i'm working with climate data from Global circulation models (monthly averages) so as to analyse the possible future drought frequency for the area. the values from the ensembe models are quite different from the observed values particularly for rainfall and hence i need to perform bias correction. the aim is to compute drought indices (using the data from ensemble models) so as to gauge the impact of climate change on the frequency and intensity of drought. unfortunately i'm a novice in this field and hence i need some assistance.
You get prediction and have observed data, so you have residual or error data. Unless there is a pattern in the errors I don't know what you correct for, you just have bad fit. If you have a pattern you can try to transform data or tweak the model!