Acta Oceanologica Sinica

, Volume 32, Issue 7, pp 66–77 | Cite as

An effective method for improving the accuracy of Argo objective analysis

  • Chunling Zhang
  • Jianping Xu
  • Xianwen Bao
  • Zhenfeng Wang
Article

Abstract

Based on the optimal interpolation objective analysis of the Argo data, improvements are made to the empirical formula of a background error covariance matrix widely used in data assimilation and objective analysis systems. Specifically, an estimation of correlation scales that can improve effectively the accuracy of Argo objective analysis has been developed. This method can automatically adapt to the gradient change of a variable and is referred to as “gradient-dependent correlation scale method”. Its effect on the Argo objective analysis is verified theoretically with Gaussian pulse and spectrum analysis. The results of one-dimensional simulation experiment show that the gradient-dependent correlation scales can improve the adaptability of the objective analysis system, making it possible for the analysis scheme to fully absorb the shortwave information of observation in areas with larger oceanographic gradients. The new scheme is applied to the Argo data objective analysis system in the Pacific Ocean. The results are obviously improved.

Key words

gradient-dependent correlation scale background error covariance optimal interpolation spectrum analysis Argo data 

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Copyright information

© The Chinese Society of Oceanography and Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • Chunling Zhang
    • 1
    • 2
  • Jianping Xu
    • 1
    • 2
    • 3
  • Xianwen Bao
    • 1
  • Zhenfeng Wang
    • 4
  1. 1.Institute of Marine EnvironmentOcean University of ChinaQingdaoChina
  2. 2.Second Institute of OceanographyState Oceanic AdministrationHangzhouChina
  3. 3.State Key Laboratory of Satellite Oceanography Environment Dynamics, Second Institute of OceanographyState Oceanic AdministrationHangzhouChina
  4. 4.Marine Hydrologic Meteorological CenterCommand of Navy East China Sea FleetNingboChina

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