Decadal Variability of the Kuroshio Extension: Observations and an Eddy-Resolving Model Hindcast*

Abstract Low-frequency variability of the Kuroshio Extension (KE) is studied using observations and a multidecadal (1950–2003) hindcast by a high-resolution (0.1°), eddy-resolving, global ocean general circulation model for the Earth Simulator (OFES). In both the OFES hindcast and satellite altimeter observations, low-frequency sea surface height (SSH) variability in the North Pacific is high near the KE front. An empirical orthogonal function (EOF) analysis indicates that much of the SSH variability in the western North Pacific east of Japan is explained by two modes with meridional structures tightly trapped along the KE front. The first mode represents a southward shift and to a lesser degree, an acceleration of the KE jet associated with the 1976/77 shift in basin-scale winds. The second mode reflects quasi-decadal variations in the intensity of the KE jet. Both the spatial structure and time series of these modes derived from the hindcast are in close agreement with observations. A linear Rossby wave...

[1]  B. Qiu.  Interannual Variability of the Kuroshio Extension System and Its Impact on the Wintertime SST Field , 2000 .

[2]  P. Killworth,et al.  Mechanisms of Decadal Variability of the Wind-Driven Ocean Circulation , 2005 .

[3]  R. Reynolds,et al.  The NCEP/NCAR 40-Year Reanalysis Project , 1996, Renewable Energy.

[4]  J. Fyfe,et al.  NOTES AND CORRESPONDENCE Characterizing Midlatitude Jet Variability: Lessons from a Simple GCM , 2005 .

[5]  J. McWilliams,et al.  Dynamically balanced absolute sea level of the global ocean derived from near‐surface velocity observations , 2003 .

[6]  B. Qiu.  Kuroshio Extension variability and forcing of the Pacific Decadal Oscillations , 2003 .

[7]  James W. Hurrell,et al.  Decadal atmosphere-ocean variations in the Pacific , 1994 .

[8]  G. Ierley,et al.  A Model of the Inertial Recirculation Driven by Potential Vorticity Anomalies , 1987 .

[9]  Masami Nonaka,et al.  Covariations of Sea Surface Temperature and Wind over the Kuroshio and Its Extension: Evidence for Ocean-to-Atmosphere Feedback(. , 2003 .

[10]  Shintaro Kawahara,et al.  A Global Eddy-Resolving Coupled Physical-Biological Model: Physical Influences on a Marine Ecosystem in the North Pacific , 2006, Simul..

[11]  W. Dewar.  Nonlinear Midlatitude Ocean Adjustment , 2003 .

[12]  D. Pierce,et al.  Anatomy of North Pacific Decadal Variability , 2002 .

[13]  A. Miller,et al.  Predicting Western North Pacific Ocean Climate , 2001 .

[14]  John D. McCalpin,et al.  Phenomenology of the low-frequency variability in a reduced-gravity, quasigeostrophic double-gyre model , 1996 .

[15]  B. Qiu,et al.  Interannual Variability of the Kuroshio Extension System and Its Impact on the Wintertime SST Field , 2022 .

[16]  Gilles Reverdin,et al.  Global high-resolution mapping of ocean circulation from TOPEX/Poseidon and ERS-1 and -2 , 2000 .

[17]  B. Taguchi,et al.  Atmospheric sounding over the winter Kuroshio Extension: Effect of surface stability on atmospheric boundary layer structure , 2006 .

[18]  T. P. Barnett,et al.  Causes of Decadal Climate Variability over the North Pacific and North America , 1994, Science.

[19]  H. Mitsudera,et al.  Response of the Kuroshio Extension to Rossby Waves Associated with the 1970s Climate Regime Shift in a High-Resolution Ocean Model* , 2005 .

[20]  S. Xie,et al.  Atmospheric Response to Zonal Variations in Midlatitude SST: Transient and Stationary Eddies and Their Feedback* , 2003 .

[21]  W. White.  Design of a global observing system for gyre-scale upper ocean temperature variability , 1995 .

[22]  Michael Ghil,et al.  Multiple Equilibria, Periodic, and Aperiodic Solutions in a Wind-Driven, Double-Gyre, Shallow-Water Model , 1995 .

[23]  Shang-Ping Xie,et al.  Satellite Observations of Cool Ocean–Atmosphere Interaction , 2004 .

[24]  Y. Masumoto.  A fifty-year eddy-resolving simulation of the world ocean : Preliminary outcomes of OFES (OGCM for the Earth Simulator) , 2004 .

[25]  Naomi Naik,et al.  Wind-Driven Shifts in the Latitude of the Kuroshio–Oyashio Extension and Generation of SST Anomalies on Decadal Timescales* , 2001 .

[26]  A. Ishida,et al.  Subduction of the North Pacific Mode Waters in a Global High-Resolution GCM* , 2002 .

[27]  Takashi T. Sakamoto,et al.  Responses of the Kuroshio and the Kuroshio Extension to global warming in a high‐resolution climate model , 2005 .

[28]  Bo Qiu,et al.  Variability of the Kuroshio Extension Jet, Recirculation Gyre, and Mesoscale Eddies on Decadal Time Scales , 2005 .

[29]  C. Deser,et al.  Evidence for a Wind-Driven Intensification of the Kuroshio Current Extension from the 1970s to the 1980s , 1999 .

[30]  Hisashi Nakamura,et al.  10-km Mesh Meso-scale Resolving Simulations of the Global Atmosphere on the Earth Simulator - Preliminary Outcomes of AFES (AGCM for the Earth Simulator) - , 2004 .

[31]  T. Nitta,et al.  Recent Warming of Tropical Sea Surface Temperature and Its Relationship to the Northern Hemisphere Circulation , 1989 .

[32]  David W. Pierce,et al.  The role of ocean dynamics in producing decadal climate variability in the North Pacific , 2001 .

[33]  Bruce D. Cornuelle,et al.  The Forcing of the Pacific Decadal Oscillation , 2005 .

[34]  Yasuhiro Yamanaka,et al.  Chlorofluorocarbons in a global ocean eddy‐resolving OGCM: Pathway and formation of Antarctic Bottom Water , 2004 .

[35]  Masami Nonaka,et al.  Far‐reaching Hawaiian Lee Countercurrent driven by wind‐stress curl induced by warm SST band along the current , 2006 .

[36]  Hisashi Nakamura,et al.  Decadal Variability in the Kuroshio–Oyashio Extension Simulated in an Eddy-Resolving OGCM , 2006 .

[37]  B. Qiu.  The Kuroshio Extension System: Its Large-Scale Variability and Role in the Midlatitude Ocean-Atmosphere Interaction , 2002 .

[38]  Keizo Sakurai,et al.  Interdecadal variability of the sea surface height around Japan , 2006 .

[39]  B. Qiu,et al.  Predictability of SST in a Stochastic Climate Model and Its Application to the Kuroshio Extension Region , 2003 .

[40]  I. Yasuda,et al.  Empirical biomass model for the Japanese sardine, Sardinops melanostictus, with sea surface temperature in the Kuroshio Extension , 2003 .

[41]  S. Xie,et al.  Estimates of Surface and Subsurface Forcing for Decadal Sea Surface Temperature Variability in the Mid-Latitude North Pacific , 2002 .

[42]  B. Qiu,et al.  Kuroshio Extension Variability and Forcing of the Pacific Decadal Oscillations : Responses and Potential Feedback , 2022 .

[43]  Hisashi Nakamura,et al.  An active role of extratropical sea surface temperature anomalies in determining anomalous turbulent heat flux , 2003 .

[44]  Hisashi Nakamura,et al.  Mesoscale resolving simulations of the global atmosphere and ocean on the Earth simulator , 2005 .

[45]  B. Qiu.  The Kuroshio Extension System : Its Large-Scale Variability and Role in the Midlatitude Ocean-Atmosphere Interaction , 2002 .

[46]  H. Nakamura,et al.  Observed Associations Among Storm Tracks, Jet Streams and Midlatitude Oceanic Fronts , 2013 .

[47]  B. Qiu.  Large-Scale Variability in the Midlatitude Subtropical and Subpolar North Pacific Ocean : Observations and Causes , 2002 .

[48]  Michael Ghil,et al.  Low‐frequency variability of the large‐scale ocean circulation: A dynamical systems approach , 2005 .

[49]  T. Barnett,et al.  Interdecadal variability of the Pacific Ocean: model response to observed heat flux and wind stress anomalies , 1994 .

[50]  S. Xie,et al.  Interdecadal Thermocline Variability in the North Pacific for 1958–97: A GCM Simulation* , 2000 .

[51]  W. White,et al.  A westward-intensified decadal change in the North Pacific thermocline and gyre-scale circulation , 1998 .

[52]  B. Qiu.  Large-Scale Variability in the Midlatitude Subtropical and Subpolar North Pacific Ocean: Observations and Causes , 2002 .