High- and low-latitude forcing on the subarctic Pacific environment and productivity over the past 230 kyr.

The subarctic Pacific Ocean, which is linked to both polar and tropical climates, is an area of high marine productivity and is sensitive to ocean-atmosphere CO 2 flux. However, the mechanisms underlying the drivers of its productivity dynamics or patterns remain elusive. Using biogenic barium, opal, and terrigenous input in a sediment core for the past 230 kyr, we present a continuous high-resolution nutrient availability dynamic for the subarctic Pacific Ocean and assess possible changes to sea ice and glacial North Pacific Intermediate Water on nutrient upwelling in the region. We suggest that export production in this region is controlled by the freshwater discharge associated with moisture and heat from low-latitude and the iceberg discharge from Kamchatka glaciations under a weak Aleutian Low. These findings indicate that both high- and low-latitude climate systems forced the evolution of the marine environment and primary productivity in the high-latitude North Pacific. • The reduced nutrient availability was governed by expanding sea ice and North Pacific Intermediate Water formation. • The melting water variations in freshwater discharge associated with the low latitude moisture. • High- and low-latitude climate systems force the evolution of the high-latitude marine primary productivity. [ABSTRACT FROM AUTHOR]