Ocean Dynamics

, Volume 64, Issue 5, pp 655–665 | Cite as

Time-calibrated estimates of oceanographic profiles using empirical orthogonal functions and clustering

  • Karina Hjelmervik
  • Karl Thomas Hjelmervik
Part of the following topical collections:
  1. Topical Collection on the 5th International Workshop on Modelling the Ocean (IWMO) in Bergen, Norway 17-20 June 2013


Oceanographic climatology is widely used in different applications, such as climate studies, ocean model validation and planning of naval operations. Conventional climatological estimates are based on historic measurements, typically by averaging the measurements and thereby smoothing local phenomena. Such phenomena are often local in time and space, but crucial to some applications. Here, we propose a new method to estimate time-calibrated oceanographic profiles based on combined historic and real-time measurements. The real-time measurements may, for instance, be SAR pictures or autonomous underwater vehicles providing temperature values at a limited set of depths. The method employs empirical orthogonal functions and clustering on a training data set in order to divide the ocean into climatological regions. The real-time measurements are first used to determine what climatological region is most representative. Secondly, an improved estimate is determined using an optimisation approach that minimises the difference between the real-time measurements and the final estimate.


Climatology Validation Empirical orthogonal functions Clustering 


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Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  1. 1.Vestfold University CollegeTønsbergNorway
  2. 2.Norwegian Defence Research Establishment (FFI)KjellerNorway

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