A functional group may get larger, more or less fluorescent during a certain months. This interseasonal variability will be species specific and zone specific. But it affects where the cytogram boundaries lie. One way to train a better model would be to have the month as a predictor. This is risky though, as we start to mix the particle's physical characteristics with predictors that may cause odd behaviours like being more likely to predict a bloom species at any particle in the cytogram just because it is april.
...Perhaps we could have a different model trained for each month?
This one is a "further research" question.