Spotlight Researcher: Dr. Gretchen Mullendore
Spotlight Researcher: Dr. Gretchen Mullendore
At some time or another, every one of us has found ourselves sitting at a stoplight behind a massive 18-wheeler. The light turns green and we watch as the truck belches out a cloud of thick black smoke, rumbles a few feet, shifts gears, and throws another cloud of smoke into the air as it struggles to get up to speed.
Much of that smoke is made up of nitrogen oxides (NOx), sulfur oxides (Sox), and microscopic carbon soot particles, chemicals released at ground level and into the air. After a few seconds the cloud disappears, but what actually happens to the chemicals being released?
This is one of the many challenging questions atmospheric scientists, like UND's Dr. Gretchen Mullendore, try to answer.
Atmospheric Science is a broad field of study that encompasses multiple disciplines of research and analysis.
“The first connection people have is to the branch of atmospheric science that deals with forecasting and hazard awareness,” says Mullendore. “At this level, we interact with the work of atmospheric scientists every day on The Weather Channel, our local news, or in the paper.”
“The second major area of study in the field of atmospheric science is climate studies where scientists look at how our climate changes over time. In recent years, this has become extremely politicized.”
Specifically, a large part of Mullendore’s research looks at the transport of mass in deep, convective storms. “I model big severe storms,” she says with a smile.
Simply put, Mullendore measures the movement of pollution from near the earth's surface up through the atmosphere.
"There are chemicals near the surface of the earth in what we call the boundary layer.... Things like car emissions, factories, some natural things emitted by the soil, those are all trapped near the surface unless something comes along to pull that material away from near the surface. And the thing that can do that most quickly are big, deep convections--big storms. These big rotating storms are one of the most efficient ways...transporting material ten kilometers into the atmosphere in half an hour, with particle velocities getting up to 16 meters per second."
The movement of these chemicals and particles higher into the atmosphere allows them to travel much further. Exhaust from the semi in front of you at a stoplight, with the help of a large storm, could be spread through thousands of miles of the earth's atmosphere.
"Included in that are [chemicals] from factories and car emissions, things that might have been only emitted locally, can be transported upwards and then spread far out into the atmosphere," says Mullendore. "Even to the point where we know that chemicals that have gotten into the upper atmosphere that may have started in the US could be transported to Europe and to Asia; things that started in Asia can be transported to the US and to Europe."
The complex dance of particles and chemicals swirling in the atmosphere is mind-bogglingly complicated to imagine for most of us. The forces are great, the distances vast, the variables complex, but for Mullendore, the abstract art of chemical patterns in air is a seductive science, though not her original choice.
"I've always enjoyed nature, and always been fascinated by disasters--the power of nature, big earthquakes, big storms--but really what I got excited about when I was in high school was programming.... When I first went off to undergraduate [school] I continued on in programming, but at some point I realized that I also really loved science. It turns out the natural sciences needs lots of people who can program and are comfortable with computing."
Through an early oceanography class, Mullendore discovered an interest in weather. Her professor told her "if you love weather, take lots of physics and math," which Mullendore says is "the best advice I ever got." In graduate school at the University of Washington she was able to help write one of the models they used to study weather, and earned her Ph.D.
After stops in Seattle and Los Angeles, Mullendore and her husband chose to look for a place that would support her research as well as allow for the opportunity to teach. And beyond her work, Mullendore has found the area to be full of many of the fun exciting activities of larger cities with the convenience of a smaller place. "I think this [UND and Grand Forks] is the perfect place for me."
News & Features Editor
Craig Garaas-Johnson. "Spotlight Researcher: Dr. Gretchen Mullendore" (2012). UND News Features. 145.