HR: 09:45h
AN: OS31C-08    [Abstracts]
TI: Atmospheric Supply of Trace Elements to the Oceans: Results from the CLIVAR Repeat Hydrography project 2003-2007
AU: * Landing, W M
EM: wlanding@fsu.edu
AF: Department of Oceanography, Florida State University, Tallahassee, FL 32306-4320, United States
AU: Buck, C S
EM: cbuck@ocean.fsu.edu
AF: Department of Oceanography, Florida State University, Tallahassee, FL 32306-4320, United States
AU: Measures, C I
EM: chrism@soest.hawaii.edu
AF: Department of Oceanography, University of Hawaii, Honolulu, HI 96822, United States
AU: Hiscock, W
EM: hiscock@hawaii.edu
AF: Department of Oceanography, University of Hawaii, Honolulu, HI 96822, United States
AU: Hatta, M
EM: mhatta@hawaii.edu
AF: Department of Oceanography, University of Hawaii, Honolulu, HI 96822, United States
AB: Aerosol and water column samples were collected from the A16N, P2, P16S/P16N, and I8S/I9N CLIVAR Repeat Hydrography cruises to study the impact of soluble trace element deposition on the chemistry of the upper water column (0-1000 meters). The "instantaneous" solubility of aerosol material was measured on replicate aerosol filters using ultrapure water and filtered surface seawater by passing 100 mL of the leach solution through the filters within 10 seconds. Rainfall samples were filtered ASAP using 0.4 um PCTE filters; an aliquot of unfiltered rain was also analyzed. Water column samples were collected using the CLIVAR trace metal clean rosette system loaded with 12 liter Teflon-coated GoFlo bottles. Seawater samples were filtered through 0.4 um PCTE filters and analyzed using either shipboard FIA analysis (for Al, Mn, Fe, and Fe(II)) or shore-based extraction and ICPMS analysis (for Al, Mn, Fe, Co, Ni, Cu, Zn, Cd, and Pb). The impact of recent atmospheric deposition on water column chemistry is most obvious in the North Atlantic where the Saharan dust plume deposits significant quantities of Al, Mn, Fe, and Co. Lower magnitude impact from the Asian dust plume is also observed in the North Pacific, and in the South Pacific near Tahiti from Australian desert dust. Dust loads in the South Pacific and southern Indian Ocean are much lower, and the impact of dust deposition on water column chemistry is not detectable south of 50S. Residence times for dissolved Al and Fe in the upper water column with respect to atmospheric deposition of soluble Al and Fe range from a few days in the North Atlantic to many months in the southern ocean.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0414 Biogeochemical cycles, processes, and modeling (0412, 0793, 1615, 4805, 4912)
DE: 4805 Biogeochemical cycles, processes, and modeling (0412, 0414, 0793, 1615, 4912)
DE: 4875 Trace elements (0489)
SC: Ocean Sciences [OS]
MN: 2007 Fall Meeting