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| Titel |
Internal waves and associated mixing in the Deep Western Boundary Current at 16°N |
| VerfasserIn |
Janna Köhler, Christian Mertens, Maren Walter, Monika Rhein, Torsten Kanzow |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250046519
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| Zusammenfassung |
| Turbulent mixing contributes crucially to maintain the oceans stratification and to close the
energy budget of the thermohaline circulation. The mixing is strongly correlated with internal
wave activity, as their breaking provides a major source of mechanical energy for the
turbulent mixing in the oceans interior.
The generation processes and the evolution of internal waves are analyzed in the
region of the Deep Western Boundary Current at 16°N in the Atlantic. Previous
results show that internal wave dissipation is possibly dependent on the background
velocity, which makes the variable DWBC an excellent study region for internal
waves.
Two different data sets are used to address the dependence of internal wave activity
on the strength of the DWBC, tides, stratification, and wind forcing: shipboard
measurements from five cruises and time series measurements of temperature and salinity
from the MOVE array at 16°N. Both data sets cover the timespan from 2000 to
2005.
First results from shipboard measurements of velocity and density finestructure show
enhanced internal wave activity in the region of the DWBC and the MAR. Here, diapycnal
diffusivities are well above oceanic background values of 10-5 m2 s-1 and reach magnitudes
of up to 10-3 m2 s-1.
The spectra of MOVE timeseries contain dominant spectral contributions from the major tidal
constituents as well as from the inertial frequency. The high frequency variance shows long
term variability at all depth, indicating possible relations between internal wave activity and
background conditions. |
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