The Barents Sea's high biological productivity supports crucial fish stocks. This study demonstrates that phytoplankton abundance, the marine food web's base, is predictable up to five years in advance using the Norwegian Climate Prediction Model. Two prediction mechanisms are identified: advection of waters with anomalous nitrate concentrations from the Subpolar North Atlantic in the southern Atlantic Domain, and skillful prediction of summer ice concentration influencing light availability in the northern Polar Domain. This improved predictability is a significant step towards more accurate numerical ecosystem predictions for the Barents Sea.

Filippa Fransner, Are Olsen, Marius Årthun, François Counillon, Jerry Tjiputra, Annette Samuelsen, Noel Keenlyside