The OPeNDAP team was at the American Geophysical Union (AGU) annual conference from Dec 15-19, 2025 in New Orleans, LA. 

The annual AGU conference represents one of the world’s largest gatherings of Earth science professionals, researchers, educators, policymakers, and journalists, who come together to discuss, share, and learn about new scientific discoveries and environmental solutions. Over 25,000 people attend the conference each year. 

OPeNDAP has had a presence at AGU for over 20 years. Take a look at our previous posts to see what we did for the 2024 conference and the 2023 conference. 

While we were at AGU this year, we hosted a booth, and gave poster and oral presentations. We also met many colleagues–both new and known, and learned about recent advances and ideas in the exciting field of Earth Science. 

Below are more details about our activities at the conference.  

Booth in the AGU Exhibition Hall

For three years in a row, we’ve been hosting booths at AGU in the Exhibition Hall. It’s one of the best places where we can learn more about how people use OPeNDAP–or might want to use OPeNDAP in the future. 

We talked to just over 100 people, who were students, faculty, data managers, researchers, and scientists. They came from universities, research labs, nonprofits, government agencies, and businesses based in the US and around the world. 

We asked visitors questions like: 

• What kind of data do you use in your work? 
• Have you used tools like OPeNDAP before? 
• Is there anything you wish these tools could do better? 
• How do you make your data available to others? 

We learned some truly interesting things, including how OPeNDAP could improve the way it communicates about its services and benefits. Some visitors gave us suggestions of features and additions that OPeNDAP could add to its services to help their users. Importantly, we learned more about what data access looks and feels like from a data user perspective, so we might be better partners in their efforts to use scientific data. 

Here’s a photo of what our table looked like (below), and some of the great stuff that we handed out to visitors. Our new cotton OPeNDAP bags were our most popular item! 

Presented posters

Metadata Stewardship

Poster title: “Sidecars in the Cloud: Metadata Stewardship for Large-Scale Scientific Archives”.

Poster session: “Evolving Science Commons: Stewardship of Science Data in a Changing World, the Cloud, and a Shifting Federal Climate”.

Authors: James Gallagher (presenter) and Miguel Jimenez-Urias from OPeNDAP.

Presentation date: Dec 17, 2025. 

About the poster: As NASA and other Earth science agencies migrate massive data archives to cloud platforms like Amazon Web Services, traditional on-premises data management approaches are proving inadequate, especially within systems like NASA Earthdata Cloud that host billions of files. To enable efficient access in cloud object storage, OPeNDAP and partners have developed sidecar metadata files that allow data reconstruction via HTTP Range-GET requests, but this doubles file counts and introduces new preservation and synchronization challenges. While cloud platforms support decentralized collaboration, maintaining consistency between data files, sidecars, and metadata repositories such as NASA Common Metadata Repository creates new stewardship risks that require updated strategies for long-term archival integrity.

OPeNDAP in the Cloud

Poster title: “OPeNDAP in the Cloud: Metadata Driving Performant, Interoperable, and Sustainable Geospatial Workflows”.

Poster Session: “Open-Source Geospatial Workflows in the Cloud: Tools and Techniques for Data Access, Analysis, Visualization, Storytelling, and Sharing in the Python and Jupyter Ecosystem”.

Authors: Miguel Jimenez-Urias (presenter) and James Gallagher from OPeNDAP. 

Presentation date: Dec 17, 2025. 

About the poster: Earth science data is growing rapidly, with NASA’s archives projected to exceed 400 petabytes, much of it stored in the cloud—even though many datasets were never designed for cloud-native access. Instead of rewriting massive files into new formats, OPeNDAP uses DMR++, a sidecar metadata file that maps a dataset’s internal structure and enables efficient server-side subsetting, web streaming without full downloads, and cloud-native virtualization through tools like VirtualiZarr and Kerchunk.

Oral presentation at AGU

Enabling Earth Science at Scale

Title: “Virtual dataset integration into earthaccess: Community contributions to enable Earth science at scale”.

Authors: Daniel Edward Kaufman, Amy E Steiker, Joseph H Kennedy, Chris Battisto, Luis Alberto Lopez, Dean Henze, Ayush Nag, Miguel Jimenez-Urias (presenter), Thomas Nicholas, Julius Johannes Marian Busecke, and Julia Stewart Lowndes.

Presentation date: Dec 17, 2025. 

About the presentation: NASA’s cloud transition has been greatly supported by the community-developed earthaccess software, which enables reproducible data search and access across local and cloud environments, though large collections can still require managing thousands of files. By integrating virtual dataset technology through VirtualiZarr and exploring next-generation versioning with Icechunk, researchers can treat massive collections as single, analysis-ready datacubes that stream data in seconds instead of hours. Demonstrated across oceanographic, atmospheric, and reanalysis case studies—including TEMPO air quality and MERRA-2 analyses—this approach dramatically reduces processing time and advances efficient, cloud-native scientific computing on modest hardware.

See more about the presentation here: https://agu.confex.com/agu/agu25/meetingapp.cgi/Paper/1972814 

This presentation is also highlighted in a recent NASA Earthdata article sharing how Openscapes and earthaccess have collaborated to add capability to VirtualiZarr, the DMR++ parser, and Python libraries to enhance the use of non-cloud-optimized data.

Visiting New Orleans

One of the best parts of the AGU annual conference is that we get to re-visit a wonderful U.S. city year after year. New Orleans is certainly one of our favorite locations. The convention center is located along the great Mississippi River. It’s easy to move around the city either by bike, foot, or street car. There is delicious food and unique music, art, and architecture on every corner, and warm and friendly people. During December, the city was especially festive. What is there not to like?

We hope to see you at next year’s AGU 2026 conference in San Francisco!