monthly:anomaly: Calculate monthly anomalies based on a baseline period.

The anomaly is derived by first calculating the climatological monthly mean for the given baseline period. Monthly means are then calculated for each year and the anomaly is calculated compared with the baseline mean. This is calculated separately for each file in a multi-file dataset.


baseline (list) – Baseline years. This needs to be the first and last year of the climatological period. Example: a baseline of [1985,2005] will result in anomolies against 20 year climatology from 1986 to 2005.


If you wanted to calculate a monthly anomaly where values are compared with the climatological monthly mean for the years 1950-1969, you would do this:

>>> ds.monthly_anomaly(baseline = [1950, 1969])