ACMD Seminar: Calibration and Verification of Expensive Chaotic Models; Short Runs, Ensembles, and Approximate Gradients

Teo Price-Broncucia
PhD Candidate, Computer Science, University of Colorado - Boulder

Tuesday, Mar. 25, 2025, 3:00-4:00 PM ET (1:00-2:00 PM MT)

A video of this talk will be made available to NIST staff in the Math channel on NISTube, which is accessible from the NIST internal home page. It will be taken down from NISTube after 12 months at which point it can be requested by emailing the ACMD Seminar Chair.

Abstract: Expensive chaotic models, like those used in weather simulation, present a unique set of challenges for tasks like validation and calibration. Often, they are computationally expensive, highly sensitive to parameters, and are written in languages that don't support approaches like automatic differentiation. This talk will provide an overview of approaches that employ ultra-short runs and ensembles to address these challenges with a specific focus on methods to detect unwanted changes in large model codes.

Bio: Teo Price-Broncucia is a PhD candidate in computer science at the University of Colorado - Boulder, advised by Rebecca Morrison, and a visiting student researcher at the National Center for Atmospheric Research, mentored by Allison Baker. He received his undergraduate degree in physics at Colorado College as a Boettcher Scholar, advised by Shane Burns. Teo's research primarily concerns calibration, verification and uncertainty quantification of expensive, chaotic computer models like those used for weather prediction. Often this work involves the use of ensembles and characterization of model output distributions. Broadly, he is interested in how we combine knowledge in the form of physical laws or domain expertise with observations to make reliable and practical computer models.

Host: Zach Grey

Note: This talk will be recorded to provide access to NIST staff and associates who could not be present to the time of the seminar. The recording will be made available in the Math channel on NISTube, which is accessible only on the NIST internal network. This recording could be released to the public through a Freedom of Information Act (FOIA) request. Do not discuss or visually present any sensitive (CUI/PII/BII) material. Ensure that no inappropriate material or any minors are contained within the background of any recording. (To facilitate this, we request that cameras of attendees are muted except when asking questions.)

*Safety Precaution: The hallway leading from the Courtyard to the exit closest to B-111 and B-113 will be used by contractors to move debris, machinery, and other supplies, as well as will be heavily trafficked by the contractors throughout the process. Be aware of the safety precautions posted during this time.

Note: Visitors from outside NIST must contact Meliza Lane at least 24 hours in advance.