Print Email Facebook Twitter Computation-Efficient Parameter Estimation for a High-Resolution Global Tide and Surge Model Title Computation-Efficient Parameter Estimation for a High-Resolution Global Tide and Surge Model Author Wang, X. (TU Delft Mathematical Physics) Verlaan, M. (TU Delft Mathematical Physics; Deltares) Apecechea, Maialen Irazoqui (Deltares) Lin, H.X. (TU Delft Mathematical Physics) Date 2021 Abstract In this study, a computation-efficient parameter estimation scheme for high-resolution global tide models is developed. The method is applied to Global Tide and Surge Model with an unstructured grid with a resolution of about 2.5 km in the coastal area and about 4.9 million cells. The estimation algorithm uses an iterative least squares method, known as DUD. We use time-series derived from the FES2014 tidal database in deep water as observations to estimate corrections to the bathymetry. Although the model and estimation algorithm run in parallel, directly applying of DUD would not be affordable computationally. To reduce the computational demand, a coarse-to-fine strategy is proposed by using output from a coarser model to replace the fine model. There are two approaches; One is completely replacing the fine model with a coarser model during calibration (Coarse Calibration) and the second is Coarse Incremental Calibration, that replaces the output increments between the initial model and model with modified parameters by coarser grid model simulations. To further reduce the computation time, the parameter dimension is reduced from O(106) to O(102) based on sensitivity analysis, which greatly reduces the required number of model simulations and storage. In combination, these methods form an efficient optimization strategy. Experiments show that the accuracy of the tidal representation can be improved significantly at affordable cost. Validation for other time-periods and using coastal tide-gauges shows that the accuracy is improved significantly. However, the calibration period of two weeks is short and leads to some over-fitting of the model. Subject bathymetry calibration and validationcoarse-to-fine strategycomputational time reductionglobal parameter estimationglobal tide and surge modelsensitivity analysis To reference this document use: http://resolver.tudelft.nl/uuid:b6b9c657-3d3d-42bf-83fb-47d50b5be514 DOI https://doi.org/10.1029/2020JC016917 ISSN 2169-9275 Source Journal Of Geophysical Research-Oceans, 126 (3) Part of collection Institutional Repository Document type journal article Rights © 2021 X. Wang, M. Verlaan, Maialen Irazoqui Apecechea, H.X. Lin Files PDF 2020JC016917.pdf 6.19 MB Close viewer /islandora/object/uuid:b6b9c657-3d3d-42bf-83fb-47d50b5be514/datastream/OBJ/view