A few studies on the impact of radar data assimilation
were also performed for the European area using different
forecast models: AROME (Application of Research to Operations
at MEsoscale) in France and HIRLAM (HIgh Resolution
Limited Area Model) in Sweden. Montmerle and
Faccani (2009) applied the 3DVAR assimilation technique
for assimilating radial velocities from Doppler radars of the
French ARAMIS (Application Radar la Météorologie InfraSynoptique)
network. They found a positive impact of
radar wind data on the analyses and on precipitation forecasts.
Lindskog et al. (2004) also assimilated radial wind velocity.
They used the velocity–azimuth display (VAD) technique
that provides vertical profiles of horizontal winds from
the Doppler radar raw radial wind and the Doppler radar radial
wind superobservations (SOs), which is based on spatial
averaging. They found improvements in the wind and temperature
forecasts of the low and middle troposphere using
either VAD or SOs data.