Contributing knowledge for society in the Barents Sea

The variability in sea ice extent affects human activities. Seasonal forecasting of the ice edge position is therefore required for safe operations in the Arctic. 

Seasonal sea ice forecasting is still in its infancy, but different algorithms already produce seasonal sea ice edge forecasts. In a recent study,  Cyril Palerme and co-workers  compared historical 25-member ensemble ice edge forecast to satellite ice observations, and showed that different methods for verification for probabilities of meeting ice covered waters have different strengths and weaknesses. The choice of method will therefore depend on the purpose of the seasonal forecast.

In addition to seasonal forecast, ship navigation in the Arctic requires shorter-term ice forecasts of high quality. 

For this purpose, there are many monitoring and forecast products available. Information on the expected accuracy of data or model results from these are traditionally available as a set of metrics that comes with the products.  Arne Melsom and colleagues  examined a large number of metrics used, and concluded with a recommended best practice for the validation of sea ice edge forecasts. 

One of the key elements for understanding the rapid climate change in the Arctic is the surface energy budget. In the Arctic this budget is not consistently described across the various climate models, reanalyses and observation products. Recognising the physical causes of these inconsistencies is highly relevant for improving climate predictions and projections. 

 Yurii Batrak and Malte Müller  show that a 5 to 10 °C warm bias of the sea ice surface temperature in global atmospheric reanalyses and weather forecasts is mainly caused by a missing representation of the snow layer on top of the sea-ice.  

The work has improved Norwegian weather forecasts.

Predicting fish stock variations on interannual to decadal time scales is one of the major issues in fisheries science and management.  

Based on the strong co-variability between subpolar North Atlantic water temperature anomalies and the Barents Sea cod stock,  Marius Årthun and co-workers  show that retrospective predictions for the period 1957-2017 capture well multi-year to decadal variations in cod biomass in the Barents Sea.  

The study demonstrates the potential for ecosystem-based fisheries management, which could enable strategic planning on longer time scales. Future predictions show a gradual decline in the cod stock towards 2024.

"Balanced harvesting” management aims at increasing fishing yields while protecting the oceans. The Barents Sea has been managed according to an ecosystem-based approach for many years, not been subjected to the fishing pattern proposed by the «Balanced harvesting» approach. 

Using model simulations,  Ina Nilsen and co-workers  show that implementation of “Balanced harvesting” practice would hardly increase the yields of currently commercially exploited fish stocks. However, expanding the fishery to include species that are not commercially exploited today can produce higher total yields.