Nitrogen cycle deep nitrate

Lourey, M. J., Trull, T. W., and Sigman, D. M. (2003). Sensitivity of delta N-15 of nitrate, surface suspended and deep sinking particulate nitrogen to seasonal nitrate depletion in the Southern Ocean. Global Biogeochem. Cycles 17(3), doi 10.1029/2002GB001973. 

The nitrogen cycle occnrs in the oceans as well as in the soil. Nitrates (N03 ) at the surface of the ocean are almost completely nsed up by living organisms. As these organisms die, they sink. As they sink, the nitrogen componnds inside their bodies are oxidized back to N03. In very deep waters, ocean currents mix the... 

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