[CF-metadata] approval of standard_names for aerosols and chemistry for HTAP

[Jonathan Gregory]

Dear Christiane

Thanks for thinking about it. I agree that the "tendency of content" is the
most consistent naming. You could simplify these slightly:

> emission_at_the_surface
> dry/wet_deposition_to_the_surface

as "surface_emission" and "dry/wet_deposition", which always means "surface"
(doesn't it)? Certainly I would think names of tendency_of_X_of_Y_due_to_
surface_emission would be fine. The main question with whether the chemistry/
aerosol community will be happy with these longer names. If you think they
are, that's OK.

Best wishes

Jonathan