Coupling strategies for operational kilometer-scale weather, wave, ocean, and ice forecasting systems are developed and implemented in the operational forecasting infrastructure of the Norwegian Meteorological Institute.

The Arctic weather forecasting system operated by MET Norway (AROME Arctic) is a kilometer-scale forecasting system covering the Euro Atlantic Sector. The forecasting system provides short-term weather forecasts which are disseminated via several dissemination channels to the public and different stakeholders. The AROME Arctic system uses a three-dimensional variational data assimilation and optimal interpolation schemes in order to integrate in situ and satellite observation in a three hourly cycle.

A fully coupled model system of AROME Arctic with the wave model WaveWatch III will be developed and operationalized within the project period. It has proven to improve forecast accuracy for strong wind and high waves, and it will be beneficial for combined forecast products like sea-spray icing.

Further coupling strategies will be developed to integrate and improve ocean-ice processes and the ocean-ice forecasting system BarentsROMS, which is forced by the AROME Arctic forecasting system. A specific focus is on snow-on-ice processes, sea-ice leads, and wave-ice-atmosphere interactions in the Marginal Ice Zone. Observations from the Nansen Legacy Process Cruises are integrated in the model development of atmosphere-wave-ice interactions.

Nansen Legacy publications connected to AROME Arctic model simulations:

Batrak Y, Müller M (2018) Atmospheric response to kilometer-scale changes in sea ice concentration within the marginal ice zone. Geophysical Research Letters 45: 6702-6709. doi.org/10.1029/2018GL078295

Batrak Y, Müller M (2019) On the warm bias in atmospheric reanalyses induced by the missing snow over arctic sea-ice. Nature Communications 10: 4170. doi.org/10.1038/s41467-019-11975-3