Journal of Oceanology and Limnology

, Volume 37, Issue 2, pp 423–433 | Cite as

The seasonal variation of the North Pacific Meridional Overturning Circulation heat transport

  • Hongwei Liu
  • Qilong ZhangEmail author
  • Chongguang Pang
  • Yongliang Duan
  • Jianping Xu


Based on the 50-year SODA reanalysis data, we investigated the basic characteristics and seasonal changes of the meridional heat transport carried by the North Pacific Meridional Overturning Circulation. And we also examined the dynamical and thermodynamic mechanisms responsible for these heat transport variability at the seasonal time scale. Among four cells, the tropical cell (TC) is strongest with a northward heat transport (NHT) of (1.75±0.30) PW (1 PW=1.0×1015 W) and a southward heat transport (SHT) of (-1.69±0.55) PW, the subtropical cell (STC) is second with a NHT of (0.71±0.65) PW and SHT of (-0.63±0.53) PW, the deep tropical cell (DTC) is third with a NHT of (0.18±0.03) PW and SHT of (-0.18±0.11) PW, while the subpolar cell (SPC) is weakest with a NHT of (0.09±0.05) PW and SHT of (-0.07±0.09) PW. These four cells all have different seasonal changes in their NHT and SHT. Of all, the TC has stronger change in its SHT than in its NHT, so do both the DTC and SPC, but the seasonal change in the STC SHT is weaker than that in its NHT. Therefore, their dynamical and thermodynamic mechanisms are different each other. The local zonal wind stress and net surface heat flux are mainly responsible for the seasonal changes in the TC and STC NHTs and SPC SHT, while the local thermocline circulations and sea temperature are primarily responsible for the seasonal changes of the TC, STC and DTC SHTs and SPC NHT.


meridional overturning circulation heat transport North Pacific seasonal variation 


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The authors duly acknowledge the various data sources for the freely available data: SODA data from, NCEP reanalysis data from


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Copyright information

© Chinese Society for Oceanology and Limnology, Science Press and Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  • Hongwei Liu
    • 1
    • 2
    • 5
  • Qilong Zhang
    • 1
    • 5
    Email author
  • Chongguang Pang
    • 1
    • 5
  • Yongliang Duan
    • 3
    • 4
  • Jianping Xu
    • 2
  1. 1.Key Laboratory of Ocean Circulation and Waves, Institute of OceanologyChinese Academy of Sciences and Qingdao National Laboratory for Marine Science and TechnologyQingdaoChina
  2. 2.State Key Laboratory of Satellite Ocean Environment Dynamics, MNRHangzhouChina
  3. 3.Center for Ocean and Climate ResearchFirst Institute of Oceanography, MNRQingdaoChina
  4. 4.Laboratory for Regional Oceanography and Numerical ModelingQingdao National Laboratory for Marine Science and TechnologyQingdaoChina
  5. 5.Center for Ocean Mega-ScienceChinese Academy of SciencesQingdaoChina

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