SMALL-SCALE STRUCTURE OF TEMPERATURE AND SALINITY NEAR STATION CAVALL

A series of T.S.D. probe observations of the temperature and salinity profiles in the Bay of Biscay shows that it is possible to obtain a short-term repeatability of ± 0·001 σgq in deep water using a Hytech T.S.D. system. This is achieved by recording the period values of the sensors so that thickness of the pen trace does not mask the desired detail. The features seen near Station Cavall (46° 26·5′N, 8° 02·9′W) bear out Cooper's (1967) tentative ideas about the structure at Station Cavall. It is also possible to observe different T and S, at the same σθ, at the same depth in the deep water. The T and S variations at constant σθ are of order 0·1°C and 0·01% over separations of a few kilometres at 2500 m. The microstructure observed in the neighbourhood of the Mediterranean water shows phase relationships between T and S variations that differ above and below the salinity maximum. The microstructure might be generated by local mixing and horizontal spreading. © 1969.