Nudging capabilities in ACCESS

Atmosphere Unified Model
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ACCESS-CM2/AM2 can be nudged with reanalysis meteorology (e.g. ERA5). Constraining the meteorology is useful in several applications (e.g. comparing model to composition measurements, sensitivity tests etc).

There are a few steps to make this more widely available.

  1. write-up instructions to add nudging to CM2 [Matt W]
  2. update CM2 release package nudging code with some minor changes (back-ported from later release) [Atmos team? Releases team?]
  3. retrieve, process and store ERA5 data. Likely requires approval of SAC, due to scale of storage required.

I’m happy to co-ordinate this request. We will need to estimate the storage required as part of this request, and what levels / resolution can be made available.

Are there any other potential users of this data and/or nudging? It would be good to know how wide the audience is for this feature. Anyone interested please reply and follow this topic!

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For nudging - my initial numbers are:

12.6G/month for the initial download.
We convert to N48 at 3hrs, which results in 96M per day…

I have a script which @Fraser gave me that downloads the ERA5 stuff and another to do the conversion. So a lot of the ‘work’ is already done - just needs a home and maintenance.

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Now marked with ‘help’ tag

Re: step 2 of first post

Can I request that the dev branch:
main/branches/dev/mohitdalvi/vn10.6_nudge_with_era_plev@69770

is merged into the CM2 package branch:
main/branches/pkg/Rel/vn10.6_access_cm2

The dev branch adds missing functionality to convert from ECMWF pressure levels to UM model levels as part of the nudging process. Including this branch will simplify the instructions to add nudging.

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Draft instructions for adding ERA-I nudging. The data for this is already available for the full ERA-I time period.

ERAI_nudging.pdf (131.4 KB)

Anyone willing to test in AM2/CM2?!

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@sonyafiddes and @Matt_Woodhouse - Re: ERA5 data storage request in Item 3 of Nudging capabilities in ACCESS post, ACCESS-NRI is currently asking each of the working groups about their reference dataset needs for the 2023/2024 financial year. It would be great if you could post your request on this topic with a clear indication of the storage required before the next Atmosphere Working Group meeting on 19.10.2023.
Based on this feedback from each of the Working Groups and our funded capacity, prioritisation of the datasets supported by ACCESS-NRI will occur.

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I know this is an old topic but I just wanted to say we are going to close this. This dataset has been flagged as well to be supported as a data collection by ACCESS-NRI. We will handle this with the other requests for data collection instead of through this topic.

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