July 6, 2012 | Fresh faces in the lobbies, lively discussions in the halls, old friendships renewed—it’s summer at NCAR & UCAR, and that means visitors. Hundreds of people attend our colloquia and workshops each year from June to August.
Two of the biggest confabs are centered on flagship software: the NSF- and DOE-sponsored Community Earth System Model (CESM) and the multiagency Weather Research and Forecasting model (WRF). On June 18–21 nearly 400 people attended the 17th CESM Workshop, held in Breckenridge. The following week WRF conducted its 13th annual workshop, which drew 240 participants from 22 countries to Center Green.
And for longevity, it’s hard to beat the ASP Summer Colloquium, which marked its 47th year on June 4–22 at the Mesa and Foothills Labs with an exploration of the interface between weather and climate.
The ASP colloquia give early-career scientists a chance to dive deep into a topic and learn from renowned experts, with plenty of time for Q&A. This year provided a rich vein of material: the Madden-Julian Oscillation, which sits at the weather-climate intersection, was one of the key discussion topics.
Last year ASP expanded the meeting from two weeks to three, with the middle week designated as a researcher colloquium that drew a wide range of specialists to discuss especially knotty science problems. For example, hurricane expert Kerry Emanuel (Massachusetts Institute of Technology) posed a simple but tantalizing question: why does our planet generate around 90 tropical cyclones each year, rather than 9 or 900? “It remains an enigma,” said Emanuel.
This year’s colloquium brought 28 students from several nations. “We had a fantastic group,” says George Kiladis (NOAA), who coorganized the meeting with Mitch Moncrieff (NESL/MMM) and Lance Bosart (University at Albany, State University of New York). George was especially impressed at the projects carried out by seven groups of students and presented on the final two days. “In several cases, I believe that the students will continue to pursue their projects, which to me is the ultimate sign of success,” says George.
The interface theme of the workshop carried through to extracurricular activities. On a weekend trip to Rocky Mountain National Park, the students observed the intersection of winter and summer first hand. “Nothing like walking through snow on a blazing June day at 12,000 feet to achieve that,” says Kiladis. The group also witnessed the Venus solar transit from the Mesa Lab tree plaza.
“I was pleased to see the depth and liveliness of the discussions of science throughout, the high caliber of the students, and the level of engagement across the experience spectrum, from student to senior researcher,” says ASP director Chris Davis.
It’s been a busy year for CESM and its many users. The model continues to gain new features and options, and it’s been called on extensively for studies that must be submitted by the end of July in order to be referenced in the next Intergovernmental Panel on Climate Change (IPCC) assessment. More than 30 of these papers—most with NCAR authors or coauthors—will appear in a special issue of Journal of Climate focusing on CESM and its predecessor model, CCSM4.
Some of the initial results from IPCC-related work were previewed at the CESM workshop in Breckenridge, which included daily plenaries, extensive working group meetings, and a poster session. In his plenary talk, NCAR postdoc Reto Knutti, now a professor at ETH Zurich, examined the notion of whether CESM is the “best” climate model. (Short answer: it’s excellent overall, but no model is perfect for every modeling task.)
CESM chief scientist Marika Holland (NESL/CGD) called out recent model developments in an opening plenary session. Among the highlights:
Ice modeler William Lipscomb (Los Alamos National Laboratory), winner of this year’s CESM Distinguished Scientist Award, discussed the enduring quest to understand rising sea levels. The ocean surface has risen by an average of about 3 millimeters a year since the early 1990s, but there’s some uncertainty over how much of that total comes from various sources, including glaciers and ice caps as well as the groundwater that flows to the sea after people draw on it.
“I liked that Bill gave a challenge to the community to quantitatively address all the various factors that contribute to sea level rise,” says Marika. “I think that we are close to being able to do that. As in past years, this meeting really helps highlight the amazing work—and the breadth and community nature of that work—being done under the CESM.”
When it comes to short-term weather modeling, WRF continues to be a global leader. The number of people using the model’s NCAR-based advanced research version, WRF-ARW, has doubled in the last three years to nearly 20,000, as noted by Joe Klemp (NESL/MMM) in his opening remarks at the WRF workshop. There are now registered users at some 6,300 universities, labs, and private firms in 140 countries.
The model itself continues to evolve, too, as covered by Jimy Dudhia (NESL/MMM) in his update on WRF developments. Version 3.4, released in April, includes new options for depicting cloud microphysics, radiation, and the land surface, among other enhancements.
The workshop was framed by an afternoon of pre-workshop lectures on the model’s treatment of cumulus convection, as well as five post-workshop tutorials on topics ranging from regional climate downscaling to visualization software. More than 100 attendees took advantage of these add-ons, says Jordan Powers (NESL/MMM).
Workshop participants had plenty of research to share, and most of them did so at the poster session that filled the CG auditorium on the workshop’s second day, June 27. The night before, an icebreaker scheduled for the ML tree plaza was hastily moved to the CG patio in the wake of the Flagstaff Fire’s rapid growth. The reception was a success, even if it had a surreal quality, says Kevin Manning (NESL/MMM). Instead of looking over Boulder from a mesa-top perch, “people were watching the smoke and flames and speculating on where the fire was going to go,” says Kevin.