Vertical representation of ocean temperature profiles with a gradient feature model

Vertical ocean profiles of temperature and salinity versus depth are collected by many oceanographic institutions for a variety of research and applied purposes. For many applications, the important aspect of the profile is not the temperature (salinity) at any particular depth, but the relationship of the temperatures (salinities) of the entire profile; i.e. the “shape” of the profile. For example, underwater acoustic problems are usually driven more by the shape of the profile than by the average temperature/salinity of the profile. This is especially true in shallow water where travel distances are short because of high reverberation and geometrical constraints of the bottom and coastlines. It is desirable to be able to describe ocean profiles in terms of the features that are important for a particular application. This paper discusses a technique to transform an ocean profile from “temperature space” into “coefficient space”, using coefficients that are directly related to physical features of the profile, such as mixed layer depth, gradient in the thermocline, etc. The technique is also applicable to salinity and derived values such as sound speed, density, and conductivity