ISSAOS Meeting Focuses on Supercomputing Concepts

A total of 45 students participated in the 2016 International Summer School on Atmospheric and Oceanic Sciences (ISSAOS), titled “Advanced Programming Techniques for the Earth System Science.” Six continents were represented both in person and remotely, as all the summer school materials—lectures, workshop examples, and tutorial information—were also offered online to the students.

This year the International Summer School on Atmospheric and Oceanic Sciences (ISSAOS) in L’Aquila, Italy, featured a high-performance computing (HPC) theme for the first time in an effort to introduce earth sciences and climate students from around the globe to supercomputing concepts. Valentine Anantharaj, computational scientist at the Oak Ridge Leadership Computing Facility (OLCF), a US Department of Energy Office of Science User Facility located at Oak Ridge National Laboratory (ORNL), contributed to the event’s organization by suggesting HPC topics, delivering lectures, and leading workshops.

Since its beginning in 2000, ISSAOS has featured themes such as aerosols and climate change, atmospheric data assimilation, and chaos in geophysical flows. People from various institutions and backgrounds in the climate sciences come to the weeklong summer school to engage in lectures taught by computational scientists representing institutions in North America and Europe. This year’s summer school, titled “Advanced Programming Techniques for the Earth System Science,” informed climate-science PhD students about computer architectures, HPC programming techniques, and osftware tools that may benefit their research. A total of 45 students attended the 2016 ISSAOS.

“Students might know their science but also may have to face many technical aspects that are difficult in the beginning and aren’t fully covered in university courses,” said Gabriele Curci, researcher at the University of L’Aquila and organizer for the event. “The aim was to provide the basics for these students.”

This was the first year a staff member from ORNL played a leadership role at ISSAOS, which is organized by the Center of Excellence for the Forecast of Severe Weather at the University of L’Aquila. Anantharaj is a member of the Advanced Data and Workflow Group at the OLCF.

During the HPC overview lecture on the history of the field and the world’s top computers, Anantharaj emphasized the critical role of HPC services—often behind the scenes—that are provided via user assistance and HPC operations. On the second day he gave a lecture on how to parallelize code using Message Passing Interface (MPI), a standard communication protocol for programming with parallel computers. The lecture was followed by a hands-on session in which students employed techniques discussed during the lecture.

Anantharaj said that many of the hands-on sessions featured exercises that students could do on their own to strengthen their HPC skills in relation to their fields. Anantharaj has adopted a two-dimensional shallow water model, often used in academic coursework, and provided it as a take-home exercise for the students to apply their newly learned MPI and other HPC programming skills.

“Learning how to take simple examples from their studies and implement them into an HPC framework is going to be useful for this community,” said Anantharaj, who is collaborating with Peter Duben from Oxford University to further refine some of the session material to make it available to the community. “This approach, based on the domain science, allows the students to get a deeper understanding on how to solve real-world problems they are likely to encounter.”

Anantharaj also talked about OLCF resources with attendees. Anantharaj’s hands-on MPI session gave students access to Metis, a scaled-down version of the OLCF’s leadership-class hybrid Cray XK7, Titan. The summer school provided informal opportunities to discuss the challenges of computational climate sciences in the exascale era and explore other science collaborations in the future through the OLCF’s discretionary allocation projects.

Curci said he felt the hands-on sessions were the most useful part of the school for the students because they provided a way for them to apply techniques they learned in the theoretical lectures. “This is really the typical example of the idea that you can’t understand something until you do it,” he said. “The students all said that it was really useful, both for their careers and for their continued education. I think they have a good path going forward.”

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