Nitrogen oceans

Christensen J. P., Murray, J. W., Devol, A. H. and Codispoti, L. A. (1987). Denitrification in continental shelf sediments has major impact on oceanic nitrogen cycle. Glob. Biogeochem. Cycles 1,97-116. 

Sweeney, R. E., Liu, K. K., Kaplan, I. R., Oceanic Nitrogen Isotopes and Their Uses in Determining the Source of Sedimentary Nitrogen, In Stable Isotopes in the Earth Sciences, pp. 9-26, Wellington, New Zealand, 1978. 

Sweeney RE, Kaplan IR (1980) Natural abundance of as a source indicator for near-shore marine sedimentary and dissolved nitrogen. Mar Chem 9 81-94 Sweeney RE, Liu KK, Kaplan IR (1978) Oceanic nitrogen isotopes and their use in determining the source of sedimentary nitrogen. In Robinson BW (ed.) DSIR Bull 220 9-26 Swihart GH (1996) Instrumental techniques for boron isotope analysis. Rev Miner 33 845-862 Swihart GH, Moore PB (1989) A reconnaissance of the boron isotopic composition of tourmaline. Geochim Cosmochim Acta 53 911-916... 

Fig. 1.2), most of which escapes to the atmosphere (see Fig. 1.1 as well as Chapter 2 by Bange, this volume). Nitrous oxide acts as a greenhouse gas that is more than 200 times more potent than CO2 (Ramaswamy et ah, 2001). Therefore variations of this gas in the atmosphere can lead to changes in Earth s temperature and cHmate. Since the oceanic emission of N2O constitutes a substantial fraction to the total emission of N2O into the atmosphere, N2O provides for a direct potential link between the ocean nitrogen cycle and Earth s climate. 

The inventory of NH in the ocean is approximately three orders of magnitude smaller than that ofNO. Nevertheless, the cycHng ofNH in the ocean is a cmcial component of the upper ocean nitrogen cycle. In fact, the chemical distinction of NO3 versus NH permits oceanographers to investigate the sources and fate of nitrogen in the upper ocean in a much more detailed way than it would be possible if nitrogen existed just in one major chemical form, such as is the case for PO, for example. 

Nitric oxide (NO), nitrous oxide (N2O), dinitrogen (N2), and ammonia (NH3) are constituents of the Earth s atmosphere. They play important roles in the chemistry and climate of the present-day Earth. Moreover, they are intermediates of the oceanic nitrogen cycle. In contrast to most of the other components of the oceanic nitrogen cycle, they exist as dissolved gaseous molecules. Being gases they can be transferred across the seasurface-troposphere interface. 

Isotopic studies of the oceanic nitrogen cycle are discussed in Chapter 31. 

Sigman, D. M., Altabet, M. A., McCorkle, D. C., Francois, R., and Fischer, G. (2000). The delta N-15 of nitrate in the Southern Ocean Nitrogen cycling and circulation in the ocean interior. Journal of Geophysical Research Oceans 105(C8), 19599—19614. 

Table Z(.3 Some Recent Extrapolations of Oceanic Nitrogen fixation...

The purpose of this chapter is to emphasise the role of the microbial loop in the oceanic nitrogen cycle. It begins by briefly introducing classical concepts of microbial loop function, then shifts to the increase in our knowledge that has occurred in the past three decades. It then introduces the components of the microbial loop that... 

Denitrification is the largest loss term for oceanic nitrogen and plays a key role in regulating the avadabifity of combined nitrogen in the ocean on long time scales (Codispoti et al., 2001 Codispoti, 2007) (see Devol, Chapter 6, this volume). While sedimentary denitrification is unhkely to alter the of oceanic NOs" (Fig. 29.3), pelagic denitrification plays a central role in the isotopic balance of the ocean since it does not typically go to completion and therefore produces residual with an... 

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