Sorry, this email went just to Jonathan instead of the list. Stupid computers….
It still appears timely, though. John Begin forwarded message: > From: John Graybeal <grayb...@marinemetadata.org> > Subject: Re: [CF-metadata] new standard name: total_totals_index > Date: May 18, 2013 9:39:27 AM PDT > To: Jonathan Gregory <j.m.greg...@reading.ac.uk> > > The totals appear from the definition to be not totals, but differences. Is > there some reason it isn't called total_differences_index? > > And am I the only one who gets anxious at a name whose principal measured > object is "totals" (or "differences")? They are differences of *particular* > things, air temperatures and dew point temperatures -- which could be > relevant when we want to total differences of other things, for example if > one creates an atmospheric stability index based on differences in air > densities and wind speeds. > > Jonathan's modifier goes a long way to limit the overreach, and I could > imagine the topics being differenced could go into auxiliary metadata in some > way. But I'll at least float my preference > > atmosphere_stability_total_differences_index_due_to_air_temperature_and_dew_point_temperature > > John > > > On May 18, 2013, at 07:06, Jonathan Gregory <j.m.greg...@reading.ac.uk> wrote: > >> r Jonathan >> >>> total_totals_index >>> >>> with the associated definition: >>> >>> The Total Totals Index (TT) indicates the likelihood of severe >>> convection. The index is derived from the difference in air >>> temperature between 850 and 500 hPa (the vertical totals) and the >>> difference between the dew point temperature at 850 hPa and the air >>> temperature at 500 hPa (the cross totals). The vertical totals and >>> cross totals are summed to obtain the Total Totals Index. >> >> This term is not self-explanatory and presents the same kind of difficulty as >> "lifted index" (see my last email). In this case, however, it seems >> impossible >> to devise a short definition. Moreover, unlike lifted index, it is not a >> quantity applicable to any level; the two levels concerned are hard-wired >> into >> the definition. It's a one-off ad-hoc empirical quantity. >> >> As a standard name, it would be good if we could add some context to it. For >> instance, what about >> >> atmosphere_stability_total_totals_index >> >> If I have understood the definitions online and yours above, this quantity is >> actually not a dimensionless index. Its unit is K, because it is calculated >> by >> adding temperature differences. >> >> Best wishes >> >> Jonathan >> _______________________________________________ >> CF-metadata mailing list >> CF-metadata@cgd.ucar.edu >> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata >> > > > --------------- > John Graybeal > Marine Metadata Interoperability Project: http://marinemetadata.org > grayb...@marinemetadata.org > > > > --------------- John Graybeal Marine Metadata Interoperability Project: http://marinemetadata.org grayb...@marinemetadata.org _______________________________________________ CF-metadata mailing list CF-metadata@cgd.ucar.edu http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
