Add glomap/UKCA dust mode variables

[mo-hlawrence]

This PR adds in new aerosol variables needed for the Met Office LFRIC forecast model. These are the number and mass fractions for the two dust modes in the UKCA/GLOMAP aerosol model.

[climbfuji]

Should this be "accumulation" or "accumulated"? Same for 456 and then in the other file, of course.

[mo-hlawrence]

There are 2 dust modes in UKCA/GLOMAP - coarse mode and accumulation mode. So 'accumulation' refers to this mode. That's my understanding but I can double check again with model experts if you feel strongly it should be accumulated.

[climbfuji]

I was just curious, but if the mode is called "accumulation" then that is fine with me. Thanks!

[mo-hlawrence]

FYI To be on the safe side I just double-checked with one of the scientists working on glomap and they said that accumulation is the right term for the mode.

[gold2718]

No issues

[ss421]

Thankyou for the addition.

[jeromebarre]

I wish I was added during the review.
I have one request please:

Change this:

`number_fraction_of_coarse_aerosol_particles_in_air`: Number fraction of coarse mode dust aerosol particles
    * `real(kind=kind_phys)`: units = 1
* `number_fraction_of_accumulation_aerosol_particles_in_air`: Number fraction of accumulation mode dust aerosol particles
    * `real(kind=kind_phys)`: units = 1

To this as I believe the number fraction here is the same as a mole fraction but brings more clarity of what this fraction really is:

`mole_fraction_of_coarse_aerosol_particles_in_air`: Number fraction of coarse mode dust aerosol particles
    * `real(kind=kind_phys)`: units = mol mol-1
* `mole_fraction_of_accumulation_aerosol_particles_in_air`: Number fraction of accumulation mode dust aerosol particles
    * `real(kind=kind_phys)`: units = mol mol-1

[jeromebarre]

Alternatively, if number_fraction has to be kept then at least have the unit changed to molecules molecules-1 or more precisely in the dust case particles particles-1. We just want to make sure that if someone needs to perform unit conversion it is possible.

[climbfuji]

I wish I was added during the review. I have one request please:

Change this:

`number_fraction_of_coarse_aerosol_particles_in_air`: Number fraction of coarse mode dust aerosol particles
    * `real(kind=kind_phys)`: units = 1
* `number_fraction_of_accumulation_aerosol_particles_in_air`: Number fraction of accumulation mode dust aerosol particles
    * `real(kind=kind_phys)`: units = 1

To this as I believe the number fraction here is the same as a mole fraction but brings more clarity of what this fraction really is:

`mole_fraction_of_coarse_aerosol_particles_in_air`: Number fraction of coarse mode dust aerosol particles
    * `real(kind=kind_phys)`: units = mol mol-1
* `mole_fraction_of_accumulation_aerosol_particles_in_air`: Number fraction of accumulation mode dust aerosol particles
    * `real(kind=kind_phys)`: units = mol mol-1

Hi Jerome, now that we have a std names governance team, it's up to your organization's representative to inform people about changes and adding them as reviewers.

[svahl991]

Hi Jerome, now that we have a std names governance team, it's up to your organization's representative to inform people about changes and adding them as reviewers.

Sorry @jeromebarre @climbfuji , I guess I dropped the ball on this. Still learning my responsibilities as part of the governance team since I just started.

[mo-hlawrence]

@jeromebarre I'm on annual leave until 2 June now but will address this when I get back.

[mo-hlawrence]

I will set up a new PR to make the change you requested @jeromebarre. Do you have a preference for mole_fraction with mol mol-1 units or number_fraction with particles particles-1 units? If not I might just go for the latter. It seems like they are numerically the same anyway.