During dust storms Saharan dust is deposited in the ocean and can potentially change the biological productivity and phytoplankton composition by their fertilizer properties. The dust particles in the water interact with the solar radiation by their absorption and scattering properties which can enhance the turbidity and can decrease the penetration depth of solar radiation. The interactions between dust and ocean and their feedbacks are only partly understood. Therefore, the remote sensing group of the Leibniz Institute for Baltic Sea Research investigates the Sahara dust impact on optical water properties and phytoplankton development within the SOPRAN project.

The main questions in the third phase of this project are:

• Is there any relationship between direct dust input and absorbing as well as scattering phytoplankton blooms in the study area?

• Can we quantify the dust influence on inherent and apparent optical properties and derive relationships to implement the impact into circulation and ecosystem models?

The project will deliver the following products:

• Statistics of real dust events compared to satellite derived dust aerosol optical depth and to absorbing and scattering phytoplankton blooms and their relationships.

• Synthesis between the approaches of dust influence on the inherent and apparent optical properties in the water column for dust in atmosphere and dust in water.

• Derivation of relationships describing the dust impact on optical water properties for the implementation in different models.

PI's: H. Siegel, T. Ohde
Contact: Thomas Ohde (thomas.ohde@io-warnemuende.de)