Taxonomy term

cloud

From silver to snow: Full cloud seeding cycle observed

Cloud seeding — adding particles to clouds to modify precipitation patterns — has been suggested as a way to trigger rain and snowfall, which could help sustain mountain snowpack and water supplies across the western U.S. However, it has been challenging to demonstrate the technique’s effectiveness and efficiency, in part because direct observations of the full chain of events involved in cloud seeding have been lacking.

25 May 2018

Lollipop-shaped ice found in clouds

A sky full of lollipops might sound like a candy-filled dream, but these “treats” aren’t what you might think.

Researchers discovered tiny lollipop-shaped ice crystals, or ice-lollies, during research flights in 2009 and 2016 over the Atlantic Ocean. 

09 Oct 2017

New cloud types recognized

Familiar clouds like cumulonimbus, cirrocumulus and nimbostratus have some new company. The World Meteorological Organization (WMO) has published a new edition of its International Cloud Atlas, the first revision since 1987. The updated version — released in digital format for the first time — compiles recent observations and introduces about a dozen new terms, such as “asperitas,” which refers to a cloud whose sweeping undulations resemble the surface of a stormy sea, as well as names for clouds induced by wildfires and by human activity. There is even a new cloud species, “volutus,” which describes long, tube-shaped rolling clouds.

27 Jun 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

Red Planet Roundup: February 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.

14 Feb 2017

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

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

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

AGU: Colorado ski industry owes Great Salt Lake thank you note

SAN FRANCISCO — Colorado skiers have long suspected that snowfall is fluffiest when winds blow salt and dust eastward from the Great Salt Lake in Utah. Now that wisdom is confirmed by science.

After measuring cloud particles from plane flights over Colorado, atmospheric chemist Kim Prather of Scripps Institution of Oceanography in La Jolla and colleagues determined that nascent snow largely formed as a result of suspended Utah salt.

In order for snow and rain droplets to form, water needs a particle base on which to accumulate. This process is called nucleation.

20 Dec 2008