Dear John and Karl, Thanks for your comments about the changes.
John Graybeal wrote: > > I have a few suggestions for the area_type info. Well, more like > questions. > > An area_type that I imagine being useful within a year or two, if not > within months, is the benthic floor (i.e., land under the sea). And > by analog: land under a lake, or the more general > water_covered_ground. I'm not recommending those changes now, but they > raise the following question: Is 'land' is intended to be all- > encompassing in this regard? Definitions would help make this clear. My own understanding of 'land' is that it means dry land, i.e. not covered by seas. I think essentially it corresponds to those areas that would be flagged as land in the land-sea mask of a climate model. I have wondered myself if this definition of 'land' actually includes lakes and rivers. I'd welcome any suggestions as to what the precise definition should be. > As a general observation, discussing terms without associated > definitions can lead to confusion on all parts. I couldn't agree more! It is often only when I come to write the definitions of standard names that I realise just how woolly is my own understanding of some of the concepts involved. I would very much like to move to a situation where all area_type strings and all standard_names have help text associated. The reasons that very few area_types have descriptions at the moment are: (a) none were discussed under ticket 17; (b) I didn't want to simply invent descriptions without having the opportunity to discuss them first; (c) we wanted to make a first draft of the area_type table available quickly because the list is already starting to grow and people need to get at the information. > > I don't see how all_standard_names makes sense as an area_type. > I think this is a typo and the string should in fact read all_area_types. Thanks for pointing this out and I'm sure Velimir will correct it shortly. > If lake_ice_or_sea_ice excludes icebergs, does sea_ice? This is > counterintuitive to a lay person, admittedly not the target audience. > (Also note, this is where the relation between terms is useful > information to have -- somewhere in my assumed hierarchy > floating_ice > lake_ice_or_sea_ice > sea_ice > there is a discrepancy, perhaps intentional. Suggest the discontinuity > be made explicit in the definition (i..e, explain why > lake_ice_or_sea_ice excludes icebergs, while floating_ice does not; > and address whether sea_ice includes icebergs. The definition is > where people will look to understand the relationships. Again, I agree completely with your general point. I think we do need to be clear about the definitions, or to be able to say when and why we are being deliberately vague. Quite a number of the standard name descriptions contain information about relationships and I can see no reason not to do the same with area_types. As to whether sea_ice includes icebergs, I suspect the answer is no (because climate model sea-ice masks don't include icebergs) but my answer could well be wrong! I hope that Jonathan may be able to help out with the ice area_types as it is more his field of expertise than mine. > > I assume the absence of lake_ice is deliberate. (Just a thought: > Sometimes completeness is helpful for clarity, especially when there > are no definitions, even though there may not be any immediate use for > the term. Otherwise it makes some of us wonder why something *wasn't* > included.) > A lake_ice area type hasn't been included at the moment because nobody has asked for it. The underlying philosophy for adding standard names is that we don't add them unless there is a specific proposal, even if that means that some obvious 'sets' of standard names are incomplete. In the first instance I have adopted a similar philosophy for area_types. As you know, there is a lot of discussion at the moment about the general direction standard names should take in the future and I suggest that would be a suitable place for further debate of this particular point. I would note, however, that the current position is consistent with the overall CF development philosophy of not trying to anticipate all possible future needs. Best wishes, Alison ==> Please note new email address: [EMAIL PROTECTED] <== ------ J Alison Pamment Tel: +44 1235 778065 NCAS/British Atmospheric Data Centre Fax: +44 1235 446314 Rutherford Appleton Laboratory Email: [EMAIL PROTECTED] Chilton, Didcot, OX11 0QX, U.K. -- Scanned by iCritical. _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
