Validation of the SAFRAN meteorological analysis over the French Mediterranean region
SAFRAN is a mesoscale atmospheric analysis system for surface variables. It produces an analysis at the hourly time step using ground data observations. One of its main originalities is the analysis being based on climatically homogeneous zones and its ability to take vertical variations into account. Originally intended for mountain areas, it was afterwards extended to France. This work focuses on the validation of the extended version over France, with a special emphasis on the Mediterranean region.
The analysis was tested for five parameters (air temperature and humidity, wind speed, rainfall and incoming radiation), using the Météo-France observation network and data of some well instrumented stations. Temperature and relative humidity were well reproduced, presenting no bias, wind speed was also well reproduced, even though its bias was -0.3 m/s. The interpolation from the six hours step of the analysis to the hourly time step was one of the error sources. The precipitation analysis was robust and not biased, its RMSE was 2.4 mm/d. This error was mainly due to the spatial heterogeneity of the precipitation within the geographical zones of analysis (1000 km2). The analysis of incoming solar radiation presented some biases, specially in coastal areas. The results of the comparison with some well instrumented sites were encouraging.
SAFRAN is being run operationally at Météo-France at a real time basis for various applications. In research, among other applications, it is used to feed the SAFRAN-ISBA-MODCOU (SIM) hydrological model with meteorological data and the whole system will be applied to study the effects of climate change over the Mediterranean watersheds of France under the framework of the CYPRIM project.
HyMeX – Hydrological cycle in the Mediterranean Experiment 2010-2020