Opened 5 months ago

Closed 6 weeks ago

#2119 closed help (answered)

Running UKCA from a different start date

Reported by: ajamieson Owned by: um_support
Priority: normal Component: UKCA
Keywords: Cc:
Platform: UM Version: 7.3



I'm trying to run vn7.3 UKCA Trop-Isop (xfvfd) (my job: xmxi) from 1950 to 2000. I have netCDF files for my tracers surface emissions (for longer than those dates) and I'm following the website and documentation to turn this into an ancillary files with the other emissions.

Earlier Luke mentioned changing the start date and reference time might cause problems, so I'm wondering how I go about making a job run from these dates, i.e. UMUI changes and the changes exiting emissions and setting etc.

Thanks for any advice,

Change History (5)

comment:1 Changed 4 months ago by luke

Hi Andrew,

Sorry for not responding to this earlier. Is this still an issue?

If the inputs into the model are all climatologies rather than timeseries (as should be the case with this job I believe, but you can check - the best to check are the SSTs as if these are just for 12 months then usually everything else would be too) then the date doesn't actually matter - you could run it out to the year 3000 and beyond, but so long as the files are representative of e.g. present day, then that would be fine.

I'm not sure if you're wanting to run with a timeseries, or just run for 50 years. Can you clarify?

If this is no longer an issue, please let me know and I'll close this ticket.

Many thanks,

comment:2 Changed 3 months ago by ajamieson

Hi Luke,

I would be running a time series, my emission data spans from 1850-2000 but a run from 1950 is all I need. I have shorter experiments I could run but those would be climatologies.


comment:3 Changed 3 months ago by luke

The SSTs in your job start in 1951/01/01 and end in 2006, so you won't be able to run earlier than that (indeed, starting on 1st January at midnight could conceivably cause problems). Your sulphur-cycle starts in 1850 and ends in 2000, so it looks like you could do 1951-2000.

However, the current UKCA emissions in xfvfd are year 2000 timeslice. When you made your new 1950-2000 emissions, did you do it for all species? If so, that would be fine (although the aircraft emissions would be a problem as they would be too high for the 1950s - you could instead use files from /work/n02/n02/ukca/ANCILS/CCMI/AirEms although covering 1950-2000 would need two files (1950-1960, & 1960-2000), so you would probably want to make up the aircraft emissions again. You can easily do 1960-2000 without needing to change anything or make anything else up I think.

The reference date for meaning is 1900/12/01 (Atmosphere -> Control -> Post-processing, Dumping & Meaning) which is fine, but you'll need to change the start date and run length in Input/Output Control and Resources -> Start Date & Run Length Options.

Does this make sense? Is 1951 - 2000 acceptable?

comment:4 Changed 3 months ago by ajamieson

Hi Luke,

Thanks for this, it does make sense and is really helpful. In fact 1960-2000 would be great as I have another dateset from 1960.

Thanks again.

comment:5 Changed 6 weeks ago by grenville

  • Resolution set to answered
  • Status changed from new to closed
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