Bias Correction Error


We have identified a problem in all of the bias-corrected data (all mbcn-gridMET and mbcn-Daymet files) in the NA-CORDEX archive.

There is an offset of approximately 1 month in the data values relative to the time coordinate. Essentially, January model data was bias-corrected to match February observations, February was corrected to look like March, and so on.

We do not yet know the cause of this problem. We are working to find it, and will then redo the bias-correction and republish the data.

This problem went unnoticed until now because it only shows up clearly in the monthly distribution of values averaged over a medium-sized region. At shorter time scales and over smaller regions, the problem is hidden by variability, and at longer timescales and over larger regions, it's hidden by the effects of the seasonal cycle and topography, respectively.

For more details, contact Seth McGinnis (

Our apologies for any inconvenience that has resulted.