Hello,
I have a question about the meaning of field 'time' when downloading data from "ERA5 hourly data on single levels from 1979 to present" (here: https://cds.climate.copernicus.eu/cdsapp#!/dataset/reanalysis-era5-single-levels?tab=form) for "Ensemble Mean" (forecasts).
In that case, 'time' can have values 0:00, 3:00, 6:00, 9:00, etc. But given that the model runs twice a day, at 6:00 and 18:00, should I interpret that 'time' 9:00 is the first step of the 6:00-run (6:00+3h), 'time' 12:00 is the second step, and so on?. And that 'time' 21:00 is the first step of the 18:00-run (18:00+3h)? Would that be correct?
Thanks a lot for your help,
Ricardo.
2 Comments
Kevin Marsh
Hi Ricardo,
Yes the ERA5 data on the CDS are presented in such a way that the 'validity time' is shown as the value of the time coordinate/on the CDS web form. This page explains the relationship between the validity time and the analysis time/forecast step:
ERA5: data documentation
See the section "Date and time specification":
Table 0: the mapping, for forecasts, between MARS date, time and step and the CDS date and time
Hope that helps,
Kevin
Ricardo Aler
Hello Kevin, Table 0 says it all, thanks a lot!!
Regards, Ricardo.