[ferret_users] calculating extreme january temperatures

[Hein Zelle <hein.zelle@xxxxxxxxxxxxx>]

Dear Ferret users,

I'm getting stuck with an analysis problem - does anyone know a
solution?  Given an hourly time series (e.g. 10 years), I would like
to calculate the maximum value that occurs in any january month of the
whole time series.  Same for february, march, etcetera.

I can calculate the climatological monthly mean and anomalies without
problems using the climatological_axes.  I can calculate the maximum
temperature in each january month separately by doing

  ! define a monthly_axis for the full 10 year period
  let monthly_max_data = hourly_data[t=monthly_axis@max]

Now I'm stuck.  How do I get the maximum of the individual january
maxima?  I can compute the climatological average january maximum by
using monthly_max_data[gt=month_irreg@mod], but I can't use @mod and
@max at the same time.

I would like to write 

  let extreme_max = monthly_max_data[gt=month_irreg@max] 

but ferret doesn't like that.

Any hints will be appreciated.
Thanks,

	Hein


-- 

Dr. Hein Zelle
Senior consultant meteorology & oceanography
BMT ARGOSS

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