|Anne Douglass: Making the World Safe for Blondes||
When Anne Douglass tells you what she does for a living, she laughs and says she is "making the world safe for blondes" -- not exactly the way her job is described in her NASA employment file.|
Image to right: Anne Douglass hopes to make the world safer not just for blondes, but also for her young grandchildren. Credit: NASA
Douglass guides a team of NASA scientists working to answer fundamental questions about our planet and its atmosphere. One of those questions has to do with the amount of ozone present in the atmosphere's upper reaches. As this stratospheric ozone decreases, more harmful ultraviolet radiation penetrates to the Earth's surface.
It's this harmful ultraviolet radiation you try to block with your sunscreen and shades -- the kind with the bad reputation for causing sunburns and skin cancers. People with light-colored skin, like blondes, are particularly susceptible. So, Douglass's job description makes sense. And it goes without saying that making the world safe for blondes makes it that much safer for the rest of us as well.
Officially, Douglass is the co-leader for the validation working group on NASA's Aura mission. Onboard Aura will be several instruments for reading the chemical composition of the atmosphere. What does validation have to do with anything?
Right or Wrong Answers
Think about this example. When you solve a math problem, your teacher can usually check your results. That's because often there's only one correct answer, and only one or two ways to reach that answer. In other words, the final answer could be predicted in advance.
But when it comes to dealing with Mother Nature, there aren't any predetermined right answers. For a mission like Aura, scientists must pay close attention to make sure that all measurements are accurate. Whether the answers are right or wrong depends on exactly that.
For measuring the concentrations of gases in the vast mixture that we call the atmosphere, Aura relies on a set of four satellite-based instruments. It is also supported by instruments located on balloons, airplanes and on the ground. A key strategy in validating data is to use all of these instruments to check one another.
All instruments have their strengths and limits. Ground-based systems often work by gathering real samples of the atmosphere, making the data very accurate and verifiable. However, these earthbound instruments read relatively small areas for short periods of time.
Satellites are able to cover the entire globe. Without collecting any actual air samples, they collect huge amounts of data for longer periods of time. However, while the onboard remote sensors measure conditions in the upper atmosphere fairly easily, they encounter problems when they try to look downward through the lower atmosphere, or troposphere. For example, measurements can be obscured by clouds, dust, aerosols or other obstacles. Since these measurements are so difficult to get right, it is especially critical that they are validated by readings from other instruments. That way, scientists can have confidence in the results.
Steps Along the Way
Douglass not only leads the Aura mission validation team, but as a scientist she conducts her own research. And lately she also finds a little time for her newest pastime: tap dancing. Dancing poses a tough challenge, but Douglass meets it the way she's met many others -- with determination and hard work, attributes that make her both a good scientist and a good student.
Douglass's interest in science and math started in high school. She was inspired by her math teacher, Sister Barbara Garland, who demonstrated that women could excel in math and science. Sister Garland selected Douglass for special math classes in which she was encouraged to develop her own approach to problem solving.
In college, Douglass was attracted to physics because it told the story of how the world works. She especially liked analyzing crashes and collisions and explaining them using math. In contrast, the worlds of biology and chemistry were "too smelly and messy" for her undergraduate tastes -- tastes that have changed since receiving her doctorate from Iowa State University.
At NASA, her research cuts across the worlds of biology, chemistry, physics and math, as she plays a key role in creating accurate global computer models of the Earth's atmosphere. Douglass has been working to refine these models for more than a decade. She points out that their accuracy steadily improves as new and valid data become available. And data from the Aura mission should be the best to date.
The research is critical. The world's scientists depend on good models for making predictions about future changes in global climate and the rates at which the changes will occur. And, on the basis of these predictions, world leaders consider policies necessary for the health of a changing planet. A tough assignment? No one said that keeping the world safe for blondes was going to be easy!
Adapted with permission: ChemMatters magazine © American Chemical Society 2002
Edited by Dan Stillman, Institute for Global Environmental Strategies