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

Rainbows reclassified

Rainbows — those arches of color that streak across wet skies — are recognizable to almost everyone. Our understanding of rainbows, though, particularly how they form and the diversity of shapes they can take, is still fuzzy.

21 Dec 2015

Is aviation 'whitening' the sky?

Clear blue skies may not be as clear as they appear. Skies are actually becoming less clear, causing incoming sunlight to scatter in different directions, rather than striking the planet directly — and aviation may be to blame, according to research presented this week at the fall meeting of the American Geophysical Union (AGU) in San Francisco.

17 Dec 2015

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

Santa Ana winds get a fiery boost from the stratosphere

Southern California’s Santa Ana winds have long been implicated in the region’s dangerous and destructive wildfires. Now, a new study in Geophysical Research Letters points the finger at an accomplice: a phenomenon called stratospheric intrusions, which are natural atmospheric events that bring warm, dry air from the upper atmosphere down to the surface. These intrusions may exacerbate fires, as well as the region’s infamously bad air pollution.
23 Oct 2015

Earth-like atmosphere enough to set some exoplanets spinning

Earth is “Exhibit A” in showing that planetary rotation — which moderates global climate, keeps a lot of water in liquid form and generally makes the place more livable — is a plus when it comes to sustaining life. But scientists have thought that many of the rocky, Earth-like exoplanets discovered recently, which might otherwise be considered potentially hospitable to life, aren’t so fortunate. On these unlucky worlds, unable to rotate because they’re held too tightly by their parent stars’ gravity, one half of the planet is perpetually roasted by stellar radiation while the other is left frigid and dark. Now, however, a new study suggests that a little atmosphere can go a long way toward helping exoplanets rotate.

22 Aug 2015

As an aerosolizer, dust devils demoted

Dust is an inescapable byproduct of a rocky planet reworked by tectonic forces, extraterrestrial impacts and human activities. And though it may seem like a nuisance, airborne dust plays an integral role in the Earth system, fertilizing downwind ecosystems and influencing climate. But just how dust gets lofted into the air has long puzzled scientists. Previous studies have suggested that dust devils could stir up as much as a third of the atmosphere’s dust budget, but new work reveals these twisters contribute just a tenth of that amount.

01 Aug 2015

New satellite maps carbon dioxide sources and sinks in high definition

A recently launched satellite is now measuring atmospheric carbon dioxide with greater precision than ever before. Launched on July 2, the Orbiting Carbon Observatory-2 (OCO-2) is already mapping levels of carbon dioxide, the presence of which in the air constantly varies by region and over time. It has also validated a new technique of analysis that was not even contemplated when the mission was planned, according to scientists who discussed the mission at a press conference during the annual meeting of the American Geophysical Union (AGU) in San Francisco.

23 Dec 2014