Figure 3
Observations and model results.
(a–c) Snapshots from the MITgcm numerical simulation showing the bottom velocity magnitude during the northward tidal current (See panel (d) and Movie S1 in Supplementary Information). The white arch shows the passage of the refracting ISW over the topographic mound (see Fig. 1a). The yellow star indicates position of the NOMEC3 current-meter. The dashed red line corresponds to the vertical transect in (f). Maps are generated by IDL 8.0 (www.harrisgeospatial.com/IntelliEarthSolutions/GeospatialProducts/ IDL.aspx). (d) Bottom velocity field for the MITgcm numerical simulation over the sand waves field. The vertical shaded (blue) bar indicates the passage of the ISW showed in panel (a–c) and (f)). (e) Time series of the velocity magnitude (velocity component toward 195°N) recorded by the NOMEC3 current-meter (from 1 October 1981 to 31 December 1981). The two extremely large peaks (>80 cm/s) demonstrate the intense northward velocity due to the ISW passage (see orientation of the reference system in Fig. 1a). The dashed line indicates the flow speed that marks the critical value for sediment transport. (f) Salinity cross-section along transect in (a–c) as obtained from the MITgcm numerical simulation. The isohalines show the passage of a concave-up ISW over the topographic mound. Note that the MITgcm model, being hydrostatic, cannot simulate the change of polarity of the ISW due to the topographic effects.
