Assimilation of TOPEX/Poseidon altimeter data into a global ocean circulation model: How good are the results?

The feasibility of assimilating satellite altimetry data into a global ocean general circulation model is studied. Three years of TOPEX/Poseidon data are analyzed using a global, three-dimensional, nonlinear primitive equation model. The assimilation's success is examined by analyzing its consistency and reliability measured by formal error estimates with respect to independent measurements. Improvements in model solution are demonstrated, in particular, properties not directly measured. Comparisons are performed with sea level measured by tide gauges, subsurface temperatures and currents from moorings, and bottom pressure measurements. Model representation errors dictate what can and cannot be resolved by assimilation, and its identification is emphasized.

[1]  Ichiro Fukumori,et al.  Nature of global large‐scale sea level variability in relation to atmospheric forcing: A modeling study , 1998 .

[2]  F. Bretherton,et al.  A technique for objective analysis and design of oceanographic experiments applied to MODE-73 , 1976 .

[3]  Stephen E. Cohn,et al.  An Introduction to Estimation Theory (gtSpecial IssueltData Assimilation in Meteology and Oceanography: Theory and Practice) , 1997 .

[4]  Dimitris Menemenlis,et al.  Error Estimates for an Ocean General Circulation Model from Altimeter and Acoustic Tomography Data , 2000 .

[5]  Ralph J. Slutz,et al.  A Comprehensive Ocean-Atmosphere Data Set , 1987 .

[6]  R. Pacanowski,et al.  Parameterization of Vertical Mixing in Numerical Models of Tropical Oceans , 1981 .

[7]  Alexey Kaplan,et al.  Mapping tropical Pacific sea level : Data assimilation via a reduced state space Kalman filter , 1996 .

[8]  Jin Wu.  Wind‐stress coefficients over sea surface from breeze to hurricane , 1982 .

[9]  Keith Haines,et al.  Data assimilation in ocean models , 1996 .

[10]  P. Malanotte‐Rizzoli,et al.  An approximate Kaiman filter for ocean data assimilation: An example with an idealized Gulf Stream model , 1995 .

[11]  M. Ghil,et al.  Data assimilation in meteorology and oceanography , 1991 .

[12]  M. K rn,et al.  Stochastic Optimal Control , 1988 .

[13]  Andrew F. Bennett,et al.  Inverse Methods in Physical Oceanography: Frontmatter , 1992 .

[14]  George L. Mellor,et al.  Continuous assimilation of Geosat altimeter data into a three-dimensional primitive equation Gulf Stream model , 1994 .

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

[16]  Ichiro Fukumori,et al.  Assimilation of TOPEX sea level measurements with a reduced‐gravity, shallow water model of the tropical Pacific Ocean , 1995 .

[17]  Sol Hellerman,et al.  Normal Monthly Wind Stress Over the World Ocean with Error Estimates , 1983 .

[18]  Arthur Gelb,et al.  Applied Optimal Estimation , 1974 .

[19]  Carl Wunsch,et al.  Assimilation of Sea Surface Topography into an Ocean Circulation Model Using a Steady-State Smoother , 1993 .

[20]  A. E. Gill,et al.  The theory of the seasonal variability in the ocean , 1973 .

[21]  Thomas Kaminski,et al.  Recipes for adjoint code construction , 1998, TOMS.

[22]  Ichiro Fukumori,et al.  Fitting Dynamic Models to the Geosat Sea Level Observations in the Tropical Pacific Ocean. Part II: A Linear, Wind-driven Model , 1993 .

[23]  D. Halpern,et al.  Observations of 20-Day Period Meridional Current Oscillations in the Upper Ocean along the Pacific Equator , 1988 .

[24]  Carl Wunsch,et al.  The global ocean circulation estimated from TOPEX/POSEIDON altimetry and the MIT general circulation model , 1997 .

[25]  R. Ponte.  Variability in a homogeneous global ocean forced by barometric pressure , 1993 .

[26]  Robert N. Miller,et al.  A Kalman Filter Analysis of Sea Level Height in the Tropical Pacific , 1989 .

[27]  K. Haines,et al.  A Direct Method for Assimilating Sea Surface Height Data into Ocean Models with Adjustments to the Deep Circulation , 1991 .

[28]  Y. Sasaki.  SOME BASIC FORMALISMS IN NUMERICAL VARIATIONAL ANALYSIS , 1970 .

[29]  G. Evensen.  Sequential data assimilation with a nonlinear quasi‐geostrophic model using Monte Carlo methods to forecast error statistics , 1994 .

[30]  Gary T. Mitchum,et al.  Comparison of TOPEX sea surface heights and tide gauge sea levels , 1994 .