Harmonize the description of several standard names for various types of precipitation

[larsbarring]

Some time ago, when looking at #159, I discovered inconsistent and/or rather too brief description(s) of several standard names for various types precipitation. Hence I think that it would be useful to make a concerted effort to harmonise these.

problem	standard name	description	canonical unit
too brief	convective_rainfall_amount	"Amount" means mass per unit area.	kg m-2
too brief	convective_rainfall_flux	In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics.	kg m-2 s-1
too brief	convective_rainfall_rate	No help available	m s-1
too brief	rainfall_amount	"Amount" means mass per unit area.	kg m-2
too brief	rainfall_flux	In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics.	kg m-2 s-1
too brief	rainfall_rate	No help available	m s-1
term mixup	stratiform_graupel_ flux Alias: large_scale_graupel_ flux	In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. Stratiform precipitation, whether liquid or frozen, is precipitation that formed in stratiform cloud. Graupel consists of heavily rimed snow particles, often called snow pellets; often indistinguishable from very small soft hail except when the size convention that hail must have a diameter greater than 5 mm is adopted. Reference: American Meteorological Society Glossary http://glossary.ametsoc.org/wiki/Graupel. There are also separate standard names for hail. Standard names for "graupel_and_hail" should be used to describe data produced by models that do not distinguish between hail and graupel.	kg m-2 s-1
term mixup (#159)	stratiform_rainfall_amount Alias: large_scale_rainfall_amount	Stratiform precipitation, whether liquid or frozen, is precipitation that formed in stratiform cloud. "Amount" means mass per unit area.	kg m-2
term mixup	stratiform_rainfall_flux Alias: largescale``rainfall`flux	In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. Stratiform precipitation, whether liquid or frozen, is precipitation that formed in stratiform cloud.	kg m-2 s-1
term mixup	stratiform_rainfall_rate Alias: large_scale_rainfall_rate	Stratiform precipitation, whether liquid or frozen, is precipitation that formed in stratiform cloud.	m s-1
term mixup	stratiform_snowfall_amount Alias: large_scale_snowfall_amount	Stratiform precipitation, whether liquid or frozen, is precipitation that formed in stratiform cloud. "Amount" means mass per unit area.	kg m-2
term mixup	stratiform_snowfall_flux Alias: large_scale_snowfall_flux	In accordance with common usage in geophysical disciplines, "flux" implies per unit area, called "flux density" in physics. Stratiform precipitation, whether liquid or frozen, is precipitation that formed in stratiform cloud.	kg m-2 s-1

This table only include standard names where I think that there is room for improvements and/or clarifications. Related to these 12 ones there are 43 other standard names from which useful boilerplate pieces of text can be extracted, or otherwise used as inspiration. Thus I believe the work involved is not overwhelming to improve the description of these 12 standard names.

In addition to these standard names in need of better descriptions, there is one standard name that I believe is wrong or at least inconsistent:

standard name	description	canonical unit
convective_precipitation_rate	"Precipitation rate" means the depth or thickness of the layer formed by precipitation per unit time. Convective precipitation is that produced by the convection schemes in an atmosphere model. "Precipitation" in the earth's atmosphere means precipitation of water in all phases.	m s-1	convective_precipitation_rate is the sum of convective_rainfall_rate and what (and the three non-existing convectivesnow| hail | _graupel_fall_rate)? This would be inconsistent because of what the height represents. This quantity is better represented by the already existing lwe_convective_precipitation_rate

The problem with this is that convective_precipitation_rate (supposedly, and in line with other standard names) is the sum of convective_rainfall_rate and what (and the three non-existing convective_snow_| _hail_ | _graupel_fall_rate)? This would be inconsistent because of what the height represents.

Thus I suggest that convective_precipitation_rate is deprecated in favour of lwe_convective_precipitation_rate.

The full table of the standard names is attached as an .xls spreadsheet file: Precip_Standard_Names_gh.xlsx

[github-actions[bot]]

Thank you for your proposal. These terms will be added to the cfeditor (http://cfeditor.ceda.ac.uk/proposals/1) shortly. Your proposal will then be reviewed and commented on by the community and Standard Names moderator.

[larsbarring]

ping @japamment and @ethanrd for inclusion as a hackaton theme in the schedule for the CF2023 workshop.

[efisher008]

Hello @ethanrd, @japamment,

Was there more offline discussion on this topic in the 2023 CF workshop in October?

Best wishes, Ellie

[larsbarring]

Yes, thanks for reminding me. I will update with some notes from our breakout conversation.

[efisher008]

Hello @larsbarring,

Yes, thanks for reminding me. I will update with some notes from our breakout conversation.

Would you be able to update the post with notes from the conversation at the CF workshop, please? It looks like the last edit to the original post was October and it would be useful to have any more discussion recorded. Thank you!

Best wishes, Ellie