Re: seasonal climatology

```Alice,

You're right, a seasonal climatology with l=1 centered on 15-Feb does average
(Jan, Feb, Mar) at that point.  You can modify the time axis to center the
averaging in January instead with the following script.  Let me know if this
doesn't do what you are looking for.

Regards,

Jerry Davison

--------------------

use climatological_axes.cdf

def grid/t=seasonal_reg season_old
sh grid season_old

! Move the time axis back 31 days -- time units are hours
let tnew = t[g=season_old] - 24*31

def axis/from_data/t/name=tseason_new/units=hours/t0=1-jan-0000/modulo tnew
def grid/t=tseason_new season_new
sh grid season_new

! Test the new axis
set data monthly_navy_winds
let vwnd_late80s = vwnd[d=monthly_navy_winds,T=1-jan-1986:31-dec-1989]
set reg/x=50w/y=40n

plot/sym=18/line/l=1:12 vwnd_late80s[gt=season_new@mod],
vwnd_late80s[gt=season_old@mod]

On Jan 26,  4:14pm, Alice Larkin wrote:
> Subject: seasonal climatology
> Hello, I am computing season climatologies using
[gt=seasonal_reg@mod,d=1,l=1] and I noticed that the dates given on the plots
are 15th Feb for l=1, 15th May for l=2, 15th Aug for l=3 and 15th Nov for l=4.
Does that mean that the seasons
> are averaged as Jan,Feb,Mar for l=1,  Apr,May,Jun for l=2, etc.
> or is it as I would expect, eg Dec,Jan,Feb for l=1  Mar,Apr,May for l=2 etc?
> Alice
>-- End of excerpt from Alice Larkin

--
davison@pmel.noaa.gov

```