Characterization of “dead-zone” eddies in the eastern tropical North Atlantic
نویسندگان
چکیده
منابع مشابه
Deoxygenation in the oxygen minimum zone of the eastern tropical North Atlantic
[1] Observations and model results both indicate increasing oxygen minimum zones (OMZ) in the tropical oceans. Here we report on record low dissolved oxygen minimum concentrations in the eastern tropical North Atlantic in fall of 2008, with less than 40 mmol kg 1 in the core of the OMZ. There we find a deoxygenation rate of 0.5 mmol kg 1 a 1 during the last decades on two repeat sections at 7.5...
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Here we present first observations, from instrumentation installed on moorings and a float, of unexpectedly low (< 2 μmolkg) oxygen environments in the open waters of the tropical North Atlantic, a region where oxygen concentration does normally not fall much below 40 μmolkg. The low-oxygen zones are created at shallow depth, just below the mixed layer, in the euphotic zone of cyclonic eddies a...
متن کاملParticle export fluxes to the oxygen minimum zone of the eastern tropical North Atlantic
In the ocean, sinking of particulate organic matter (POM) drives carbon export from the euphotic zone and supplies nutrition to mesopelagic communities, the feeding and degradation activities of which in turn lead to export flux attenuation. Oxygen (O2) minimum zones (OMZs) with suboxic water layers (< 5 μmol O2 kg−1) show a lower carbon flux attenuation compared to welloxygenated waters (> 100...
متن کاملEnvironmental Forcing of Nitrogen Fixation in the Eastern Tropical and Sub-Tropical North Atlantic Ocean
During the winter of 2006 we measured nifH gene abundances, dinitrogen (N(2)) fixation rates and carbon fixation rates in the eastern tropical and sub-tropical North Atlantic Ocean. The dominant diazotrophic phylotypes were filamentous cyanobacteria, which may include Trichodesmium and Katagnymene, with up to 10(6) L(-1)nifH gene copies, unicellular group A cyanobacteria with up to 10(5) L(-1)n...
متن کاملChanges in the Ventilation of the Oxygen Minimum Zone of the Tropical North Atlantic
Changes in the ventilation of the oxygen minimum zone (OMZ) of the tropical North Atlantic are studied using oceanographic data from 18 research cruises carried out between 28.58 and 238W during 1999–2008 as well as historical data referring to the period 1972–85. In the core of the OMZ at about 400-m depth, a highly significant oxygen decrease of about 15 mmol kg is found between the two perio...
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ژورنال
عنوان ژورنال: Biogeosciences
سال: 2016
ISSN: 1726-4189
DOI: 10.5194/bg-13-5865-2016