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Struggling to get output frequency for hourly data

HazelMooney

Hazel Mooney
New Member
What version of the code are you using?
CLM4.5, CESM2.2

Describe your problem or question:
I am trying to generate hourly data for BVOC emissions from the CLM. I had my settings in user_nl_clm as: hist_mfilt = 720 hist_nhtfrq = -1
I did this following several examples in CESM documentation using -1 for hourly data. However, this has not generated a data point per hour, i still only have 1 data point per month (720 hours).
I am seeing mixed messages online about whether using nhfrq <0 causes averaging or not.
The only examples i can find for hourly output use -1, but i do not want averaging, i want a data point for every hour.
I can see that the model timestep is 1800 seconds = 30 minutes.
Please can you advise?

Do i need to instead use hist_nhtfrq =2 for output per 2 timesteps ?
 

HazelMooney

Hazel Mooney
New Member
I would like to add that for previous runs i did the following
for daily data i used hist_mfilt = 1 hist_nhtfrq = -24 for 1 file per day
for monthly data i used hist_mfilt = 1 hist_nhtfrq = 0
STOP_OPTION has been set to nyears
 

slevis

Moderator
Staff member
@HazelMooney
Nothing stands out as wrong to me in what you've done, so I would try a few things until I got something that worked if I were you. For example...

Since you wrote that
hist_mfilt = 1 hist_nhtfrq = -24 for 1 file per day worked, then I would try this next:
hist_mfilt = 1 hist_nhtfrq = -1 for 1 file per hour
If this doesn't work, then I'm at a loss. Whereas if this works, then you can attempt other mfilt values until you get one that you like.
 

slevis

Moderator
Staff member
Oh, but your other idea should also work
hist_mfilt = 1 hist_nhtfrq = 2 for 1 file per hour
and again, assuming that this works, then change mfilt to something else that works and that you prefer.
 

HazelMooney

Hazel Mooney
New Member
Thank you for your reply @slevis
I will give that a try.

Another example that might help, i used hist_mfilt = 24 hist_nhtfrq = -1 i got 1 file per day. For 1 year this is equivalent to an array of 744 (time) by 384 and 576 coords. With chunk size showing as 24. Giving me 1 value every hour.

However for the output using hist_mfilt = 720 hist_nhtfrq = -1 i got 1 file per month as expected. But the array is showing as 2 by 384 by 576 for data variables. Chunk size showing at 2. I’m not sure if this is helpful in shedding any light?
 
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