Zheng, X and C.S. Frederiksen, 1999 : Validating Interannual Variability induced by Forcing in an ensemble of AGCM Simulations. J. Climate, 12, 2386-2396.
Formulae for estimated variability for simulated data
Formulae for estimated variability for observed data
Formulae for estimated covariances and correlation coefficients
Example
New Zealand Surface Temperature Variances