Resolution of sharp fronts in the presence of model error in variational data assimilation
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Thu, 11/02/2010 14:00 |
Dr. Melina Freitag (University of Bath) |
Computational Mathematics and Applications  |
Rutherford Appleton Laboratory, nr Didcot |
We show that data assimilation using four-dimensional variation
(4DVar) can be interpreted as a form of Tikhonov regularisation, a
familiar method for solving ill-posed inverse problems. It is known from
image restoration problems that  -norm penalty regularisation recovers
sharp edges in the image better than the  -norm penalty
regularisation. We apply this idea to 4DVar for problems where shocks are
present and give some examples where the -norm penalty approach
performs much better than the standard -norm regularisation in 4DVar. |
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