Interannual Variability of Primary Production in the Laptev Sea

Studies of the interannual variability of primary production, surface water temperature, photosynthetically active radiation, and sea ice cover in the Laptev Sea were performed based on MODIS-Aqua data (2002–2018). For a 17-year period, a statistically significant positive trend of surface temperature ( R 2 = 0.27) and a negative trend of photosynthetically active radiation ( R 2 = 0.24) were established. For the investigated period, the average annual water temperature in the Laptev Sea increased by 1.38°C and photosynthetically active radiation decreased by 3.4 Ein m –2 d –1 . The ice-free water area extended insignificantly (0.15% y –1 ). The total primary production declined by 1.87 TgC or by 1.4% y –1 . This decline was accompanied by a decrease in area-specific primary production. For the investigated period, the average annual area-specific primary production values declined by 37.4 mgC m –2 d –1 or by 1.6% y –1 . The presented results suggest that changes in Laptev Sea primary productivity for the last 17 years were mainly caused by a decrease in photosynthetically active radiation and area-specific primary production rather than the dynamics of the sea ice cover.