Advances in Atmospheric Sciences

, Volume 33, Issue 3, pp 339–351 | Cite as

Assessment of interannual sea surface salinity variability and its effects on the barrier layer in the equatorial Pacific using BNU-ESM

  • Hai Zhi
  • Rong-Hua ZhangEmail author
  • Fei Zheng
  • Pengfei Lin
  • Lanning Wang
  • Peng Yu


As salinity stratification is necessary to form the barrier layer (BL), the quantification of its role in BL interannual variability is crucial. This study assessed salinity variability and its effect on the BL in the equatorial Pacific using outputs from Beijing Normal University Earth System Model (BNU-ESM) simulations. A comparison between observations and the BNU-ESM simulations demonstrated that BNU-ESM has good capability in reproducing most of the interannual features observed in nature. Despite some discrepancies in both magnitude and location of the interannual variability centers, the displacements of sea surface salinity (SSS), barrier layer thickness (BLT), and SST simulated by BNU-ESM in the equatorial Pacific are realistic. During El Ni˜no, for example, the modeled interannual anomalies of BLT, mixed layer depth, and isothermal layer depth, exhibit good correspondence with observations, including the development and decay of El Ni˜no in the central Pacific, whereas the intensity of the interannual variabilities is weaker relative to observations. Due to the bias in salinity simulations, the SSS front extends farther west along the equator, whereas BLT variability is weaker in the central Pacific than in observations. Further, the BNU-ESM simulations were examined to assess the relative effects of salinity and temperature variability on BLT. Consistent with previous observation-based analyses, the interannual salinity variability can make a significant contribution to BLT relative to temperature in the western-central equatorial Pacific.

Key words

feedback interannual variability sea surface salinity barrier layer thickness 


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Authors and Affiliations

  • Hai Zhi
    • 1
  • Rong-Hua Zhang
    • 2
    Email author
  • Fei Zheng
    • 3
  • Pengfei Lin
    • 4
  • Lanning Wang
    • 5
  • Peng Yu
    • 6
  1. 1.Earth System Modeling Center and College of Atmospheric SciencesNanjing University of Information Science and TechnologyNanjingChina
  2. 2.Key Laboratory of Ocean Circulation and Waves, Institute of OceanologyChinese Academy of SciencesQingdaoChina
  3. 3.International Center for Climate and Environment Science, Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina
  4. 4.State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina
  5. 5.College of Global Change and Earth System ScienceBeijing Normal UniversityBeijingChina
  6. 6.Cooperative Institute for Climate and SatellitesUniversity of MarylandCollege ParkUSA

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