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| Titel |
Angular momentum budget of the radiational S1 ocean tide |
| VerfasserIn |
Michael Schindelegger, Henryk Dobslaw, Lea Poropat, David Salstein, Johannes Böhm |
| 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 |
250123366
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| Publikation (Nr.) |
 EGU/EGU2016-2601.pdf |
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| Zusammenfassung |
| The balance of diurnal S1 oceanic angular momentum (OAM) variations through torques at
the sea surface and the bottom topography is validated using both a barotropic
and a baroclinic numerical tide model. This analysis discloses the extent to which
atmosphere-driven S1 forward simulations are reliable for use in studies of high-frequency
polar motion and changes in length-of-day. Viscous and dissipative torques associated with
wind stress, bottom friction, as well as internal tidal energy conversion are shown to be small,
and they are overshadowed by gravitational and pressure-related interaction forces. In
particular, the zonal OAM variability of S1 is almost completely balanced by the water
pressure torque on the local bathymetry, whereas in the prograde equatorial case also the air
pressure torque on the seafloor as well as ellipsoidal contributions from the non-spherical
atmosphere and solid Earth must be taken into account. Overall, the OAM budget is well
closed in both the axial and the equatorial directions, thus allowing for an identification of
the main diurnal angular momentum sinks in the ocean. The physical interaction
forces are found to be largest at shelf breaks and continental slopes in low latitudes,
with the most dominant contribution coming from the Indonesian archipelago. |
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