HR: 11:05h
AN: OS22B-04    [Abstracts]
TI: Estimate of Atmospheric Fluxes of Bioavailable Nutrients to the Gulf of Aqaba
AU: * Chen, Y
EM: ychen04@stanford.edu
AF: Stanford University, Geological & Environmental Sciences, Stanford, CA 94305 United States
AU: Street, J
EM: jstreet@stanford.edu
AF: Stanford University, Geological & Environmental Sciences, Stanford, CA 94305 United States
AU: Paytan, A
EM: apaytan@pangea.stanford.edu
AF: Stanford University, Geological & Environmental Sciences, Stanford, CA 94305 United States
AB: The atmosphere is an important pathway by which many nutrients and metals reach the surface ocean. The impact of dust deposition on an oceanic ecosystem is dependent on the amount of bioavailable nutrients exported along with the dust. To estimate the atmospheric fluxes of bioavailable nutrients to the Gulf of Aqaba, a suit of investigations have been made on the concentrations of nutrient species in aerosols, the solubility of aerosol nutrients in seawater and the deposition rates of aerosol particles over the Gulf. Our results suggest that (1) the soluble inorganic N (SIN) and P (SIP) in pure water can be converted to their seawater-soluble concentrations through two linear equations and used for estimation of bioavailable N and P fluxes; (2) the total aerosol Fe concentrations and the mean solubility of aerosol Fe in seawater (0.3 percent) should be used for the Fe flux calculation. Atmospheric fluxes are calculated from atmospheric concentrations using deposition velocities which are derived from the deposition rate study. Our estimates show that the ratio between SIN and SIP fluxes is about a factor of 4 higher than Redfield ratio (16) suggesting that atmospheric input of nutrients increases the likelihood of P limitation in the Gulf. Soluble Fe flux is in excess compared to that required for the phytoplankton growth driven by the major nutrient deposition. Atmospheric nutrient input can support over 10 percent of surface primary production during the summer months, and may constitute a significant fraction of surface new production of the Gulf.
DE: 1615 Biogeochemical cycles, processes, and modeling (0412, 0414, 0793, 4805, 4912)
DE: 3339 Ocean/atmosphere interactions (0312, 4504)
DE: 4801 Aerosols (0305, 4906)
DE: 4805 Biogeochemical cycles, processes, and modeling (0412, 0414, 0793, 1615, 4912)
DE: 4845 Nutrients and nutrient cycling (0470, 1050)
SC: Ocean Sciences [OS]
MN: Fall Meeting 2005