Direct velocity observations from drogued drifters in the Hawaiian Island region are used to map the time-mean and seasonal variability of the Hawaiian Lee Countercurrent (HLCC). The density of these data has more than doubled since the initial discovery of the HLCC. They provide valuable absolute estimates of HLCC velocity structure and variability, complementing data derived from geostrophy and numerical simulations. The data demonstrate that the HLCC has a peak annual mean velocity > 9 cm s–1, with the strongest velocities along 19.75°N and eastward speeds in the longitudinal range 170°W to 157°W. The HLCC is relatively weak from March to May compared to its strength in other months. In the longitude band 160°–168°W, an eddy-to-mean energy flux of 3.3 ± 1.2 µW m–3 is found in the annual mean associated with the Reynolds shear stress, maintaining the shear between the HLCC and the North Equatorial Current to its south. This shear stress is associated with energetic anticyclonic eddies that are shed from the Big Island of Hawaii and propagate west-southwest. This energy flux is nearly twice as large during the peak HLCC months of August to January. It is sufficient to spin up the HLCC in O(10 days), and it is associated with an eddy spin-down time of O(100 days).
Bauer, S., M.S. Swenson, A. Griffa, A.J. Mariano, and K. Owens. 1998. Eddy–mean flow decomposition and eddy-diffusivity estimates in the tropical Pacific Ocean: 1. Methodology. Journal of Geophysical Research 103 (C13):30,855–30,871, https://doi.org/10.1029/1998JC900009.
Chavanne, C., P. Flament, R. Lumpkin, B. Dousset, and A. Bentamy. 2002. Scatterometer observations of wind variations induced by oceanic islands: Implications for wind-driven ocean circulation. Canadian Journal of Remote Sensing 28:466–474.
Flament, P. 1993. Wind-driven mesoscale oceanic processes in the lee of the Hawaiian Islands. Proceedings of the third scientific meeting of The Oceanography Society, Seattle, WA (abstract only).
Flament, P. 1994. Wind-driven oceanic processes in the lee of the island of Hawaii. Annales Geophysicae. European Geophysical Society, Grenoble, C-268 (abstract only).
Flament, P., R. Lumpkin, J. Tournadre, and L. Armi. 2001. Vortex pairing in an unstable anticyclonic shear flow: Discrete subharmonics of one pendulum day. Journal of Fluid Mechanics 440:401–409, https://doi.org/10.1017/S0022112001004955.
Hansen, D., and C.A. Paul. 1984. Genesis and effects of long waves in the equatorial Pacific. Journal of Geophysical Research 89:10,431–10,440, https://doi.org/10.1029/JC089iC06p10431.
Hansen, D., and P.-M. Poulain. 1996. Quality control and interpolations of WOCE-TOGA drifter data. Journal of Atmospheric and Oceanic Technology 13:900–909, https://doi.org/10.1175/1520-0426(1996)013<0900:QCAIOW>2.0.CO;2.
Jia, Y., P.H.R. Calil, E.P. Chassignet, E.J. Metzger, J.T. Potemra, K.J. Richards, and A.J. Wallcraft. 2011. Generation of mesoscale eddies in the lee of the Hawaiian Islands. Journal of Geophysical Research 116, C11009, https://doi.org/10.1029/2011JC007305.
Johnson, G.C. 2001. The Pacific Ocean subtropical cell surface limb. Geophysical Research Letters 28:1,771–1,774, https://doi.org/10.1029/2000GL012723.
Kersalé, M., A.M. Doglioli, and A.A. Petrenko. 2011. Sensitivity study of the generation of mesoscale eddies in a numerical model of the Hawaii islands. Ocean Science 7:277–291, https://doi.org/10.5194/os-7-277-2011.
Kobashi, F., and H. Kawamura. 2002. Seasonal variation and instability nature of the North Pacific Subtropical Countercurrent and the Hawaiian Lee Countercurrent. Journal of Geophysical Research 107(C11), 3185, https://doi.org/10.1029/2001JC001225.
Leonardi, A.P. 1998. Dynamics of the North Hawaiian Ridge Current. Master’s thesis, College of Arts and Sciences, Florida State University.
Lumpkin, R. 1998. Eddies and currents of the Hawaiian Islands. PhD dissertation, University of Hawaii at Manoa.
Lumpkin, R., and P. Flament. 2001. Lagrangian statistics in the central North Pacific. Journal of Marine Systems 29:141–155, https://doi.org/10.1016/S0924-7963(01)00014-8.
Lumpkin, R. 2003. Decomposition of surface drifter observations in the Atlantic Ocean. Geophysical Research Letters 30, 1753, https://doi.org/10.1029/2003GL017519.
Lumpkin, R., and M. Pazos. 2007. Measuring surface currents with Surface Velocity Program drifters: The instrument, its data and some recent results. Pp. 39–67 in Lagrangian Analysis and Prediction of Coastal and Ocean Dynamics. A. Griffa, A.D. Kirwan, A. Mariano, T. Özgökmen, and T. Rossby, eds, Cambridge University Press.
Lumpkin, R., S. Grodsky, L. Centurioni, M.-H. Rio, J. Carton, and D. Lee. 2013. Removing spurious low-frequency variability in drifter velocities. Journal of Atmospheric and Oceanic Technology 30(2):353–360, https://doi.org/10.1175/JTECH-D-12-00139.1.
McGary, J.W. 1955. Mid-Pacific Oceanography, Part VI: Hawaiian Offshore Waters: December 1949–November 1951. Technical Report 152, U.S. Fish and Wildlife Service, Special Science Report.
Niiler, P.P. 2001. The world ocean surface circulation. Pp. 193–204 in Ocean Circulation and Climate: Observing and Modelling the Global Ocean. G. Siedler, J. Church, and J. Gould, eds, International Geophysics Series, vol. 77, Academic Press.
Niiler, P.P., and J.D. Paduan. 1995. Wind-driven motions in the northeast Pacific as measured by Lagrangian drifters. Journal of Physical Oceanography 25:2,819–2,830, https://doi.org/10.1175/1520-0485(1995)025<2819:WDMITN>2.0.CO;2.
Niiler, P.P., A. Sybrandy, K. Bi, P. Poulain, and D. Bitterman. 1995. Measurements of the water-following capability of holey-sock and TRISTAR drifters. Deep Sea Research Part I 42:1,951–1,964, https://doi.org/10.1016/0967-0637(95)00076-3.
Patzert, W.C. 1969. Eddies in Hawaiian Waters. Hawaii Institute of Geophysics Report 69-8, 51 pp.
Qiu, B., D. Koh, R. Lumpkin, and P. Flament. 1997. Existence and formation mechanism of the North Hawaiian Ridge Current. Journal of Physical Oceanography 27:431–444, https://doi.org/10.1175/1520-0485(1997)027<0431:EAFMOT>2.0.CO;2.
Ralph, E.A., and P.P. Niiler. 1999. Wind-driven currents in the Tropical Pacific. Journal of Physical Oceanography 29:2,121–2,129, https://doi.org/10.1175/1520-0485(1999)029<2121:WDCITT>2.0.CO;2.
Sasaki, H., and M. Nonaka. 2006. Far-reaching Hawaiian Lee Countercurrent driven by wind-stress curl induced by warm SST band along the current. Geophysical Research Letters 33, L13602, https://doi.org/10.1029/2006GL026540.
White, W.B., and A.E. Walker. 1985. The influence of the Hawaiian Archipelago upon the wind-driven subtropical gyre of the western North Pacific. Journal of Geophysical Research 90:7,061–7,074, https://doi.org/10.1029/JC090iC04p07061.
Xie, S.-P., W.T. Liu, Q. Liu, and M. Nonaka. 2001. Far-reaching effects of the Hawaiian Islands on the Pacific ocean-atmosphere system. Science 292:2,057–2,060, https://doi.org/10.1126/science.1059781.
Yoshida, S., B. Qiu, and P. Hacker. 2011. Low-frequency eddy modulations in the Hawaiian Lee Countercurrent: Observations and connection to the Pacific Decadal Oscillation. Journal of Geophysical Research 116, C12009, https://doi.org/10.1029/2011JC007286.
Yu, Z., N. Maximenko, S.-P. Xie, and M. Nonaka. 2003. On the termination of the Hawaiian Lee Countercurrent. Geophysical Research Letters 30, 1215, https://doi.org/10.1029/2002GL016710.
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