## 3 Results
### Comparison of Atmospheric Parameters
Analysis of the data presented in Table 3 shows that for intensive dust transport (with a large AOT and high concentrations of dust aerosol particles), more significant error flags are present, namely LOWLW (very low sea brightness) and TURBIDW (turbid water detected). Figure 7 demonstrates the spectral variability of the mean Rrs(\(\lambda\)) values. According to the data presented in Table 3, the value of the correlation of Rrs(\(\lambda\)) data of different qualities was calculated. As a result, it was found that the correlation between the 2 dates was 28% for the L3 data and 27% for L2, which is a low indicator of the atmospheric correction quality of the results on the days of intense dust transfers. For dates other than 12 September 2017, a sharp increase (by a factor of 2) in the chlorophyll-a concentration values between the 2 dates, which is not typical for the Black Sea region, was observed. This may be due to \begin{table}
\begin{tabular}{c c c c c c c c c} \hline  & \multicolumn{2}{c}{**10.09.2020**} & \multicolumn{2}{c}{**27.09.2020**} & \multicolumn{2}{c}{**29.09.2020 (MODIS)**} & \multicolumn{2}{c}{**29.09.2020 (VIIRS)**} \\ \hline  & **Quality\_L2** & **Quality\_L3** & **Quality\_L2** & **Quality\_L3** & **Quality\_L2** & **Quality\_L3** & **Quality\_L2** & **Quality\_L3** \\ \hline   Pixels & 102,965 & 99,512 & 104,986 & 100,470 & 33,027 & 25,111 & 32,688 & 25,096 \\   AOT(869) & 0.032 & 0.030 & 0.232 & 0.233 & 0.210 & 0.193 & 0.186 & 0.172 \\   Angstrom & 1.542 & 1.551 & 0.922 & 0.916 & 0.799 & 0.856 & 0.759 & 0.801 \\ \hline   Rrs (412 nm) & 0.003 & 0.003 & \(-\)0.001 & \(-\)0.001 & \(-\)0.001 & 0.000 & 0.000 & 0.000 \\   Rrs (443 nm) & 0.003 & 0.003 & 0.001 & 0.001 & 0.001 & 0.001 & 0.003 & 0.003 \\ \hline   Rrs (469 nm) & 0.004 & 0.004 & 0.002 & 0.002 & 0.001 & 0.001 & & \\   Rrs (488 nm) & 0.003 & 0.003 & 0.002 & 0.002 & 0.002 & 0.002 & 0.003 & 0.003 \\   Rrs (531 nm) & 0.003 & 0.003 & 0.002 & 0.002 & 0.001 & 0.001 & 0.001 & 0.002 & 0.002 \\   Rrs (547 nm) & 0.002 & 0.002 & 0.002 & 0.002 & 0.001 & 0.001 & & \\   Rrs (555 nm) & 0.002 & 0.002 & 0.002 & 0.002 & 0.001 & 0.001 & & \\   Rrs (645 nm) & 0.000 & 0.000 & 0.001 & 0.001 & 0.000 & 0.000 & & \\   Rrs (667 nm) & 0.000 & 0.000 & 0.001 & 0.001 & 0.000 & 0.000 & 0.000 & 0.002 \\ \hline  & & & & & & & & \\ \end{tabular}
\end{table} 
Table 3: The statistics and average values of Rrs(\(\lambda\)) for pixels from the selected area of the Black Sea water area of Ocean color products for the days on which dust transfer occurred from 27–29 September 2020 and the days on which the atmosphere was clean before transfer on 10 September 2020, according to the MODIS satellite data. Figure 7: Spectral distribution of the average Rrs(\(\lambda\)) values according to the MODIS (Aqua) data on 27.09.2020 depending on the error flags. incorrect atmospheric correction of the level 1B products. As can be seen from the data in Table 3 the values of Rrs(\(\lambda\)) were significantly underestimated in the visible region of the spectrum, and the spectral curve of Rrs(\(\lambda\)) in the long-wavelength region showed twice the values of Rrs(\(\lambda\)), which were overestimated in comparison with the day on which the atmosphere was clean. On 29.09.2020, the performed calculation of the correlation between the results of the L2 and L3 data in the case of dust transport according to the MODIS results showed a 99% accuracy (while negative values at a wavelength of 412 nm were retained) and VIIRS was 87%. It is also shown in the table that the chlorophyll-a measurements for the 2 m satellites differed. The correlation of data from a day on which the atmosphere was clean in the Black Sea region (10.09.2020) according to the MODIS L2 data was 47% and 58% according to the L3 data, which is also a low indicator of the reliability of the results. Similar to the previous cases, a statistical analysis of the error flags of the satellite images obtained on 29.09.2020 was carried out and the correlation of the spectral luminance coefficient values was considered.