{ "id": "2304.05858", "version": "v1", "published": "2023-04-12T13:42:50.000Z", "updated": "2023-04-12T13:42:50.000Z", "title": "Convergence properties of a Gauss-Newton data-assimilation method", "authors": [ "Nazanin Abedini", "Svetlana Dubinkina" ], "categories": [ "math.DS", "cs.NA", "math.NA" ], "abstract": "Four-dimensional weak-constraint variational data assimilation estimates a state given partial noisy observations and dynamical model by minimizing a cost function that takes into account both discrepancy between the state and observations and model error over time. It can be formulated as a Gauss-Newton iteration of an associated least-squares problem. In this paper, we introduce a parameter in front of the observation mismatch and show analytically that this parameter is crucial either for convergence to the true solution when observations are noise-free or for boundness of the error when observations are noisy with bounded observation noise. We also consider joint state-parameter estimation. We illustrated theoretical results with numerical experiments using the Lorenz 63 and Lorenz 96 models.", "revisions": [ { "version": "v1", "updated": "2023-04-12T13:42:50.000Z" } ], "analyses": { "keywords": [ "gauss-newton data-assimilation method", "convergence properties", "observation", "weak-constraint variational data assimilation estimates", "four-dimensional weak-constraint variational data assimilation" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }