Cite this paper:
LIN Wenqiang, ZHAI Fangguo, GU Yanzhen, LI Peiliang. Decadal variations of the North Pacific Tropical Water at 137°E[J]. HaiyangYuHuZhao, 2019, 37(5): 1495-1509

Decadal variations of the North Pacific Tropical Water at 137°E

LIN Wenqiang1, ZHAI Fangguo1, GU Yanzhen1, LI Peiliang2
1 Physical Oceanography Laboratory, College of Oceanic and Atmospheric Sciences, Ocean University of China, Qingdao 266003, China;
2 Institute of Physical Oceanography and Remote Sensing, Ocean College, Zhejiang University, Zhoushan 316021, China
The decadal variations of the North Pacific Tropical Water (NPTW) at 137°E in the western North Pacific Ocean are investigated based on the repeated hydrographic observations along with two global gridded ocean products. The results indicate that the maximum salinity of NPTW experiences significant quasi-decadal variations, having maxima around 1979, 1987, 1995, 2004, and 2012, while minima around 1974, 1983, 1991, 1999, and 2008 during the period of interest. The NPTW area also shows similar quasidecadal variation, expanding/shrinking as its maximum salinity increases/decreases at the 137°E section. These variations are induced mainly by changes in the mixed layer salinity in the source region and largescale circulation in the northwestern tropical Pacific Ocean, both of which are related to the Pacific Decadal Oscillation. The underlying processes at work are further confirmed through conducting the subsurface salinity budget analysis. Besides, short-term processes are also at work through nonlinear interactions, especially after 2000.
Key words:    North Pacific Tropical Water (NPTW)|decadal variation|subsurface salinity budget|Pacific Decadal Oscillation   
Received: 2018-04-29   Revised: 2018-06-22
PDF (2275 KB) Free
Print this page
Add to favorites
Email this article to others
Articles by LIN Wenqiang
Articles by ZHAI Fangguo
Articles by GU Yanzhen
Articles by LI Peiliang
Balmaseda M A, Mogensen K, Weaver A T. 2013. Evaluation of the ECMWF ocean reanalysis system ORAS4.Quarterly Journal of the Royal Meteorological Society, 139(674):1 132-1 161,
Balmaseda M A, Vidard A, Anderson D L T. 2008. The ECMWF ocean analysis system:ORA-S3. Monthly Weather Review, 136(8):3 018-3 034, 1175/2008MWR2433.1.
Bingham F M, Suga T, Hanawa K. 2002. Origin of waters observed along 137°E. Journal of Geophysical Research:Oceans, 107(C7):3 073,
Boyer T P, Antonov J I, Baranova O K, Garcia H E, Johnson D R, Locarnini R A, Mishonov A V, O'Brien T D, Seidov D, Smolyar I V, Zweng M M. 2009. World ocean database 2009. In:Levitus S ed. NOAA Atlas NESDIS 66. Springer, Washington, D.C. 216p.
Boyer T P, Levitus S, Antonov J I, Locarnini R A, Garcia H E. 2005. Linear trends in salinity for the World Ocean, 1955-1998. Geophysical Research Letters, 32(1):L01604,
Cannon G A. 1966. Tropical waters in the western Pacific Ocean, August-September 1957. Deep Sea Research and Oceanographic Abstracts, 13(6):1 139-1 148,
Curry R, Dickson B, Yashayaev I. 2003. A change in the freshwater balance of the Atlantic Ocean over the past four decades. Nature, 426(6968):826-829,
Delcroix T, McPhaden M J, Dessier A, Gouriou Y. 2005. Time and space scales for sea surface salinity in the tropical oceans. Deep Sea Research Part I:Oceanographic Research Papers, 52(5):787-813,
Fukumori I, Lee T, Cheng B, Menemenlis D. 2004. The origin, pathway, and destination of Niño-3 water estimated by a simulated passive tracer and its adjoint. Journal of Physical Oceanography, 34(3):582-604,
Good S A, Martin M J, Rayner N A. 2013. EN4:quality controlled ocean temperature and salinity profiles and monthly objective analyses with uncertainty estimates.Journal of Geophysical Research:Oceans, 118(12):6 704-6 716,
Guinehut S, Coatanoan C, Dhomps A L, Le Traon P Y, Larnicol G. 2009. On the use of satellite altimeter data in Argo quality control. Journal of Atmospheric and Oceanic Technology, 26(2):395-402,
Guo Y Q, Lin X P, Wei M, Liu C, Men G. 2018. Decadal variability of North Pacific eastern subtropical mode water. Journal of Geophysical Research:Oceans, 123(9):6 189-6 206,
Hu S J, Sprintall J. 2016. Interannual variability of the Indonesian Throughflow:the salinity effect. Journal of Geophysical Research:Oceans, 121(4):2 596-2 615,
Ingleby B, Huddleston M. 2007. Quality control of ocean temperature and salinity profiles-historical and real-time data. Journal of Marine Systems, 65(1-4):158-175,
Kaneko I, Takatsuki Y, Kamiya H, Kawae S. 1998. Water property and current distributions along the WHP-P9 section (137°-142°E) in the western North Pacific.Journal of Geophysical Research:Oceans, 103(C6):12 959-12 984,
Katsura S, Oka E, Qiu B, Schneider N. 2013. Formation and subduction of North Pacific tropical water and their interannual variability. Journal of Physical Oceanography, 43(11):2 400-2 415,
Li Y L, Wang F, Han W Q. 2013. Interannual sea surface salinity variations observed in the tropical North Pacific Ocean. Geophysical Research Letters, 40(10):2 194-2 199,
Li Y L, Wang F, Zhai F G. 2012. Interannual variations of subsurface spiciness in the Philippine Sea:observations and mechanism. Journal of Physical Oceanography, 42(6):1 022-1 038,
Li Y L, Wang F. 2012. Spreading and salinity change of North Pacific tropical water in the Philippine Sea. Journal of Oceanography, 68(3):439-452,
Lukas R. 2001. Freshening of the upper thermocline in the North Pacific subtropical gyre associated with decadal changes of rainfall. Geophysical Research Letters, 28(18):3 485-3 488,
Mantua N J, Hare S R, Zhang Y, Wallace J M, Francis R C. 1997. A Pacific interdecadal climate oscillation with impacts on salmon production. Bulletin of the American Meteorological Society, 78(6):1 069-1 079,<1069:APICOW>2.0.CO;2.
Nakano T, Kitamura T, Sugimoto S, Suga T, Kamachi M. 2015. Long-term variations of North Pacific Tropical Water along the 137°E repeat hydrographic section.Journal of Oceanography, 71(3):229-238,
Nan F, Yu F, Xue H J, Wang R, Si G C. 2015. Ocean salinity changes in the northwest Pacific subtropical gyre:the quasi-decadal oscillation and the freshening trend.Journal of Geophysical Research:Oceans, 120(3):2 179-2 192,
Nie X W, Gao S, Wang F, Qu T D. 2016. Subduction of North Pacific Tropical Water and its equatorward pathways as shown by a simulated passive tracer. Journal of Geophysical Research:Oceans, 121(12):8 770-8 786,
Oka E, Ishii M, Nakano T, Suga T, Kouketsu S, Miyamoto M, Nakano H, Qiu B, Sugimoto S, Takatani Y. 2018. Fifty years of the 137°E repeat hydrographic section in the western North Pacific Ocean. Journal of Oceanography, 74(2):115-145,
Oka E, Katsura S, Inoue H, Kojima A, Kitamoto M, Nakano T, Suga T. 2017. Long-term change and variation of salinity in the western North Pacific subtropical gyre revealed by 50-year long observations along 137°E. Journal of Oceanography, 73(4):479-490,
Qu T D, Lukas R. 2003. The bifurcation of the North Equatorial Current in the Pacific. Journal of Physical Oceanography, 33(1):5-18,<0005:TBOTNE>2.0.CO;2.
Qu T D, Mitsudera H, Yamagata T. 1998. On the western boundary currents in the Philippine Sea. Journal of Geophysical Research:Oceans, 103(C4):7 537-7 548,
Qu T D, Mitsudera H, Yamagata T. 1999. A climatology of the circulation and water mass distribution near the Philippine coast. Journal of Physical Oceanography, 29(7):1 488-1 505,<1488:ACOTCA>2.0.CO;2.
Ren L, Riser S C. 2010. Observations of decadal time scale salinity changes in the subtropical thermocline of the North Pacific Ocean. Deep Sea Research Part Ⅱ:Topical Studies in Oceanography, 57(13-14):1 161-1 170,
Shuto K. 1996. Internnual variations of water temperature and salinity along the 137°E meridian. Journal of Oceanography, 52(5):575-595,
Smith D M, Cusack S, Colman A W, Folland C K, Harris G R, Murphy J M. 2007. Improved surface temperature prediction for the coming decade from a global climate model. Science, 317(5839):796-799,
Suga T, Kato A, Hanawa K. 2000. North Pacific Tropical Water:its climatology and temporal changes associated with the climate regime shift in the 1970s. Progress in Oceanography, 47(2-4):223-256,
Tsuchiya M. 1968. Upper waters of the intertropical Pacific Ocean. In:Reid J L Jr ed. The Johns Hopkins Oceanographic Studies. The Johns Hopkins Press, Baltimore. 50p,
Vergara O, Dewitte B, Ramos M, Pizarro O. 2017. Vertical energy flux at E NSO time scales in the subthermocline of the Southeastern Pacific. Journal of Geophysical Research:Oceans, 122(7):6 011-6 038.
Vinayachandran P N, Nanjundiah R S. 2009. Indian Ocean sea surface salinity variations in a coupled model. Climate Dynamics, 33(2-3):245-263,
Wong A P S, Bindoff N L, Church J A. 1999. Large-scale freshening of intermediate waters in the Pacific and Indian Oceans. Nature, 400(6743):440-443,
Yan Y F, Chassignet E P, Qi Y Q, Dewar W K. 2013. Freshening of subsurface waters in the Northwest Pacific Subtropical Gyre:observations and dynamics. Journal of Physical Oceanography, 43(12):2 733-2 751,
Zhai F G, Hu D X, Qu T D. 2013. Decadal variations of the North Equatorial Current in the Pacific at 137°E. Journal of Geophysical Research:Oceans, 118(10):4 989-5 006,
Zhai F G, Wang Q Y, Wang F J, Hu D X. 2014. Decadal variations of Pacific North Equatorial Current bifurcation from multiple ocean products. Journal of Geophysical Research:Oceans, 119(2):1 237-1 256,