## 3 Results  
### Verification of the Results Obtained  
Before analyzing the obtained materials, it is necessary to verify the obtained materials with the results worked out by other methods. It makes no sense to compare the absolute values of primary production and measured values of phytoplankton biomass.  
Figure 4: Relationship equation between salinity (psu) and \(\delta^{18}\)O (%) in the Barents Sea.  
Nevertheless, it is possible to compare the relative values of diatoms and dinoflagellates' contribution to the total production (calculated values), on the one hand, and to the total biomass in the case of its direct measurement (Figure 5), on the other hand.  
The biomass values are from the archive of the Murmansk Marine Biological Institute, Russian Academy of Sciences, from 1970 to 2013, for the season from July to September, the period with the most data available. In addition, this comparison may not seem entirely correct, since for the case of calculated values, integrated values are presented for the depth of the euphotic layer, and for the case of direct measurements of biomass, only the surface layer is presented. Nevertheless, the nature of the distribution of these values, as well as the values of the relative contribution values of these two systematic groups, are quite close. In addition, by the beginning of summer, the intensity of the photosynthesis process reaches its maximum and reaches a plateau, which leads to the maximum values of primary production--and the maximum values of the decrease in the nutrient supply. Under these conditions, the relative values of calculation error are minimal.  
The results for the verification of the calculated values of the diatom and dinoflagellate systematic groups' relative contribution to the total primary production with direct measurements of these systematic groups' contribution to the total phytoplankton biomass showed the similarity of not only the nature of the distribution but also the values themselves.  
The results of our calculation in the Barents Sea can be compared to [PERSON] et al. [6] for the water area, surrounding the Svalbard archipelago. In more detail, the results of this comparison are presented in the work of [PERSON] et al. [48]. In work [6], calculations  
Figure 5: Relative values of total sum diatoms “d” (**A**) and dinoflagellates “p” (**B**) contribution to the total production (calculated values Equation (16)). Relative contribution diatoms (**C**) and dinoflagellates (**D**) to the total phytoplankton biomass (direct measurements), July—September.  
of primary production are made based on hydrodynamic and ecosystem models. The hydrodynamic model is a large-scale model with a horizontal grid spacing of 20 km and a nested model resolution of 4 km. The ecosystem module includes nitrates, ammonium, silicates, diatoms, flagellates, microzooplankton, bacteria, heterotrophic nanoflagellates, fast-sinking detritus, slow-sinking detritus, and two groups of mesozooplankton _Calanus finmarchicus_ and _Calanus glacialis_.  
Based on the modeling results, water areas with different PP values were identified in this area. Because the resolution of the used model was much higher than in our investigations, as a result, six regions were identified (Table 4). According to the results of our study, there are three identified regions, but we believe that the boundaries of the three regions that we obtained include the water areas of six regions from the article above [6] (Table 4), and the results have pretty good convergence. A particularly high degree of similarity was obtained from the PP estimate in Region III, adjacent to the archipelago in the northeastern part and extending further to the northeast of the sea. According to the results of both studies, a decrease in PP values is two times compared to other areas. However, according to available data [40], the relative value of the standard deviation from the mean value of PP in this area is several times greater than that presented in the compared work.