Atlantic Ocean atmospheric deposition

Prospero JM, Barrett K, Church T, et al. (1996) Nitrogen dynamics of the North Atlantic Ocean - Atmospheric deposition of nutrients to the North Atlantic Ocean. Biogeochemistry 35 27-73. 

Our estimates of atmospheric deposition in preindustrial and modern times indicate that Hg inputs have increased by a factor of 3.4 in 130 years (3.7 to 12.5 xg/m2 per year). Alternatively, a factor of 3.7 is obtained by averaging the increase factor from each lake (Table II). The 3.7-fold increase translates to an average increase of about 2.2% per year, compared to an annual increase of 1.5% measured in air over the north Atlantic Ocean for the period 1977-1990 (26). 

Curry W.B. and Lohmann G.P. (1985) Carbon deposition rates and deep water residence time in the equatorial Atlantic Ocean throughout the last 160,000 years. In The Carbon Cycle and Atmospheric CO2 Natural Variations Archean to Present (eds. E.T. Sundquist and W.S. Broecker), pp. 285-301. Amer. Geophys. Union, Washington, D.C. 

Sarthou G, Baker AR, Blain S, Achterberg EP, Boye M, Bowie AR, Croot P, Laan P, de Baar HJW, Jickells TD, Worsfold PJ (2003) Atmospheric iron deposition and sea-surface dissolved iron concentrations in the eastern Atlantic Ocean. Deep-Sea Res 50 1339-1352 Schafer H, Muyzer G (2001) Denaturing gradient gel electrophoresis in marine microbial ecology. In Paul J (ed) Methods in microbiology, vol 30. Academic Press, London, pp 425-468... 

Alaska (PF), Katherine, Australia (KA), Amsterdam Island, Indian Ocean, (AI), and Bermuda, Atlantic Ocean (BD). The eastern U.S. sites include Multistate Atmospheric Power Production Pollution Study (MAP3S) sites at Whiteface Mountain, NY (WH) Ithaca, NY (IT), Pennsylvania State University (PS), Charlottesville, VA (CV) and Urbana, IL (IL). The western states are National Atmospheric Deposition Program (NADP) sites with a continuous record between 1981-1984 (in Colorado, California, Washington, Oregon and Arizona). 

Prospero, J. M., Barrett, K., Church, T., Dentener, P., Duce, R. A., Galloway, J. N., Levy, H. II., Moody, J., and Quinn, P. (1996). Atmospheric deposition of nutrients to the North Atlantic Basin. In Nitrogen cycling in the North Atlantic Ocean and its watersheds report of the international SCOPE project (Howard, R. W., ed.), Kluwer, Dordrecht, pp. 27-74. 

Paerl, H. W., and Fogel, M. L. (1994). Isotopic characterization of atmospheric nitrogen inputs as sources of enhanced primary production in coastal Atlantic Ocean waters. Mar. Biol. 119, 635—645. Paerl, H. W., Dennis, R. L., and Whitah, D. R. (2002). Atmospheric deposition of nitrogen Implications for nutrient over-enrichment of coastal waters. Estuaries 25, 677—693. 

The atmosphere, in turn, affects soil development by providing oxygen and by wind erosion and deposition. Sand dunes are only the most obvious example. Loess soils are deposits of silt-sized particles carried by winds from riverbeds and glacial outwash. A large fraction of the clay content of the soils along the eastern shores of the Mediterranean Sea has been carried by winds several thousand kilometers from the Sahara Desert and Atlas Mountains of North Africa. Trade winds carry Saharan clay particles several thousand kilometers out into the Atlantic Ocean. 

Atmospheric deposition is also a major source of metal input into many aquatic ecosystems (Salomons 1986). Helmers and Schrems (1995) reported for the tropical North Atlantic Ocean that wet trace element deposition dominates over dry input. From the increased enrichment factors relative to the Earth s crust, the determined trace metal concentrations were assumed to originate from anthropogenic sources. For atmospheric wet depositional fluxes of selected trace elements at two mid-Atlantic sites, Kim et al. (2000) reported that at least half of the Cr and Mn and more than 90% of the Cd, Zn, Pb, and Ni are from non-crustal (presumably anthropogenic) sources. 

Although it is accepted that atmospheric mercury burdens have increased substantially since the pre-industrial period, it is uncertain whether overall atmospheric mercury levels are currently increasing, decreasing, or remaining stable. Measurements of mercury over remote areas of the Atlantic Ocean show increasing levels up until 1990 and a decrease for the period 1990-1994 (Slemr 1996, Pirrone et al. 2000, Munthe et al. 2001). However, other measurements at remote sites in northern Canada and Alaska show deposition rates... 

The ubiquity of PCBs is indicated by then-presence in environmental samples from the polar regions of air, snow, ice, water, and in living organisms. The presence of PCBs in such remote areas suggests the importance of atmospheric transport. The Committee on the Assessment of Polychlorinated Biphenyls in the Environment estimated that 50-80% of the PCBs derived from the United States were now in sediments and waters of the North Atlantic Ocean. Of the estimated total world PCB production of 1.2 million tons to date, about 374,000 tons are now in various portions of the terrestrial, coastal, and open ocean ecospheres (Table 25.1). Another 783,(XX) tons are still in use in electrical equipment and other products or deposited in landfills and dumps and represent a potential source of... 

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