Russian Journal of Earth Sciences Russian Journal of Earth Sciences Russian Journal of Earth Sciences 1681-1208 75698 10.2205/2025ES000943 sdycmn ОРИГИНАЛЬНЫЕ СТАТЬИ ORIGINAL ARTICLES ОРИГИНАЛЬНЫЕ СТАТЬИ Spatial and Temporal Variability of Chlorophyll-a and the Modeling of High-Productivity Zones Based on Environmental Parameters: a Case Study for the European Arctic Corridor Spatial and Temporal Variability of Chlorophyll-a and the Modeling of High-Productivity Zones Based on Environmental Parameters: a Case Study for the European Arctic Corridor https://orcid.org/0009-0005-0759-7086 Кузьмина Софья Константиновна Kuzmina Sofia Konstantinovna so.k.kuzmina@gmail.com https://orcid.org/0000-0001-8915-8039 Лобанова Полина Вячеславовна Lobanova Polina Vyacheslavovna https://orcid.org/0000-0002-4805-5348 Чепикова Светлана Сергеевна Chepikova Svetlana Sergeevna Санкт-Петербургский государственный университет St. Petersburg State University Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung Германия Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung Germany Государственный гидрологический институт Россия State Hydrological Institute Russian Federation 10 03 2025 10 03 2025 25 1 1 18 05 03 2024 15 10 2024 https://rjes.ru/en/nauka/article/75698/view

Over the past 20 years, increasing temperature and receding ice-cover have led to changes in the Arctic ecosystem. Our study aims to create models that predict the position of high chlorophyll-a concentration (Chl-a) zones in the European Arctic Corridor (the Barents, Norwegian and Greenland Seas) to monitor these changes. Firstly, we use remotely sensed data to assess spatial and temporal changes in correlation between Chl-a and environmental parameters that could influence Chl-a in the region – Photosynthetically Active Radiation (PAR), Sea Surface Temperature (SST), Mixed Layer Depth (MLD) and Sea Surface Salinity (SSS) – over the 2010–2019 time period. We found significant correlation (∣r∣ = 0.6–0.8) between Chl-a and PAR and SST, and medium correlation (∣r∣ = 0.4–0.6) between Chl-a and SSS and MLD, correlation was highest during spring periods. Then, using a Random Forest Machine Learning algorithm in the Classifier modification, we created models for each sea to predict the position of high-productivity zones (Chl-a > 1 mg m−3) using environmental parameters. Our results suggested that Chl-a variability in the European Arctic Corridor is mostly determined by PAR (28–32% of Chl-a class variability), SST (25–29%), and SSS (26–31%); MLD played a lesser role (12–17%). According to validation, all the models showed high performance scores (F1-score = 66–95%) and slightly underestimated the total area of high productivity.

Over the past 20 years, increasing temperature and receding ice-cover have led to changes in the Arctic ecosystem. Our study aims to create models that predict the position of high chlorophyll-a concentration (Chl-a) zones in the European Arctic Corridor (the Barents, Norwegian and Greenland Seas) to monitor these changes. Firstly, we use remotely sensed data to assess spatial and temporal changes in correlation between Chl-a and environmental parameters that could influence Chl-a in the region – Photosynthetically Active Radiation (PAR), Sea Surface Temperature (SST), Mixed Layer Depth (MLD) and Sea Surface Salinity (SSS) – over the 2010–2019 time period. We found significant correlation (∣r∣ = 0.6–0.8) between Chl-a and PAR and SST, and medium correlation (∣r∣ = 0.4–0.6) between Chl-a and SSS and MLD, correlation was highest during spring periods. Then, using a Random Forest Machine Learning algorithm in the Classifier modification, we created models for each sea to predict the position of high-productivity zones (Chl-a > 1 mg m−3) using environmental parameters. Our results suggested that Chl-a variability in the European Arctic Corridor is mostly determined by PAR (28–32% of Chl-a class variability), SST (25–29%), and SSS (26–31%); MLD played a lesser role (12–17%). According to validation, all the models showed high performance scores (F1-score = 66–95%) and slightly underestimated the total area of high productivity.

 chlorophyll-a ocean productivity Arctic Ocean modeling ocean colour remote sensing Barents Sea Norwegian Sea Greenland Sea chlorophyll-a ocean productivity Arctic Ocean modeling ocean colour remote sensing Barents Sea Norwegian Sea Greenland Sea The authors acknowledge Saint Petersburg State University for a research project no. 116442164. The authors acknowledge Saint Petersburg State University for a research project no. 116442164.

Anderson, G. F. (1986), Silica, diatoms and a freshwater productivity maximum in Atlantic Coastal Plain estuaries, Chesapeake Bay, Estuarine, Coastal and Shelf Science, 22(2), 183–197, https://doi.org/10.1016/0272-7714(86)90112-5. Anderson, G. F. (1986), Silica, diatoms and a freshwater productivity maximum in Atlantic Coastal Plain estuaries, Chesapeake Bay, Estuarine, Coastal and Shelf Science, 22(2), 183–197, https://doi.org/10.1016/0272-7714(86)90112-5. Ardyna, M., and K. R. Arrigo (2020), Phytoplankton dynamics in a changing Arctic Ocean, Nature Climate Change, 10(10), 892–903, https://doi.org/10.1038/s41558-020-0905-y. Ardyna, M., and K. R. Arrigo (2020), Phytoplankton dynamics in a changing Arctic Ocean, Nature Climate Change, 10(10), 892–903, https://doi.org/10.1038/s41558-020-0905-y. Ardyna, M., M. Babin, M. Gosselin, et al. (2014), Recent arctic ocean sea ice loss triggers novel fall phytoplankton blooms, Geophysical Research Letters, 41(17), 6207–6212, https://doi.org/10.1002/2014gl061047. Ardyna, M., M. Babin, M. Gosselin, et al. (2014), Recent arctic ocean sea ice loss triggers novel fall phytoplankton blooms, Geophysical Research Letters, 41(17), 6207–6212, https://doi.org/10.1002/2014gl061047. Arrigo, K. R., and G. L. van Dijken (2015), Continued increases in Arctic Ocean primary production, Progress in Oceanography, 136, 60–70, https://doi.org/10.1016/j.pocean.2015.05.002. Arrigo, K. R., and G. L. van Dijken (2015), Continued increases in Arctic Ocean primary production, Progress in Oceanography, 136, 60–70, https://doi.org/10.1016/j.pocean.2015.05.002. Arrigo, K. R., D. K. Perovich, R. S. Pickart, et al. (2012), Massive Phytoplankton Blooms Under Arctic Sea Ice, Science, 336(6087), 1408–1408, https://doi.org/10.1126/science.1215065. Arrigo, K. R., D. K. Perovich, R. S. Pickart, et al. (2012), Massive Phytoplankton Blooms Under Arctic Sea Ice, Science, 336(6087), 1408–1408, https://doi.org/10.1126/science.1215065. Babin, M., K. Arrigo, S. Bélanger, and M.-H. Forget (Eds.) (2015), Ocean Colour Remote Sensing in Polar Seas, IOCCG Report Series, No. 16, International Ocean Colour Coordinating Group, Dartmouth, Canada. Babin, M., K. Arrigo, S. Bélanger, and M.-H. Forget (Eds.) (2015), Ocean Colour Remote Sensing in Polar Seas, IOCCG Report Series, No. 16, International Ocean Colour Coordinating Group, Dartmouth, Canada. Balch, W. (1992), The remote sensing of ocean primary productivity: Use of a new data compilation to test satellite algorithms, Journal of Geophysical Research: Oceans, 97(C3), 3689–3689, https://doi.org/10.1029/92jc00372. Balch, W. (1992), The remote sensing of ocean primary productivity: Use of a new data compilation to test satellite algorithms, Journal of Geophysical Research: Oceans, 97(C3), 3689–3689, https://doi.org/10.1029/92jc00372. Balch, W. M., P. M. Holligan, S. G. Ackleson, and K. J. Voss (1991), Biological and optical properties of mesoscale coccolithophore blooms in the Gulf of Maine, Limnology and Oceanography, 36(4), 629–643, https://doi.org/10.4319/lo.1991.36.4.0629. Balch, W. M., P. M. Holligan, S. G. Ackleson, and K. J. Voss (1991), Biological and optical properties of mesoscale coccolithophore blooms in the Gulf of Maine, Limnology and Oceanography, 36(4), 629–643, https://doi.org/10.4319/lo.1991.36.4.0629. Bashmachnikov, I. L., A. M. Fedorov, A. V. Vesman, et al. (2018), Thermohaline convection in the subpolar seas of the North Atlantic from satellite and in situ observations. Part 1: localization of the deep convection sites, Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa, 15(7), 184–194, https://doi.org/10.21046/2070-7401-2018-15-7-184-194 (in Russian). Bashmachnikov, I. L., A. M. Fedorov, A. V. Vesman, et al. (2018), Thermohaline convection in the subpolar seas of the North Atlantic from satellite and in situ observations. Part 1: localization of the deep convection sites, Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa, 15(7), 184–194, https://doi.org/10.21046/2070-7401-2018-15-7-184-194 (in Russian). Behrenfeld, M. J. (2010), Abandoning Sverdrup’s Critical Depth Hypothesis on phytoplankton blooms, Ecology, 91(4), 977–989, https://doi.org/10.1890/09-1207.1. Behrenfeld, M. J. (2010), Abandoning Sverdrup’s Critical Depth Hypothesis on phytoplankton blooms, Ecology, 91(4), 977–989, https://doi.org/10.1890/09-1207.1. Behrenfeld, M. J., and P. G. Falkowski (1997), Photosynthetic rates derived from satellite-based chlorophyll concentration, Limnology and Oceanography, 42(1), 1–20, https://doi.org/10.4319/lo.1997.42.1.0001. Behrenfeld, M. J., and P. G. Falkowski (1997), Photosynthetic rates derived from satellite-based chlorophyll concentration, Limnology and Oceanography, 42(1), 1–20, https://doi.org/10.4319/lo.1997.42.1.0001. Behrenfeld, M. J., E. Boss, D. A. Siegel, and D. M. Shea (2005), Carbon-based ocean productivity and phytoplankton physiology from space, Global Biogeochemical Cycles, 19(1), https://doi.org/10.1029/2004GB002299. Behrenfeld, M. J., E. Boss, D. A. Siegel, and D. M. Shea (2005), Carbon-based ocean productivity and phytoplankton physiology from space, Global Biogeochemical Cycles, 19(1), https://doi.org/10.1029/2004GB002299. Bode, A., J. Hare, W. K. W. Li, et al. (2011), Chlorophyll and primary production in the North Atlantic, in ICES Status Report on Climate Change in the North Atlantic, pp. 77–102, International Council for the Exploration of the Sea, Denmark. Bode, A., J. Hare, W. K. W. Li, et al. (2011), Chlorophyll and primary production in the North Atlantic, in ICES Status Report on Climate Change in the North Atlantic, pp. 77–102, International Council for the Exploration of the Sea, Denmark. Børsheim, K. Y., S. Milutinović, and K. F. Drinkwater (2014), TOC and satellite-sensed chlorophyll and primary production at the Arctic Front in the Nordic Seas, Journal of Marine Systems, 139, 373–382, https://doi.org/10.1016/j.jmarsys.2014.07.012. Børsheim, K. Y., S. Milutinović, and K. F. Drinkwater (2014), TOC and satellite-sensed chlorophyll and primary production at the Arctic Front in the Nordic Seas, Journal of Marine Systems, 139, 373–382, https://doi.org/10.1016/j.jmarsys.2014.07.012. Borstad, G. A., and J. F. R. Gower (1984), Phytoplankton Chlorophyll Distribution in the Eastern Canadian Arctic, ARCTIC, 37(3), https://doi.org/10.14430/arctic2195. Borstad, G. A., and J. F. R. Gower (1984), Phytoplankton Chlorophyll Distribution in the Eastern Canadian Arctic, ARCTIC, 37(3), https://doi.org/10.14430/arctic2195. Brody, S. R., and M. S. Lozier (2015), Characterizing upper-ocean mixing and its effect on the spring phytoplankton bloom with in situ data, ICES Journal of Marine Science, 72(6), 1961–1970, https://doi.org/10.1093/icesjms/fsv006. Brody, S. R., and M. S. Lozier (2015), Characterizing upper-ocean mixing and its effect on the spring phytoplankton bloom with in situ data, ICES Journal of Marine Science, 72(6), 1961–1970, https://doi.org/10.1093/icesjms/fsv006. Carr, M.-E. (2001), Estimation of potential productivity in Eastern Boundary Currents using remote sensing, Deep Sea Research Part II: Topical Studies in Oceanography, 49(1–3), 59–80, https://doi.org/10.1016/s0967-0645(01)00094-7. Carr, M.-E. (2001), Estimation of potential productivity in Eastern Boundary Currents using remote sensing, Deep Sea Research Part II: Topical Studies in Oceanography, 49(1–3), 59–80, https://doi.org/10.1016/s0967-0645(01)00094-7. Carr, M.-E., M. A. M. Friedrichs, M. Schmeltz, et al. (2006), A comparison of global estimates of marine primary production from ocean color, Deep Sea Research Part II: Topical Studies in Oceanography, 53(5–7), 741–770, https://doi.org/10.1016/j.dsr2.2006.01.028. Carr, M.-E., M. A. M. Friedrichs, M. Schmeltz, et al. (2006), A comparison of global estimates of marine primary production from ocean color, Deep Sea Research Part II: Topical Studies in Oceanography, 53(5–7), 741–770, https://doi.org/10.1016/j.dsr2.2006.01.028. Cazzaniga, I., G. Zibordi, and F. Mélin (2021), Spectral variations of the remote sensing reflectance during coccolithophore blooms in the Western Black Sea, Remote Sensing of Environment, 264, 112,607, https://doi.org/10.1016/j.rse.2021.112607. Cazzaniga, I., G. Zibordi, and F. Mélin (2021), Spectral variations of the remote sensing reflectance during coccolithophore blooms in the Western Black Sea, Remote Sensing of Environment, 264, 112,607, https://doi.org/10.1016/j.rse.2021.112607. Chandler, D. M., J. D. Alcock, J. L. Wadham, et al. (2015), Seasonal changes of ice surface characteristics and productivity in the ablation zone of the Greenland Ice Sheet, The Cryosphere, 9(2), 487–504, https://doi.org/10.5194/tc-9-487-2015. Chandler, D. M., J. D. Alcock, J. L. Wadham, et al. (2015), Seasonal changes of ice surface characteristics and productivity in the ablation zone of the Greenland Ice Sheet, The Cryosphere, 9(2), 487–504, https://doi.org/10.5194/tc-9-487-2015. Chiswell, S. M. (2011), Annual cycles and spring blooms in phytoplankton: don’t abandon Sverdrup completely, Marine Ecology Progress Series, 443, 39–50, https://doi.org/10.3354/meps09453. Chiswell, S. M. (2011), Annual cycles and spring blooms in phytoplankton: don’t abandon Sverdrup completely, Marine Ecology Progress Series, 443, 39–50, https://doi.org/10.3354/meps09453. Cutler, D. R., T. C. Edwards, K. H. Beard, et al. (2007), Random Forests for Classification in Ecology, Ecology, 88(11), 2783–2792, https://doi.org/10.1890/07-0539.1. Cutler, D. R., T. C. Edwards, K. H. Beard, et al. (2007), Random Forests for Classification in Ecology, Ecology, 88(11), 2783–2792, https://doi.org/10.1890/07-0539.1. Dalpadado, P., K. R. Arrigo, G. L. van Dijken, et al. (2020), Climate effects on temporal and spatial dynamics of phytoplankton and zooplankton in the Barents Sea, Progress in Oceanography, 185, 102,320, https://doi.org/10.1016/j.pocean.2020.102320. Dalpadado, P., K. R. Arrigo, G. L. van Dijken, et al. (2020), Climate effects on temporal and spatial dynamics of phytoplankton and zooplankton in the Barents Sea, Progress in Oceanography, 185, 102,320, https://doi.org/10.1016/j.pocean.2020.102320. Delafontaine, Y., and R. Peters (1986), Empirical relationship for marine primary production - the effect of environmental variables, Oceanologica Acta, 9, 65–72. Delafontaine, Y., and R. Peters (1986), Empirical relationship for marine primary production - the effect of environmental variables, Oceanologica Acta, 9, 65–72. Demidov, A. B., V. M. Sergeeva, V. I. Gagarin, et al. (2022), Size-Fractionated Primary Production and Chlorophyll in the Kara Sea during the First-Year Ice Retreat, Oceanology, 62(3), 346–357, https://doi.org/10.1134/s0001437022030031. Demidov, A. B., V. M. Sergeeva, V. I. Gagarin, et al. (2022), Size-Fractionated Primary Production and Chlorophyll in the Kara Sea during the First-Year Ice Retreat, Oceanology, 62(3), 346–357, https://doi.org/10.1134/s0001437022030031. Estrada, M., C. Marrasé, M. Latasa, et al. (1993), Variability of deep chlorophyll maximum characteristics in the Northwestern Mediterranean, Marine Ecology Progress Series, 92, 289–300, https://doi.org/10.3354/meps092289. Estrada, M., C. Marrasé, M. Latasa, et al. (1993), Variability of deep chlorophyll maximum characteristics in the Northwestern Mediterranean, Marine Ecology Progress Series, 92, 289–300, https://doi.org/10.3354/meps092289. Falkowski, P. G., R. T. Barber, and V. Smetacek (1998), Biogeochemical Controls and Feedbacks on Ocean Primary Production, Science, 281(5374), 200–206, https://doi.org/10.1126/science.281.5374.200. Falkowski, P. G., R. T. Barber, and V. Smetacek (1998), Biogeochemical Controls and Feedbacks on Ocean Primary Production, Science, 281(5374), 200–206, https://doi.org/10.1126/science.281.5374.200. Fischer, A., E. Moberg, H. Alexander, et al. (2014), Sixty Years of Sverdrup: A Retrospective of Progress in the Study of Phytoplankton Blooms, Oceanography, 27(1), 222–235, https://doi.org/10.5670/oceanog.2014.26. Fischer, A., E. Moberg, H. Alexander, et al. (2014), Sixty Years of Sverdrup: A Retrospective of Progress in the Study of Phytoplankton Blooms, Oceanography, 27(1), 222–235, https://doi.org/10.5670/oceanog.2014.26. Hansen, B., U. C. Berggreen, K. S. Tande, and H. C. Eilertsen (1990), Post-bloom grazing by Calanus glacialis, C. finmarchicus and C. hyperboreus in the region of the Polar Front, Barents Sea, Marine Biology, 104(1), 5–14, https://doi.org/10.1007/bf01313151. Hansen, B., U. C. Berggreen, K. S. Tande, and H. C. Eilertsen (1990), Post-bloom grazing by Calanus glacialis, C. finmarchicus and C. hyperboreus in the region of the Polar Front, Barents Sea, Marine Biology, 104(1), 5–14, https://doi.org/10.1007/bf01313151. Hansen, C., E. Kvaleberg, and A. Samuelsen (2010), Anticyclonic eddies in the Norwegian Sea; their generation, evolution and impact on primary production, Deep Sea Research Part I: Oceanographic Research Papers, 57(9), 1079–1091, https://doi.org/10.1016/j.dsr.2010.05.013. Hansen, C., E. Kvaleberg, and A. Samuelsen (2010), Anticyclonic eddies in the Norwegian Sea; their generation, evolution and impact on primary production, Deep Sea Research Part I: Oceanographic Research Papers, 57(9), 1079–1091, https://doi.org/10.1016/j.dsr.2010.05.013. Haug, T., B. Bogstad, M. Chierici, et al. (2017), Future harvest of living resources in the Arctic Ocean north of the Nordic and Barents Seas: A review of possibilities and constraints, Fisheries Research, 188, 38–57, https://doi.org/10.1016/j.fishres.2016.12.002. Haug, T., B. Bogstad, M. Chierici, et al. (2017), Future harvest of living resources in the Arctic Ocean north of the Nordic and Barents Seas: A review of possibilities and constraints, Fisheries Research, 188, 38–57, https://doi.org/10.1016/j.fishres.2016.12.002. Hegseth, E. N., and A. Sundfjord (2008), Intrusion and blooming of Atlantic phytoplankton species in the high Arctic, Journal of Marine Systems, 74(1–2), 108–119, https://doi.org/10.1016/j.jmarsys.2007.11.011. Hegseth, E. N., and A. Sundfjord (2008), Intrusion and blooming of Atlantic phytoplankton species in the high Arctic, Journal of Marine Systems, 74(1–2), 108–119, https://doi.org/10.1016/j.jmarsys.2007.11.011. Joseph, V. R. (2022), Optimal ratio for data splitting, Statistical Analysis and Data Mining: The ASA Data Science Journal, 15(4), 531–538, https://doi.org/10.1002/sam.11583. Joseph, V. R. (2022), Optimal ratio for data splitting, Statistical Analysis and Data Mining: The ASA Data Science Journal, 15(4), 531–538, https://doi.org/10.1002/sam.11583. Kahru, M., V. Brotas, M. Manzano-Sarabia, and B. G. Mitchell (2011), Are phytoplankton blooms occurring earlier in the Arctic?: PHYTOPLANKTON BLOOMS IN THE ARCTIC, Global Change Biology, 17(4), 1733–1739, https://doi.org/10.1111/j.1365-2486.2010.02312.x. Kahru, M., V. Brotas, M. Manzano-Sarabia, and B. G. Mitchell (2011), Are phytoplankton blooms occurring earlier in the Arctic?: PHYTOPLANKTON BLOOMS IN THE ARCTIC, Global Change Biology, 17(4), 1733–1739, https://doi.org/10.1111/j.1365-2486.2010.02312.x. Kondrik, D., D. Pozdnyakov, and L. Pettersson (2017), Tendencies in Coccolithophorid Blooms in Some Marine Environments of the Northern Hemisphere according to the Data of Satellite Observations in 1998-2013, Izvestiya, Atmospheric and Oceanic Physics, 53(9), 955–964, https://doi.org/10.1134/s000143381709016x. Kondrik, D., D. Pozdnyakov, and L. Pettersson (2017), Tendencies in Coccolithophorid Blooms in Some Marine Environments of the Northern Hemisphere according to the Data of Satellite Observations in 1998-2013, Izvestiya, Atmospheric and Oceanic Physics, 53(9), 955–964, https://doi.org/10.1134/s000143381709016x. Kuzmina, S., P. Lobanova, and I. Bashmachnikov (2022), Spatial and temporal variability of chlorophyll-a and its relation to physical and biological parameters: a case study for the European Arctic Corridor, in PICES-2022 Book Abstracts, p. 127, PICES Secretariat, Busan, Korea. Kuzmina, S., P. Lobanova, and I. Bashmachnikov (2022), Spatial and temporal variability of chlorophyll-a and its relation to physical and biological parameters: a case study for the European Arctic Corridor, in PICES-2022 Book Abstracts, p. 127, PICES Secretariat, Busan, Korea. Kuzmina, S., P. Lobanova, and S. Chepikova (2023), Modeling Chlorophyll a Concentration for the European Arctic Corridor Based on Environmental Parameters, in Complex Investigation of the World Ocean (CIWO-2023), pp. 456–462, Springer Nature Switzerland, https://doi.org/10.1007/978-3-031-47851-2_55. Kuzmina, S., P. Lobanova, and S. Chepikova (2023), Modeling Chlorophyll a Concentration for the European Arctic Corridor Based on Environmental Parameters, in Complex Investigation of the World Ocean (CIWO-2023), pp. 456–462, Springer Nature Switzerland, https://doi.org/10.1007/978-3-031-47851-2_55. Lee, Y. J., P. A. Matrai, M. A. M. Friedrichs, et al. (2015a), An assessment of phytoplankton primary productivity in the Arctic Ocean from satellite ocean color/in situ chlorophyll-a based models, Journal of Geophysical Research: Oceans, 120(9), 6508–6541, https://doi.org/10.1002/2015jc011018. Lee, Y. J., P. A. Matrai, M. A. M. Friedrichs, et al. (2015a), An assessment of phytoplankton primary productivity in the Arctic Ocean from satellite ocean color/in situ chlorophyll-a based models, Journal of Geophysical Research: Oceans, 120(9), 6508–6541, https://doi.org/10.1002/2015jc011018. Lee, Z., J. Marra, M. J. Perry, and M. Kahru (2015b), Estimating oceanic primary productivity from ocean color remote sensing: A strategic assessment, Journal of Marine Systems, 149, 50–59, https://doi.org/10.1016/j.jmarsys.2014.11.015. Lee, Z., J. Marra, M. J. Perry, and M. Kahru (2015b), Estimating oceanic primary productivity from ocean color remote sensing: A strategic assessment, Journal of Marine Systems, 149, 50–59, https://doi.org/10.1016/j.jmarsys.2014.11.015. Levasseur, M. (2013), Impact of Arctic meltdown on the microbial cycling of sulphur, Nature Geoscience, 6(9), 691–700, https://doi.org/10.1038/ngeo1910. Levasseur, M. (2013), Impact of Arctic meltdown on the microbial cycling of sulphur, Nature Geoscience, 6(9), 691–700, https://doi.org/10.1038/ngeo1910. Lewandowska, A. M., M. Striebel, U. Feudel, et al. (2015), The importance of phytoplankton trait variability in spring bloom formation, ICES Journal of Marine Science, 72(6), 1908–1915, https://doi.org/10.1093/icesjms/fsv059. Lewandowska, A. M., M. Striebel, U. Feudel, et al. (2015), The importance of phytoplankton trait variability in spring bloom formation, ICES Journal of Marine Science, 72(6), 1908–1915, https://doi.org/10.1093/icesjms/fsv059. Lewis, K. M., G. L. van Dijken, and K. R. Arrigo (2020), Changes in phytoplankton concentration now drive increased Arctic Ocean primary production, Science, 369(6500), 198–202, https://doi.org/10.1126/science.aay8380. Lewis, K. M., G. L. van Dijken, and K. R. Arrigo (2020), Changes in phytoplankton concentration now drive increased Arctic Ocean primary production, Science, 369(6500), 198–202, https://doi.org/10.1126/science.aay8380. Lobanova, P. V. (2017), Satellite Derived Algorithms of Primary Production Assessment in Waters With Various Oceanographic Conditions: Case Studies of the Northeast Atlantic and the Japan/East Sea, candthesis, Saint Petersburg State University, Saint Petersburg (in Russian). Lobanova, P. V. (2017), Satellite Derived Algorithms of Primary Production Assessment in Waters With Various Oceanographic Conditions: Case Studies of the Northeast Atlantic and the Japan/East Sea, candthesis, Saint Petersburg State University, Saint Petersburg (in Russian). Longhurst, A. R. (2007), Ecological geography of the sea, ii ed., Elsevier, Amsterdam; Boston, MA, https://doi.org/10.1016/b978-0-12-455521-1.x5000-1. Longhurst, A. R. (2007), Ecological geography of the sea, ii ed., Elsevier, Amsterdam; Boston, MA, https://doi.org/10.1016/b978-0-12-455521-1.x5000-1. Makarevich, P., V. Vodopianova, and A. Bulavina (2022), Dynamics of the Spatial Chlorophyll-A Distribution at the Polar Front in the Marginal Ice Zone of the Barents Sea during Spring, Water, 14(1), 101, https://doi.org/10.3390/w14010101. Makarevich, P., V. Vodopianova, and A. Bulavina (2022), Dynamics of the Spatial Chlorophyll-A Distribution at the Polar Front in the Marginal Ice Zone of the Barents Sea during Spring, Water, 14(1), 101, https://doi.org/10.3390/w14010101. Martyanov, S. D., A. Y. Dvornikov, V. A. Ryabchenko, et al. (2018), Investigation of the relationship between primary production and sea ice in the Arctic seas: Assessments based on a small-component model of marine ecosystem, Fundamentalnaya i Prikladnaya Gidrofizika, 11(2), 108–117, https://doi.org/10.7868/S2073667318020107. Martyanov, S. D., A. Y. Dvornikov, V. A. Ryabchenko, et al. (2018), Investigation of the relationship between primary production and sea ice in the Arctic seas: Assessments based on a small-component model of marine ecosystem, Fundamentalnaya i Prikladnaya Gidrofizika, 11(2), 108–117, https://doi.org/10.7868/S2073667318020107. Morel, A. (1978), Available, usable, and stored radiant energy in relation to marine photosynthesis, Deep Sea Research, 25(8), 673–688, https://doi.org/10.1016/0146-6291(78)90623-9. Morel, A. (1978), Available, usable, and stored radiant energy in relation to marine photosynthesis, Deep Sea Research, 25(8), 673–688, https://doi.org/10.1016/0146-6291(78)90623-9. Morel, A., and L. Prieur (1977), Analysis of variations in ocean color, Limnology and Oceanography, 22(4), 709–722, https://doi.org/10.4319/lo.1977.22.4.0709. Morel, A., and L. Prieur (1977), Analysis of variations in ocean color, Limnology and Oceanography, 22(4), 709–722, https://doi.org/10.4319/lo.1977.22.4.0709. Mousing, E. A., I. Ellingen, S. S. Hjøllo, et al. (2023), Why do regional biogeochemical models produce contrasting future projections of primary production in the Barents Sea?, Journal of Sea Research, 192, 102,366, https://doi.org/10.1016/j.seares.2023.102366. Mousing, E. A., I. Ellingen, S. S. Hjøllo, et al. (2023), Why do regional biogeochemical models produce contrasting future projections of primary production in the Barents Sea?, Journal of Sea Research, 192, 102,366, https://doi.org/10.1016/j.seares.2023.102366. Naustvoll, L. J., W. Melle, T. Klevjer, et al. (2020), Dynamics of phytoplankton species composition, biomass and nutrients in the North Atlantic during spring and summer - A trans-Atlantic study, Deep Sea Research Part II: Topical Studies in Oceanography, 180, 104,890, https://doi.org/10.1016/j.dsr2.2020.104890. Naustvoll, L. J., W. Melle, T. Klevjer, et al. (2020), Dynamics of phytoplankton species composition, biomass and nutrients in the North Atlantic during spring and summer - A trans-Atlantic study, Deep Sea Research Part II: Topical Studies in Oceanography, 180, 104,890, https://doi.org/10.1016/j.dsr2.2020.104890. Nguyen, Q. H., H.-B. Ly, L. S. Ho, et al. (2021), Influence of Data Splitting on Performance of Machine Learning Models in Prediction of Shear Strength of Soil, Mathematical Problems in Engineering, 2021, 1–15, https://doi.org/10.1155/2021/4832864. Nguyen, Q. H., H.-B. Ly, L. S. Ho, et al. (2021), Influence of Data Splitting on Performance of Machine Learning Models in Prediction of Shear Strength of Soil, Mathematical Problems in Engineering, 2021, 1–15, https://doi.org/10.1155/2021/4832864. Nielsen, E. S. (1963), Productivity, definition and measurement, in The Sea. Volume 2, pp. 129–164, Wiley, New York. Nielsen, E. S. (1963), Productivity, definition and measurement, in The Sea. Volume 2, pp. 129–164, Wiley, New York. Odum, E. P. (1971), Fundamentals of Ecology, third ed., 574 pp., W. B. Saunders Co., Philadelphia. Odum, E. P. (1971), Fundamentals of Ecology, third ed., 574 pp., W. B. Saunders Co., Philadelphia. Oliver, H., H. Luo, R. M. Castelao, et al. (2018), Exploring the Potential Impact of Greenland Meltwater on Stratification, Photosynthetically Active Radiation, and Primary Production in the Labrador Sea, Journal of Geophysical Research: Oceans, 123(4), 2570–2591, https://doi.org/10.1002/2018jc013802. Oliver, H., H. Luo, R. M. Castelao, et al. (2018), Exploring the Potential Impact of Greenland Meltwater on Stratification, Photosynthetically Active Radiation, and Primary Production in the Labrador Sea, Journal of Geophysical Research: Oceans, 123(4), 2570–2591, https://doi.org/10.1002/2018jc013802. Oziel, L., A. Baudena, M. Ardyna, et al. (2020), Faster Atlantic currents drive poleward expansion of temperate phytoplankton in the Arctic Ocean, Nature Communications, 11(1), https://doi.org/10.1038/s41467-020-15485-5. Oziel, L., A. Baudena, M. Ardyna, et al. (2020), Faster Atlantic currents drive poleward expansion of temperate phytoplankton in the Arctic Ocean, Nature Communications, 11(1), https://doi.org/10.1038/s41467-020-15485-5. Oziel, L., P. Massicotte, M. Babin, and E. Devred (2022), Decadal changes in Arctic Ocean Chlorophyll a: Bridging ocean color observations from the 1980s to present time, Remote Sensing of Environment, 275, 113,020, https://doi.org/10.1016/j.rse.2022.113020. Oziel, L., P. Massicotte, M. Babin, and E. Devred (2022), Decadal changes in Arctic Ocean Chlorophyll a: Bridging ocean color observations from the 1980s to present time, Remote Sensing of Environment, 275, 113,020, https://doi.org/10.1016/j.rse.2022.113020. Perrette, M., A. Yool, G. D. Quartly, and E. E. Popova (2011), Near-ubiquity of ice-edge blooms in the Arctic, Biogeosciences, 8(2), 515–524, https://doi.org/10.5194/bg-8-515-2011. Perrette, M., A. Yool, G. D. Quartly, and E. E. Popova (2011), Near-ubiquity of ice-edge blooms in the Arctic, Biogeosciences, 8(2), 515–524, https://doi.org/10.5194/bg-8-515-2011. Platt, T., and S. Sathyendranath (1988), Oceanic Primary Production: Estimation by Remote Sensing at Local and Regional Scales, Science, 241(4873), 1613–1620, https://doi.org/10.1126/science.241.4873.1613. Platt, T., and S. Sathyendranath (1988), Oceanic Primary Production: Estimation by Remote Sensing at Local and Regional Scales, Science, 241(4873), 1613–1620, https://doi.org/10.1126/science.241.4873.1613. Qu, B., and A. J. Gabric (2022), The multi-year comparisons of chlorophyll and sea ice in Greenland Sea and Barents Sea and their relationships with the North Atlantic Oscillation, Journal of Marine Systems, 231, 103,749, https://doi.org/10.1016/j.jmarsys.2022.103749. Qu, B., and A. J. Gabric (2022), The multi-year comparisons of chlorophyll and sea ice in Greenland Sea and Barents Sea and their relationships with the North Atlantic Oscillation, Journal of Marine Systems, 231, 103,749, https://doi.org/10.1016/j.jmarsys.2022.103749. Qu, B., and X. Liu (2020), The effect of wind and temperature to phytoplankton biomass during blooming season in Barents Sea, Dynamics of Atmospheres and Oceans, 91, 101,157, https://doi.org/10.1016/j.dynatmoce.2020.101157. Qu, B., and X. Liu (2020), The effect of wind and temperature to phytoplankton biomass during blooming season in Barents Sea, Dynamics of Atmospheres and Oceans, 91, 101,157, https://doi.org/10.1016/j.dynatmoce.2020.101157. Reigstad, M., P. Wassmann, C. Wexels Riser, et al. (2002), Variations in hydrography, nutrients and chlorophyll a in the marginal ice-zone and the central Barents Sea, Journal of Marine Systems, 38(1–2), 9–29, https://doi.org/10.1016/s0924-7963(02)00167-7. Reigstad, M., P. Wassmann, C. Wexels Riser, et al. (2002), Variations in hydrography, nutrients and chlorophyll a in the marginal ice-zone and the central Barents Sea, Journal of Marine Systems, 38(1–2), 9–29, https://doi.org/10.1016/s0924-7963(02)00167-7. Riley, G. A. (1940), Limnological Studies in Connecticut. Part III. The Plankton of Linsley Pond, Ecological Monographs, 10(2), 279–306, https://doi.org/10.2307/1948608. Riley, G. A. (1940), Limnological Studies in Connecticut. Part III. The Plankton of Linsley Pond, Ecological Monographs, 10(2), 279–306, https://doi.org/10.2307/1948608. Rivero-Calle, S., A. Gnanadesikan, C. E. D. Castillo, et al. (2015), Multidecadal increase in North Atlantic coccolithophores and the potential role of rising CO2, Science, 350(6267), 1533–1537, https://doi.org/10.1126/science.aaa8026. Rivero-Calle, S., A. Gnanadesikan, C. E. D. Castillo, et al. (2015), Multidecadal increase in North Atlantic coccolithophores and the potential role of rising CO2, Science, 350(6267), 1533–1537, https://doi.org/10.1126/science.aaa8026. Ryther, J. H., and C. S. Yentsch (1957), The Estimation of Phytoplankton Production in the Ocean from Chlorophyll and Light Data, Limnology and Oceanography, 2(3), 281–286, https://doi.org/10.1002/lno.1957.2.3.0281. Ryther, J. H., and C. S. Yentsch (1957), The Estimation of Phytoplankton Production in the Ocean from Chlorophyll and Light Data, Limnology and Oceanography, 2(3), 281–286, https://doi.org/10.1002/lno.1957.2.3.0281. Sakshaug, E., G. H. Johnsen, and K. M. Kovacs (Eds.) (2009), Ecosystem Barents Sea, 587 pp., Tapir Academic Press, Trondheim. Sakshaug, E., G. H. Johnsen, and K. M. Kovacs (Eds.) (2009), Ecosystem Barents Sea, 587 pp., Tapir Academic Press, Trondheim. Sathyendranath, S., R. Ji, and H. Browman (2015), Revisiting Sverdrup’s critical depth hypothesis, ICES Journal of Marine Science, 72(6), 1892–1896, https://doi.org/10.1093/icesjms/fsv110. Sathyendranath, S., R. Ji, and H. Browman (2015), Revisiting Sverdrup’s critical depth hypothesis, ICES Journal of Marine Science, 72(6), 1892–1896, https://doi.org/10.1093/icesjms/fsv110. Shigesada, N., and A. Okubo (1981), Analysis of the self-shading effect on algal vertical distribution in natural waters, Journal of Mathematical Biology, 12(3), 311–326, https://doi.org/10.1007/bf00276919. Shigesada, N., and A. Okubo (1981), Analysis of the self-shading effect on algal vertical distribution in natural waters, Journal of Mathematical Biology, 12(3), 311–326, https://doi.org/10.1007/bf00276919. Siegel, D. A., S. C. Doney, and J. A. Yoder (2002), The North Atlantic Spring Phytoplankton Bloom and Sverdrup’s Critical Depth Hypothesis, Science, 296(5568), 730–733, https://doi.org/10.1126/science.1069174. Siegel, D. A., S. C. Doney, and J. A. Yoder (2002), The North Atlantic Spring Phytoplankton Bloom and Sverdrup’s Critical Depth Hypothesis, Science, 296(5568), 730–733, https://doi.org/10.1126/science.1069174. Silva, E., F. Counillon, J. Brajard, et al. (2021), Twenty-One Years of Phytoplankton Bloom Phenology in the Barents, Norwegian, and North Seas, Frontiers in Marine Science, 8, https://doi.org/10.3389/fmars.2021.746327. Silva, E., F. Counillon, J. Brajard, et al. (2021), Twenty-One Years of Phytoplankton Bloom Phenology in the Barents, Norwegian, and North Seas, Frontiers in Marine Science, 8, https://doi.org/10.3389/fmars.2021.746327. Skogen, M. D., E. Svendsen, J. Berntsen, et al. (1995), Modelling the primary production in the North Sea using a coupled three-dimensional physical-chemical-biological ocean model, Estuarine, Coastal and Shelf Science, 41(5), 545–565, https://doi.org/10.1016/0272-7714(95)90026-8. Skogen, M. D., E. Svendsen, J. Berntsen, et al. (1995), Modelling the primary production in the North Sea using a coupled three-dimensional physical-chemical-biological ocean model, Estuarine, Coastal and Shelf Science, 41(5), 545–565, https://doi.org/10.1016/0272-7714(95)90026-8. Slagstad, D., and K. Støle-Hansen (1991), Dynamics of plankton growth in the Barents Sea: model studies, Polar Research, 10(1), 173–186, https://doi.org/10.3402/polar.v10i1.6736. Slagstad, D., and K. Støle-Hansen (1991), Dynamics of plankton growth in the Barents Sea: model studies, Polar Research, 10(1), 173–186, https://doi.org/10.3402/polar.v10i1.6736. Smith, R. C., and K. S. Baker (1978), The bio-optical state of ocean waters and remote sensing, Limnology and Oceanography, 23(2), 247–259, https://doi.org/10.4319/lo.1978.23.2.0247. Smith, R. C., and K. S. Baker (1978), The bio-optical state of ocean waters and remote sensing, Limnology and Oceanography, 23(2), 247–259, https://doi.org/10.4319/lo.1978.23.2.0247. Sverdrup, H. U. (1953), On Conditions for the Vernal Blooming of Phytoplankton, ICES Journal of Marine Science, 18(3), 287–295, https://doi.org/10.1093/icesjms/18.3.287. Sverdrup, H. U. (1953), On Conditions for the Vernal Blooming of Phytoplankton, ICES Journal of Marine Science, 18(3), 287–295, https://doi.org/10.1093/icesjms/18.3.287. Talling, J. F. (1957), Photosynthetic Characteristics of Some Freshwater Plankton Diatoms in Relation to Underwater Radiation, New Phytologist, 56(1), 29–50, https://doi.org/10.1111/j.1469-8137.1957.tb07447.x. Talling, J. F. (1957), Photosynthetic Characteristics of Some Freshwater Plankton Diatoms in Relation to Underwater Radiation, New Phytologist, 56(1), 29–50, https://doi.org/10.1111/j.1469-8137.1957.tb07447.x. Teira, E., B. M. no, E. M. nón, et al. (2005), Variability of chlorophyll and primary production in the Eastern North Atlantic Subtropical Gyre: potential factors affecting phytoplankton activity, Deep Sea Research Part I: Oceanographic Research Papers, 52(4), 569–588, https://doi.org/10.1016/j.dsr.2004.11.007. Teira, E., B. M. no, E. M. nón, et al. (2005), Variability of chlorophyll and primary production in the Eastern North Atlantic Subtropical Gyre: potential factors affecting phytoplankton activity, Deep Sea Research Part I: Oceanographic Research Papers, 52(4), 569–588, https://doi.org/10.1016/j.dsr.2004.11.007. Torres-Valdés, S., T. Tsubouchi, S. Bacon, et al. (2013), Export of nutrients from the Arctic Ocean, Journal of Geophysical Research: Oceans, 118(4), 1625–1644, https://doi.org/10.1002/jgrc.20063. Torres-Valdés, S., T. Tsubouchi, S. Bacon, et al. (2013), Export of nutrients from the Arctic Ocean, Journal of Geophysical Research: Oceans, 118(4), 1625–1644, https://doi.org/10.1002/jgrc.20063. Tremblay, J.-E., and J. Gagnon (2009), The effects of irradiance and nutrient supply on the productivity of Arctic waters: a perspective on climate change, in Influence of Climate Change on the Changing Arctic and Sub-Arctic Conditions, pp. 73–93, Springer Netherlands, https://doi.org/10.1007/978-1-4020-9460-6_7. Tremblay, J.-E., and J. Gagnon (2009), The effects of irradiance and nutrient supply on the productivity of Arctic waters: a perspective on climate change, in Influence of Climate Change on the Changing Arctic and Sub-Arctic Conditions, pp. 73–93, Springer Netherlands, https://doi.org/10.1007/978-1-4020-9460-6_7. Vernet, M., I. Ellingsen, C. Marchese, et al. (2021), Spatial variability in rates of net primary production (NPP) and onset of the spring bloom in Greenland shelf waters, Progress in Oceanography, 198, 102,655, https://doi.org/10.1016/j.pocean.2021.102655. Vernet, M., I. Ellingsen, C. Marchese, et al. (2021), Spatial variability in rates of net primary production (NPP) and onset of the spring bloom in Greenland shelf waters, Progress in Oceanography, 198, 102,655, https://doi.org/10.1016/j.pocean.2021.102655. Wassmann, P., D. Slagstad, C. W. Riser, and M. Reigstad (2006), Modelling the ecosystem dynamics of the Barents Sea including the marginal ice zone, Journal of Marine Systems, 59(1–2), 1–24, https://doi.org/10.1016/j.jmarsys.2005.05.006. Wassmann, P., D. Slagstad, C. W. Riser, and M. Reigstad (2006), Modelling the ecosystem dynamics of the Barents Sea including the marginal ice zone, Journal of Marine Systems, 59(1–2), 1–24, https://doi.org/10.1016/j.jmarsys.2005.05.006. Wassmann, P., D. Slagstad, and I. Ellingsen (2010), Primary production and climatic variability in the European sector of the Arctic Ocean prior to 2007: preliminary results, Polar Biology, 33(12), 1641–1650, https://doi.org/10.1007/s00300-010-0839-3. Wassmann, P., D. Slagstad, and I. Ellingsen (2010), Primary production and climatic variability in the European sector of the Arctic Ocean prior to 2007: preliminary results, Polar Biology, 33(12), 1641–1650, https://doi.org/10.1007/s00300-010-0839-3.