The 13°C isotherm is associated with a significant salinity gradient. As in Leg 1, the temperature field dominates the density field, and a (weak) density gradient is found at the location of the 13°C isotherm.
Note the high variability in the temperature and salinity fields and the presence of inversions at kms 75 and 250. The reason for this variability is presumably the closeness of the STF which runs parallel to the section. Most of it is density compensated and not seen in the density field.