How good is the GTC site?

Water vapour metardeements (poster by Kidger et. al.) show that the GTC site is good.

• Globally some 10% of nights have <1-mm of water
• Runs of up to 4 consecutive nights <1-mm
• Runs of up to 10 consecutive nights <2-mm
• Winter median water vapour approx. 2-mm

The GTC site is good even for 20-microns and in the wings of the 10-micron window where the atmosphere is critical.

CanariCam will have narrow filters tuned to lines and to the best sub-windows.