August 4, 2010 | During the week of June 15–18, more than 70 upper-atmosphere researchers looked back—and up—at the history and current state of research on climate change in the stratosphere, mesosphere, thermosphere, and ionosphere. The week was capped by a daylong symposium on June 19 in honor of HAO’s Ray Roble, who recently retired and is now a senior scientist emeritus.
Every two years, members of several scientific organizations (IAGA/ICMA/CAWSES) hold a meeting to discuss the latest on long-term changes and trends in the upper atmosphere. NCAR’s Center Green played host to TRENDS 2010, which was the sixth such workshop.
Once the TRENDS 2010 meeting had been set for Boulder, organizers saw a perfect opportunity to honor Ray’s 40 years of solar and aeronomy research. In 1989, Ray and longtime NCAR colleague Bob Dickinson (now at the University of Texas at Austin) were the first to model and study changes to the upper atmosphere that human-produced greenhouse gases might induce.
“People in the community really wanted to have a symposium to honor Ray, but we were afraid that he would not agree,” says Liying Qian (HAO), one of the meeting’s organizers. Once Liying finally told Ray about the plan, the ever-humble Ray acquiesced.
The meeting turned out to be a festive reunion of key people from throughout Ray’s long career, from recent graduate students to Ray’s thesis adviser at the University of Michigan, Paul Hays. Among the highlights, a certain S. Solomon (Stan, from HAO) introduced a talk by another S. Solomon (Susan, from NOAA). As Stan noted, their two paths have intersected in sometimes confusing ways: “I came to NCAR in the fall of 1987 and discovered that all my mail had been forwarded to Antarctica [where Susan was stationed at the time],” he said. “It’s an honor to be mistaken for Stan," Susan said. And, she added, "It’s a tremendous honor to speak at this symposium.”
Susan’s talk addressed the relationship between solar proton events and the middle atmosphere. Also on the program was former NCAR director Tim Killeen (NSF), who spent several summers visiting NCAR and working with Ray in the early 1980s. “I think I learned how to write by watching Ray Roble write papers,” he said. Tim also noted Ray’s “unselfishness in scientific collaboration, but with an insistence on rigor” and his “patient training and mentoring of several generations of atmospheric scientists.”
Bob Dickinson recapped his prolific work with Ray, including a two-dimensional model of the upper atmosphere forged in the early 1970s with software engineer Cicely Ridley. Encouraged by the results of 2-D modeling, he and Ray built a comprehensive 3-D upper-atmosphere model in the early 1980s. It was extended to the atmospheres of Mars and Venus later in the decade before Ray and Bob used it to study global change on Earth.
“I’ve worked with many people in my career,” Bob said, “but I think [Ray] was probably the most productive, hardest-working person I’ve worked with, and I learned the most from him.”
The symposium opened with a talk from Ray himself, who brought his landmark 1989 climate-change paper up to date with more recent data. In this new “extreme sensitivity” study, Ray found that many of the 1989 calculations remained on track. However, new data on nitrogen oxide show roughly five times as much in the thermosphere as previously thought, which influences predictions of future NO concentrations and highlights the upper atmosphere’s sensitivity to climate change. Overall, Ray said, the new work reinforced the notion that signs of climate change in the upper atmosphere should be most evident during solar minimum.
Ray noted that there are “all sorts of dynamic and other interactions that should be looked at” in the future, including variations in atmospheric tides and the global electric circuit.
As for the symposium itself: “This is just incredible,” Ray said at the start of his talk. “It’s very exciting.” Afterward, he added, “Special thanks go to Stan and Liying for making this day such a memorable event.”
Watch videos of each presentation at the Roble Symposium.