Temperature structure in the upper 250 metres in the East Australian Current area

Temperature profiles to 250 m, obtained by using a bathythermograph, are presented and discussed in relation to geostrophic currents in the East Australian Current Area. There is a very close relation between dynamic height and temperature at 240 m depth in this area. Regression equations connecting the two quantities are given. The depth of the mixed layer is shown to cover a wide range, even on a single cruise in a relatively small area, and it is suggested that the extremes of very shallow (< 20 m) and very deep (≥ 200 m) mixed layers are due to divergence and convergence associated with the strong and variable circulation in the area. Seasonal warming and cooling affect approximately the upper 70-100 m, and have a range of about 3�C.