This is an archived article that was published on sltrib.com in 2007, and information in the article may be outdated. It is provided only for personal research purposes and may not be reprinted.
Correction: A story in Sunday's paper about clouds and climate change contained the wrong spelling of graduate student and cloud researcher Lis Cohen's name.
When Gerald "Jay" Mace peers out the window of his seventh-story office, he sees more than just a wispy smattering of cirrus clouds floating across the sky.
The research meteorologist sees high-altitude questions inching their way across the University of Utah campus. Hiding somewhere deep inside these constantly changing, ethereal entities lie answers that could help create better climate change forecasts.
"They're right there in front of you," he said. "It doesn't make any sense [that] it's so difficult."
The cloud research Mace does has grown in importance in the past few decades as concerns over global warming have increased. Global climate models - complicated computer simulations that are a key tool in assessing climate change - don't always represent clouds well.
"Clouds are that 800-pound gorilla," he said.
Condensing the essence of clouds into numbers that can be plugged into computer models is a serious challenge. Because it's so difficult, different models treat clouds in different ways, resulting in global temperature predictions that vary widely. The latest Intergovernmental Panel on Climate Change report issued Friday reminded meteorologists of the need for more work in this area.
Decades of research already have yielded many fundamental facts about clouds - such as that they are made up of water droplets and ice crystals. But many questions linger.
"We really do not know what's going on," said Tim Garrett, a U. meteorologist. "There are so many basic unanswered questions on how they work."
Some of those questions include:
* Researchers need a better understanding of how clouds interact with the planet's energy budget. Clouds act to both cool and warm the Earth. High clouds can reflect radiation away from the planet, while they can also act to trap heat in the atmosphere.
* Cloud droplets can last for less than a second, while whole clouds live out their lives in minutes or days. These short-time scales can be tough to put into a model that simulates decades of weather patterns.
* Small clouds, which can cover the area of a city park, can be tough to represent in models that divide the world into boxes up to 60 miles on a side.
Figuring the inner workings of clouds
Global warming researchers project temperatures will increase globally by the end of the century by two degrees at the low end and 10 degrees at the high end.
Mace said a two-degree rise would be bad, but a 10-degree jump could be catastrophic.
While a better understanding of clouds wouldn't eliminate all the projected temperature variation, it would help narrow the range, said David Randall, a Colorado State University meteorologist.
Cirrus clouds are of particular interest.
"It's been argued whether cirrus clouds amplify or act as a brake" on global warming, Garrett said. "The answer to that question is affecting the future of temperature on this planet."
Another question revolves around cloud brightness, which determines how much heat clouds reflect.
U. researchers last year worked as part of a team in Australia to help answer some of these questions. Researchers spent several weeks with planes, radars and satellites studying cloud systems moving across the country.
The project involved special planes flying through high altitude clouds to photograph ice crystals, said Lis Cohen, a meteorology grad student who worked with Mace.
"We're finally getting the technology to actually be able to probe the clouds and figure out what's going on within the clouds," she said.
The U. is also involved in a pair of NASA projects, CloudSat and CALIPSO. Both satellite programs are aimed at teasing out more details of clouds from above.
Technological limitations hinder cloud modeling
Even as these various projects begin to answer questions, more hurdles remain. Scientists must determine how to insert this new information into future climate models.
Steven Krueger, a U. meteorologist, said limits in computing power hurt realistic cloud modeling in these global simulations.
"If we had big enough computers, we could run models that would be much more accurate," he said.
In addition, current climate models do not represent features such as the Rocky Mountains well, he said, and that must improve because mountain ranges contribute to some types of cloud formation. Statistics must be added to the program to mimic the effect of mountain ranges in certain locations.
Krueger said future models, coupled with more powerful computers, should better represent geographical features that influence cloud formation.
A final problem with computer simulations that continues to irk Mace and other researchers is that clouds are sometimes manipulated to achieve certain benchmarks.
For each model to prove its meteorological worthiness, it has to predict conditions in the upper atmosphere from a certain date in the past. When versions of the model are off, programmers tweak the clouds in order to reach the right conditions.
"My goal in my professional life is to take the tuning knobs out of the climate modelers' hands," Mace said.
Each cloud alteration can change what's going on down below.
"If you can't get the clouds right, it's difficult to get the precipitation right," Cohen said.
For places like Utah, where drafts have dominated recently, future precipitation is a key issue for planning purposes.
Garrett said rain and snow are among the factors that make clouds an important area of study beyond climate prediction.
"We get so used to them, we don't look up and appreciate them," he said. "You think about what makes the planet livable and clouds have to be pretty much top of the list."
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* GREG LAVINE can be reached at glavine@sltrib.com or 801- 257-8620.