Doug SistersonBy Louise Lerner • February 5, 2012
Doug Sisterson is a research meteorologist at Argonne who works with the Atmospheric Radiation Measurement (ARM) Climate Research Facility as manager of its Southern Great Plains site and Instrument Mentor Coordinator. The user facility has been operating climate observing sites around the world for nearly two decades.
How did you get interested in science?
I was always good at numbers. When I went to college I was a physics major. And it was fine, but I realized after getting through physics that a lot of it involved small particles I couldn't see, and I realized as time went on, what would I do with this when I graduated? I really liked being able to see what I was studying.
And I remember the summer before senior year we were moving into a new physics building, putting all the equipment into a truck and moving it over to the new location, and a thunderstorm blew up. Boy, the skies got blue-green, and the winds came up and the sirens went off and hail started falling the size of golf balls and it was shattering windows and people running and screaming and I was there going "WOW! What is this?" "Meteorology!" "What do you need to understand this?" "You need to know physics." "I'M THERE!" So that shaped it for me. When I came back to school that fall, I learned more about what it meant to be in meteorology, and that shaped what I did in graduate school, and ultimately what I've come to do at Argonne.
And what exactly is it you do at Argonne?
Well, when I first came to Argonne, the first thing I did was launching weather balloons to study: How does the atmosphere work? How does the lowest three miles of the atmosphere form? The atmosphere warms up during the day because of the sun's energy, and we get vertical air plumes—eagles soar because they see the updrafts, for example—but at night, the atmosphere seems to be very calm at the ground. I remember very clearly, my first year here, that at nighttime you think the atmosphere is very calm—you can drop a blade of grass and it falls straight down—and yet we were in the middle of nowhere with this windmill 100 feet in the air and that thing was turning to beat the band. So we are sitting there saying, "It's zero at the surface but it's 25 miles an hour just 100 feet above the ground; how could that be?"
We were looking at understanding just the basic fundamental behavior of the atmosphere, how it breathes and exchanges air at the lowest 3,000 feet, and it was just fascinating. Our findings had their first application with wind energy. (Gas got expensive in the seventies.)
What did you discover?
Everybody thought that by the sea or in canyons the wind would blow all the time, but they didn't realize that at nighttime the wind blows too. We thought the entire lower atmosphere was all calm, because all of our instruments measure weather near the surface and indicated no wind. As soon as we started staying up till 4 a.m. launching all these weather balloons, we realized that maybe 40% of the evenings here in the Midwest had more than enough wind energy to turn windmills and generate wind energy.
So that was the first jumping from basic research about how all this works to "Oh wow, here's an application for wind energy." That helped me get into the next segue, which was acid rain. That was the big thing in the late seventies. What researchers thought was local pollution was responsible for acid rain. Most of the atmospheric models were based on Chicago making its own pollution; i.e., during the day we breathe in all of the pollution from Chicago and the next day we breathe it all again. Because researchers used to think the wind speeds were near zero, all the computer models would never move the pollution from Chicago. But researchers eventually realized that the wind does move at night and pollution does move with the winds. So Chicago's pollution was not only from Chicago, but also from upwind cities, like St. Louis. Well, now that we knew the wind blows at night, all the models were corrected and we could see that St. Louis pollution would be carried on the nighttime breeze and be carried longer distances in the evening air and mix with in with the Chicago air. Any pollution source that is upwind can contribute to the Chicago problem. So, not all of the pollution in Chicago is Chicago's fault.
So that gave the idea of what we call long-range transport of pollution. One city isn't just responsible for its own pollution; Chicago could be mucking up air that's in the northern parts of Michigan that are supposed to be pristine. It created a whole new way of thinking—that pollution isn't just a local problem.
What did you learn about acid rain?
Yeah, so I got into looking at acid rain; how do these sulfur gases and sulfates and nitrogen and nitrates get into the rain, and how do they change the acidity of the rain? I found out that it made a difference what type of rain was occurring, whether it was thunderstorms or just the all-day lazy kind of rain with no thunder or lightning; the chemistry of the rain was substantially different. And that was pretty cool, because there were now working with terrestrial ecologists trying to figure why, after acid rain, sometimes the crops showed damage and sometimes they didn't. And the difference was explained by the storm type. For example, when it starts to rain during a big thunderstorm, it just sucks up all that air and makes it all part of the cloud process. Because it only rains slowly at first, the rainfall has high concentrations of pollutants. As soon as it starts to rain harder, the rain dilutes all those pollutants and the concentration of pollutants becomes much less.
If you were to take a rain sample every minute in a thunderstorm—which is what I did at Argonne—and watch how the chemistry changes, it's very different during the course of a rain. In the beginning there's more pollutant than rain and the rain can be very acidic. But as the rain intensifies, the atmosphere got cleaner, and so there was less pollutants and the acidity of the rain was much less. And the case of non-thunderstorm rain, which is just steady rain all day long, it doesn't rain hard enough to remove all the pollution all at once. It removes the pollutants at a rather steady rate, so if you looked at sequential samples, the acidity did not change much during the rain event.
If you just collected one bulk sample, you would never know there was such a wide range acidity of rainfall during a storm. But the plants know! In talking with the terrestrial ecologists, the plants could respond to changes in chemistry on the order of seconds. If the rain acidity hits a threshold that was toxic to them, that was it—they'd show some form of damage.
Like human-built cities modified weather, human-produced pollution could modify the rain chemistry and affect plants. I found a connection between human activity and Mother Nature. Studying human impact on weather led me to climate.
But I made a transition from researcher to manager for climate studies. It seemed that all my experiences and personality were more suitable for managing a facility that would provide data to a large number of researchers. I was good with that!
What keeps you interested in your work?
It's never the same. The problems that we have when we manage researchâ€”we have sites all over the world—are never the same. We go where the measurements need to be made—often to small nations like Nauru or Papua New Guinea, to large countries like China, India, or Africa. Events in these countries have a huge impact on weather patterns in our country. When you have worldwide operations like that, you have to negotiate with governments just to do the science. There are aspects to doing science that you never thought of. And that keeps the job hopping. It's typical issues like trust and politics and security, but each country goes about these things very differently. It's nice in that it's busy, but it's never repetitive. And it's never boring!
What's the Holy Grail in your field?
Science is by consensus. There's no book with the right answers that we can look up the cure for cancer and that's that. We have to do scientific experiments and get colleagues to believe that what we've proposed to explain this set of events has some universal application. And if we can get one more than half to believe it, then that becomes what we believe: the consensus viewpoint, a theory. So the earth is getting warmer because we're burning fossil fuels. There's a great deal of scientists agreeing to that statement—something like 95% out of 5,000 scientists studying climate agree. But the problem is, you want to know what's going to happen where you live. But that's very complex. That's where we don't have consensus. So we have consensus on the earth getting warmer but we don't have consensus on how that will manifest itself through local weather patterns where we live. So that can get really confusing to the public with one scientist saying one particular thing will happen and another saying "No, you didn't take into account that the earth wobbles or has sunspots or whatever."
I think the hardest part for me personally is to give credibility to the research we're doing for climate, so the public can understand fact from fiction. Is global warming the real deal, or is it just a good story? That's the title of many of the presentations I've given. Climate change on the global scale is the real deal, but the timing and magnitude is not certain.
Do you have any advice for people who want to get into science?
Oh, yeah. Pet peeve for me—I didn't realize that you could have a career as a scientist. When we were growing up it was all about doctors and lawyers and so forth. So smart people thought that they had to be lawyers, or doctors. Well, why couldn't you be a scientist? If you are smart and curious about how things work, maybe you should be a scientist.
People don't think of science as a profession, they think of scientists as these nerdy kinda people like Albert Einstein who wear lab coats and walk into walls and talk to themselves. And yet it's a noble profession and also a fun one. It's social, too. You're your own boss, but you do work with colleagues, so it's highly social. I think there's a lot of creativity. You can come up with good ideas, and if you are right, they'll name the theory after you. For the most part I think it's a very engaging profession, so if you've got kids—my favorite group to go talk to is always the middle-school group—let them be aware there are other professions. Do you ever think about science, engineering, the weather, computers? Science is a career. Scientists make a pretty good living!
What do you do for fun when you're not working?
I'm an outdoors person, and so are my wife and three kids. We do rock climbing, fishing, canoeing, white-water rafting, biking, skiing. We also garden. I have a pond that I dug by hand—it's pretty big, too!—that we stocked with fish and native plants. We also love camping. Yeah, I'd like to think that I'm a real person in my spare time.