Science in China Series D: Earth Sciences

, Volume 49, Issue 11, pp 1212–1222 | Cite as

A three-dimensional variational ocean data assimilation system: Scheme and preliminary results

  • Zhu Jiang 
  • Zhou Guangqing 
  • Yan Changxiang 
  • Fu Weiwei 
  • You Xiaobao 
Article

Abstract

A new 3DVAR-based Ocean Variational Analysis System (OVALS) is developed. OVALS is capable of assimilating in situ sea water temperature and salinity observations and satellite altimetry data. As a component of OVALS, a new variational scheme is proposed to assimilate the sea surface height data. This scheme considers both the vertical correlation of background errors and the nonlinear temperature-salinity relationship which is derived from the generalization of the linear balance constraints to the nonlinear in the 3DVAR. By this scheme, the model temperature and salinity fields are directly adjusted from the altimetry data. Additionally, OVALS can assimilate the temperature and salinity profiles from the ARGO floats which have been implemented in recent years and some temperature and salinity data such as from expendable bathythermograph, moored ocean buoys, etc. A 21-year assimilation experiment is carried out by using OVALS and the Tropical Pacific circulation model. The results show that the assimilation system may effectively improve the estimations of temperature and salinity by assimilating all kinds of observations. Moreover, the root mean square errors of temperature and salinity in the upper depth less than 420 m reach 0.63°C and 0.34 psu.

Keywords

data assimilation 3DVAR sea surface height ARGO floats 

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Copyright information

© Science in China Press 2006

Authors and Affiliations

  • Zhu Jiang 
    • 1
    • 2
  • Zhou Guangqing 
    • 1
  • Yan Changxiang 
    • 1
  • Fu Weiwei 
    • 1
  • You Xiaobao 
    • 1
    • 3
  1. 1.International Center for Climate and Environment Sciences, Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina
  2. 2.Jiangsu Key Laboratory of Meteorological DisasterNanjing University of Information Science and TechnologyNanjingChina
  3. 3.Beijing Institute of Applied MeteorologyBeijingChina

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