Presentation
In fields like weather forecasting, combining empirical data with complex physical models under uncertainty is a major challenge. Equinor faces similar difficulties in the subsurface, when integrating geological and physical models with data.
In practice, ensemble-based data assimilation is used to address this challenge. It draws its strength from Monte Carlo sampling—powerful for inspecting probability distributions after nonlinear transformations—but struggles with conditioning the realisations on data. The resulting solutions are often riddled with random updates and lead to an unwarranted collapse in ensemble uncertainty.
Ensemble methods based on triangular measure transport offer a promising path forward. Specifically, we introduce the Ensemble Information Filter (EnIF) as a statistically sound alternative to the popular Ensemble Kalman Filter (EnKF). EnIF eliminates the need for ad-hoc localisation, improves statistical efficiency, and remains automatic and accessible to practitioners. It also enhances explainability while addressing the significant computational challenges posed by models with millions of parameters.
Speaker
Berent ?nund Str?mnes Lunde is a Principal Scientific Developer at Equinor, specialising in ensemble-based data assimilation. He holds a PhD in Statistics from the University of Stavanger. His work combines stochastic processes, machine learning, and computational statistics to advance data assimilation techniques for large-scale systems.
Program
11:30 – Doors open and lunch is served
12:00 – "Towards consistent ensemble based data assimilation at scale" by Berent ?nund Str?mnes Lunde (Principal Scientific Developer, Equinor)
This event is open for all students, PhD candidates, postdocs, and everyone else who is interested in the topic. Please register to participate:
About the seminar series
Once a month, dScience will invite you to join us for lunch and professional talks at the Science Library. In addition to these, we will serve lunch in our lounge in Kristine Bonnevies house every Thursday. Due to limited space (40 people), this will be first come, first served. See how to find us here.
Our lounge can also be booked by PhDs and Postdocs on a regular basis, whether it is for a meeting or just to hang out – we have fresh coffee all day long!