Lis Cohen always was bored by swing sets and monkey bars.

"In elementary school I used to lay out in the field on the playground and get my friends to lay down with me and look at the clouds."

Ed Zipser became hooked on weather-watching after a hurricane knocked down trees where he used to ride his tricycle. "I loved big, nasty storms. When I was 5 years old my aunt taught me how to read the New York Times weather map."

Jay Mace was a late bloomer by comparison. He didn't develop a passion for storm study until he joined the Navy. "I became a weather guy because it kept me from turning bolts in the engine room."

Now, the University of Utah threesome has nearly 70 years of combined experience researching storms, and this month they took that expertise to Australia.

For several weeks Zipser and Mace, both U. meteorology professors, and Cohen, a meteorology graduate student, represented Utah and the United States in a multimillion-dollar storm experiment featuring more than 100 researchers from 10 countries, including the United States, Canada, Australia, Japan and several European nations.

The Tropical Warm Pool International Cloud Experiment (TWP ICE) is a $4.5 million dollar project funded mostly by the U.S. Department of Energy and the Australian Bureau of Meteorology.

The primary focus of the experiment: to figure out how clouds work.

"The effect of clouds on climate is one of the great unknowns of science," according to Zipser.

That's because the clouds we see with the naked eye aren't the giant, fluffy, slow-moving dinosaurs and puppy dogs they seem.

"Clouds consist of tiny droplets of water or tiny ice crystals, and can range in size from a micrometer (1/1000th of a millimeter) right on up to a millimeter size and bigger — big enough to see," Zipser explained.

Depending on the type of cloud, they can form and evaporate in seconds.

"A thunderstorm goes through an entire life cycle in an hour. That makes forecasting very difficult," Zipser said.

In fact, scientists have yet to formulate a precise picture of what they call the dynamics and microphysics of clouds. Meteorologists, who rely on models and simulations, are working without an accurate model of why, for example, a cloud forms, or how particles within a cloud are sized and spaced, and what determines a cloud's life cycle.

Why is this important?

"We want to understand clouds on a microscopic scale so we can determine the impact on a massive scale," said Mace, who is one of half a dozen lead scientists who conceived of the experiment.