Hi Ansley,
I am trying to do “Leaving only JJA SLP data”
from a monthly NCEP SLP data “slp.mon.mean.nc”. I have looked at http://ferret.pmel.noaa.gov/Ferret/FAQ/analysis/seasonal_masking.html.
But I could not get a solution because of my poor ferret skills. Could
you please give me a help here?
Thanks,
Yun
From: Ansley Manke
[mailto:Ansley.B.Manke@noaa.gov]
Sent: Wednesday, 20 September 2006
3:02 AM
To: Li, Yun (CMIS, Floreat)
Cc: oar.pmel.ferret_users@noaa.gov
Subject: Re: [ferret_users] How
can I produce a time series of JJA averages (or other intervals) from a monthly
time series?
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.
http://ferret.pmel.noaa.gov/Ferret/FAQ/analysis/seasonal_masking.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 http://ferret.pmel.noaa.gov/Ferret/FAQ/analysis/climatologies.html
Ansley
Yun.Li@csiro.au wrote:
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?"
http://ferret.wrc.noaa.gov/Ferret/FAQ/analysis/annual_from_monthly.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 ansley.b.manke@noaa.gov
7600 Sand Point Way NE, Seattle WA
Phone 206-526-6246, FAX 206-526-6744