Professor of geology and geophysics Steven Sherwood resembles Indiana Jones in the photograph on his Web site: he wears a cowboy hat, a strap-on canteen, a five o’clock shadow and a charming half-smile. John Williams ’05, who has taken two classes with Sherwood, was surprised when he saw the picture.

“I imagined him working at a desk, deriving really complex formulas,” Williams said.

Described by several colleagues and students as serious and hardworking, Sherwood recently won the 2005 Clarence Leroy Meisinger Award for his research on the interaction between clouds and particles. The American Meteorological Society gives this award annually to “young, promising atmospheric scientists” under 40 years of age, according to the society’s Web site.

“It’s the best award that I’ve gotten,” Sherwood said when reached in New Zealand, where he vacationed with his family this week. “I’m proud of that.”

Sherwood studies atmospheric processes in the tropics where frequent forest fires release aerosols — particles of dust and smoke — into the air. He uses satellite data to analyze the impact of aerosols on clouds.

To explain the basics behind his research, Sherwood referred to a poster of a cold Steinlager bottle covered in beads of water.

“Droplets always have to form on something, whether it’s a beer bottle or an aerosol particle,” Sherwood said.

He explained that a cloud is a swarm of water droplets suspended on aerosol particles. When forest fires produce aerosols, clouds are affected, and the climate changes. Sherwood has found that aerosols might decrease rainfall, and he said some speculate that they could reduce global warming.

Sherwood looks at “deep clouds,” which are further away from the atmosphere than the more-studied “shallow clouds.”

“The cloud types I am looking at have received almost no attention,” Sherwood said. “This is a kind of area where there’s a lot of work to be done.”

At Yale, Sherwood teaches various courses on meteorology, radiation and climate. In the two courses Williams took, Sherwood explained atmospheric phenomena that are familiar but difficult to understand.

“He gave us a lab on bathroom studies — why a shower curtain moves into you when you’re taking a shower,” Williams said.

Sherwood also described why things appear darker when they are wet, Williams said.

Catherine Izard ’06 remembered making radiometers in Sherwood’s “Introduction to Meteorology and Climate” class. Students built the radiometers using construction paper, Saran wrap, tin foil and shoeboxes and then went to the roof to measure radiation. While Sherwood’s more interactive classes sound fun, his lectures could be dry or difficult to understand, some students said.

“He’s obviously brilliant, but his effort isn’t really in teaching,” said Williams, voicing a common sentiment. “Some of it went over my head.”

Williams said Sherwood’s course on “Radiative Transfer and Climate” was the hardest he has taken at Yale.

If scholarship is Sherwood’s strong suit, he is in the right place this semester. Sherwood will spend the next few months writing and researching at Monash University in Melbourne, Australia. According to his Web site, Sherwood has authored 31 studies and articles.

“It’s quite a few papers,” professor of geology and geophysics Alexey Fedorov said. “It’s quite a few for the place he’s now in in his career.”

Sherwood has a lighter side as well. Fedorov, who graduated from Scripps Institution of Oceanography two years after Sherwood, recalled spending Friday nights on the beach with him. They and other graduate students would chat and drink beer.

“He was a very serious person, not a nerdy type of person,” Fedorov said. “It’s a very nice combination of being serious and hardworking without becoming a nerd.”

A Dilbert cartoon on Sherwood’s Web site reflects his work ethic and his humor. In the cartoon, Wally reports to his colleagues: “This week, I achieved unprecedented levels of unverifiable productivity.”

Sherwood sometimes made jokes in class, though they often went over students’ heads.

“He had a dry sense of humor which was scientifically based,” Williams said.

Sherwood said his greatest personal achievement is his family. He has a wife and two young children, whom Izard described as “oh my gosh, adorable.”

In 2003, Sherwood agreed to add his name to list of scientists named “Steve” who believe that science curricula in public schools should not include creationism or intelligent design. The list, compiled by the National Center for Science Education, was a lighthearted jab at creationists who assemble lists of “scientists who doubt evolution,” according to the NCSE Web site.

Sherwood praised the federal judge who recently ordered a suburban Atlanta school system to remove stickers from its high school biology textbooks. The stickers called evolution “a theory, not a fact.”

Still, Sherwood said the word theory is inappropriate in this context only because the public misunderstands it.

“To the average person, theory has a connotation of dubiousness,” Sherwood said. “The word ‘theory’ to a scientist is not disparaging. Gravity and relativity are theories. Evolution is only a theory. Science should be taught not as ‘this is the way it is,’ but as ‘this is a theory we have.’ Science is never done.”