PhD Defence – Short-term metocean forecasts

On 13 September at 2 pm (CEST), Robin Marcille will defend his PhD on the application of deep learning methods to the short-term forecasting of metocean variables (wind, waves) for the planning of maintenance operations at sea. His work was carried out as part of the FLOWTOM R&D project.

Connection link to the defence

Abstract

Offshore wind turbine maintenance operations are sensitive to uncertainties in weather and ocean forecasts. Numerical forecasting models are limited by their computational cost for estimating uncertainties, leading to the development of methods based on deep learning. The importance of in-situ measurements at sea is highlighted by the results of this PhD. A method based on unsupervised clustering of numerical model data is proposed for the definition of an optimal sensor network for wind resource reconstruction. Deep learning methods are proposed for probabilistic ocean weather forecasting. We show that they are useful for assimilating a large number of input data. A Gaussian posterior hypothesis and a generative approach using normalising flows are compared. These allow us to relax the assumptions on the posterior distribution, while maintaining the ability to sample and calculate the likelihood accurately. A realistic case study is constructed for a representative offshore wind zone in France. For the joint forecast of wind and waves, the non-Gaussian properties of the normalising waves have proved beneficial for forecast calibration. A representative evaluation framework for offshore operations is proposed, including scenario generation and measuring the economic impact and risk of decision-making. We show that it is crucial to consider the risk in selection and assessment forecasting models.

Jury members

• Ronan FABLET, Professor – IMT Atlantique
• Pierre PINSON, Professor – Imperial College London
• Pierre TANDEO, Lecturer – IMT Atlantique
• Georges KARINIOTAKIS, Professor – Mines Paris PSL
• Laure RAYNAUD, Researcher – Centre National de Recherches Météorologiques
• François ROUSSEAU, Professor – IMT Atlantique
• Valérie MONTBET, Professor – Université de Rennes 1
• Jethro BROWELL, Senior lecturer – University of Glasgow

Photo credit: NWimages by Sabrina-Eickhoff / Pixabay, France Energies Marines