P103
The Sensitivity of
Orographically Enhanced Extreme
Precipitation
Events in Western Norway to Changes in SST
Sandvik, Mari Ingeborg, and Asgeir Sorteberg, Geophysical
Institute, University in Bergen, Norway
Studies indicate an
increased risk of more frequent precipitation extremes in a warming world,
which may result in more frequent flooding, avalanches and landslides. Thus,
the ability to understand how processes influence extreme precipitation events
could result in a better representation in models used in both research and
weather forecasting. The WRF model
has been used in 3 case studies where a uniform change in SST (±2¡C) was
applied to test the sensitivity of both precipitation intensity and distribution
to a warmer and colder Atlantic Ocean. As the precipitation events are strongly
dependent on the path of the low-pressure systems we apply spectral nudging of
the large-scale system in order to keep the synoptic flow similar in the
control and sensitivity runs. Preliminary results (10km resolution) suggest
that even if the large scale flow is forced to not change the extreme
precipitation changes does not follow Clausius-Clapeyron scaling for the
individual cases as changes in vertical velocities are very different from case
to case. Future work will contain more case studies with similar properties,
found by cluster analysis, simulated by the WRF model to look for sensitivity patterns
due to changes in SST.