Opened 11 years ago

Closed 10 years ago

#336 closed help (fixed)

Regional modelling with HadCM3

Reported by: iamack Owned by: lois
Component: UM Model Keywords: Regional modelling
Cc: Platform:
UM Version: 4.5

Description

Hello,

I'm planning to run HadCM3 vn4.5 on our local Edinburgh cluster to generate boundary conditions for subsequent runs of a higher-resolution, regional version of the model. I have a couple of general queries:

1) Is the regional UM always run in atmosphere-only mode? (I tried
configuring the 'LBC's out' umui panel for both the atmosphere and
ocean in HadCM3 but only atmospheric LBC's appeared.)

2) Is there any standard method for generating SST and sea-ice
ancillary files on a LAM region from HadCM3 output for subsequent
use in an atmosphere-only regional run?

Regards,

Ian

Change History (5)

comment:1 Changed 11 years ago by lois

  • Owner changed from um_support to lois
  • Status changed from new to assigned

Hello Ian,

The only information I remember that we have about regional coupling is here

http://ncas-cms.nerc.ac.uk/index.php/um-faq/132-how-do-i-do-regional-coupling

It might not be quite what you want to do but it is a place to start.
I will investigate further.

We have been discussing how to generate ancillaries for vn4.5. Because it has been
such an infrequent event Grenville has been creating these from the old CAP (Central
Ancillary Program) software. If there are going to be more requests we will have to
set up the old CAP system to run alongside the new CAP system. However there is some
information about a 'hand-made' mechanism on the regional coupling web pages which
may be sufficient until we set up a system.

Lois

comment:2 Changed 11 years ago by lois

Hello Ian,

I have been asking around various groups who have used vn4.5 for climate studies and both PRECIS and UKCIP (both vn4.5 based) use/used climatological SSTs. I can find noone who has used the ocean LBCs (both inside and outside the Met Office) and there was a suggestion that even if it is an option in the UMUI it was not used or possibly usable.

If the route you want to take means that you want to be able to easily generate SSt's then we will accelarte the installation of the old CAP service to help you do this.

Lois

comment:3 Changed 11 years ago by iamack

Thanks Lois,
I had suspected that oceanic LBCs weren't being used, but I just wanted to check. My plan then is to run the regional model uncoupled, using atmospheric LBCs from HadCM3 along with SST and sea-ice ancillaries created from the same HadCM3 run. This means I'll be generating vn4.5 LAM SST/ice ancillaries from HadCM3 output on a fairly regular basis. Can the CAP service be used to create ancillaries from supplied UM output files? (I don't see any way to do this on the current web interface.) If not, then it may be a better option for me to use Xancil to create the ancillaries from my HadCM3 data. The stumbling block there is sensibly interpolating from the global to the high-resolution regional grid, but I can experiment with that. I'm aware that I'll probably also need to create soil and vegetation ancillaries for my LAM grids, but I haven't yet reached that problem.

Ian

comment:4 Changed 11 years ago by lois

Hello Ian,

There are scripts to extract regional ancillaries from global files. PRECIS does this with ERA data. The scripts, extracted from PRECIS, are a bit cobbled together but there are people who have used them so I am sure we can get them for you to try.

We will keep in mind you need the old CAP the new one will not deal with vn4.5.

Lois

comment:5 Changed 10 years ago by lois

  • Resolution set to fixed
  • Status changed from assigned to closed
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