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Nitrogen cycling in the suboxic Arabian Sea: Implications for atmospheric chemistry and climate

Naqvi, S.W.A. (Indian National Science Academy, New Delhi (India), 1999)

An acute oxygen deficiency at mid-depths in the Arabian SEa leads to large-scale microbial conversion (denitrification) of the oxidised combined nitrogen species to molecular nitrogen (N sub(2)) at an estimated rate of ...

Denitrifying bacterial community composition changes associated with stages of denitrification in oxygen minimum zones

Jayakumar, D.A.; O'Mullan, G.D.; Naqvi, S.W.A.; Ward, B.B. (Springer, 2009)

Denitrification in the ocean is a major sink for fixed nitrogen in the global N budget, but the process is geographically restricted to a few oceanic regions, including three oceanic oxygen minimum zones (OMZ) and hemipelagic ...

Nitrogen cycling in the suboxic waters of the Arabian Sea

Devol, A.H.; Naqvi, S.W.A.; Codispoti, L.A. (Springer, 2006)

Arabian Sea contains one of the world's three large oxygen deficient zones (ODZ). Within the ODZ oxygen concentration is vanishingly small between about 200 and 800 m depth and in this depth interval denitrifications is ...

Seasonal oxygen deficiency over the western continental shelf of India

Naqvi, S.W.A.; Naik, H.; Jayakumar, D.A.; Shailaja, M.S.; Narvekar, P.V. (Springer, 2006)

The North Indian Ocean contains about two-third of the global continental-margin area affected by natural oxygen deficiency (O2 less than 0.2 mL L sup(-1)) in the water column. Also, the littoral countries of this ...

The nitrogen cycle in the Arabian Sea

Bange, H.W.; Naqvi, S.W.A.; Codispoti, L.A. (Elsevier, 2005)

Despite their importance for the global oceanic nitrogen (N) cycle, estimates of N fluxes in the Arabian Sea remain in considerable uncertainty. In this report, we summarize current knowledge of important processes, including ...

Denitrification processes in the Arabian Sea

Naqvi, S.W.A. (Indian Academy of Sciences, Bangalore, 1994)

Recent information on some consequences of the acute mid-water oxygen deficiency in the Arabian Sea, especially on carbon-nitrogen cycling, is reviewed. An evaluation of published estimates of water column denitrification ...

Nitrogen isotopic studies in the suboxic Arabian Sea

Naqvi, S.W.A.; Yoshinari, T.; Brandes, J.A.; Devol, A.H.; Jayakumar, D.A.; Narvekar, P.V.; Altabet, M.A.; Codispoti, L.A. (Indian Academy of Sciences, Bangalore, India, 1998)

Measurements of sup(15)N/ sup(14)N in dissolved molecular nitrogen (N sub(2)), nitrate (NO sub(3) sup(-)) and nitrous oxide (N sub(2)O) and sup(18)O/ sup(16)O in N sub(2)O [expressed as delta sup(15)N and delta sup(18)O, ...

Diversity of nitrite reductase genes (nirS) in the denitrifying water column of the coastal Arabian Sea

Jayakumar, D.A.; Francis, C.A.; Naqvi, S.W.A.; Ward, B.B. (Inter-Research, 2004)

Denitrification often occurs in the water column, underlying zones of intense productivity and decomposition in upwelling regions. In the denitrifying zone off the southwest coast of India, high concentrations of nitrite ...

Isotopic composition of nitrate in the central Arabian Sea and eastern tropical North Pacific: A tracer for mixing and nitrogen cycles

Brandes, J.A.; Devol, A.H.; Yoshinari, T.; Jayakumar, D.A.; Naqvi, S.W.A. (American Society of Limnology and Oceanography, 1998)

The delta sup(15)N composition of nitrate and N sub(2) gas was measured in the eastern tropical North Pacific (ETNP) and central Arabian Sea (AS) suboxic regions. The delta sup(15)N of nitrate increased from 6 ppt at 2,500 ...