Hi Alison, I still have not found any datasets using the existing name atmosphere_specific_convective_available_potential_energy, so I suspect that it doesn't actually matter which way it is aliased.
I stated the argument for aliasing it to (7) rather than (8) in the previous argument, but I don't feel strongly about it, and would be happy with either. If we haven't had any discussion from the list in, say, two weeks, could we consider it resolved? Thanks, --Seth On 11/7/13 4:52 AM, [email protected] wrote: > Dear Seth, All, > > I have reviewed these proposals along with Jonathan W's stability > index names. The CIN, LFC and LCL proposals are in good shape and can > be accepted. > > The following standard names will be added at the next update. > > 1) atmosphere_convective_inhibition (J kg-1) > > ' Convective inhibition is the amount of energy per unit mass > required to overcome the negatively buoyant energy exerted by the > environment on a parcel of air. Convective inhibition is often > abbreviated as "CIN" or "CINH". It is calculated by integrating the > negative temperature difference between the surrounding atmosphere > and a parcel of air lifted adiabatically from a given starting height > to its equilibrium level. A coordinate variable of > original_air_pressure_of_lifted_parcel should be specified to > indicate the starting height of the lifted parcel.' > > 2) atmosphere_convective_inhibition_wrt_surface (J kg-1) > > 'Convective inhibition is the amount of energy per unit mass required > to overcome the negatively buoyant energy exerted by the environment > on a parcel of air. Convective inhibition is often abbreviated as > "CIN" or "CINH". It is calculated by integrating the negative > temperature difference between the surrounding atmosphere and a > parcel of air lifted adiabatically from the surface to its > equilibrium level.' > > 3) atmosphere_lifting_condensation_level (m) > > 'The lifting condensation level is the height at which the relative > humidity of an air parcel cooled by dry adiabatic lifting would reach > 100%. A coordinate variable of original_air_pressure_of_lifted_parcel > should be specified to indicate the starting height of the lifted > parcel.' > > 4) atmosphere_lifting_condensation_level_wrt_surface (m) > > 'The lifting condensation level is the height at which the relative > humidity of an air parcel cooled by dry adiabatic lifting from the > surface would reach 100%.' > > 5) atmosphere_level_of_free_convection (m) > > 'The level of free convection is the altitude where the temperature > of the environment decreases faster than the moist adiabatic lapse > rate of a saturated air parcel at the same level. It is calculated by > lifting a parcel of air dry adiabatically to the LCL (lifted > condensation level), then moist adiabatically until the parcel > temperature is equal to the ambient temperature. A coordinate > variable of original_air_pressure_of_lifted_parcel should be > specified to indicate the starting height of the lifted parcel.' > > 6) atmosphere_level_of_free_convection_wrt_surface (m) > > 'The level of free convection is the altitude where the temperature > of the environment decreases faster than the moist adiabatic lapse > rate of a saturated air parcel at the same level. It is calculated by > lifting a parcel of air dry adiabatically from the surface to the LCL > (lifting condensation level), then moist adiabatically until the > parcel temperature is equal to the ambient temperature.' > > The two proposed CAPE parameters are agreed in principle: > > 7) atmosphere_convective_available_potential_energy (J kg-1) > > 'Convective(ly) available potential energy (often abbreviated CAPE) > is a stability measure calculated by integrating the positive > temperature difference between the surrounding atmosphere and a > parcel of air lifted adiabatically from a given starting height to > its equilibrium level. A coordinate variable of > original_air_pressure_of_lifted_parcel should be specified to > indicate the starting height of the lifted parcel. CAPE exists under > conditions of potential instability, and measures the potential > energy per unit mass that would be released by the unstable parcel if > it were able to convect upwards to equilibrium.' > > 8) atmosphere_convective_available_potential_energy_wrt_surface (J > kg-1) > > 'Convective(ly) available potential energy (often abbreviated CAPE) > is a stability measure calculated by integrating the positive > temperature difference between the surrounding atmosphere and a > parcel of air lifted adiabatically from the surface to its > equilibrium level. CAPE exists under conditions of potential > instability, and measures the potential energy per unit mass that > would be released by the unstable parcel if it were able to convect > upwards to equilibrium.' > > There is still a question mark as to whether the existing name > atmosphere_specific_convective_available_potential_energy should be > made an alias of proposal (7) or (8). Once we can resolve that > question the names can be added. Please see > http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2013/056725.html > and > http://mailman.cgd.ucar.edu/pipermail/cf-metadata/2013/056730.html > for the most recent comments on this topic. > > Best wishes, Alison > > ------ Alison Pamment Tel: +44 1235 778065 > NCAS/British Atmospheric Data Centre Email: > [email protected] STFC Rutherford Appleton Laboratory R25, > 2.22 Harwell Oxford, Didcot, OX11 0QX, U.K. > > >> -----Original Message----- From: CF-metadata >> [mailto:[email protected]] On Behalf Of Seth >> McGinnis Sent: 01 July 2013 23:49 To: Jonathan Gregory; >> [email protected] Subject: Re: [CF-metadata] new standard >> names for CIN, LFC,LCL; update to CAPE >> >> Hi Jonathan, >> >> Frankly, no, I'm not certain. My thinking is that if anyone is >> using the existing standard_name, their data is somewhat >> underspecified, and since it could in principle be one of many >> types of CAPE, it would be preferable to point to the more generic >> name. >> >> If anybody on the mailing list has an opinion about whether >> generic "CAPE" would make you think surface-based or something >> else, please speak up! >> >> (Because to be honest, I'm not much of an expert either; I just >> have some data that I need to make CF-compliant, and have been >> learning this topic as I go.) >> >> On the plus side, I suspect the question of where the alias points >> may well be entirely moot; the only CAPE data I've been able to >> find in netcdf form "in the wild" is CF-1.0 and has an empty >> standard_name. >> >> Cheers, >> >> --Seth >> >> >> On Mon, 1 Jul 2013 18:08:23 +0100 Jonathan Gregory >> <[email protected]> wrote: >>> Dear Seth >>> >>> It seems fine to delete "specific", I agree. The new names look >>> good to me. >>> >>> Are you sure that >>>> atmosphere_specific_convective_available_potential_energy >>> should be an alias of >>>> atmosphere_convective_available_potential_energy >>> and not of >>>> atmosphere_convective_available_potential_energy_wrt_surface >>> Which is the more likely understanding of the existing name? (I >>> don't know - you're the expert!) >>> >>> Best wishes and thanks >>> >>> Jonathan _______________________________________________ >>> CF-metadata mailing list [email protected] >>> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata >> >> _______________________________________________ CF-metadata mailing >> list [email protected] >> http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata _______________________________________________ CF-metadata mailing list [email protected] http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
