meteorological basis

The driving of the precipitation treatment was based on local climate data 1960-2010 (WMO standard, temperature and precipitation, 1960-2003 St Michel l’Observatoire/ Meteo France 04192001; 2003-2010 Dauphine/ Meteo France 04068001 - on and close to the property of the Observatoire de Haute Provence OHP, respectively). Wind data was evaluated as based on a Vaisala multisensor at the OHP, installed since 2008.

 

An increase in mean annual temperature had been observed and was linearly interpolated between 2000 and 2100, which results in a mean annual temperature of 12.4 and 14.8°C respectively (Fig. 1a). The relationship between mean annual temperature and the sum of annual precipitation explained 12% (R²) of the variation (Fig. 1b). This (negative) relation improved considerably to 19% when beginning the interval for the mean annual temperature was set to the dry season (15th August instead of 1st January). However, this also increased the negative slope of relationship (Fig. 1c). The sum of precipitation was (linearly) interpolated to year 2100 and the mean result of the two approaches was 450 mm per year. Compared to the year 2000 this corresponds to a 40% reduction in annual precipitation.

Climograph for the reference plot and the treatment