I've been looking at ice/snow land/sea area types too. I have a microwave algorithm that together with a DEM separates the world into four mutually exclusive categories: - land with ice or snow - land without ice or snow - lake/sea with ice or snow - lake/sea without ice or snow
I'm currently planning to use: "ice_and_snow_on_land" "land" "lake_ice_or_sea_ice" "sea" or "ice_free_sea" "ice_and_snow_on_land" is perfect. I'd like to replace "land" with something like "land_without_snow_or_ice". The closest choices are "bare_ground", "snow_free_land", and "ice_free_land". I assume "bare_ground" means no vegetation, not no frozen water, so I'm avoiding it. (There's no help text.) I guess "lake_ice_or_sea_ice" is OK. I'd like it better if it explicitly included snow, but probably the assumption is that snow that's on lake/sea and not over ice will melt immediately? If there is no need to mention snow for water surfaces then "ice_free_sea" is pretty good. But it's odd there's no option for "ice_free_lake" or "ice_free_lake_or_sea". -- Evan On 10/4/18, 1:29 PM, "Taylor, Karl E." <[email protected]> wrote: Hi all, I think there might be a mistake in the descriptions of "ice_sheet" and/or "land_ice" in the "area type" table at http://cfconventions.org/Data/area-type-table/current/build/area-type-table.html . I find there the following definitions: ice_sheet: An area type of "ice sheet" indicates where ice sheets are present. It includes both grounded ice sheets resting over bedrock and ice shelves flowing over the ocean, but excludes ice-caps and glaciers (in contrast to land_ice, which includes all components). land_ice: "Land ice" means glaciers, ice-caps, grounded ice sheets resting on bedrock and floating ice-shelves. ice_on_land: The area type "ice_on_land" means ice in glaciers, ice caps, grounded ice sheets (grounded and floating shelves), river and lake ice, and any other ice on a land surface, such as frozen flood water. This is distinct from the area type 'land ice' which has a narrower definition. Are "ice-caps" and "glaciers" really excluded from "ice_sheet". I would have thought that "ice-cap" would be an ice_sheet located over a pole (or something to that effect). And i thought ice_sheets were just big glaciers. ice_on_land is pretty clearly any frozen water, except sea ice, icebergs, and ice particles in clouds, that is exposed to the atmosphere. So, I guess I'm trying to understand the difference between ice_sheet and land_ice, and why do we need both of these? thanks and best regards, Karl _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
