Supply of Natural and Industrial Aerosols to the Indian Ocean
Brent Alan Summers1, Peter L Morton1, Nathaniel J Buck2, William M Landing3, Clifton S Buck4, Pamela M Barrett2,5 and Joseph A Resing2, (1)National High Magnetic Field Laboratory, Tallahassee, FL, United States, (2)University of Washington PMEL/NOAA, Joint Institute for the Study of the Atmosphere and Ocean, Seattle, WA, United States, (3)Florida State University, Earth, Ocean, and Atmospheric Science, Tallahassee, FL, United States, (4)Skidaway Institute of Oceanography, Savannah, GA, United States, (5)University of Washington, Seattle, WA, United States
Abstract:
To estimate the atmospheric deposition of bioactive trace elements to the Indian Ocean, aerosol dust samples were collected during three CLIVAR/CO
2 Repeat Hydrography Indian Ocean transects (I5, I8S/I9N, and I6S). These aerosols were collected on polycarbonate track-etched filters and analyzed by ICP-MS at the National High Magnetic Field Laboratory (Tallahassee, FL, USA), for total and DI water-soluble trace element concentrations.
Atmospheric fluxes of lithogenic elements such as Fe, Al, Ti and Mn were highest in the Bay of Bengal and near the coasts of Australia and South Africa. Estimated Fe fluxes in the Bay of Bengal were 0.5-2 µmol/m2d, and compared well with literature values reported for the same region (0.6-1 µmol/m2d, Grand et al. 2015; 0.02-1.2 µmol/m2d, Srinivas and Sarin 2013). Anthropogenic species including aerosol Pb, V, and non-seasalt sulfate were also highest in the Bay of Bengal, indicating industrial contributions to aerosol dust fluxes. However, while aerosol Fe solubility was also high along the coast, no clear trend with industrial tracers (i.e., nss-sulfate) was observed, in contrast to previous reports. These trends will be discussed in greater detail in the context of trace metal solubility, provenance, and possible impacts on marine biota.
