Proceedings - C-SRNWP Project

case study. The method of the initial conditions perturbation used in LAEF is Breeding.
The results are shown in Fig. 5.
The performance of the LAMEPS system is very sensitive to the LBC generated by
different perturbation methods in the global EPS system. It is shown that LAEF couples
with NCEP breeding perturbation has more diversity than LAEF couples with ARPEGE
SV perturbation.
Figure 5. Comparison of the spreads of 850hPa Temperature and kinetic energy, 500hPa
Geopotential, surface pressure, LAEF Breeding coupling with ARPEGE EPS and NCEP EPS.
2.3 Dealing with uncertainties in model physics
• Multi-physics parameterization
ALADIN dynamical downscaling of ARPEGE PEARP members with and without
multi-physics options has been carried out. 11 combinations of different physics
parameterizations and tunings in ALADIN have been chosen for dealing with the
Figure 6. Percentage of outliers of LAEF experiment with and without multi-physics.
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