Colorado State Programs & People

His Head in the Clouds...
Exploring the Science & Poetry of Clouds

Published November 2005

As Colorado State’s newest University Distinguished Professor, Graeme Stephens explores the science and poetry of clouds.

Best known for his scientific studies of clouds, Graeme Stephens' paintings hang in private collections and line the hallways of CSU’s Cooperative Institute for Research in the Atmosphere. To the left is The Cumulonimbus Hot Tower, oil on canvas.

New University Distinguished Professor Graeme Stephens joins a team of internationally renowned faculty committed to leading the University with dedication and farreaching scholarship. Stephens is a leading authority on the study of atmospheric radiation, remote sensing, and climate change. As a professor of atmospheric science and a pioneer in space-based observation of Earth's atmosphere, Stephens' latest endeavor involves the upcoming NASA CloudSat satellite mission.

Stephens work involves elements you can see but are too vaporous to touch. In fact, you could say that Stephens' head is in the clouds, but that's nothing new. He's been doing research on clouds – one of the planet's most dynamic and vital climate phenomena – for decades, but he also considers clouds a source of pure wonder.

Stephens can speak equally well about 17th-century science or current, groundbreaking research in atmospheric science. And although he admires the work of historic figures such as Aristophanes, Descartes, and the great artists of the Romantic period who helped advance studies in meteorology, he now is deeply involved in a project to gather an unprecedented amount of data on clouds via CloudSat, a revolutionary satellite.

Scheduled to launch soon from Vandenberg Air Force Base in California, CloudSat is a complex, ambitious experiment designed to measure the vertical structure of clouds from space and produce detailed, three-dimensional images of cloud structures to help better predict clouds and climate change. For 12 years, Stephens has been the principal investigator for the $160 million NASA mission, one of the largest university-led projects in the space agency's history. The CloudSat Mission is a partnership between Colorado State, NASA’s Jet Propulsion Laboratory, Canadian Space Agency, U.S. Air Force, and the U.S. Department of Energy. The industrial partner, Ball Aerospace, is building the spacecraft.

Artist's concept of NASA's CloudSat spacecraft, which will provide the first global survey of cloud properties to better understand their effects on both weather and climate. [image credit: NASA/JPL]

"The international research community is quite excited about this project," Stephens says in his rumbling, Australian-accented voice. "This is cutting-edge technology that will give us observations we've never had before. We're going to be surprised, and we're going to discover new things."

Stephens compared the science behind CloudSat to CATscan imagery used in medicine to see layers within the body and to make diagnoses. "CloudSat allows us to peer inside and observe the processes that convert clouds to rain, for example, or mechanisms that produce hail," Stephens says. "We're interested in imaging the water cycle of the climate system, which is crucial to life as we know it."

Stephens adds that the two-year, short-term goal of the project is data collection. "Understanding and applying the data is the long-range part of the project," he says. "Our ability to understand the water cycle in the atmosphere is limited quite a lot because our observations of that cycle have been pretty crude – so far.

"Underpinning the science of CloudSat is research into the fresh water we drink. We're observing and trying to understand the key components of the cycle that provides water – but we need the kinds of observations that CloudSat gives to start piecing together that understanding."

CloudSat also will give new insight into questions of global warming. One of the key uncertainties in the prediction of whether the earth is warming or not, and by how much, has to do with clouds.

The CloudSat spacecraft sits encapsulated within its Boeing Delta launch vehicle dual payload attach fitting at Vandenberg Air Force Base, Calif. [image credit: NASA/JPL]

"As you perturb the climate system by adding greenhouse gases, for example, or aerosols, the system is forced into a state of change," he says. "The response comes back through the water cycle and clouds in particular, and that response is widely considered by the scientific community as the largest uncertainty associated with climate change prediction. Models are still fairly crude in the way they represent the water cycle. Compounding the challenge is the fact that observations have to be done globally, because what changes locally in Colorado doesn't necessarily represent a change in the whole system. Drought in one area may be occurring at the same time another area has excessive precipitation."

Stephens, who grew up in Ballarat, a rural town in Victoria, Australia, became interested in the sciences, particularly physics, when he was in high school. "At that time, it wasn't clear that physics would lead to job opportunities, so I looked for a discipline that was very much rooted in the basic sciences but also offered employment of some sort. A tutor (similar to teaching assistants in the United States) I knew at college was working in aeronautics, and he suggested that atmospheric science and related concentrations were exciting areas to work in. Math, physics, chemistry, engineering, and other disciplines all get mixed up in a big melting pot and become atmospheric science. It's challenging but a lot of fun."

Stephens' life may move along at a brisk pace – in addition to teaching and research, he loves working with graduate students – but he still manages to explore and contribute to historical perspectives in meteorology. His oil paintings of clouds line the hallways of Colorado State’s Cooperative Institute for Research in the Atmosphere and have been published in books, national magazines, and journals. Some of his paintings hang in private collections.

An intriguing and popular article Stephens wrote, published in American Scientist magazine in 2003, touched on many aspects that he finds fascinating about the planet’s ethereal elements. The article, called The Useful Pursuit of Shadows, discusses the intersection of science and art: how clouds profoundly influenced science and human culture in the past and how future research may well benefit from that same intersection. Through the eyes of 17th- and 18th-century scientists and artists, Stephens explores the beginnings of meteorology and the earliest attempts to classify clouds. He also laments that the "focus of modern meteorology has largely relegated the study of clouds to a minor subdiscipline" – but that’s not surprising to hear from a man devoted to such lofty work.

What is readily apparent in the article is Stephens' own poetic inclinations. He includes a brief passage from the 17th-century philosopher Rene Descartes, that evokes a lasting image of the two men from different centuries but with similar passions, standing together and gazing at clouds. In the words of Descartes: "Since one must turn his eyes toward heaven to look at them, we think of them...as the throne of God....That makes me hope that if I can explain their nature...one will easily believe that it is possible in some manner to find the causes of everything wonderful about Earth."

- Paul Miller, originally published in the Fall 2005 Colorado State University Alumni Magazine.