Atmospheric Dust and Irradiation effects on Ocean Surface processes - Biogeochemistry in the Atlantic Ocean (ADIOS-BAO)

• Applicant: Dr. Peter Leslie Croot
• Subject Area: Oceanography
• Term: from 2010 to 2013
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 166158443

Funding is requested for participation in the Polarstern expedition ANTXXVI-4 from Punta Arenas to Bremerhaven scheduled for Apr-May 2010. This cruise will provide a further opportunity to continue ongoing studies into the aerosol deposition of trace elements to the open ocean and its effect on ocean biogeochemical cycles. In cooperation with national and intemational partners we propose to assess the combined impacts of aerosol deposition and irradiation on the near surface biogeochemistries of P, N, Fe, Al and Ti. The proposed transect crosses regions potentially influenced by dust sources from Patagonia and the Sahara, providing the opportunity to compare the oceanic response to these different aerosol sources. Our work will focus on the simultaneous daily collection of atmospheric aerosols and surface seawater samples, along the cmise track, for analysis at sea and in the laboratory in Kiel. At each daily station, shipboard measurements will be made of coloured dissolved organic matter (CDOM), phosphate, Fe, Al, Ti and the transient redox species Fe(ll) and H2O2 in near surface waters to examine the influence of dust supply and irradiation along the transect. Specific at sea experiments will focus on the instantaneous dissolution ofthe daily sampled aerosols with freshly collected seawater. Additional longer term experiments will utilize archived dust sources from the Sahara and Patagonia with clean seawater collected from different regions during the voyage to assess possible regional differences in the dissolution processes.

• DFG Programme: Research Grants