Geoscientific Model Development Discussions www.geosci-model-dev-discuss.net 1991-9611 1991-962X 3 2 2010 10.5194/gmdd-3-517-2010 http://www.geosci-model-dev-discuss.net/3/517/2010/ http://www.geosci-model-dev-discuss.net/3/517/2010/gmdd-3-517-2010.html http://www.geosci-model-dev-discuss.net/3/517/2010/gmdd-3-517-2010.pdf 517 540 2010-05-11 Physically-based data assimilation G. Levy gad@nwra.com M. Coon G. Nguyen D. Sulsky NorthWest Research Associates, Seattle, Washington, USA Department of Mathematics and Statistics, University of New Mexico, Albuquerque, New Mexico, USA currently at: The School of Civil Engineering, University of Sydney, Sydney, NSW, Australia deceased Ideally, a validation and assimilation scheme should maintain the physical principles embodied in the model and be able to evaluate and assimilate lower dimensional features (e.g., discontinuities) contained within a bulk simulation, even when these features are not directly observed or represented by model variables. We present such a scheme and suggest its potential to resolve or alleviate some outstanding problems that stem from making and applying required, yet often non-physical, assumptions and procedures in common operational data assimilation. As proof of concept, we use a sea-ice model with remotely sensed observations of leads in a one-step assimilation cycle. 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