Sea state climatology in the North-East Atlantic Ocean : analysis of the present climate and future evolutions under climate change scenarios by means of dynamical and statistical downscaling methods

• Main Author: Laugel, Amélie
• Other Authors: Laboratoire d'Hydraulique Saint-Venant / Saint-Venant Laboratory for Hydraulics (LHSV), École des Ponts ParisTech (ENPC)-PRES Université Paris-Est-EDF (EDF)-Avant création Cerema, Université Paris-Est, Michel Benoit
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 2013
• Subjects: Wave climate; Dynamical downscaling method; Statistical downscaling method; Climate change; Spectral wave modelling; Weather type; Climat de vague; Descente d'échelle dynamique; Descente d'échelle statistique; Changement climatique; Modélisation spectrale de vagues; Types de temps; [SPI.OTHER]Engineering Sciences [physics]/Other; Salas; North East Atlantic
• Online Access: https://pastel.hal.science/tel-00966849; https://pastel.hal.science/tel-00966849/document; https://pastel.hal.science/tel-00966849/file/TH2013PEST1120_incomplete.pdf

Wave climate analysis is of utmost importance to understand the evolution and dynamics of coastal zones, to estimate the occurrence of extreme events, to design protections for ports, onshore and offshore infrastructure, to characterize wave resources for wave energy conversion, to quantify sediment erosion and accretion processes, et cetera. Thus, this thesis project aims to improve knowledge of wave climatology in the growing context of climate change prediction with a two-step approach: (i) enhancement of the understanding of the present wave climate along the French coastline facing the Atlantic Ocean, English Channel and North Sea and (ii) estimation of possible future wave climate evolution. For this purpose, the estimation of climate change impacts on the wave climate requires three key parameters: (i) detailed knowledge of current wave climate variability, (ii) the application of climate change scenarios from Global Climate Models and (iii) the definition of an appropriate downscaling method. To answer these questions, ANEMOC-2, a hindcast sea-state data base has been built based on the third-generation spectral wave model TOMAWAC (Benoit et al., 1996) over the period 1979-2009, and the future wave climate has been simulated over the period 2061-2100 by means of dynamical and statistical downscaling methods. In particular, an original approach comparing sea-state projections obtained from dynamical and statistical downscaling methods has been applied over the period 2061-2100 for B1, A1B and A2 scenarios (Forth Assessments Reports, IPCC, 2007), based on the ARPEGE-CLIMAT (Salas-Mélia et al., 2005) model simulations. The wave spectral parameters resulting from the projections (i.e. significant wave height, mean period, mean direction and wave energy flux) have been compared in term of mean, joint distribution and seasonal and interannual variability.The possible climate change impacts on the wave climate along the Atlantic, English Channel and North Sea French coastline have also been evaluated. The ...