Model and observation-error covariance matrix information in the physical nudging equations
Conti, G., Leeuwen, P. J. v., Anderson, J. L.. (2025). Model and observation-error covariance matrix information in the physical nudging equations. Quarterly Journal of the Royal Meteorological Society, doi:https://doi.org/10.1002/qj.4979
| Title | Model and observation-error covariance matrix information in the physical nudging equations |
|---|---|
| Genre | Article |
| Author(s) | G. Conti, P. J. van Leeuwen, Jeffrey L. Anderson |
| Abstract | In this work we show how to extend the deterministic physical nudging scheme in order to include two important ingredients, the model and observation-error covariance matrices, which are common features of classical data-assimilation schemes. The method exploits the relation between a stochastic differential equation and the evolution of its probability density via the Fokker–Planck equation. Observations are introduced by evolving the posterior probability density backward in time to obtain a so-called smoother. To obtain a computationally feasible scheme, we used the small-time approximation, resulting in an efficient nudging scheme built from first principles. We explored the capabilities of this new nudging method with the low-dimensional Lorenz 1963 model and a surface quasi-geostrophic turbulence model on a (Formula presented.) grid, with many degrees of freedom. We show that the new method is more accurate than a 3DVar at similar computational cost, and is accurate and easy to implement in the high-dimensional system. The new scheme has the potential to be used in extremely high-dimensional systems, because ensemble integrations and adjoint models are avoided. |
| Publication Title | Quarterly Journal of the Royal Meteorological Society |
| Publication Date | Jul 1, 2025 |
| Publisher's Version of Record | https://doi.org/10.1002/qj.4979 |
| OpenSky Citable URL | https://n2t.net/ark:/85065/d7c82ft6 |
| OpenSky Listing | View on OpenSky |
| CISL Affiliations | DARES |