Dear Dan The surface type can be described by using a coordinate or scalar coordinate variable with a standard_name of area_type. You may need to request new area types. This is a controlled CF vocabulary, like the standard names. I can only find the area type table in XML on the new CF website. It used to be in HTML as well. It is at http://cf-convention.github.io/Data/cf-standard-names/27/src/area-type-table.xml
Best wishes Jonathan ----- Forwarded message from "Hollis, Dan" <dan.hol...@metoffice.gov.uk> ----- > From: "Hollis, Dan" <dan.hol...@metoffice.gov.uk> > To: "'alison.pamm...@stfc.ac.uk'" <alison.pamm...@stfc.ac.uk>, "Gregory, > Jonathan" <j.m.greg...@reading.ac.uk>, "cf-metadata@cgd.ucar.edu" > <cf-metadata@cgd.ucar.edu> > Subject: RE: [CF-metadata] New standard name: > number_of_days_with_surface_temperature_below_threshold > Date: Thu, 11 Sep 2014 16:04:28 +0000 > > Hi Alison, Jonathan, all > > I was discussing this request with some colleagues yesterday and someone > asked how 'surface' was defined. The definition for 'surface_temperature' > simply says: > > "The surface called "surface" means the lower boundary of the atmosphere. The > surface temperature is the temperature at the interface, not the bulk > temperature of the medium above or below." > > This is exactly what we want, except for the fact that the *type* of surface > is undefined. > > My original request related to days of ground frost (i.e. grass minimum > temperature below zero) simply because this is one of our routine variables > and therefore near the top of the list of data sets to convert to NetCDF. > However we also have grids of the number of days of concrete frost (computed > from minimum temperature observations from a thermometer with its bulb in > contact with a concrete slab). These will have different characteristics to > the grass minimum values and therefore the two fields should not be > combined/compared without knowing that the surface type is different. > > What is the correct way to define/declare the surface type? We think this > issue must also apply to model data and that therefore someone may have > already answered this question. Furthermore, given that models can generate > fields of *air* temperature for different uniform surface types (grass, > forest, urban etc) we wondered if the need to declare a surface type might > also apply to 'air_temperature'. As well as uniform types there would also > need to be a type of 'real land cover' (which is what we'd need for our > data). Any suggestions? > > Regards, > > Dan > > > -----Original Message----- > From: CF-metadata [mailto:cf-metadata-boun...@cgd.ucar.edu] On Behalf Of > Hollis, Dan > Sent: 04 September 2014 11:16 > To: 'alison.pamm...@stfc.ac.uk'; Gregory, Jonathan; cf-metadata@cgd.ucar.edu > Subject: Re: [CF-metadata] New standard name: > number_of_days_with_surface_temperature_below_threshold > > Hi Alison, > > Many thanks for clarifying how the process works. I look forward to the new > name being added in due course. > > Regards, > > Dan > > -----Original Message----- > From: alison.pamm...@stfc.ac.uk [mailto:alison.pamm...@stfc.ac.uk] > Sent: 03 September 2014 13:07 > To: Hollis, Dan; Gregory, Jonathan; cf-metadata@cgd.ucar.edu > Subject: RE: [CF-metadata] New standard name: > number_of_days_with_surface_temperature_below_threshold > > Dear Dan, > > Thanks for your standard name proposal - you have done all that is necessary > for it to be 'picked up'. I am the person responsible for updating the > standard name table (the latest version can be viewed on the CF website at > http://cfconventions.org/Data/cf-standard-names/27/build/cf-standard-name-table.html). > I also maintain a list of proposals that are in the pipeline, so to speak, > which is linked from the website 'Discussions' page > (http://cfconventions.org/discussion.html) or can be viewed directly at > > http://cfeditor.ceda.ac.uk/proposals/1?status=active&namefilter=&proposerfilter=&descfilter=&filter+and+display=filter. > Your proposal has been added to this list. (N.B. I am also in the process of > adding other recent proposals to bring the list up to date as it hasn't been > done for a while). > > I agree with Jonathan that your proposal for > number_of_days_with_surface_temperature_below_threshold is fine and since it > is so similar to an existing name I think that unless anyone raises any > objections within the next week it can be accepted for publication in the > standard name table. > > Best wishes, > Alison > > ------ > Alison Pamment Tel: +44 1235 778065 > NCAS/British Atmospheric Data Centre Email: alison.pamm...@stfc.ac.uk > STFC Rutherford Appleton Laboratory > R25, 2.22 > Harwell Oxford, Didcot, OX11 0QX, U.K. > > > > -----Original Message----- > > From: Hollis, Dan [mailto:dan.hol...@metoffice.gov.uk] > > Sent: 03 September 2014 11:20 > > To: Gregory, Jonathan; cf-metadata@cgd.ucar.edu > > Subject: Re: [CF-metadata] New standard name: > > number_of_days_with_surface_temperature_below_threshold > > > > Hi Jonathan, > > > > Thanks for your support for the proposed standard name. > > > > I'm new to this process. I appreciate more time needs to be given to allow > > others to comment but I was wondering if there is anything else I need to > > do i.e. assuming there are no objections raised via the mailing list will > > the > > Standard Names Committee pick this up automatically and add it to the next > > release? > > > > Regards, > > > > Dan > > > > > > -----Original Message----- > > From: CF-metadata [mailto:cf-metadata-boun...@cgd.ucar.edu] On Behalf > > Of Jonathan Gregory > > Sent: 01 September 2014 17:36 > > To: cf-metadata@cgd.ucar.edu > > Subject: [CF-metadata] New standard name: > > number_of_days_with_surface_temperature_below_threshold > > > > Dear Dan > > > > > number_of_days_with_surface_temperature_below_threshold > > > > > > The definition would be similar to that for the existing standard name > > 'number_of_days_with_air_temperature_below_threshold', the only > > difference being that it would relate to surface temperature rather than air > > temperature. We require this to allow us to store values of the number of > > days of ground frost i.e. the number of days when the grass minimum > > temperature (= surface temperature) dropped below 0 degC. Following the > > approach for air temperature, the threshold would be specified via a > > coordinate variable called 'surface_temperature'. > > > > That seems fine to me. Thanks for your efforts to convert to CF. > > > > Cheers > > > > Jonathan > > _______________________________________________ > > CF-metadata mailing list > > CF-metadata@cgd.ucar.edu > > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata > > _______________________________________________ > > CF-metadata mailing list > > CF-metadata@cgd.ucar.edu > > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata > -- > Scanned by iCritical. > _______________________________________________ > CF-metadata mailing list > CF-metadata@cgd.ucar.edu > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata ----- End forwarded message ----- _______________________________________________ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
