DD-OceanVar: a Domain Decomposition fully parallel Data Assimilation software for the Mediterranean Forecasting System

OceanVar is a Data Assimilation (DA) software which is being used in Italy within the Mediterranean Forecasting System (MFS) to combine observational data (Sea level anomaly, sea-surface temperatures, etc.) with backgrounds produced by computational models of ocean currents for the Mediterranean Sea (namely, the NEMO framework). OceanVAR is based on a three-dimensional variational approach. We describe computational efforts aimed to design a fully parallel OceanVar software, based on Domain Decomposition (DD), which involves modification of the variational scheme on each sub domain. Our approach aims to face to the ever greater multi-level parallelism and scalability of the current and of the next generation of leadership computing facility systems, while fulfilling the specific requirements of OceanVar within the MFS.