Extended Abstract (84K)13.2
High winds and high resolution at the Met Office
Andrew J. Malcolm, Met Office, Bracknell, Berks., United Kingdom
The Unified Model (UM) at the Met Office is designed to be applicable over a range of space and times scales; from mesoscale modeling to climate research. A new integration scheme has been developed for the UM with the following features:
(i) Non-hydrostatic.
(ii) Height as vertical coordinate.
(iii) Charney-Phillips staggered vertical grid.
(iv) C grid staggered horizontal grid.
(v) Semi-Lagrangian advection scheme.
(vi) Semi-implicit without the removal of a basic state profile and with a 3-dimensional solver for a variable coefficient problem.
On the 25th February 2002 a low pressure system passed over the British Isles. Associated with it were extremely high gusts of wind (over 90 mph).
The New Met Office model was in pre-operational testing which involved it running in parallel to the current model. This meant that forecasts were available from both models.
The New Met Office operational model was run at varying resolutions to investigate the effect of resolution on the simulations. The Global model was run at N144, N216 and N324 (5/4,5/6 and 5/9 degree EW) resolution. The mesoscale model was run at 12,4,2 and 1km horizontal resolution. Vertical resolution changes have also been explored.
Results from these comparisons will be presented.
Session 13, High Resolution Prediction
Thursday, 15 August 2002, 3:30 PM-5:45 PM
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