Speaker: Hamidreza Moazzami
When: Mar 18, 2026
Time: 12:30 -13:20pm
Where: Hamilton Hall, 410
Title: Numerical Approaches for Variational Data Assimilation Using Multigrid Methods, Adaptive Wavelets, and Fourier Neural Operators
Bio: Hamidreza Moazzami is a PhD candidate in the School of Computational Science and Engineering at McMaster University. His research interests include PDE-constrained optimization problems, numerical analysis, and data assimilation. His previous work has involved time series analysis, Kalman filtering, and stochastic differential equations. His current research focuses on variational data assimilation and the development of methods to accelerate it using adaptive wavelets, multiscale and spectral analysis, and machine learning.
Abstract:
Variational data assimilation plays a central role in many scientific and engineering applications, particularly in areas such as weather prediction and geophysical modelling. Data assimilation combines sparse observational data with mathematical models governed by partial differential equations (PDEs) to produce improved estimates of the system state. However, solving the resulting optimization problems can be computationally expensive due to the high dimensionality of the underlying systems.
In this talk, we present approaches to accelerate Hessian-based variational data assimilation by leveraging the multigrid method, the adaptive wavelet collocation method, and the Fourier neural operator (FNO). By exploiting the inherent multiscale structure of PDE-constrained optimization problems, these methods enable more efficient computations and improved scalability.
The talk will discuss the mathematical formulation of the problem, the proposed acceleration strategies, and preliminary results demonstrating their effectiveness in data assimilation applications.