Digital Filter Initialization for HIRLAM

Peter Lynch, Ray McGrath and Aidan McDonald

Met Éireann, Dublin

HIRLAM Technical Report No. 42

June, 1999


A digital filter initialization scheme has been introduced into the HIRLAM model and compared to the reference implicit normal mode initialization scheme. This report presents details of the scheme and the results of extensive tests showing its advantages. The scheme is shown to be more effective than the reference normal mode initialization scheme in eliminating spurious high frequency noise from the forecasts. In a parallel run using FASTEX data, the scores produced by the DFI run were significantly better than those of the reference run. The advantages of digital filter initialization demonstrated in this report should justify the adoption of the digital filtering initialization scheme as a new reference scheme for HIRLAM.

Back to Publications List