Application of climatological monitoring for the candidate CTA site at Izana (Tenerife)

The location of Izana (Tenerife, Canary Islands) has been proposed for hosting the Cherenkov Telescope Array (CTA). To support the site-testing campaign, we obtained climate normals from the 10 year long series recorded at Izana by the atmospheric Observatory (CIAI), we have also compared the wind regime with a simultaneous 10 year database at the neighbouring astronomical site (OT) and with the available simultaneous preliminary wind data for the proposed CTA location. The results show a smooth temperature profile with sporadic but moderate extremes and a low daily (24 h) temperature range. Rainfall is extremely sporadic (287 mm/y) with low intensity. Wind speed and gusts show high stability and moderate values and dispersions. The lowest winds are in the summer. Speed episodes greater than 100 km/h are very rare and 11 data points have been recorded with gusts above 150 km/h over the 10 years. The dominant wind direction is WNW. There is an excellent correlation for wind speed between the CIAI and OT, with a slight difference in the dominant wind direction (N versus WNW). The wind data recorded directly at the CTA location also show very good correlation in trends, the wind speed at the CTA site being approximate to 24% lower. The dominant wind direction at the CTA site is NW.