Hi dear all!
I am sorry for my post, since I found that some thing similar has been published here (ERA5: how to calculate daily total precipitation:ERA5: How to calculate daily total precipitation).
Although it seems that the solution has been explained in that post, I would like to be sure if I am really doing the things (accumulating ERA5 precipitation for each day of the year) correctly.
After retrieving the data (Jan 1, 1979 to Dec 31, 2018) from CDS, I have in the input file 24 houly steps (0, 1, 2, 3, 4,..,23) for each calendar day starting from Jan 1 to Dec 31 of each considered year.
As far as I know and from the post mentioned (ERA5: how to calculate daily total precipitation:ERA5: How to calculate daily total precipitation) the accumulated precipitation for Jan 1, 1979 is obtained by summing the steps 1, 2,...,23 of Jan 1 and step 0 of Jan 2. It means that the step 0 of Jan 1, 1979 is not included in calculation of the total precipitation for that day. For calculation of total precipitation for Jan 2, 1979 we use also the steps 1, 2, 3,...,23 of that day plus step 0 of Jan 3 and so on.
I am doing all the operations through CDO operators as ilustrated bellow:
cdo -f nc copy out.nc aux.nc
cdo -delete,timestep=1, aux.nc aux1.nc
cdo -b 32 timselsum,24 aux1.nc aux2.nc
cdo -expr,'ppt=tp*1000' -setmissval,-9999.9 -remapbil,r240x120 aux2.nc era5_ppt_prev-0_1979-2018.nc
The problem raises for Dec 31 of last year (2018) in may sample as I have not retrieved the step 0 of Jan 1, 2019 which should be used in calculation of total precipitation for Dec 31 according to explanation above.
In this regards, i started wondering if I am doing correctly or no. After googling for many time, I found the above mentioned ECMWF post (ERA5: how to calculate daily total precipitation:https://confluence.ecmwf.int/display/CKB/ERA5%3A+How+to+calculate+daily+total+precipitation). Of course I tried to run the code as is explained in the blog, but it suggests that deffinitively I should have the step 0 of Jan 1, 2019 for my case.
So I have four questions:
1. Is it correct what I am doing?
2. Is it correct exluding the step 0 of Jan 1, 1979 from the calculation of total precipitation for that day (Jan 1, 1979)?
3. Is it correct that for precipitation of Dec 31, 2018 I need to retrieve the step of Jan 1, 2019?
4. Is it aplied for other variables, such wind at any pressure levels?
Thank all of you in advance for your guidance and quickly replay.
Sincerely,
KCS