A small ice particle made of a needle-shaped ice crystal and a single drizzle-sized water droplet
Right now, somewhere in the world, it could be raining lollies. A 2009 research flight through clouds above the British Isles gathered ice particles with an unusually sweet look. Each millimeter-sized particle consisted of a stick-shaped piece of ice with a single water droplet frozen on the end, giving it the appearance of a lollipop. Atmospheric scientist Stavros Keppas of the University of Manchester in England and colleagues report the discovery of the atmospheric confections in a paper to be published in Geophysical Research Letters.
Along a sun-drenched coastline, puffy little clouds stretch to the horizon like a vast set of beach umbrellas. Strolling along the sand or splashing in the surf, you probably wouldn’t even notice them.
Paquita Zuidema does, though. She is an atmospheric scientist at the University of Miami in Florida. And she notes that most people don’t appreciate these marine low clouds. “They aren’t very interesting from a weather point of view,” she admits. They’re small. They don’t cause big storms. They barely even produce rain. Yet marine low clouds intrigue her far more than other, flashier ones.
In part because there are so many of them, these clouds are very effective at reflecting sunlight, she explains. Layers of the bright white clouds can stretch for miles. By keeping some of the sun’s energy from reaching Earth’s surface, those clouds help keep Earth relatively cool.
When most of us see clouds, we see animal shapes, a chance of rain or maybe a bit of welcome shade. Scientists, such as Zuidema, see much, much more. For these researchers, clouds are an integral part of the planet, transferring water, dust and even life around the globe.
Little clouds that can
As a kid, Zuidema wanted to be a naturalist — a scientist who looks at the natural world in a broad way. She now thinks that was “kind of a romantic vision.” When she got to college, she picked what she thought was a more practical path, studying physics along with public policy. That combination led her to atmospheric sciences.
But Zuidema didn’t really notice low clouds until graduate school at the University of Washington, in Seattle. That city “has a lot of low clouds,” the scientist says. She suddenly realized how important their reflection of heat back into space was for Earth’s climate. She continued studying low clouds at the University of Colorado in Boulder. There she earned her PhD.
Seattle’s skies may be home to plenty of low clouds, but there are even better places to spot these little puffs. The greatest gatherings tend to occur off the coasts of places like Namibia, in Africa, and northern Chile. These places are home to some of Earth’s driest deserts. At about 430 to 600 meters (some 1,400 to 2,000 feet) above the surface, moist air rising from the ocean cools and condenses into clouds. But instead of growing taller, the clouds are trapped by the dry, sinking air that creates desert conditions. The result is a layer, or deck, of marine low clouds. They can stretch for miles.
“The marine clouds are trying to rise but are being squished down,” Zuidema explains. Though most of these clouds form over oceans, they can be found anywhere warm moist air is pressed down by dry, descending air.
The more Zuidema learns about these little clouds, the more fascinating she finds them. “I’m really interested in the myriad ways these low clouds respond to their environment,” she says. Because there are so many low clouds, and because they help keep Earth cool by reflecting heat, anything that affects them can also affect overall climate. “It feeds back to the whole energy balance of the planet,” she explains.
Lately Zuidema has been exploring how smoke that drifts over decks of marine clouds might change the way that these clouds absorb or reflect sunlight. Such smoke — from burning trees and grasses — can drift thousands of kilometers. If that smoke affects clouds, it might also affect climate. Last year, she spent a month on remote Ascension Island in the South Atlantic Ocean setting up instruments to track the interaction between low clouds there and smoke from southern Africa.
Zuidema appreciates the variety in her work. Besides the occasional trip to distant islands, she also teaches and collaborates with other scientists to better understand Earth’s climate system. Along the way, she’s helping elevate one type of low cloud into the spotlight it deserves.
Catch and release clouds
The ancient West African town of Sidi Ifni sits on the coast of Morocco. Here, on the edge of the bone-dry Sahara Desert, there’s never seems to be enough water to go around. For many women and girls here, carrying water from distant wells has become a day-long chore. As drought has worsened, many villagers have simply left. Today, communities and traditions there are crumbling.
Yet, half the year, water surrounds Sidi Ifni. There’s just one big problem: It’s locked into dense fog — clouds that touch the ground. Sidi Ifni isn’t alone. Thirsty coastal dwellers in Peru, Chile and Namibia also suffer thirst, even as they also are often cloaked in moist fog.
Cassini has beamed back stunning images from the spacecraft’s daring dive between Saturn and its rings.
The first closeup pictures of the planet’s atmosphere reveal peculiar threadlike clouds and puffy cumulus ones, plus the giant hurricane first spotted on Saturn in 2008 (SN: 11/8/08, p. 9). Released April 27, the images of Saturn’s cloud tops are a “big step forward” for understanding the planet’s atmosphere, says Cassini imaging team member Andy Ingersoll, an atmospheric scientist at Caltech.
Tequila Cloud is an art installation that is a cloud made of tequila, that rains tequila on command. In case you’re thinking of renting one for your next party, there’s only one, and it was on display earlier this month in Germany.
The Mexican Tourism Board installed the cloud in Berlin at the Urban Spree compound in an art gallery and said “real…