Influence of Atmospheric Aerosol Deposition and its Elemental Composition on Marine Productivity in the Central Arabian/Persian Gulf 

Influence of Atmospheric Aerosol Deposition and its Elemental Composition on Marine Productivity in the Central Arabian/Persian Gulf The Arabian Gulf is a shallow, warm oligotrophic, and hypersaline marginal sea of the Indian Ocean. Due to intense evaporation, limited freshwater input, recurrent dust event and harsh environmental conditions, nutrient concentrations and productivity are significantly impacted by the harsh and changing environmental conditions. Atmospheric aerosols can impact surface ocean biology and biogeochemical processes in the Arabian Gulf as a result of the dust events and limited inputs. However, the rates of macro- and micronutrient inputs from the atmosphere to the Arabian Gulf are not well constrained. Both inorganic and organic forms of nitrogen and phosphorus may contribute to productivity in the Arabian/Persian Gulf. Productivity and by proxy precious resources such as fisheries can be closely linked to aerosols nutrient deposition. In this study, we use the Arabian Gulf as a natural laboratory for investigating the temporal variability of atmospheric macro- and micronutrients, the partitioning between organic and inorganic forms of nitrogen and phosphorus, and the role of trace metals in marine productivity. Based on annual time-series aerosol measurements, we provide new insights into atmospheric concentrations of macro- and micronutrients in the central Arabian/Persian Gulf. Additionally, using 1-dimensional biogeochemical model simulations, we investigate the influence of atmospheric aerosol deposition on primary productivity in the Gulf. The results obtained suggest that atmospheric deposition is an important process regulating marine productivity in the Arabian Gulf.