An intercomparison of internal solitary waves in the Bay of Biscay and resulting from Korteweg-de Vries-Type theory

A recently developed Korteweg-de Vries (KdV)-type theory is used to study the formation of internal ‘solitary’ waves from internal tides in the Bay of Biscay, and detailed comparisons are made with observations. The theory is for a continuously-stratified fluid, and includes both first order non-linearity and dispersion, as well as the earth's rotation without restriction at the lowest order. We investigate and compare the detailed structure of the waves, paying particular attention to the horizontal and vertical velocity fields, as well as to the more usual characteristics, since it appears this has not been undertaken before. The comparison shows that the simplified but often-used ‘KdV physics’ is able to reproduce almost all features of the observed solitary waves, such as wavelengths, amplitudes, phase speeds, and horizontal velocity structure, with reasonable success. The magnitude of the vertical velocities, however, is significantly underestimated by the theory, although their qualitative structure is reproduced. The comparison also indicates that the internal solitary waves in nature are likely to produce significant mixing of the seasonal thermocline

Atlantic Multidecadal Oscillation (AMO) and Sea Surface Temperature in the Bay of Biscay and adjacent regions.

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Annual westward propagating anomalies near 26ºN and eddy generation south of the Canary Islands: remote sensing /altimeter/ SeaWiFS) and in situ measurement.

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Constraining the effect of mesoscale features on the carbon budget of the photic layer in the NE subtropical Atlantic

An oceanographic cruise was carried out in the subtropical NE Atlantic in April 1999 with the aim of investigating the role of the Azores Current, the STORM (subtropical oceanic rings of magnitude) cyclonic eddies and the Great Meteor Tablemount in triggering phytoplankton production. This information combined with previous studies allowed us to determine the role of these features in the carbon budget of the photic layer in this oligotrophic region. The results suggest that mesoscale dynamics, although modifying hydrographic characteristics and phytoplankton spatial distribution, do not appear to significantly affect primary production in the NE subtropical Atlantic

Can the Subtropical North Atlantic permanent thermocline be observed from space?

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