P-vector inverse method evaluated using the modular ocean model (MOM)

被引:25
作者
Chu P.C. [1 ]
Fan C. [1 ]
Cai W. [2 ]
机构
[1] Naval Postgraduate School, Monterey
[2] CSIRO Div. of Atmospheric Research, Aspendale, Vic.
关键词
Beta spiral; Geostrophic balance; Inverse method; P vector; Primitive equation model; Stream function; Thermal wind relation;
D O I
10.1007/BF02751694
中图分类号
学科分类号
摘要
Several major inverse methods (Stommel-Schott method, Wunsch method, and Bernoulli method) have been successfully developed to quantitatively estimate the geostrophic velocity at the reference level from hydrographic data. No matter the different appearance, they are based on the same dynamical sophistication: geostrophy, hydrostatic, and potential density (ρ) conservation (Davis, 1978). The current inverse methods are all based on two conservation principles: potential density and potential vorticity (q =f∂p/∂z) and require β-turning. Thus, two necessary conditions can be incorporated into any inverse methods: (1) non-coincidence of potential density and potential vorticity surfaces and (2) existence of vertical turning of the velocity (β-turning.) This can be done using the P-Vector, a unit vector in the direction of ∇ρ×Vq (Chu, 1994,1995). The first necessary condition becomes the existence of the P-vector, and the second necessary condition leads to the existence of the P-vector turning in the water column. Along this line, we developed the P-vector inverse method with a pre-requirement check-up. The method was verified in this study using the Modular Ocean Model (MOM) from Pacanowski et al. (1991) version of Bryan-Cox-Semtner ocean general circulation model (OGCM), which is based on the work of Bryan (1969). The statistically steady solutions of temperature and salinity from MOM are used as a "no-error data" set for computing absolute geostrophic velocities by the P-vector inverse method. Circulations are similar between the MOM statistically steady solutions and the P-vector solutions. Furthermore, the quantitative analysis shows that this inverse method has capability of picking up the major signal of the velocity field.
引用
收藏
页码:185 / 198
页数:13
相关论文
共 18 条
  • [1] Behringer D.W., Stommel H., The beta spiral in the North Atlantic subtropical gyre, Deep Sea Res., 27 A, pp. 225-238, (1980)
  • [2] Bryan K., Parameter sensitivity of primitive equation ocean general circulation models, J. Phys. Oceanogr., 17, pp. 970-985, (1987)
  • [3] Cai W., Godfrey S.J., Surface heat flux parameterization and the variability of thermocline circulation, J. Geophys. Res., 100, (1995)
  • [4] Chu P.C., P-vector method for determining ocean circulation from hydrographic data, Ocean Modeling, 104, (1994)
  • [5] Chu P.C., P-vector method for determining absolute velocity from hydrographie data, Marine Technology Society Journal, 29, 3, pp. 3-14, (1995)
  • [6] Cox M.D., GFDL Ocean Model Circular No. 7, (1987)
  • [7] Davis R., On estimating velocity from hydrographie data, J. Geophys. Res., 83, pp. 5507-5509, (1978)
  • [8] Haney R.L., Surface boundary condition for ocean circulation models, J. Phys. Oceanogr., 1, pp. 241-248, (1971)
  • [9] Holland W.R., Baroclinic and topographic influences on the transport in western boundary currents, Geophys. Fluid Dyn., 4, pp. 187-210, (1973)
  • [10] Killworth P., A Bernoulli in verse method for determining the ocean circulation, J. Phys. Oceanogr., 16, pp. 2031-2051, (1986)