A filtering integration scheme is developed, using a modification of the contour
used to invert the Laplace transform (LT). It is shown to eliminate components
with frequencies higher than a specified cut-off value. Thus it is valuable
for integrations of the equations governing atmospheric flow. The scheme is
implemented in a shallow water model with an Eulerian treatment of advection.
It is compared to a reference model using the semi-implicit (SI) scheme. The LT
scheme is shown to treat dynamically important Kelvin waves more accurately
than the SI scheme.
Irish Research Council for Science, Engineering and Technology
Type of Material
Quarterly Journal of the Royal Meteorological Society