#2976 closed help (answered)

Using CLASSIC instead of GLOMAP-MODE aerosol in UKESM-AMIP

Reported by: yaweiqu Owned by: um_support
Component: UM Model Keywords:
Cc: Platform: Monsoon2
UM Version:



I'm trying to do some simulations related to the aerosol-photolysis feedback in 2014. Since the GLOMAP MODE aerosols haven’t been coupled with the Fast-JX photolysis but the sulfate aerosols in CLASSIC scheme have, I switched off the GLOMAP MODE and switched on the CLASSIC in a UKESM-AMIP nudging suite (u-bl031). I’m unsure whether I did the right thing when switching the aerosol scheme. Is there a guide or a default CLASSIC suite for me to learn?

So far I have found the emission files for CLASSIC aerosol from /projects/um1/ancil/atmos/n96e/classic_aerosol/cmip5/1970_2010/v1, but they are only for 1970-2010. Could you please tell me the emission file directory for CLASSIC scheme (2014-)?

I also got an error relating the CLASSIC prognostics initialise.

?  Error code: 30
?  Error from routine: RCF_RESET_DATA_SOURCE
?  Error message: Section   0 Item   101 : Required field is not in input dump!
?  Error from processor: 20
?  Error number: 2

Do you know where I can find the startdump for this suite? I’ve found that Alan has done a similar thing (https://code.metoffice.gov.uk/trac/roses-u/changeset/96590) but the GA6 startdump files he used were not for 2014 and not on MONSoon.

Thank you in advance.


Change History (7)

comment:1 Changed 18 months ago by willie

Hi Yawei,

You can find CLASSIC suites by typing CLASSIC in the Rose search window. It is probably a good idea to contact the owner to find the status of specific suites before proceeding too far.

The documentation for the CLASSIC scheme can be found at https://code.metoffice.gov.uk/doc/um/latest/papers/umdp_020.pdf.

I don't know if the ancillary files for 2014+ even exist.

If you change the science configuration, the original start dump may be inappropriate. In this case it is saying a field is missing. You may be able to set the field to zero or initialise it from an ancillary file using the reconfiguration.


comment:2 Changed 18 months ago by willie

Sorry that should be "Rosie search window".

comment:3 Changed 18 months ago by luke

Hi Yawei,

The use of CLASSIC aerosols won't be supported in UKESM1 I suspect, as CLASSIC has not been used as the default aerosol scheme for GA7 (the base atmosphere configuration used). While it would likely be possible to turn it on the model will not have been tuned and may behave strangely. Similarly no CMIP6 emissions will have been generated for this configuration. Changing the aerosol scheme is quite a large change to this model.

What exactly are you trying to do with your configuration? It may be possible to get the same result a different way.


comment:4 Changed 18 months ago by yaweiqu

Hi Willie and Luke,

Thanks for your reply.

I've searched the Rosie and found a few CLASSIC configurations with GA7.0, UM11.1. I'll try to contact the owner as you suggested.

I am trying to study the changes in tropospheric O3 caused by the interaction of aerosols with photochemistry. However, there is no coupling between the GLOMAP-MODE scheme and the FAST-JX photolysis (https://code.metoffice.gov.uk/trac/um/ticket/2689). I've contacted Michael Hollaway and he is still working on getting the updates into the model, he told me that the CLASSIC aerosol scheme is currently coupled to Fast-JX photolysis (sulphate only at present). So I'm trying to use the CLASSIC scheme to study the effects of aerosols until the updates are ready. If it's not likely to switch to the CLASSIC scheme in the current model, is there another possible way to get the result?

Thank you very much.


comment:5 Changed 18 months ago by luke

Hi Yawei,

If there are GA7 suites with full CLASSIC then it should be possible to get them working with chemistry as you want, although there might be some "unknown unknowns" that need dealing with. You'll likely need to make up the CMIP6 emissions yourself though unless the owner of these suites has done this.

Michael would have been the person I suggest you contact, but as you have already done this then it sounds like continuing as you are is the best course of action at the moment.


comment:6 Changed 18 months ago by yaweiqu

Hi Luke,

Many thanks for your help! I'll test the GA7 suites and see what happens.


comment:7 Changed 16 months ago by grenville

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