The authors thank Troy Stribling for assistance with model configuration and plotting packages and David Adamec for informative discussions and advice through the course of this study. The helpful comments from two reviewers are gratefully acknowledged. Much of this work was done while M.D. was a student supported through the Joint Center for Earth System Science in the Department of Meteorology at the University of Maryland. This project was funded by the NASA Physical Oceanography Program through the NASA RTOP 568-21-05.
Adamec, D., and R. W. Garwood Jr., 1985: The simulated response of an upper-ocean density front to local atmospheric forcing. J. Geophys. Res.,90, 917–928.
Bingham, F. M., 1992: Formation and spreading of subtropical mode water in the North Pacific. J. Geophys. Res.,97, 11 177–11 189.
Bleck, R., R. Onken, and J. D. Woods, 1988: A two-dimensional model of mesoscale frontogenesis in the ocean. Quart. J. Roy. Meteor. Soc.,114, 347–371.
Camerlengo, A., 1982: Large-scale response of the Pacific Ocean subarctic front to momentum transfer: A numerical study. J. Phys. Oceanogr.,12, 1106–1121.
Cushman-Roisin, B., 1981: Effects of horizontal advection on upper ocean mixing: A case of frontogenesis. J. Phys. Oceanogr.,11, 1345–1356.
——, 1984: On the maintenance of the subtropical front and its associated countercurrent. J. Phys. Oceanogr.,14, 1179–1190.
daSilva, A. M., C. C. Young, and S. Levitus, 1995: Atlas of Surface Marine Data 1994. Vol. 1: Algorithms and Procedures. NOAA Atlas NESDIS 7, U.S. Department of Commerce, 74 pp.
ECMWF, 1994: The description of the ECMWF/WCRP level III-A global atmospheric data archive. Tech. Attach., Reading, England, 72 pp. [Available from ECMWF, Shinfield Park, Reading RG2 9AX, United Kingdom.].
Kazmin, A. S., and M. M. Rienecker, 1996: Variability and frontogenesis in the large-scale oceanic frontal zones. J. Geophys. Res.,101, 907–921.
Levine, E. R., and W. B. White, 1983: Bathymetric influences upon the character of North Pacific fronts. J. Geophys. Res.,88, 9617–9625.
Levitus, S., 1982: Climatological Atlas of the World Ocean. NOAA Prof. Pap. No. 13, U.S. Govt. Printing Office, Washington, D.C., 173 pp.
Lynn, R. J., 1986: The subarctic and northern subtropical fronts in the eastern North Pacific Ocean in spring. J. Phys. Oceanogr.,16, 209–222.
Niiler, P. P., and R. W. Reynolds, 1984: The three-dimensional circulation near the eastern North Pacific subtropical front. J. Phys. Oceanogr.,14, 217–230.
Pacanowski, R. C., 1995: MOM 2 documentation, user’s guide and reference manual. GFDL Ocean Tech. Rep. No. 3, 232 pp. [Available from Geophysics Fluid Dynamics Laboratory, P.O. Box 308, Princeton, NJ 08542-0308.].
Qiu, B., 1995: Why is the spreading of the North Pacific Intermediate Water confined on density surfaces around σθ = 26.8? J. Phys. Oceanogr.,25, 168–180.
Roden, G. I., 1972: Temperature and salinity fronts at the boundaries of the subarctic–subtropical transition zone in the western Pacific. J. Geophys. Res.,77, 7175–7187.
——, 1975: On the North Pacific temperature, salinity, sound velocity and density fronts and their relation to the wind and energy flux fields. J. Phys. Oceanogr.,5, 557–571.
——, 1977: Oceanic subarctic fronts of the central Pacific: Structure of and response to atmospheric forcing. J. Phys. Oceanogr.,7, 761–778.
——, 1980a: On the subtropical frontal zone north of Hawaii during winter. J. Phys. Oceanogr.,10, 342–362.
——, 1980b: On the variability of surface temperature fronts in the western Pacific, as detected by satellite. J. Geophys. Res.,85, 2704–2710.
——, 1991: Subarctic–subtropical transition zone of the North Pacific: Large-scale aspects and mesoscale structure. NOAA Tech. Rep. NMFS 105, 1–38.
——, and D. F. Paskausky, 1978: Estimation of rates of frontogenesis and frontolysis in the North Pacific Ocean using satellite and surface meteorological data from January 1977. J. Geophys. Res.,83, 4545–4550.
Smith, E., 1992: A user’s guide to the NOAA advanced very high resolution radiometer multichannel sea surface temperature data set produced by the University of Miami/Rosenstiel School of Marine and Atmospheric Science. JPL Tech. Rep. 037-D001, Jet Propulsion Laboratory, Pasadena, CA, 22 pp. [Available from JPL Archives and Records Management Facility, Sherikon Space Systems, Inc., 145 N. Aldena Drive, Pasadena, CA 91107.].
Suga, T., Y. Takei, and K. Hanawa, 1997: Thermostad distribution in the North Pacific subtropical gyre: The central mode water and the subtropical mode water. J. Phys. Oceanogr.,27, 140–152.
Takeuchi, K., 1984: Numerical study of the subtropical front and the subtropical counter-current. J. Oceanogr. Soc. Japan,40, 371–381.
——, 1986: Numerical study of the seasonal variations of the subtropical front and the subtropical countercurrent. J. Phys. Oceanogr.,16, 919–926.
Trenberth, K. E., W. G. Large, and J. E. Olson, 1989: The effective drag coefficient for evaluating wind stress over the oceans. J. Climate,2, 1507–1516.
Tziperman, E., J. R. Toggweiler, Y. Feliks, and K. Bryan, 1994: Instability of the thermohaline circulation with respect to mixed boundary conditions: Is it really a problem for realistic models? J. Phys. Oceanogr.,24, 217–232.
White, W. B., K. Hasunuma, and H. Solomon, 1978: Large-scale seasonal and secular variability of the subtropical front in the western North Pacific from 1954 to 1974. J. Geophys. Res.,83, 4531–4544.
Yuan, X., 1994: Characteristics and frontogenesis of the subarctic front in the North Pacific. Ph.D. dissertation, University of California, San Diego, 172 pp.
——, and L. D. Talley, 1996: The subarctic frontal zone in the North Pacific: Characteristics of frontal structure from climatological data and synoptic surveys. J. Geophys. Res.101, 16 491–16 508.
Zhang, R.-C., and K. Hanawa, 1993: Features of the water-mass front in the northwestern North Pacific. J. Geophys. Res.,98, 967–975.