Adaptation of NEMO-LIM3 model for multigrid high resolution Arctic simulation
This work provides more flexible tools for domain-specific Arctic simulations, but it is incremental as it builds on an existing model with modifications for efficiency and customization.
The researchers tackled the problem of improving high-resolution Arctic ocean and sea ice simulations for shipping and operational risk assessment by modifying the NEMO-LIM3 model with a multigrid setup, resulting in lower computational costs compared to existing nesting systems.
High-resolution regional hindcasting of ocean and sea ice plays an important role in the assessment of shipping and operational risks in the Arctic Ocean. The ice-ocean model NEMO-LIM3 was modified to improve its simulation quality for appropriate spatio-temporal resolutions. A multigrid model setup with connected coarse- (14 km) and fine-resolution (5 km) model configurations was devised. These two configurations were implemented and run separately. The resulting computational cost was lower when compared to that of the built-in AGRIF nesting system. Ice and tracer boundary-condition schemes were modified to achieve the correct interaction between coarse- and fine grids through a long ice-covered open boundary. An ice-restoring scheme was implemented to reduce spin-up time. The NEMO-LIM3 configuration described in this article provides more flexible and customisable tools for high-resolution regional Arctic simulations.