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| Titel |
A multidisciplinary glider survey of an open ocean dead-zone eddy |
| VerfasserIn |
Johannes Karstensen, Florian Schütte, Alice Pietri, Gerd Krahmann, Björn Fiedler, Carolin Löscher, Damian Grundle, Helena Hauss, Arne Körtzinger, Pierre Testor, Nuno Viera |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250128949
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| Publikation (Nr.) |
 EGU/EGU2016-8998.pdf |
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| Zusammenfassung |
| The physical (temperature, salinity) and biogeochemical (oxygen, nitrate, chlorophyll
fluorescence, turbidity) structure of an anticyclonic modewater eddy, hosting an open ocean
dead zone, is investigated using observational data sampled in high temporal and spatial
resolution with autonomous gliders in March and April 2014. The core of the eddy is
identified in the glider data as a volume of fresher (on isopycnals) water in the depth
range from the mixed layer base (about 70m) to about 200m depth. The width is
about 80km. The core aligns well with the 40 μmolkg−1 oxygen contour. From
two surveys about 1 month apart, changes in the minimal oxygen concentrations
(below 5μmolkg−1) are observed that indicate that small scale processes are in
operation. Several scales of coherent variability of physical and biogeochemical
variable are identified – from a few meters to the mesoscale. One of the gliders
carried an autonomous Nitrate (N) sensor and the data is used to analyse the possible
nitrogen pathways within the eddy. Also the highest N is accompanied by lowest
oxygen concentrations, the AOU:N ratio reveals a preferred oxygen cycling per N. |
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