[Thread Prev][Thread Next][Index]

[ferret_users] Re: no-leap? "days since 0001-01-01 00:00:00"



Dear Ferreters,

I asked this question a few days ago.  Ansley kindly looked at the original data and solved the mystery.

I was wondering what this time axis is:  It starts from "01-JAN-0001 00:00:00" and it doesn't include any CALENDAR attribute.  I paste the output from "ncdump -h" below.

I thought the default calendar is Gregorian or similar, but the timeseries doesn't include any leap year.  It covers from 1990-01-01 to 1997-12-31 but there is no Februrary 29 in the listing of  list t[gt=eta] .

Without a CALENDAR attribute, Ferret assumes the Proleptic Gregorian calendar.  So, there should be leap years.

The trick is that the original daily data increases the timestep from 1 day to 2 days between the February 28 and March 1 of the leap year!

Instead of this trickery, the creator of the dataset should have set the calendar attribute to "NOLEAP" and used a uniform timestep of 1 day throughout. . . .

(This is a climatological simulation, a numerical simulation under a repeated annual cycle, so the original calendar is likely to have been the no-leap calendar.)

Ryo


[Thread Prev][Thread Next][Index]
Contact Us
Dept of Commerce / NOAA / OAR / PMEL / Ferret

Privacy Policy | Disclaimer | Accessibility Statement