Re: [ferret_users] How can I produce a time series of JJA averages (orother intervals) from a monthly time series?

[Ansley Manke <ansley.b.manke@xxxxxxxx>]

Hi Yun,
Here are a couple of FAQ's for you to look at - if one of these is the kind of thing you want to do. If you need help applying the ideas, please write back to the users list.

This FAQ makes a "seasonal mask" to pick out data from part of each year.  It does the problem with units of time in days; but if you're starting with monthly data you could do a similar thing with months, with JJA being months 6,7,8.  You could combine this with the COMPRESS functions to remove the missing data and leave only the JJA data.
../../faq/creating-seasonal-masks.html

Or, did you have in mind a climatology, averaging all of the JJA data for all years, and returning just one point?  In that case, see "climatology, creating" in the Users Guide, and this FAQ for more examples ../../faq/how-do-i-calculate-climatologies-and-climatological-anomalies.html

Ansley

Dear Ferreters,

 

I am trying to produce a seasonal time series (such as JJA time series) from a monthly time series.

 

There is an example from the Ferret FAQ on "How can I produce a time series of annual averages (or other intervals) from a monthly time series?"

 

../../faq/averaging-to-regrid-a-time-series.html

 

I would be most grateful if you can let me know how to produce a seasonal averaged time series (such as June-July-August average time series) from a monthly time series by modifying the code used to produce annual time series in the above web page, that is,

 

     yes?  SET DATA monthly_navy_winds

     yes?  DEFINE AXIS/EDGES/T0=1-jan-1900/UNITS=days tann82_92 = DAYS1900(X[i=1982:1993:1],1,1)

     yes?  PLOT/X=180/Y=0 uwnd

     yes?  PLOT/X=180/Y=0/over uwnd[gt=tann82_92@ave]     ! the above plot

 

 

 

Thanks,

 

Yun Li

CSIRO, Australia

-- 

~>   ~>   ~>   ~>   ~>   ~>   ~>   ~>   ~>   ~>   ~> 

Ansley Manke, NOAA/PMEL   
7600 Sand Point Way NE, Seattle WA
Phone 206-526-6246,  FAX 206-526-6744