Ammonia oceanic distribution

Pipeline systems for transporting anhydrous ammonia that are urea and ammonium nitrate (UAN) and LNG compatible, exist in Europe, Mexico, and the Soviet Union. Export-oriented ammonia producing countries utilize huge ocean-going tankers that contain up to 50,000 t for distribution of ammonia. Co-shipment in refrigerated LNG tankers is usuaky done. 

More simultaneous measurements of NH3 in the ocean and in the atmosphere are needed to reduce the considerable uncertainties of the ocean/atmosphere flux estimates. The ongoing acidification of the ocean will shift the NH3/NH4 equilibrium to NH. On the one hand this might have implication for the atmospheric distribution of NH3, since the uptake capacity of the ocean will be increased with unknown consequences for chemistry of the atmosphere (e.g. the aerosol formation) over the ocean. On the other hand this might have severe implications for the nitrification rates in seawater because they are influenced by the pH. When the pH drops from 8 to 7, nitrification rates can be reduced by 50% (Huesemann et al., 2002). (One explanation for this is that the ammonia monooxygenase enzyme uses rather NH3 than NH4 as substrate.) Most recently it was suggested that atmospheric NH3 serves as a foraging cue for seabirds such as the blue petrel (Nevitt ei a/., 2006) is an excretion product of... 

Norman, M., and Leek, C. (2005). Distribution of marine boundary layer ammonia over the Atlantic and Indian Oceans during the Aerosols99 cruise. J. Geophys. Res. 110, D16302, doi 10.1029/ 2005JD005866. 

Bano, N., and HoUibaugh, J. T. (2000). Diversity and distribution of DNA sequences with affinity to ammonia-oxidizing bacteria of the beta subdivision of the class Proteohacteria in the Arctic Ocean. Applied and Environmental Microbiology 66, 1960-1969. 

HoUibaugh, J. T., Bano, N., and Ducklow, H. W. (2002). Widespread distribution in polar oceans of a 16S rRNA gene sequence with affinity to Nitrosospira-]ike ammonia-oxidizing bacteria. Appl. Environ. Microbiol. 68, 1478—1484. 

Figure 15.13. The sediment-water interface, (a) Direction of fluxes expected for dissolved constituents between sediment pore waters and the overlying waters (oceans and lakes), (b) For sediments and pore water, the one-dimensional distribution of concentrations is time and depth dependent. Arrows indicate fluxes at the sediment-water interface depending on the concentration gradient in pore water. The overlying water (ocean or lakes) is assumed to be well mixed, (c) Sulfate, phosphate, and ammonia versus depth in pore waters from Santa Barbara Basin, California. (From Sholkovitz, 1973.)...

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