Geoscience Reference
In-Depth Information
5. Conclusion
The ability to collect Doppler measurements up to long range resulting from the recent
deployment of a new triple-PRT scheme within the French radar network ARAMIS allows to
mitigate the Doppler dilemma and to achieve extensive multiple-Doppler coverage while
collecting high quality radial velocities. This achievement brings new perspectives in terms of
exploitation of operational Doppler measurements such as the ability to perform multiple-
Doppler wind synthesis in a fully operational framework. In this context the French weather
service has started to produce a new mosaic of wind and reflectivity covering the entire French
territory. Reflectivity and radial velocity observations collected by the 24 ARAMIS radars,
which are concentrated at the national center in Toulouse, are synthesized every 15' to
produce a nationwide, three dimensional, wind and reflectivity composite.
An evaluation of multiple-Doppler wind fields synthesized in this framework was carried
out from data collected during several weather situations characterized by fundamentally
different airflow and precipitation regimes that is, the extratropical cyclone Klaus that stoke
France with hurricane strength winds on 24 January 2009, as well as several heavy
orographic precipitation events that occurred over the Massif Central Mountains in 2008
and 2010. Airflows retrieved at different horizontal resolutions ranging from 2.5 to 1 km are
highly consistent with those documented earlier from high resolution research radar data,
which suggests that multiple-Doppler winds retrieved in this operational framework are
definitely reliable. Wind and reflectivity fields produced routinely in this framework are
archived since about a year and are already available to researchers from many countries.
This product will be used in a quasi-operational mode (real-time) to guide mobile research
systems and evaluate numerical model outputs during the field phase of the
Hydrometeorological Cycle in the Mediterranean Experiment (HyMeX) to be held in
southern France in fall 2012. It should become fully operational near year 2013 after having
been thoroughly evaluated by the forecasters of the French Weather Service.
6. References
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Bousquet, O., and M. Chong, 1998: A multiple Doppler and continuity adjustment technique
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