Atmosphere

atmosphere

Ancient wildfires suggest rising atmospheric oxygen helped end past ocean anoxia

Many times throughout Earth’s history, oxygen levels in the world’s oceans have decreased dramatically in episodes called oceanic anoxic events (OAEs), which have caused massive marine die-offs. In the Early Jurassic, for example, the Toarcian OAE has been linked with the extinction of many ammonite species and other sea life. However, how such episodes end remains largely unclear to scientists.

22 Aug 2017

Dust influences pollution levels in eastern China

Air pollution often enshrouds cities in eastern China in a thick haze that impairs visibility and causes respiratory health problems. Emissions from human activity are mainly to blame, but climate researchers now report that natural forces — namely, dust kicked into the air by wind — can also exert a strong control over how much pollution persists in the air.

22 Aug 2017

Red Planet Roundup: August 2017

With two rovers patrolling the surface of Mars, six spacecraft orbiting above it, and scientists here on Earth studying the Red Planet from afar, new findings are announced often. Here are a few of the latest updates.

03 Aug 2017

Mountains may cause huge waves in Venusian clouds

An enormous, stationary, bow-shaped feature has been detected in the cloud-tops of Venus’ thick, sulfuric acid-rich atmosphere. The structure, stretching more than 10,000 kilometers, remains fixed over Venus’ surface despite atmospheric winds that whip around the planet at 100 meters per second.

03 May 2017

Earth's largest jet stream unexpectedly disrupted

In early 2016, scientists first noticed an unexpected change in wind direction in the stratosphere some 25 kilometers above the equator. This shift signaled the beginning of a multimonth disruption of one of the most regular atmospheric phenomena known — the quasi-biennial oscillation (QBO). The disruption is the first such event observed in this system since record keeping began in the 1950s.

06 Jan 2017

Smokier U.S. West as climate changes

Extended wildfire seasons and larger and more frequent burns will likely be the consequence of the hotter and drier conditions expected to result from climate change. New research shows that this expected surge in wildfires also poses a growing threat to human health.

11 Dec 2016

Cloud feedbacks drive climate sensitivity

Fly over the tropical or subtropical oceans and you’ll see a white blanket of clouds covering the blue-green water. These low clouds, typically forming less than 2 to 3 kilometers above the ocean surface and covering up to 40 percent of Earth’s surface, play a critical role in the planet’s energy balance. Now, new research using satellite data and climate models to investigate how these clouds respond to climate change shows that they play a large role in regulating climate sensitivity.

17 Nov 2016

Newly discovered Earth-like worlds are rocky, not gassy

In May, a new planetary system was discovered just 40 light-years from Earth, including three Earth-sized planets orbiting around their red dwarf sun in a temperature range that could potentially harbor life. Now, a follow-up study on the system has found that the two innermost planets are primarily rocky with compact atmospheres, as opposed to inhospitable gas giants, like Jupiter.

15 Nov 2016

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

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