NEMO (Nucleus for European Modelling of the Ocean) is a state-of-the-art modelling framework for oceanographic research, operational oceanography seasonal forecast and climate studies. The NEMO components are NEMO-OPA (the "blue" ocean, modelling the ocean dynamics and solving the primitive equations); NEMO-LIM (the "white ocean" for modelling sea-ice), and NEMO-TOP (the "green ocean" for modelling biogeochemistry). NEMO also includes grid refinement software (AGRIF) and an assimilation component (linear-tangent NEMO-TAM, Observational operators NEMO-OBS, and increment NEMO-ASM). The "blue ocean" component is fundamental to all users. NEMO can also be interfaced to a number of other components such as atmosphere models or alternative other models of sea-ice or biogeochemistry, to enable Earth system modelling.

This Special Issue aims to collect technical and scientific manuscripts dealing with evaluation of model skill and performance as well as development of NEMO components. The main scope is to collect relevant and state of the art manuscripts to provide the NEMO users with a single portal to search, discover and understand about the NEMO modelling framework potential and evolution and submit their contributions.