Diffusion Filters for Variational Data Assimilation of Sea Surface Temperature in an Intermediate Climate Model
Chu, Peter C.
MetadataShow full item record
Sequential, adaptive, and gradient diffusion filters are implemented into spatial multiscale three-dimensional variational data assimilation (3DVAR) as alternative schemes to model background error covariance matrix for the commonly used correction scale method, recursive filter method, and sequential 3DVAR. The gradient diffusion filter (GDF) is verified by a two-dimensional sea surface temperature (SST) assimilation experiment. Compared to the existing DF, the new GDF scheme shows a superior performance in the assimilation experiment due to its success in extracting the spatial multiscale information. The GDF can retrieve successfully the longwave information over the whole analysis domain and the shortwave information over data-dense regions. After that, a perfect twin data assimilation experiment framework is designed to study the effect of the GDF on the state estimation based on an intermediate coupled model. In this framework, the assimilation model is subject to “biased” initial fields from the “truth” model. While the GDF reduces the model bias in general, it can enhance the accuracy of the state estimation in the region that the observations are removed, especially in the South Ocean. In addition, the higher forecast skill can be obtained through the better initial state fields produced by the GDF.
The article of record as published may be found at http://dx.doi.org/10.1155/2015/751404
RightsThis publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.
Showing items related by title, author, creator and subject.
Shulman, Igor; Paduan, Jeffrey D. (Elsevier, 2009);Impact of HF radar surface-current assimilation on ocean circulation model predictions in the Monterey Bay area is studied and evaluated during the time frame of the Autonomous Ocean Sampling Network (AOSN-II) experiment ...
Tokmakian, Robin Telrud (Monterey, California. Naval Postgraduate School, 1997);Two assimilation experiments have been conducted using the Semtner/Chervin Parallel Ocean Climate Model at 1/40 resolution to investigate the dynamical changes which occur with the application of the nudging method to ...
Lermusiaux, P.F.J.; Chiu, C.S. (2002);The estimation of oceanic environmental and acoustical fields is considered as a single coupled data assimilation problem. The four-dimensional data assimilation methodology employed is Error Subspace Statistical Estimation. ...