Chemical characterization of ambient aerosol collected during the northeast monsoon season over the Arabian Sea: Labile-Fe(II) and other trace metals
- Creators
- Johansen, Anne M.
- Hoffmann, Michael R.
Abstract
Ambient aerosol samples were collected over the Arabian Sea during the month of March of 1997, aboard the German R/V Sonne, as part of the German Joint Global Ocean Flux Study (JGOFS) project. This is the third study in a series of analogous measurements taken over the Arabian Sea during different seasons of the monsoon. Dichotomous high-volume collector samples were analyzed for ferrous iron immediately after collection, while trace metals, anions, and cations were determined upon return to the laboratory. The main crustal component was geochemically well represented by the average crustal composition and amounted to 5.94 ± 3.08 μg m^(−3). An additional crustal constituent of clay-like character, rich in water-soluble Ca and Mg, was seen in the fine fraction in air masses of Arabian origin. Total ferrous iron concentrations varied from 3.9 to 17.2 ng m^(−3) and averaged 9.8 ± 3.4 ng m^(−3), with 87.2% of Fe(II) present in the fine aerosol fraction. Fe(II) concentrations accounted for on average 1.3 ± 0.5% of the total Fe. While ferrous iron in the coarse fraction appeared to be correlated with the main crustal component, the fine Fe(II) fraction exhibited a more complex behavior. The anthropogenic contribution to the aerosol, as traced by Pb, Zn, and some anions and cations, was found to be considerably larger, especially during the first 10 days of this cruise, than in previously collected samples from the inter-monsoon and southwest monsoon of 1995.
Additional Information
© 2003 by the American Geophysical Union. Received 3 December 2002; revised 26 February 2003; accepted 24 March 2003; Article first published online: 18 July 2003. The authors wish to thank Meinrat O. Andreae and Hermann W. Bange of the Max Planck Institute of Biogeochemistry in Mainz, Germany, for assistance with the cruise, which was sponsored by the German Joint Global Ocean Flux Study (JGOFS) project. Appreciation is also extended to the helpful crew of the R/V Sonne. Research support was provided by the National Science Foundation and by the Environmental Now Foundation. Their support is greatly appreciated. This paper was abstracted in part from the Ph.D. thesis of A. M. Johansen, California Institute of Technology.Attached Files
Published - jgrd10448.pdf
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Additional details
- Eprint ID
- 59274
- Resolver ID
- CaltechAUTHORS:20150806-153837338
- NSF
- Environmental Now Foundation
- Created
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2015-08-07Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field