Validation of ice‐ocean models using acoustic measurements. Free

The Fram Strait is the main passage through which the ocean mass and heat exchange between the Atlantic and Arctic Oceans take place. On the eastern side of the strait the northbound West Spitzbergen Current transports Atlantic water to the Arctic Ocean, whereas on the western side the southbound East Greenland Current transports sea ice and polar water from the Arctic Ocean to the Nordic Seas and the Atlantic Ocean. The currents in the Fram Strait are characterized by significant recirculation and numerous propagating mesoscale eddies. Under the EU project DAMOCLES single‐track acoustic travel time measurements were carried out for a year. Acoustic travel time pattern is modeled by feeding oceanographic fields from ice‐ocean models into acoustic propagation models. By comparing modeled travel times to accurate acoustic observations we can validate the ocean models. Two different ice‐ocean models are considered: a single member high‐resolution model and a multi member ice‐ocean model system at coarser resolution. This validation approach is complementary to the use of point measurements or single profiles form oceanographic moorings and can provide new insight to the ocean model performance and assess feasibility of assimilating acoustic travel times in ocean models.