Van Gogh imprisoned stars like yellow daises smashed behind a sheet of blue glass. Winslow Homer abandoned a casual boater between angry waters and a bludgeoned cadre of clouds. Gerhard Richter stole and melted down the gray winter air into a series of polished mirrors. In each case, a painter sought to capture a small sliver of the dramatic and ever-changing atmosphere.

Another kind of artist, an engineer, is also attempting to frame the sky in a box; in his case, the canvas is a laboratory. Gordon McKay Professor of Environmental Chemistry Scot Martin studies the behavior of the billions of particles that comprise the atmosphere. “In the environmental area, every problem has many dimensions: biological, chemical, physical,” he says.

His research group uses a multidisciplinary approach to tackle a range of projects concerned with understanding and quantifying the chemistry of surfaces in environmental chemical systems. Although surfaces may seem better territory for geologists or archeologists than for an environmental chemist, what controls the formation and reactivity of a surface ultimately influences our entire atmosphere.

Martin views the earth as a huge chemical reactor. “Think of acid rain,” he says, citing a common example of a vicious cycle initiated by human activities. “Sulfur and coal get emitted. In the atmosphere SO2 gets transformed into sulfuric acid. Acid rain enters into the mineral-rich soil. The acids plus the H2 proton react and the minerals release aluminum, which is taken up in the plant roots. This causes phytotoxicity. Trees [and other plants] die. It is all chemistry: One thing is connected to the next, and one cycle drives the next.”

To understand such a chain of events, environmental chemists must first resolve the tension between studying the atmosphere in its full complexity and doing so in a limited but more manageable laboratory setting. In the field, researchers rely on balloons, aircraft, and on-the-ground deployments to obtain real-time atmospheric data that can be used to generate robust climate models, such as warming or cooling trends. “At the same time, if you are in the full soup, it can be difficult to understand everything is happening,” he says. “In the lab we can make things simpler so they can be better understood. But while we understand what we have in the box, we must make the bridge to relevancy. So, we try to look at the natural system and divine the most important set of factors and carry those back to the laboratory.”

As a postdoctoral student at MIT during the mid-1990s, Martin worked with a research team to “bring the ozone hole down to earth.” The group isolated the surface reactions that occurred on polar stratospheric clouds. They then set up lab studies to understand how the chemical transformations took place on surfaces and with further analysis gained a better understanding of the chemistry and causes of the ozone hole. He’s now using similar methods to put another troublesome genie into a bottle: cloud formation.

“A big effort in my research these days is the Harvard Smog Chamber. We’ve been looking at the reactions of organic particles and specifically how they interact with ozone, hydroxyl radicals, and other atmospheric species for some time now. But what we really want to know is, what’s the net result in the atmosphere?” For example, when organic particles are first released from diesel engines, water doesn’t readily condense on them to form clouds; they are hydrophobic. However, when they interact with ozone or hydroxyl radicals, the particles become more oxidized (more or water-loving or hydrophilic). The emission of organic particles and their conversion from phobic to philic is potentially changing how clouds form, which in turn effects climate change.

Currently, the oleic acid particles (like those that come from the meat smoke of outdoor barbecues) Martin uses to analyze this process in the lab are relatively pure. They last for about two minutes before breaking up. “In the atmosphere, however, we know oleic acid is present for at least two weeks. Why the difference? In the lab we study pure oleic acid, but in the atmosphere oleic acids are inside particles of other molecules, and the matrix of those other organic molecules is slowing the organic reaction with particles.”

The smog chamber allows Martin to create particles of a complexity similar to what’s actually in the atmosphere. The indoor approach also offers a great advantage: Every ingredient in the smog recipe will be known and accounted for. Even so, it takes a three-sided process to ensure the air doesn’t slip right through Martin’s hands. The three sides are lab researchers (such as his team), modelers (like Vasco McCoy Family Professor of Atmospheric Chemistry and Environmental Engineering Daniel Jacob), and in-the-field measurers (Jim Anderson, Philip S. Weld Professor of Atmospheric Chemistry, and Steven Wofsy, Abbott Lawrence Rotch Professor of Atmospheric and Environmental Science).

“A typical process is to work in the lab for several years on a particular project and get a set of results. We then have a couple of choices. We can publish the results in the open literature and wait for someone else to find them or use them; but that’s not always satisfying. Or we can take the lab results and put them into a model (that pulls additional data from hundreds of other sources) to find out what the consequences are.” At DEAS that translates into a short walk down the hall to the Harvard Atmospheric Chemistry group.

Some of Martin’s work will soon get the real test. “We have developed a number of theories on atmospheric particles over the last ten years. Now we are making an apparatus where we will actually start testing these theories directly in the atmosphere,” he says. He plans to start simply, putting a tube out the window, and then move to the roof. For the next steps, he will hit the road, taking a trip to the Harvard Forest in Petersham, Massachusetts, and then go to an oceanside location. The hardest final trip is navigating the public sphere. He hopes that all his data, whether on the ozone hole or cloud formation, will one day help inform policy makers’ decisions about climate or other environment regulations. Although progress on stemming the tide of pollution may be slow, Martin takes a philosophical approach to the state of the environment.

“Whatever condition I’ve been in all along, I’ve always tried to make the best of it,” he says. “I don’t feel frustrated or confused, and [I] focus on how to assess where we are now. Wherever we are, if it is a bad place, it is not my fault; if we are in a good place, it is not to my credit. I am a very small person in all of that. I try to assess where we are now and assess how I can change that direction for the better.”