Proceedings - C-SRNWP Project

Fig.3 RMSE difference (WDEF-NAM2). Negative
values correspond to improvements. The result is
significant if the vertical bars does not cross the 0 line.
Fig.4 RMSE difference (WLAN -WDEF). Negative
values correspond to improvements. The result is
significant if the vertical bars does not cross the 0 line.
Another important contribution to the work on observation use was given by the participation
of HMS in the EUCOS project. In this framework intensive assimilation experiments were
run to examine the relative impact of ground based observations compared to the satellites
available. The work consisted of running 8 OSEs (Observing System Experiments) for 2 one
month long periods (one summer and one winter period). Conclusions were driven by score
comparisons together with significance tests and through the analysis of case studies from
both periods. As the project has not been fully closed yet, we do not show pictures here but
our main conclusion is that the ground based observing system is a quite important
component of our assimilation suite. At the end of the year a work on the assimilation of
SEVIRI data has started as well but the results are too much preliminary for any details here.
Surface
At the Czech Hydrometeorological Institute a surface OI scheme (CANARI) has been
implemented operationally instead of the former surface blending. The OI analysis is applied
with a 6-hour frequency, that is, at each step of the blending cycle after the treatment of the
upper-air fields. The operational application of the surface OI analysis was implied by test
results showing systematic improvement in the 2m temperature and relative humidity (Fig. 5
and 6).
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