cf-convention / discuss

A forum for proposing standard names; and any discussion about interpretation, clarification, and proposals for changes or extensions to the CF conventions.
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adding river and lake to the area type table ? #306

Open gnikulin opened 2 months ago

gnikulin commented 2 months ago

There was a very long issue with many discussions https://github.com/cf-convention/discuss/issues/73 about new standard names for lake and river variables. My understanding is that there was a common agreement to add river and lake to the area type table. However, I don't see lake and river in the area type table. There are fresh_free_water that can be used but don't separate between lakes and rivers and also one area type - lake_ice_or_sea_ice where at least lake appears. Perhaps, it's easier to open a new issue focusing only on the area type for lakes and rivers.

JonathanGregory commented 2 months ago

Dear Grisha @gnikulin

I agree, that point wasn't taken up as a definite proposal. I believe you are proposing now that we should add lake and river area-types - is that correct? On that assumption, I'll change the label from question to vocabulary. Several people supported adding these new area types in principle, and raised significant points to be addressed.

Beate @GeyerB proposed definitions:

An area type of "lake" means a body of (usually fresh) water surrounded by land. An area type of "river" means a natural stream of water of considerable volume. (see http://glossary.ametsoc.org/wiki/River)

Karl @taylor13 asked:

Can we clarify in our definition what distinguishes a lake from an inland sea? I've seen descriptions that say a sea is at sea level and connected to an ocean while a lake may be above or below sea level and if connected to the ocean is not a "sea". (Under this definition the "Dead Sea" is a lake.)

Best wishes

Jonathan

gnikulin commented 2 months ago

I believe you are proposing now that we should add lake and river area-types - is that correct? On that assumption, I'll change the label from question to vocabulary.

Jonathan, yes, it's exactly what I meant - to add lake and river area-types. Changing the label from question to vocabulary is absolutely fine.

Karl @taylor13 asked:

Can we clarify in our definition what distinguishes a lake from an inland sea? I've seen descriptions that say a sea is at sea level and connected to an ocean while a lake may be above or below sea level and if connected to the ocean is not a "sea". (Under this definition the "Dead Sea" is a lake.)

One of differences between lakes and inland seas may be salinity I think, freshwater lake or salt lake . Wiki says "An inland sea will generally be brackish, with higher salinity than a freshwater lake but usually lower salinity than seawater."

taylor13 commented 2 months ago

In CF I think most folks currently interpret "sea" as a body of water of considerable size at sea level. Perhaps we could use the term "inland_seas_and_lakes" to distinguish other surface waters from rivers and streams.

gnikulin commented 2 months ago

Just chatted with a lake modeller and salinity is not the best criteria to distinguish between a lake and an inland sea as there are many salty lakes that are not inland seas. It was also mentioned that still there is no clear definition how to distinguish between lakes and inland seas. Perhaps, "inland_seas_and_lakes" as Karl suggested may be a good option.

gnikulin commented 2 months ago

Can we preliminary summarise that:

lake_and_inland_sea sounds a bit better for me ?

gnikulin commented 1 month ago

@JonathanGregory may we expect any actions here ?

github-actions[bot] commented 1 month ago

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 commented 1 month ago

I have just added the label "standard name" as the issue template specifically mentions changes to the area type table.

JonathanGregory commented 1 month ago

Please could the standard name moderators consider this proposal for the area type table? @efisher008 @japamment @feggleton