Opened 4 years ago
Closed 3 years ago
#2053 closed help (answered)
Simplest way to run UKCA nudged to 2016 meteorology?
Reported by: | earhg | Owned by: | um_support |
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Component: | UM Model | Keywords: | |
Cc: | Platform: | MONSooN | |
UM Version: | 8.4 |
Description
hi,
I would like to run UKCA in nudged mode for a few months of 2016, ideally June to August. I am happy if the ancillaries from a previous year are used.
I set up run xmmlb, and was able to reconfigure and change the date on the start dump I had for a previous run from year 2000 but then the model run failed (leave file is at /home/hamgo/output/xmmlb003.xmmlb.d17012.t200023.leave on MONSOON) because the ancillaries don't contain data for 2016. The first failure is for sea ice, I expect it would fail on others too.
Is there a straightforward way to force the model to use ancillaries for a different year? I don't mind using sea ice (or other) ancillaries from 2000, I just need the forcing meteorology to be from 2016, and I checked that the era-interim data is present on MONSOON for this (until end September). Or does someone already have ancillary files for 2016 i could use?
Many thanks Hamish
Change History (7)
comment:1 Changed 4 years ago by grenville
comment:2 Changed 4 years ago by earhg
hi Grenville,
Many thanks for the help. I don't know how to use MULE but I was able to change the sea ice and SST ancillaries using xconv and xancil, and the model seemed then to get past the step where the ancillaries are updated, so I assume (or naively hope) the rest are ok. However, the run xmmlb then crashes on the first or second timestep with a seg fault. I tried starting in February rather than June, and tried halving the timestep, but neither of these seemed to work. A sample .leave file is /home/hamgo/output/xmmlb003.xmmlb.d17017.t114430.leave on MONSOON.
Please can you suggest other things I could try?
Many thanks, best
Hamish
comment:3 Changed 4 years ago by earhg
…for example should I request a start dump or restart file to be generated for some month in 2016, so that I can run without a discontinuity in the meteorological forcing between the dump file and the model run (which sounds like the most likely cause for the crash)?
comment:4 Changed 4 years ago by earhg
hi,
Does anyone have any recommendations for this? I should add that I don't have to use UKCA 8.4, any version will do - I just happened to have 8.4 runs to hand as a starting point.
many thanks Hamish
comment:5 Changed 4 years ago by willie
Hi Hamish,
You could try modifying the ancillary reference time in the UMUI. It's at Ancillary and Inpur > In file related options > Ancillary Reference Time. I'm not sure whether you should set it to zero or to the date you want.
Regards
Willie
comment:6 Changed 4 years ago by grenville
Hamish
Is this still a problem?
Grenville
comment:7 Changed 3 years ago by willie
- Resolution set to answered
- Status changed from new to closed
Closed due to lack of activity.
Hamish
It may be simplest to change the dates is the ancillary files (I haven't counted how many there are which will fail for a 2016 run) - there are utilities in MULE which help you to do that, see https://code.metoffice.gov.uk/doc/um/mule/vn1.3/user_guide_basics.html#header-components for example. You'll need UMDP F03 handy while trying this.
Grenville