[FEATURE REQUEST] Provide climatology option for lightning NOx

[msulprizio]

@ltmurray has already provided climatology files for lightning in https://github.com/geoschem/geos-chem/issues/279#issuecomment-646120009. These files are currently available at:

• http://geoschemdata.computecanada.ca/ExtData/HEMCO/OFFLINE_LIGHTNING/v2020-03/MERRA2/CLIM/
• http://geoschemdata.computecanada.ca/ExtData/HEMCO/OFFLINE_LIGHTNING/v2020-03/GEOSFP/CLIM/

Disclaimers from the README files:

These fields are provided for user convenience when simulating more recent periods than current lightning availability. However, users should always first check with Lee Murray via e-mail to [email protected] or at http://ees.rochestere.edu/atmos/data for the most recent available lightning products.

Use of climatological lightning flashes is more appropriate than the use of none. However, lightning is no longer co-located with active convective transport of HOx-rich surface air, and the photochemical impact is therefore underestimated. Therefore, time-varying lightning should always be preferred for science applications.

In GEOS-Chem 13.2.0, we will implement the lightning climatologies as an option in HEMCO_Config.rc, along with climatology options for other emissions.

[lizziel]

Is this all set to close?

[ltmurray]

I believe so.

[msulprizio]

I think we need to leave it open. I have the file from Lee, but need to actually implement it as an easy-to-access option in HEMCO_Config.rc. I'll aim to do this for 14.1.0.