Estimating Dust Input to the Atlantic Ocean Using Surface Water Aluminium Concentrations

To understand the relationship between dust deposition and geochemically-linked biological processes, it is necessary to characterise the magnitude and location of dust deposition to the surface of the ocean. A simple model is presented to estimate the mineral dust deposition to the surface waters of the Atlantic Ocean. In the model, we assume that the dissolved aluminium (Al) in the surface waters is a steady state feature in which Al supply from the partial dissolution of incoming mineral dust balances its scavenging removal by biological processes. The model predictions are in good agreement with a wide range of measured mineral dust inputs at diverse locations in the Atlantic Ocean. The success of the model suggests that surface ocean Al distributions can be used to estimate the mineral deposition in remote regions of the ocean where logistics preclude direct measurements.