In the present investigation, the process of diffusion of salt in a vertical column of liquid, subjected to temperature variations of the types T(x) = constant, linear ( = a + bx) and parabolic ( = a + bx - cx2); with a constant concentration difference between the top and the bottom (0 and 25 per cent, respectively) is studied. It is seen that a linear temperature gradient, T(x) = a + bx, leads to a near convex parabolic salt concentration profile with maximum deviations increasing from 13.5 per cent (at 40°C) to 14.8 per cent (at 70°C) and eventually to 15.7 per cent (at 90°C) with respect to the linear concentration value of 12.5 per cent (by weight) at the midpoint. Conversely, the parabolic temperature profile as well as the modified profile due to the Soret effect leads to near cubic salt profiles which differ only by 2–3 per cent in the upper half of the pond. However, they show a point of inflexion at larger depths near the bottom around which the convex profiles change over and become concave. Subsequently, these studies have been extended to compute the salinity profiles of thermal configurations of the operational solar pond.