Primary production in the Arctic Ocean, 1998–2006

Abstract

Sea ice in the Arctic Ocean has undergone an unprecedented reduction in area and thickness in the last decade, exposing an ever increasing fraction of the sea surface to solar radiation and increasing the habitat suitable for phytoplankton growth. Here we use a primary production algorithm that utilizes remotely sensed chlorophyll a, sea surface temperature, and sea ice extent data to quantify interannual changes in phytoplankton production in the Arctic Ocean between 1998 and 2006. Our results show that since 1998, open water area in the Arctic has increased at the rate of 0.07 × 106 km2 a−1 (where a is years), with the greatest increases in the Barents, Kara, and Siberian sectors, particularly over the continental shelf. Although pan‐Arctic primary production averaged 419 ± 33 Tg C a−1 during 1998–2006, recent increases in open water area have lead to higher rates of annual production, which reached a 9‐year peak in 2006. Annual production was roughly equally distributed between pelagic waters (less productive but greater area) and waters located over the continental shelf (more productive but smaller area). Interannual differences are most tightly linked to changes in sea ice extent, with changes in sea surface temperature (related to the Arctic Oscillation) and incident irradiance playing minor roles. Estimation of primary production in the Arctic will aid the assessment of air‐sea CO2 fluxes and improve our understanding of the ecological and biogeochemical changes that could take place if ice cover continues to decrease.