Weston, Michael, Theo Fischer, and Abdul Ebrahim,
EScience Associates
We run WRF for two
regions of South Africa: the Western Cape and the Highveld. The Western Cape
represents a baroclinic atmosphere, is adjacent to a cold ocean current and is
characterised by complex terrain. The Highveld typically has a barotropic atmosphere,
is in the interior and is generally flat terrain. We evaluate wind speeds from
WRF against observations in both regions. Wind direction is modelled well for
both regions. However, evaluation of wind speed produces mixed results. For the
Western Cape, WRF performs well for wind speeds at 60m a.g.l, slightly
underestimating high wind speeds. However, at 10m a.g.l WRF slightly over
predicts wind speeds. For the Highveld region, WRF consistently over predicts
wind speeds at 10m a.g.l. A comparison of MM5 data against WRF indicates that
MM5 also over estimates wind speed for the Highveld region. Further
investigation is required to determine possible causes of over estimating wind
speed over the Highveld. These include: Evaluate input meteorological data, evaluate
surface characteristics, parametrisation tests and obtaining more observed
upper air data for model evaluation.