The impact of wave number selection and spin-up time in spectral nudging

The present work studies two relevant parameters from spectral nudging. First, the cut-off wave number, which effectively separates the nudged scales from the free running ones. And, second, the spin-up time, which determines how much time is needed to reach a balance between the nudging force and t...

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Detalles Bibliográficos
Autor: Gómez Hombre, Breogán Xacobo
Tipo de recurso: tesis doctoral
Fecha de publicación:2019
País:España
Institución:Universidad de Santiago de Compostela (USC)
Repositorio:Minerva. Repositorio Institucional de la Universidad de Santiago de Compostela
Idioma:inglés
OAI Identifier:oai:minerva.usc.gal:10347/19894
Acceso en línea:http://hdl.handle.net/10347/19894
Access Level:acceso abierto
Palabra clave:Materias::Investigación::25 Ciencias de la tierra y del espacio::2509 Metereología::250909 Predicción numérica meteorológica
Materias::Investigación::25 Ciencias de la tierra y del espacio::2509 Metereología::250918 Meteorología tropical
Descripción
Sumario:The present work studies two relevant parameters from spectral nudging. First, the cut-off wave number, which effectively separates the nudged scales from the free running ones. And, second, the spin-up time, which determines how much time is needed to reach a balance between the nudging force and the model internal climate. Our results show that the optimal cut-off wave number coincides with the Rossby Radius of Deformation, both in mid and tropical latitudes, suggesting that this parameter is related with the dynamic characteristics of the modelled area, and not with features of the experiment design. The optimal spin-up time is found to be 24/48h for mid latitudes and 72/96h for tropical latitudes. We also study the suitability of spectral nudging as an initialisation technique. Our results indicate that it is beneficial to use some nudging technique at the beginning of the simulation, but we have not found relevant differences between grid nudging and spectral nudging.