The inter-annual variations of the volume of NorthPacific Tropical Water and its mechanism

LIU Songnan; XU Dongfeng

doi:10.3969/j.issn.1001-909X.2020.02.001

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Journal of Marine Sciences ›› 2020, Vol. 38 ›› Issue (2) : 1-8. DOI: 10.3969/j.issn.1001-909X.2020.02.001

The inter-annual variations of the volume of NorthPacific Tropical Water and its mechanism

LIU Songnan^1,2, XU Dongfeng^*1,2

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Abstract

The UK Met Office EN4 analyses product revealed that the surface area and the volume of the North Pacific subtropical high-salinity center, namely North Pacific Tropical Water (NPTW), decreased in the period of 2000-2008 and 2014—2017, and grew in 2008—2014. The changing period of NPTW was highly correlated with Pacific Decadal Oscillation (PDO). Using the ECCO2 reanalyzing data, the fresh water flux was calculated through the NPTW surface. Our results show that the fresh water flux has less contribution to changes of NPTW, while the horizontal advection contributes significantly to the surface area and volume changes of NPTW, which is related to the northward(southward) swing of North Equatorial Current (NEC) during the PDO positive(negative) phase.

Key words

North Pacific Tropical Water / salinity / North Equatorial Current / fresh water flux / Pacific Decadal Oscillation

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LIU Songnan, XU Dongfeng. The inter-annual variations of the volume of NorthPacific Tropical Water and its mechanism[J]. Journal of Marine Sciences. 2020, 38(2): 1-8 https://doi.org/10.3969/j.issn.1001-909X.2020.02.001

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