E3SM Scientists Organize Numerical Methods Session at AGU Ocean Sciences

The Ocean Sciences Meeting (OSM) is the largest gathering of ocean scientists in the world, with nearly 6,000 attendees. This biannual conference, sponsored by the American Geophysical Union (AGU), encompasses physical, biological, and chemical oceanography, and topics range from shipboard studies to satellite observations and modeling campaigns.

E3SM scientist Mark Petersen of Los Alamos National Laboratory has been hosting a session titled “Numerical Methods in Computational Oceanography” for the past three OSM conferences. “All the ocean modelers attend AGU Ocean Sciences, but previously there were no sessions specific to scientists who develop algorithms, verify the models, and improve performance”, said Petersen. “We come from different institutions but struggle with many of the same issues. This is a venue to share our research and catch up on the latest methods in ocean modeling.”

At this year’s OSM, held February 18-23 in New Orleans, Petersen was joined by co-chairs Steven Brus from Argonne National Laboratory and Jeremy Lilly from Oregon State University. Petersen and Brus are team leaders for the E3SM ocean component, and Jeremy Lilly is a graduate student who develops ocean time-stepping methods for E3SM under the ICoM Project.

“Numerical Methods in Computational Oceanography” included a poster session with 15 presenters and an oral session with eight speakers. Many of the world’s top experts were presenting, including Raffaele Ferrari from MIT, Robert Hallberg from NOAA GFDL, and Oliver Fringer from Stanford University. The session provided the opportunity for five graduate students and nine early career scientists to present their work to an audience of specialists in their field.

The oral session was well attended, with 200 in the audience and standing room only for the most popular speakers. Highlights included an overview of the Oceananigans model by Raffaele Ferrari, demonstrating that the Julia-based code runs efficiently on GPU architectures for global resolutions of 1/12 degree. Another Oceananigans talk by Simone Silvestri demonstrated the ability of the Weighted Essentially Non-Oscillatory (WENO) reconstruction scheme to improve the effective resolution of the model at ⅙ degree. Theresa Morrison discussed GFDL’s efforts to have embedded sea ice in the MOM6 ocean model to allow for a representation of gravity waves due to sea ice pressure and improvements in coupled model stability. Samar Khatiwala gave a talk on an Anderson acceleration procedure to increase the efficiency of computationally expensive ocean model spin-up simulations, which is a long-standing issue in the ocean modeling community. Graduate student Aditya Saravanakumar presented his work on adaptive coupling between hydrostatic and non-hydrostatic models using the hybridizable discontinuous Galerkin method.

Building personal relationships in these sessions has long-lasting benefits. One of the presenters, Ange Ishimwe, a graduate student at Université Catholique de Louvain in Belgium, spoke about his research on ocean time-stepping methods.  He said, “This is the first time I’ve been able to speak with researchers who are so intricately familiar with my area.”  Soon after the conference, Ange invited Petersen to participate in his PhD thesis review.

The session was particularly meaningful to Jeremy Lilly, who will be defending his PhD dissertation this coming June. Due to the COVID pandemic, most of his previous conferences had been virtual, including the 2022 Ocean Sciences. As an early career co-chair, he was able to meet many researchers for the first time whose papers he had read during his PhD research. Lilly said, “The opportunity to help organize and attend this session was invaluable. Getting to see and speak with folks that I had previously only interacted with remotely was fantastic, and I look forward to many such great sessions in the future.”

This session benefited E3SM participants by providing a forum for an open exchange of ideas about the numerical methods at the heart of state-of-the-art ocean models. Bringing the together a group of model developers in this way was an opportunity for E3SM staff to expand the project’s network of potential collaborators amongst a broad community.

Additional references can be found in the previous article on Ocean Science Meeting.