Heat and salt transport throughout the North Pacific Ocean -- Journal of Oceanology and Limnology,2016,34(6):1347-1357

	Cite this paper:
	YANG Lina, YUAN Dongliang. Heat and salt transport throughout the North Pacific Ocean[J]. Journal of Oceanology and Limnology, 2016, 34(6): 1347-1357

Heat and salt transport throughout the North Pacific Ocean

YANG Lina^1,2,3, YUAN Dongliang^1,3,4

1 Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China;
2 University of Chinese Academy of Sciences, Beijing 100049, China;
3 Key Laboratory of Ocean Circulation and Waves, Chinese Academy of Sciences, Qingdao 266071, China;
4 Qingdao Collaborative Innovation Center of Marine Science and Technology, Qingdao 266003, China

Abstract:

Absolute geostrophic currents in the North Pacific Ocean are calculated using the P-vector method and gridded Argo profiling data from January 2004 to December 2012. Three-dimensional structures and seasonal variability of meridional heat transport (MHT) and meridional salt transport (MST) are analyzed. The results show that geostrophic and Ekman components are generally opposite in sign, with the southward geostrophic component dominating in the subtropics and the northward Ekman component dominating in the tropics. In combination with the net surface heat flux and the MST through the Bering Strait, the MHT and MST of the western boundary currents (WBCs) are estimated for the first time. The results suggest that the WBCs are of great importance in maintaining the heat and salt balance of the North Pacific. The total interior MHT and MST in the tropics show nearly the same seasonal variability as that of the Ekman components, consistent with the variability of zonal wind stress. The geostrophic MHT in the tropics is mainly concentrated in the upper layers, while MST with large amplitude and annual variation can extend much deeper. This suggests that shallow processes dominate MHT in the North Pacific, while MST can be affected by deep ocean circulation. In the extratropical ocean, both MHT and MST are weak. However, there is relatively large and irregular seasonal variability of geostrophic MST, suggesting the importance of the geostrophic circulation in the MST of that area.

Key words: absolute geostrophic current|P-vector|meridional heat transport (MHT)|meridional salt transport (MST)

Received: 2015-04-16 Revised: 2015-06-15

Tools

PDF (1217 KB) Free

Print this page

Add to favorites

Email this article to others

Authors

Articles by YANG Lina

Articles by YUAN Dongliang

References:
Bretherton C S, Widmann M, Dymnikov V P et al. 1999. The effective number of spatial degrees of freedom of a timevarying field. Journal of Climate, 12(7):1 990-2 009.
Bryden H L, Roemmich D H, Church J A. 1991. Ocean heat transport across 24°N in the Pacific. Deep Sea Research Part A. Oceanographic Research Papers, 38(3):297-324.
Chen G X, Gan J P, Xie Q, Chu X Q, Wang D X, Hou Y J. 2012. Eddy heat and salt transports in the South China Sea and their seasonal modulations. J. Geophys. Res., 117(C5), http://dx.doi.org/10.1029/2011JC007724.
Chu P C. 1995. P-vector method for determining absolute velocity from hydrographic data. Mar. Technol. Soc. J., 29(2):3-14.
Chu P C. 2006. P-Vector Inverse Method. Springer-Verlag, Berlin, Heidelberg, Germany. 605p.
Coachman L K, Aagaard K. 1988. Transports through Bering Strait:Annual and interannual variability. J. Geophys.Res., 93(C12):15 535-15 539.
Da Silva A M, Young C C, Levitus S. 1994. Atlas of surface marine data 1994, volume 1:algorithms and procedures.NOAA Atlas NESDIS6. U.S. Department of Conmerce, NOAA, NESDIS:83p.
Delcroix T, Hénin C. 1991. Seasonal and interannual variations of sea surface salinity in the tropical Pacific Ocean. J.Geophys. Res., 96(C12):22 135-22 150.
Douglass E, Roemmich D, Stammer D. 2010. Interannual variability in North Pacific heat and freshwater budgets.Deep Sea Research Part II:Topical Studies in Oceanography, 57(13-14):1 127-1 140.
Ganachaud A, Wunsch C. 2000. Improved estimates of global ocean circulation, heat transport and mixing from hydrographic data. Nature, 408(6811):453-457.
Ganachaud A, Wunsch C. 2003. Large-scale ocean heat and freshwater transports during the world ocean circulation experiment. Journal of Climate, 16(4):696-705.
Garratt J R. 1977. Review of drag coefficients over oceans and continents. Mon. Wea. Rev., 105(7):915-929.
Gruber A. 1977. Determination of the earth-atmosphere radiation budget from NOAA satellite data. NOAA Technical Report NESS 76, U. S. Department of Commerce, National Oceanic and Atmospheric Administration, National Environmental Satellite Service, Washington D C, UK. 28p.
Hall M M, Bryden H L. 1982. Direct estimates and mechanisms of ocean heat transport. Deep Sea Research Part A.Oceanographic Research Papers, 29(3):339-359.
Hastenrath S. 1982. On meridional heat transports in the world ocean. J. Phys. Oceanogr., 12(8):922-927.
Hsiung J, Newell R E, Houghtby T. 1989. The annual cycle of oceanic heat storage and oceanic meridional heat transport. Quart. J. Roy. Meteor. Soc., 115(485):1-28.
Hsiung J. 1985. Estimates of global oceanic meridional heat transport. J. Phys. Oceanogr., 15(11):1 405-1 413.
Kalnay E, Kanamitsu M, Kistler R, Collins W, Deaven D, Gandin L, Iredell M, Saha S, White G, Woollen J, Zhu Y, Leetmaa A, Reynolds B, Chelliah M, Ebisuzaki W, Higgins W, Janowiak J, Mo K C, Ropelewski C, Wang J, Jenne R, Joseph D. 1996. The NCEP/NCAR 40-Year Reanalysis Project. Bull. Amer. Meteor. Soc., 77(3):437-471.
Kamenkovich I, Cheng W, Schmid C, Harrison D E. 2011.Effects of eddies on an ocean observing system with profiling floats:idealized simulations of the Argo array. J.Geophys. Res., 116(C6), http://dx.doi.org/10.1029/2010JC006910.
Kim Y Y, Qu T D, Jensen T et al. 2004. Seasonal and interannual variations of the North Equatorial Current bifurcation in a high-resolution OGCM. J. Geophys. Res., 109(C3):C03040.
Klinger B A, Marotzke J. 2000. Meridional heat transport by the subtropical cell. J. Phys. Oceanogr., 30(4):696-705.
Kraus E B, Levitus S. 1986. Annual heat flux variations across the tropic circles. J. Phys. Oceanogr., 16(8):1 479-1 486.
Lamb P J, Bunker A F. 1982. The annual march of the heat budget of the north and tropical Atlantic Oceans. J. Phys.Oceanogr., 12(12):1 388-1 410.
Leith C E. 1973. The standard error of time-average estimates of climatic means. J. Appl. Meteor., 12(6):1 066-1 069.
Li P, Zhang Q L, Liu H W, Xu J P. 2011. Seasonal variation of the North Pacific meridional net heat transport. Advances in Marine Science, 29(3):275-284. (in Chinese with English abstract)
Li P, Zhang Q P, Liu H W, Xu J P. 2012. Seasonal variation of meridional salt transport in the North Pacific Ocean.Journal of Tropical Oceanography, 31(4):28-34. (in Chinese with English abstract)
Macdonald A M. 1998. The global ocean circulation:a hydrographic estimate and regional analysis. Progress in Oceanography, 41(3):281-382.
Marsh R, New A L, Roberts M J, Wood R A. 1996. An intercomparison of a Bryan-Cox-type ocean model and an isopycnic ocean model. Part II:The subtropical gyre and meridional heat transport. J. Phys. Oceanogr., 26(8):1 528-1 551.
Msadek R, Johns W E, Yeager S G, Danabasoglu G, Delworth T L, Rosati A. 2013. The Atlantic meridional heat transport at 26.5°N and its relationship with the MOC in the RAPID array and the GFDL and NCAR coupled models. Journal of Climate, 26(12):4 335-4 356.
Qu T D, Lukas R. 2003. The Bifurcation of the North Equatorial Current in the Pacific. J. Phys. Oceanogr., 33(1):5-18.
Roemmich D, Gilson J, Cornuelle B, Weller R. 2001. Mean and time-varying meridional transport of heat at the tropical/subtropical boundary of the North Pacific Ocean.J. Geophys. Res., 106(C5):8 957-8 970.
Roemmich D, Gilson J. 2009. The 2004-2008 mean and annual cycle of temperature, salinity, and steric height in the global ocean from the Argo Program. Progress in Oceanography, 82(2):81-100.
Stammer D, Wunsch C, Giering R, Eckert C, Heimbach P, Marotzke J, Adcroft A, Hill C N, Marshall J. 2003.
Volume, heat, and freshwater transports of the global ocean circulation 1993-2000, estimated from a general circulation model constrained by World Ocean Circulation Experiment (WOCE) data. J. Geophys. Res., 108(C1):3007.
Stammer D. 1998. On eddy characteristics, eddy transports, and mean flow properties. J. Phys. Oceanogr., 28(4):727-739.
Talley L D. 2003. Shallow, intermediate, and deep overturning components of the global heat budget. J. Phys. Oceanogr., 33(3):530-560.
Talley L D. 2008. Freshwater transport estimates and the global overturning circulation:shallow, deep and throughflow components. Progress in Oceanography, 78(4):257-303.
Toole J M, Zou E, Millard R C. 1988. On the circulation of the upper waters in the western equatorial Pacific Ocean.Deep Sea Research Part A. Oceanographic Research Papers, 35(9):1 451-1 482.
Trenberth K E, Caron J M. 2001. Estimates of meridional atmosphere and ocean heat transports. Journal of Climate, 14(16):3 433-3 443.
Uehara H, Kizu S, Hanawa S, Yoshikawa Y, Roemmich D. 2008. Estimation of heat and freshwater transports in the North Pacific using high-resolution expendable bathythermograph data. J. Geophys. Res., 113(C2):C02014.
Vonder Haar T H, Oort A H. 1973. New estimate of annual poleward energy transport by northern hemisphere oceans. J. Phys. Oceanogr., 3(2):169-172.
Vonderhaar T H, Ellis J S. 1974. Atlas of radiation budget measurements from satellites, 1962-1970. Atmospheric Science Technical Report no. 231, Colorado State University, Fort Collins, CO, United States. 180p.
Wang J D, Carton J A. 2002. Seasonal heat budgets of the North Pacific and North Atlantic Oceans. J. Phys.Oceanogr., 32(12):3 474-3 489.
Wang Q Y, Hu D X. 2006. Bifurcation of the North Equatorial Current derived from altimetry in the Pacific Ocean.Journal of Hydrodynamics, Series B, 18(5):620-626.
Wijffels S E, Schmitt R W, Bryden H L, Stigebrandt A. 1992.Transport of freshwater by the oceans. J. Phys. Oceanogr., 22(2):155-162.
Wunsch C. 1999. Where do ocean eddy heat fluxes matter? J.Geophys. Res., 104(C6):13 235-13 249.
Yuan D L, Zhang Z C, Chu P C, Dewar W K. 2014. Geostrophic circulation in the Tropical North Pacific Ocean based on Argo Profiles. J. Phys. Oceanogr., 44(2):558-575.
Zhang D, Johns W E, Lee T N. 2002. The seasonal cycle of meridional heat transport at 24°N in the North Pacific and in the global ocean. J. Geophys. Res., 107(C7):20-1-20-24.