Modelling the summer 2022 marine heatwave around France: disentangling atmospheric and oceanic contributions
- 1CNRM-GMGEC, Université de Toulouse/Météo-France/CNRS, Toulouse, France (jonathan.beuvier@meteo.fr)
- 2CNRM-GMME, Université de Toulouse/Météo-France/CNRS, Toulouse, France (cindy.lebeaupin-brossier@meteo.fr)
- 3CNRM-CEMS, Université de Toulouse/Météo-France/CNRS, Lannion, France (thibault.guinaldo@meteo.fr)
The AROBASE (AROme-BAsed coupled SystEm) project of CNRM aims to assemble a multi-coupled regional modelling platform of the physico-chemical atmosphere, the ocean (including sea ice and marine biogeochemistry), the waves and the continental surfaces (soil, vegetation, cities, snow, lakes and rivers), at kilometric scale.
In this context, a new high-resolution regional ocean configuration of the NEMO model has been developed. Named FRA36, it covers the maritime domain around mainland France with a resolution of ~2.5 km (ORCA 1/36° grid).
In order to prepare the future ocean-atmosphere coupled system, FRA36 is first used in a configuration forced by the operational analyses of the AROME-France atmospheric model, at a horizontal resolution of 1.3 km and a 3h temporal resolution. FRA36 uses the global Copernicus Marine Service operational oceanographic productions with data assimilation (GLO12 analyses product) for initialisation and boundary conditions.
We use this configuration to reproduce and analyse the summer 2022 succession of marine heatwave events around mainland France (English Channel, Bay of Biscay, North-Western Mediterranean Sea), using a continuous 3-month ocean simulation initialised the 1st of June 2022.
First, the spatial and temporal evolution of the Sea Surface Temperature (SST) in this simulation is validated using satellite products. FRA36 reproduces well the succession of observed long-lasting warming periods, interspersed with sudden cold spells. Then, heat budgets in the ocean mixed layer are used to separate atmospheric (solar and non-solar fluxes) and oceanic (advection, mixing, entrainment) contributions to surface and sub-surface temperature variations. Following on from the Guinaldo et al. 2023 study, we here take advantage of the added value of having a 3D oceanic component, including explicit tides, and the atmospheric forcing at high spatio-temporal resolution from AROME-France, to characterise the respective atmospheric and oceanic contributions in the occurrences, maintenances and ends of this succession of high-stakes events.
How to cite: Beuvier, J., Lebeaupin Brossier, C., and Guinaldo, T.: Modelling the summer 2022 marine heatwave around France: disentangling atmospheric and oceanic contributions, EMS Annual Meeting 2024, Barcelona, Spain, 1–6 Sep 2024, EMS2024-270, https://doi.org/10.5194/ems2024-270, 2024.
