred by pollution-fueled hazes have become increasingly common in recent years amid ongoing urbanization and industrialization. According to a new study published in Nature, much of the pollution fogging the country’s major cities is arising not from fine particles emitted directly into the sky, but by gases that react and condense in the atmosphere to form secondary aerosols.

24 Jan 2015

For cloud formation, a little aerosol goes a long way

Clouds play a starring role in creating and controlling climate, but cloud physics are notoriously difficult to model, leaving wide gaps in understanding how cloud conditions have changed since the pre-industrial era. A new study looking at pristine regions of the sky in the South Pacific is shining some much-needed light on how particulate air pollution interacts with water vapor to form clouds.

06 Oct 2014

Hurricanes suppressed by air pollutants

Understanding how often devastating tropical storms like Superstorm Sandy occur, and how humans may play a role in their frequency, is a major goal among climate scientists. Now, a new study indicates that aerosols may suppress storm formation over the Atlantic. Thus, researchers say, more frequent storms at the end of the last century might have been an unintended side effect of cleaning up the air.

25 Jun 2013

Air pollutants from "megacities" a growing problem

Megacities — cities with populations equaling or greater than 10 million people — are producing an unprecedented amount of air pollution, according to scientists at the American Chemical Society's annual meeting in Washington, D.C., on Tuesday.

21 Aug 2009

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