It’s time for using higher time resolution.
Defining time axis with daily time scale is the point.
ref1(daily), ref2(for monthly)
1. Defining a daily axis and calculating daily climatology
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]
2. Also you can calculate anomaly
yes? let anomaly = udaily – dailyclim[gt=udaily@asn]
So, Simple 🙂
Yi at Jeju Island (NIMS, Korea) 