Interannual Variability of Primary Production in the East Siberian Sea

— Interannual variability (2002–2018) of primary production, surface seawater temperature ( T 0 ), photosynthetically active radiation (PAR) and ice cover area in the East Siberian Sea (ESS) was studied based on the data of the MODIS-Aqua ocean color scanner. The annual total primary production (PP tot ) decreased by 1.7 TgC over 17 years. The multi-year negative trend in PP tot was 0.1 TgC y –1 (1.38% y –1 ). The decrease in PP tot was accompanied by the decrease in the area-specific primary production (IPP). Over the investigated period the annual mean IPP decreased by 13 mgC m –2 d –1 . The multi-year negative trend in IPP was 0.76 mgC m –2 d –1 y –1 (0.84% y –1 ). The decrease in PP tot and IPP was accompanied by statistically insignificant increase in T 0 ( R 2 = 0.09) and statistically significant decline in PAR ( R 2 = 0.29). Over the 17 years, T 0 in ESS increased by 0.68°С (0.04°С y –1 or 3.2% y –1 ) and PAR declined by 3.4 Ein m –2 d –1 (0.2 Ein m –2 d –1 y –1 or 1.9% y –1 ). The ice-free area slightly diminished during the study period ( R 2 = 0.10) by 64.94×10 3 km 2 . The statistically insignificant negative multi-year trend in the ESS ice-free area was 3.82 × 10 3 km 2 y –1 (0.87% y –1 ). Long-term variability in PP tot in ESS from 2002 to 2018 depended not only on the decrease in the ice cover but also on PAR level and IPP.