# Contribution of Atmospheric Depositions to Inventory of Nutrients in the Coastal Waters of Crimea
## 3 Results and Discussion
An assessment of possible contribution of a single event of atmospheric precipitations to the daily budget of nutrients has revealed that the maximum flux of both inorganic nitrogen and inorganic phosphorus with precipitations may reach 10.9 t day\({}^{-1}\) and 1.34 t day\({}^{-1}\), respectively, in winter. Assuming that the flux of nutrients with wastewater within the year is rather stable, the daily load should be about 4 t day\({}^{-1}\) for inorganic nitrogen and 0.8 t day\({}^{-1}\) for phosphate (Table 6). Based on the value of winter river runoff (35% of the annual value), the daily load of nutrients by the rivers is about 29.5 t day\({}^{-1}\) for nitrogen and about 1.9 t day\({}^{-1}\) for phosphorus. The contribution of atmospheric precipitation into the daily load of nutrients (especially with the observed dust transport from deserts) can reach 25% for inorganic nitrogen and 33% for phosphate during high water seasons. These values are in good agreement with other published data. Thus, [PERSON] et al., (2018) [42] applied numerical modeling to reveal that atmospheric deposition may account, on average, for 10% of nitrate and for 5-30% of inorganic phosphorus external inputs into the Mediterranean Sea. Some \begin{table}
\begin{tabular}{c c c c} \hline \hline  & **River Input,** & **Wastewater Load,** & **With Atmospheric Precipitations,** \\  & **t Day\({}^{-1}\)** & **t Day\({}^{-1}\)** & **t Day\({}^{-1}\)** \\ \hline Inorganic nitrogen & 29.5 (66\%) & 4 (9\%) & 10.9 (25\%) \\ \hline Phosphates & 1.9 (47\%) & 0.8 (20\%) & 1.34 (33\%) \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Contribution of a single event of atmospheric precipitation to the budget of nutrients. \begin{table}
\begin{tabular}{c c c c} \hline \hline  & **River Input,** & **Wastewater,** & **With Atmospheric Precipitations,** \\  & **t Year\({}^{-1}\)** & **t Year\({}^{-1}\)** & **t Year\({}^{-1}\)** \\ \hline Inorganic nitrogen & 7594 (82\%) & 1478 (16\%) & 94.11 (1\%) \\ \hline Phosphates & 171 (35.5\%) & 308 (64\%) & 1.27 (0.5\%) \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Contribution of various sources of nutrients to their annual budget in coastal areas. \begin{table}
\begin{tabular}{c c c c} \hline \hline  & **River Input,** & **Wastewater** & **With Atmospheric Precipitations,** \\  & **t Season\({}^{-1}\)** & **Load,** & **t Season\({}^{-1}\)** \\  & **Summer/Fall** & **t Season\({}^{-1}\)** & **Summer/Fall** \\ \hline \hline \multirow{2}{*}{Inorganic nitrogen} & 911.3 (66\%)/ & 369.5 (27\%)/ & 93.5 (7\%)/ \\  & 683.5 (58\%) & (32\%) & 113.9 (10\%) \\ \hline \multirow{2}{*}{Phosphates} & 57.8 (42\%)/ & 77 (57\%)/ & 1.41 (1\%)/ \\  & 43.3 (35\%) & (63\%) & 2.14 (2\%) \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Contribution of various sources of nutrients to their seasonal budget in coastal areas. researchers [43; 44] indicated that direct deposition of nitrogen onto the water's surface (not including the contribution of nitrogen to the landscape and then exported to estuaries) contributes between 1% and 40% of the total nitrogen input to an estuary. When different locations are compared, the calculated values of the inorganic nitrogen concentration in the atmospheric precipitation in the coastal cities of Crimea (Evpatoria and Kerch) for the registered amount of atmospheric precipitations resulted in different values of nitrogen fluxes. Data on the calculated fluxes of inorganic nitrogen (mmol m\({}^{-2}\) year\({}^{-1}\)) in Kerch and Yevpatoria, as well as measured fluxes in Sevastopol, in 2018-2020 are presented in Table 7.  
One of the reasons for the difference in these values can be the difference in the amount of precipitation between individual locations (Kerch vs. Sevastopol, for example). The effect of atmospheric load to the budget of nutrients in coastal waters can vary from at least 1.5-fold for other equal conditions.