Deep-Ocean Tides in the South-West Indian Ocean . . .
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Fig. 18 As Fig. 17 for diurnal frequencies, from left to right: Q1, O1, P1 and K1, respectively,
except that surface tidal amplitude (A surf , black bar) here corresponds to bar length
frequencies at lmc5a and lmc8) implies either dominance of the surface tide or a
horizontally-propagating, coherent internal tide. However, one has to keep in mind
the very small aspect ratio of MC, and the ocean in general, so that low-frequency
internal tides propagate at very small angles to the horizontal. Phase differences of
baroclinic tides that occur in transverse channel direction (seen along columns in
Figs. 17 and 18) are indicative of their shorter length scales.
Looking at the coloured vectors in Fig. 17, one notices the overall variability in
amplitude and phase of the internal tide harmonic vectors, although it seems they
are strongest in the center of the Mozambique Channel, near lmc5, lmc5a and lmc6.
It is also remarkable that the coherent internal K2 tide seems to be at least as strong
as the coherent internal M2 tide, despite the free surface K2 tide being seven times
weaker than the surface M2 tide.
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Fig. 18 As Fig. 17 for diurnal frequencies, from left to right: Q1, O1, P1 and K1, respectively,
except that surface tidal amplitude (A surf , black bar) here corresponds to bar length
frequencies at lmc5a and lmc8) implies either dominance of the surface tide or a
horizontally-propagating, coherent internal tide. However, one has to keep in mind
the very small aspect ratio of MC, and the ocean in general, so that low-frequency
internal tides propagate at very small angles to the horizontal. Phase differences of
baroclinic tides that occur in transverse channel direction (seen along columns in
Figs. 17 and 18) are indicative of their shorter length scales.
Looking at the coloured vectors in Fig. 17, one notices the overall variability in
amplitude and phase of the internal tide harmonic vectors, although it seems they
are strongest in the center of the Mozambique Channel, near lmc5, lmc5a and lmc6.
It is also remarkable that the coherent internal K2 tide seems to be at least as strong
as the coherent internal M2 tide, despite the free surface K2 tide being seven times
weaker than the surface M2 tide.