Ocean and Polar Research

Korea Institute of Ocean Science & Technology (한국해양과학기술원)
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Development of Algorithms for Extracting Thermocline Parameters in the South Sea of Korea

한국 남부해역의 수온약층 추출 알고리즘 개발

  • 윤동영 (한국해양과학기술원 해양과학데이터센터) ;
  • 최현우 (한국해양과학기술원 해양과학데이터센터)
  • Received : 2012.04.19
  • Accepted : 2012.06.18
  • Published : 2012.06.30
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Abstract

A new algorithm was developed, not only to detect the existence of a thermocline, but also to extract the thermocline parameters (such as thermocline thickness, mixed layer thickness, maximum temperature gradient, and temperature difference of thermocline), using the vertical profile of water temperature. According to Kappa analysis, in order to find adequate threshold values of vertical water temperature gradients ${\Delta}T$ ($^{\circ}C/m$), agreement and reliability were 87% and 0.74 respectively, in the conditions of maximum ${\Delta}T{\geq}0.5$ and surface and bottom layers ${\Delta}T<{\mid}0.2{\mid}$. Also, three different kinds of methods, viz. 1. Gradient method, 2. Hyperbolic tangent method, and 3. Differential hyperbolic tangent method, were tested to extract the key parameters of a thermocline. Comparing the results of three different methods, the differential hyperbolic tangent method was the most appropriate to extract the start and end point of a thermocline curve.

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