Cloud on EARTH Magazine

From silver to snow: Full cloud seeding cycle observed

Tue, 01 May 2018 15:58:44 -0400

A "Doppler on Wheels" truck, equipped with X-band radar, atop Packer John Mountain in the Salmon River Range in central Idaho tracks the formation of ice particles during cloud seeding experiments. Credit: Josh Aikens.

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.

Lollipop-shaped ice found in clouds

Tue, 19 Sep 2017 11:35:26 -0400

Researchers recently found tiny lollipop-shaped ice crystals over the Atlantic Ocean. Credit: Callan Bentley, 2017.

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

New cloud types recognized

Mon, 19 Jun 2017 13:04:49 -0400

A tubular volutus roll cloud takes shape off the coast of Uruguay. Credit: Daniela Mirner Eberl, CC BY-SA 3.0.

Wavy asperitas clouds resemble a rolling, stormy sea. Credit: ©Gary MacArthur.

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.

Mountains may cause huge waves in Venusian clouds

Wed, 19 Apr 2017 14:11:23 -0400

A huge stationary wave observed over Venus may result from mountain topography. Credit: Planet-C project/Japan Aerospace Exploration Agency (JAXA).

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.

Red Planet Roundup: February 2017

Wed, 25 Jan 2017 14:11:41 -0500

The bright spots in this ultraviolet view of Mars, assembled from images collected by the MAVEN orbiter in July, are clouds that rapidly formed over Mars' largest volcanic peaks. Credit: NASA/MAVEN/University of Colorado.

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.

Cloud feedbacks drive climate sensitivity

Tue, 15 Nov 2016 10:41:04 -0500

Low tropical clouds seen from the International Space Station. Clouds like these reflect solar radiation back into space; without them, Earth's surface warms. Credit: NASA.

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.

Clouds can form without particles

Tue, 13 Sep 2016 14:25:29 -0400

Federico Bianchi and his colleagues analyzed air samples at Jungfraujoch Research Station in the Swiss Alps to study the formation of cloud condensation nuclei from organic compounds in the troposphere. Credit: Federico Bianchi.

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.

For cloud formation, a little aerosol goes a long way

Wed, 03 Sep 2014 08:33:16 -0400

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.

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

Thu, 05 Jan 2012 06:41:58 -0500

Utah's Great Salt Lake, as seen from the International Space Station in August 2003. The north and south sections of the lake are separated by a railway and have different salt concentrations. NASA Earth Observatory

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.