Updated derivation test recipe

[schlunma]

Updated the derivation test recipe with new variables and CMIP6 data for testing of ESMValGroup/ESMValCore#754.

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Related to ESMValGroup/ESMValCore#754

[bouweandela]

Do you know if there is a reason why the variables are in separate diagnostics sections? I think they could simply be merged. Or maybe just two diagnostic sections, one for CMIP5 and one for CMIP6?

[schlunma]

I think we had some issues back then when two different derived variables needed the same variables as requirement within the same diagnostic, but I'm not 100% sure. I merged all the diagnostics and the recipe still works, so it is much simpler now.

[bouweandela]

Looks good! @mattiarighi Could you please test?

[axel-lauer]

I am running this recipe now and will take a look at the output.

[axel-lauer]

I ran the recipe_preprocessor_derive_test.yml and as far as I can tell the output looks fine. But I noticed 2 things that look like bugs to me. These two bugs are not related to this PR or ESMValGroup/ESMValCore#754, but would probably be best addressed in ESMValGroup/ESMValCore#754 as it contains already several fixes to other derivation scripts. The 2 bugs are:

1. vegfrac: the derivation script calculates "vegfrac = 1. - baresoilfrac" with baresoilfrac given in % (according to CMIP5/6 CMOR tables). This seems wrong and should be "vegfrac = 100. - baresoilfrac" instead.
2. ohc: in CMIP5, the input variable thetao is given in K while in CMIP6 it is given in degC (according to the CMOR tables). Given how ohc is calculated, I think a conversion from degC to K is needed for CMIP6 data before calculating the ocean heat content.

@schlunma : Maybe you could briefly look into those two bugs? That does not look like a big thing to fix.

Other than that, thumbs up for this PR and ESMValGroup/ESMValCore#754!

[schlunma]

Thanks for testing @axel-lauer! I will include the small changes into ESMValGroup/ESMValCore#754.

[axel-lauer]

This looks all good, just 1 small suggestion to make testing of variable ohc easier.

[bouweandela]

This was reviewed/tested as part of ESMValGroup/ESMValCore#754.

[bouweandela]

@axel-lauer I think this can be merged, right? If so, can you please approve?

[axel-lauer]

Thumbs up for merging.