2012 Rossby Medal Goes to Turbulence Researcher

August 17, 2012 · 0 comments

John Wyngaard, professor emeritus of meteorology at Penn State, is the 2012 recipient of The Carl-Gustaf Rossby Research Medal. He earned this distinction—meteorology’s highest honor—for outstanding contributions to measuring, simulating, and understanding atmospheric turbulence.

John Wyngaard

Wyngaard received the medallion at the AMS Annual Meeting in New Orleans.

The Front Page corresponded with him via email to learn more about his research interests, his academic career, and the experiences that brought him to this pinnacle of a life-long career in meteorology. The following is our Q and A session:

Tell us a little about your research accomplishments and how they relate to ongoing challenges with atmospheric turbulence.

Since the advent of numerical modeling in meteorology a principal challenge has been representing the effects of turbulence in the models.  My colleagues and I have often presented and interpreted our turbulence studies in that context. I have also worked in what I call “measurement physics,” the analytical study of the design and performance of turbulence sensors. It has been somewhat of an under-appreciated and neglected area.

What events or experiences sparked your interest in meteorology?  How about atmospheric turbulence?

My interest in meteorology developed relatively late, when I was well into in my 20s and enrolled in a PhD program in mechanical engineering. I think that is not unusual; as I look around our meteorology department here at Penn State I see that a good fraction of the faculty do not have an undergraduate degree in meteorology.  Thus I’ll relate my story in some detail because it touches on an important point that might not be well known—the great career opportunities that exist in meteorological research for people whose backgrounds are not particularly strong in meteorology.

As I grew up Madison, Wisconsin, an idyllic town in the 1950s, I came to know that I would study engineering at the University of Wisconsin.  I loved my years at UW—I worked half-time in the student bookstore, pursued my car-building hobby, had a few girlfriends, and probably drank too much beer—but  I made sure to do well in my classes. When I received my BS in mechanical engineering in 1961 I did not even consider getting a job;  I loved my student life too much, so I entered the MS program in mechanical engineering.

This was during John Kennedy’s presidency, when the funding for National Science Foundation (NSF) graduate fellowships was increased because of the perceived threat from the Soviet Union. In early 1962 I spent a cold winter Saturday in Science Hall taking the NSF graduate fellowship exam. I was awarded a three-year NSF fellowship. My father was incredulous: “They’ll pay you to go to school?”

I was then finishing my MS under a professor who was about to leave UW for a position at Penn State. In June of 1962 I followed him there.  That fall I enrolled in a course in turbulence taught by John Lumley, a young professor of Aerospace Engineering.  Turbulence was then seen as a murky and difficult field; it was not yet possible to calculate it through numerical simulation. But I was intrigued and asked Lumley if he would be my graduate adviser.  He agreed, and my academic course changed.

Under Lumley’s guidance I did experimental work—measurements in a laboratory turbulent flow—which suited me well, but I also developed some confidence with the theoretical side.  My introduction to atmospheric turbulence was Lumley’s course that gave rise to his 1964 monograph, “The Structure of Atmospheric Turbulence” with Penn State Meteorology professor Hans Panofsky.

Lumley was on sabbatical in France when I finished my PhD, so I asked Panofsky, whom I knew only by reputation—I took no classes of his—for job leads.  Panofsky graciously gave me four names. I made four interview trips and soon had four job offers, which was not unusual then.

The most enticing offer was from Duane Haugen’s group at the Air Force Cambridge Research Laboratories in Bedford, Massachusetts. They were setting out to do the most complete micrometeorological experiment up to that time, in the surface layer over a Kansas wheat field.  I had studied the surface layer and I saw this as a great opportunity. I took the job (which I later learned had been open, without applicants, for several years) and participated in the 1968 Kansas experiment. It was an overwhelming success; the resulting analyses and technical papers represented a significant advance in micrometeorology. I was hooked.

In 1975 our group was put at risk by a scheduled downsizing of the lab, and I joined the NOAA Wave Propagation Lab in Boulder; in 1979 I moved across the street to Doug Lilly’s group at NCAR.  Much of my NCAR research was collaborative with Chin-Hoh Moeng and focused on the then-new field of large-eddy simulation—numerical calculations of turbulent flows such as the atmospheric boundary layer.

In short, the key experience that sparked my interest in meteorology was my involvement in the 1968 Kansas experiment and the subsequent data analyses and journal publications.

What then brought you to, or drove you to pursue, the current facet of your career?

After many years of research I joined the Department of Meteorology at Penn State in 1991, when the opportunity for teaching was attractive to me.  I developed and taught an atmospheric turbulence course, did research with students and post-docs, and did my best to express my long experience with turbulence and micrometeorology in the textbook, “Turbulence in the Atmosphere” (Cambridge, 2010). I retired in 2010.

You stated, “Turbulence was then seen as a murky and difficult field;” was it the challenge of working to understand the so-far undefined field of turbulence that you found so intriguing?

Richard Feynman, the famous American physicist, called turbulence “the last great unsolved problem of classical physics.”  That underlies my comment “a murky and difficult field.”

Also, you mentioned that you did experimental work under Professor Lumley on laboratory turbulent flow, and stated that this “suited me well.” How so, or why—was this the connection back to your mechanical engineering experience you had been seeking (knowingly or unknowingly)?

Before we had computers the main approach to turbulence was observations— i.e., measurements.

My mechanical skills allowed me to build and use turbulence sensors to make the measurements I needed.  I was good at that—in part, I think, because I had all that car-building experience, which I now realize does translate to doing turbulence measurements. (One doesn’t often think about these kinds of things, but when I was a child—4 or 5—I began building “shacks” [little clubhouses]  in our back yard, using crates from grocery and furniture stores. My mother fostered that, God bless her.)

With an interest in NEW observational approaches to remotely sense turbulence, what has you most excited?

There is a long history of theoretical studies of the effects of turbulence on the propagation of electromagnetic and acoustic waves, and this underlies the field of remote sensing. Detecting turbulence remotely is relatively straightforward; obtaining reliable quantitative measurements of turbulence structure in this way is much more difficult. It remains an important challenge.

What would you say to colleagues as well as to recent graduates in the atmospheric and related sciences asking about the importance of such achievement?

It demonstrates a life lesson: If you find a job that you can immerse yourself in, you’ll draw on energy and skills that you might not know you have and you’ll succeed beyond your dreams.