HR: 14:25h
AN: OS33C-04    [Abstracts]
TI: Meridional Overturning Circulation of the Deep Pacific Estimated Assuming the Vertical Advective-diffusive Balance
AU: * Endoh, T
EM: endo@riam.kyushu-u.ac.jp
AF: Research Institute for Applied Mechanics, Kyushu University, 6-1 Kasuga-kouen, Kasuga, Fukuoka, 816-8580, Japan
AU: Hibiya, T
EM: hibiya@eps.s.u-tokyo.ac.jp
AF: Department of Earth and Planetary Science, Graduate School of Science, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
AB: \hspace*{3em}Assuming the vertical advective-diffusive balance, we calculate the meridional overturning circulation of the deep Pacific based on the observed density field. In addition to the global distribution of diapycnal diffusivity in the pycnocline [ Hibiya et al., 2006], bottom-intensified mixing that follows a Gaussian distribution with depth is taken into account. When diapycnal diffusivity in the pycnocline is assumed to extend uniformly to the bottom, the northward transport of the Lower Circumpolar Deep Water (LCDW) across the equator is only 1 Sv. When the bottom-intensified mixing is incorporated, the meridional overturning circulation increases, decreases, or even reverses depending on the vertical gradient of diapycnal diffusivity. The northward transport of the LCDW crossing the equator becomes comparable to the estimates from previous current meter moorings as well as hydrographic surveys only when the mixing extends well above the rough ocean bottom and hence the vertical gradient of diapycnal diffusivity is small.
DE: 4279 Upwelling and convergences (4964)
DE: 4532 General circulation (1218, 1222)
DE: 4568 Turbulence, diffusion, and mixing processes (4490)
SC: Ocean Sciences [OS]
MN: 2007 Fall Meeting