Nitrogen (N2) fixation in oligotrophic surface waters is the main source of new nitrogen to the ocean1and has a key role in fuelling the biological carbon pump2. Oceanic N2fixation has been attributed almost exclusively to cyanobacteria, even though genes encoding nitrogenase, the enzyme that fix...
This article outlines the isotope systematics of the major processes in the ocean nitrogen (N) cycle, their impact on the isotopic compositions of the major N reservoirs in the ocean, and how the N isotopes in the modern ocean and sedimentary record may record current N fluxes and past ...
This article outlines the isotope systematics of the major processes in the ocean nitrogen (N) cycle, their impact on the isotopic compositions of the major N reservoirs in the ocean, and how the N isotopes in the modern ocean and sedimentary record may record current N fluxes and past change...
Tyrrell developed a simple two-box model of oceanic nitrogen and phosphorus cycles to describe the regulation of both nitrate and phosphate concentrations in the global ocean. His criterion for nitrate deficit in the ocean, a molar ratio of N:P in surface waters (R) of less than 16, is ...
Unprecedented discoveries over the last decade have changed the way we view the marinenitrogen cycle. The critical role of picoplankton in marine ecosyste... CS Hopkinson,EJ Carpenter,DG Capone - 《Estuaries》 被引量: 768发表: 1985年 Nitrogen in the Marine Environment Although the perception tha...
It has been proposed that widespread deficits of nitrate in the ocean, like those observed today, are caused by iron limitation of marine nitrogen fixation. That is, only when iron is sufficiently abundant to satiate nitrogen fixers will the ratio of nitrate to phosphate in the ocean increase ...
Total nitrogen (TN) and total phosphorus (TP) measurements and contemporaneous measurements of chlorophyll a (Chl a) and phytoplankton nutrient deficiency have been made across a broad range of lakes and ocean sites using common methods. The ocean environment was nutrient rich in terms of TN and...
Redox control of N:P ratios in aquatic ecosystems The ratio of dissolved fixed inorganic nitrogen to soluble inorganic phosphate (N:P) in the ocean interior is relatively constant, averaging ~16 : 1 by ato... TM Quan,PG Falkowski - 《Geobiology》 被引量: 100发表: 2009年 Stimulation of ...
The unicellular pico-cyanobacteria contribute substantially to primary production, while the larger planktonic non-heterocystous genus Trichodesmium appear to be the most potent provider of new nitrogen to oceans. Although there have been rather few studies in the Indian Ocean, recent surveys suggest a...
Although the Arctic Ocean is the most riverine-influenced of all of the world’s oceans, the importance of terrigenous nutrients in this environment is poorly understood. This study couples estimates of circumpolar riverine nutrient fluxes from the PARTNERS (Pan-Arctic River Transport of Nutrients, ...