In low-latitude waters such as the equatorial region, 20 °C isothermal line is defined as the permanent thermocline. However, mid-latitude waters have variable vertical profile of water temperature with respect to the season and region. Therefore, in this study we developed an algorithm for quantifying seasonal thermocline in order to extract parameters for vertical temperature profiles of Korean waters in summer. In addition, quantified parameters were used to identify spatial distribution characteristics of thermocline, and a model for relationship between thermocline parameters was established to help understand the structure of thermocline.erefore, in this study we developed an algorithm for quantifying seasonal thermocline in order to extract parameters for vertical temperature profiles of Korean waters in summer. In addition, quantified parameters were used to identify spatial distribution characteristics of thermocline, and a model for relationship between thermocline parameters was established to help understand the structure of thermocline.