High-resolution sea ice edge forecast around Greenland: response to the forcing and forecast evaluation

Abstract

<p>The Danish Meteorological Institute (DMI) is the authority in charge of the sea ice service that supports mariners off the Greenlandic coast. DMI has offered ice charts and in-person consultancy for many years. Over time, the portfolio of sea ice products has extended to include forecast and automated retrievals and translations of remotely sensed data to sea ice products. Recently, DMI has launched an improved, high-resolution sea ice operational forecast system (SIOFS). The newly-launched DMI-SIOFS is updated with an improved model configuration with a nominal horizontal resolution of 5 km that predicts the ocean and sea ice states. The system is based on the coupling of the 3D ocean model Hybrid Coordinate Ocean Model (HYCOM; e.g., Chassignet et al. (2007)) with the Community Ice CodE model (CICE; e.g., Hunke and Dukowicz (1997); Hunke (2001)). Apart from the horizontal resolution, the sea ice component is improved with parameterization of features such as landfast sea ice and melt-ponds, as well as enhanced sea-ice salinity and thermodynamics schemes. The freshwater discharge from Greenland has also been upgraded by using inputs from the Geological Survey of Denmark and Greenland (GEUS; https://eng.geus.dk/) that improves the coastal ocean currents and, consequently, the sea ice transport nearshore Greenland. As a final product, a 144 hourly forecast of sea ice conditions is produced twice a day and released on Polarportal (http://polarportal.dk/en/home/).</p><p>With a focus on the waters surrounding Greenland, this study introduces the DMI-SIOFS and provides the first evaluation for it in terms of predicted sea ice edge location – an essential diagnostic for mariners. To do so, we make use of the Integrated Ice Edge Error (IIEE) metric introduced by Goessling et al. (2016). In addition, we provide insights on the model response to different forcing.</p><p> </p>