Dear Lars I agree it is not clear and it should be. I think the intention was to mean zero or positive, and not allow negative excesses, because there is also a standard_name integral_of_air_temperature_deficit_wrt_time. My recollection is that these were proposed for "heating degree days" and "cooling degree days".
Best wishes Jonathan ----- Forwarded message from Bärring Lars <[email protected]> ----- > Date: Mon, 23 May 2016 09:19:47 +0000 > From: Bärring Lars <[email protected]> > To: "[email protected]" <[email protected]> > Subject: [CF-metadata] clarification of standard name integral_of_Y_wrt_X > > Dear all, > > I am trying to find CF compliant representations of various degree-day > indices and find the standard name > integral_of_air_temperature_excess_wrt_time with the following > description: > > "integral_of_Y_wrt_X" means int Y dX. The data variable should have an axis > for X specifying the limits of the integral as bounds. "wrt" means with > respect to. Air temperature is the bulk temperature of the air, not the > surface (skin) temperature. The air temperature excess is the air temperature > minus the air temperature threshold. Its integral with respect to time is > often called after its units of "degree-days". > > > This seems suitable but just to clarify, does "air temperature excess" > include 'negative excess'? E.g. is it integral(T-t) or is it > integral(max(T-t),0)), where T is air temperature, and t is threshold > temperature? This is not entirely clear from the explanation " air > temperature excess is the air temperature minus the air temperature > threshold". > > > > Many thanks, > Lars > > -- > Lars Bärring > > FDr,Forskare / Gästprofessor,CEC/Lunds universitet > PhD,Senior Scientist / Guest professor,CEC/Lund University > > SMHI / Swedish Meteorological and Hydrological Institute > Rossby Centre > SE - 601 76 NORRKÖPING > http://www.smhi.se > > E-post / Email: [email protected] > Tel / Phone: +46 (0)11 495 8604 > Fax: +46 (0)11 495 8001 > Besöksadress / Visiting address: Folkborgsvägen 17 > > _______________________________________________ > CF-metadata mailing list > [email protected] > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata ----- End forwarded message ----- _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
