Practical global oceanic state estimation

@article{citeulike:1697251, abstract = {The problem of oceanographic state estimation, by means of an ocean general circulation model (GCM) and a multitude of observations, is described and contrasted with the meteorological process of data assimilation. In practice, all such methods reduce, on the computer, to forms of least-squares. The global oceanographic problem is at the present time focussed primarily on smoothing, rather than forecasting, and the data types are unlike meteorological ones. As formulated in the consortium Estimating the Circulation and Climate of the Ocean (ECCO), an automatic differentiation tool is used to calculate the so-called adjoint code of the GCM, and the method of Lagrange multipliers used to render the problem one of unconstrained least-squares minimization. Major problems today lie less with the numerical algorithms (least-squares problems can be solved by many means) than with the issues of data and model error. Results of ongoing calculations covering the period of the World Ocean Circulation Experiment, and including among other data, satellite altimetry from TOPEX/POSEIDON, Jason-1, ERS- 1/2, ENVISAT, and GFO, a global array of profiling floats from the Argo program, and satellite gravity data from the GRACE mission, suggest that the solutions are now useful for scientific purposes. Both methodology and applications are developing in a number of different directions.}, author = {Wunsch, Carl and Heimbach, Patrick }, booktitle = {Data Assimilation}, citeulike-article-id = {1697251}, doi = {http://dx.doi.org/10.1016/j.physd.2006.09.040}, journal = {Physica D: Nonlinear Phenomena}, keywords = {data, fluids, geophysical, personal}, month = {June}, number = {1-2}, pages = {197--208}, posted-at = {2007-09-26 14:15:55}, priority = {2}, title = {Practical global oceanic state estimation}, url = {http://dx.doi.org/10.1016/j.physd.2006.09.040}, volume = {230}, year = {2007} }

TY - JOUR ID - citeulike:1697251 L3 - citeulike-article-id:1697251 TI - Practical global oceanic state estimation T2 - Data Assimilation JF - Physica D: Nonlinear Phenomena VL - 230 IS - 1-2 SP - 197 EP - 208 N2 - The problem of oceanographic state estimation, by means of an ocean general circulation model (GCM) and a multitude of observations, is described and contrasted with the meteorological process of data assimilation. In practice, all such methods reduce, on the computer, to forms of least-squares. The global oceanographic problem is at the present time focussed primarily on smoothing, rather than forecasting, and the data types are unlike meteorological ones. As formulated in the consortium Estimating the Circulation and Climate of the Ocean (ECCO), an automatic differentiation tool is used to calculate the so-called adjoint code of the GCM, and the method of Lagrange multipliers used to render the problem one of unconstrained least-squares minimization. Major problems today lie less with the numerical algorithms (least-squares problems can be solved by many means) than with the issues of data and model error. Results of ongoing calculations covering the period of the World Ocean Circulation Experiment, and including among other data, satellite altimetry from TOPEX/POSEIDON, Jason-1, ERS- 1/2, ENVISAT, and GFO, a global array of profiling floats from the Argo program, and satellite gravity data from the GRACE mission, suggest that the solutions are now useful for scientific purposes. Both methodology and applications are developing in a number of different directions. KW - data KW - fluids KW - geophysical KW - personal AU - Wunsch, Carl AU - Heimbach, Patrick PY - 2007/06// UR - http://dx.doi.org/10.1016/j.physd.2006.09.040 ER -