How do I create a daily climatology for a time series?
Daily data series with climatology
We need the length of the "climatological year". This can be obtained from the climatological_axes data set. Then define a modulo axis with units of days, and regrid the time series data using the @mod transformation to this axis. See the command reference for an explanation of the qualifiers to the DEFINE AXIS command.
yes? DEFINE AXIS/T/=0:365.2425/EDGES/NPOINTS=365/T0=1-JAN-0001/UNITS=DAYS/MODULO
tdaily
yes? LET dailyclim = udaily[GT=tdaily@MOD]
The figure above was created with:
! Get the length of a climatological year; 365.2425 days
yes? USE climatological_axes
*** NOTE: regarding climatological_axes.cdf ...
*** NOTE: Climatological axes SEASONAL_REG, MONTH_REG, AND MONTH_IRREG
defined
yes? LIST/PRECISION=7 T[GT=MONTH_IRREG,L=13]
- T[GT=MONTH_IRREG,L=1]
T[GT=MONTH_IRREG,L=13]
- T[GT=MONTH_IRREG,L=1]
TIME:
15-JAN 17:49
365.2426
yes? CANCEL DATA climatological_axes
! use the length of the "climatological year" to define a daily axis
yes? DEFINE AXIS/T=0:365.2425/EDGES/NPOINTS=365/T0=1-JAN-0001/UNITS=DAYS/MODULO tdaily
! get some data to use for example. Manufacture some daily data...
yes? USE monthly_navy_winds
yes? DEFINE AXIS/T=16-JAN-1982:18-DEC-1992:1/UNITS=DAYS tnavydaily
yes? LET udaily = uwnd[GT=tnavydaily]
! define the daily climatology
yes? LET dailyclim = udaily[GT=tdaily@mod]
! sample plot
PLOT/X=180/Y=0 udaily
PLOT/X=180/Y=0/OVER/NOLABEL/T=16-Jan-1982:18-DEC-1992 dailyclim
Last modified: Jun 30, 1999