Dear Jonathan,
Thanks for these clarifications.
> > 1. Is there a standard name for "diurnal temperature range", or a combined standard name/cell method representation? Cf. the 2010 mail archive thread http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2010/054016.html that added "range" to Appendix E.
> The cell_method of range was approved in ticket 65
> http://cf-trac.llnl.gov/trac/ticket/65
> and will be added in CF 1.7, which is under preparation. You could use this, in combination with time bounds, to describe a diurnal range.
To make sure that I understand: the standard name is "air_temperature", and for monthly mean the cell method is "time: range within days time: mean over days"
But how about common continentality indices based on the annual range of monthly mean temperatures?
Is there a "within months" such that the cell method for the basic element of the continentality index would be "time: mean within months time: range within years" ? Or is there another solution?
> > 3. Several of the standard names directly targeted at climate indices (e.g. "spell_length_.....", "number_of_days_...") are dimensionless because the unit is already included in the standard name. This is of course consistent and parsimonious in terms of describing the data. But with respect of a software package producing a plot that needs a legend with units attached, it is not very enlightening to have the unit "1". For example, in a map of Frost Days the title drawn from the long name or the comment may be something like "Number of Frost Days (Tmin < 0 degC)" but the color scale should preferably have units "days" rather than "1". As this is not specific to climate indices, what is the CF accepted advice or solution to this?
> The spell_length variables have canonical units of days. The number_of_days variables have canonical units of 1, as you say. This is logical. Could you use the standard name, including the phrase "number_of_days", to derive the appropriate label?
Yes, of course we could come up with something along those lines, or maybe add an attribute. I just thought there might be a widely used solution that I did not know of.
Best wishes,
Lars
Received on Fri May 13 2016 - 02:46:30 BST
