Summer high-wind events and phytoplankton productivity in the Arctic Ocean

At the base of the marine food web, phytoplankton are an essential component of the Arctic Ocean ecosystem and carbon cycle. Especially after sea ice retreats and light becomes more available to the Arctic Ocean each summer, phytoplankton productivity is limited by nutrient availability, which can be replenished by vertical mixing of the water column. One potential mixing mechanism is gale-force wind associated with summer storm activity. Past studies show that sustained high winds (>10 m s(-1)) impart sufficient stress on the ocean surface to induce vertical mixing, and it has been speculated that greater storm activity may increase net primary productivity (NPP) on a year-to-year timescale. We test this idea using a combination of satellite products and reanalysis data from 1998 to 2018. After controlling for the amount of open water, sea-surface temperature, and wind direction, we find evidence that greater frequency of high-wind events in summer is associated with greater seasonal NPP in the Barents, Laptev, East Siberian, and southern Chukchi Seas. This relationship is only robust for the Barents and southern Chukchi Seas, which are more strongly impacted by inflow of relatively nutrient-rich water from the Atlantic and Pacific Oceans, respectively. In other words, stormier summers may have higher productivity in several regions of the Arctic Ocean, but especially the two inflow seas. Additionally, a recent rise in high-wind frequency in the Barents Sea may have contributed to the simultaneous increase in NPP.