Manchester Applied Mathematics and Numerical Analysis Seminars Autumn 2000/2001

November 1, 2000, 2.30 pm

Lecture Theatre OF/B9 Oddfellows Hall (Material Science)

Numerical Weather Prediction

Dr. Clive Temperton, European Centre for Medium-Range Weather Forecasts

Numerical weather prediction has always been a leading-edge application on supercomputers, because of the need to provide timely forecasts using sophisticated models with spatial resolution as high as possible. Currently, ECMWF runs a global spectral model with 60 unequally spaced levels in the vertical and a horizontal resolution equivalent to a gridlength of 60 km; research forecasts have already been run using this global model with a horizontal resolution of 25 km. Computational requirements dictate that the models must run on parallel machines. Algorithmic improvements have also led to a speedup by a factor of 50-100 over the past decade or so.

Providing initial conditions for the model integration (the "data assimilation" problem) presents an even bigger task, which in the current ECMWF system is formulated as an enormous four-dimensional variational problem; this generates a further set of computational challenges.

These aspects of the numerical weather prediction problem will be discussed, and some recent high-resolution results will be presented.

For further info contact either Matthias Heil (mheil@ma.man.ac.uk), Mark Muldoon (M.Muldoon@umist.ac.uk) or the seminar secretary (Tel. 0161 275 5800).