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| Titel |
On the parameterization of mixing processes at the equator |
| VerfasserIn |
Marcus Dengler, Jens Schafstall, John Toole, Donata Banyte |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250044086
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| Zusammenfassung |
| Due to reduced wave-wave interaction, mixing in the deeper water column (>200m) of the
tropical oceans is considered to be very low. Here, we use full depth microstructure profiles,
velocity and stratification measurements from the equatorial Atlantic to assess the skill of two
parameterizations at the equator. Average eddy diffusivities rarely exceed 3x10-6m2s-1
throughout the deeper water column. However, dissipation rates calculated from internal
wave-wave interaction parameterization underestimate observed dissipations rates by a factor
of 5 within about 2° of the equator. In this region, the equatorial deep jets are pronounced and
elevated dissipation rates are found in the high shear zones of the jets. The role of vertical
momentum flux divergence for differences between parameterization and observation is
discussed. A turbulence parameterization evaluated in unstable events overestimates
dissipation rates directly on the equator but agrees well with observations away (>1°) from
the equator. |
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