Hi Jonathan, Sorry for my late reply. In discussions within the science group behind our application, they suggest the following names:
northward_northward_derivative_of_gravity_potential (Txx) westward_westward_derivative_of_gravity_potential (Tyy) upward_upward_derivative_of_gravity_potential (Tzz) northward_upward_derivative_of_gravity_potential (Txz) northward_westward_derivative_of_gravity_potential (Txy) westward_upward_derivative_of_gravity_potential (Tyz) Yes they are spatial derivatives of the potential in the specified directions, ending up with unit s-2; Let me know if this can be accepted by the group. Regards, On vr, 2015-01-23 at 16:52 +0000, Jonathan Gregory wrote: > Dear Napoleon > > Thanks for your email. I'm sorry, I don't understand these, because some of > them have two directions, some only one, yet all have the same unit s-2. > > If P is the geopotential (J kg-1 = m2 s-2), the acceleration due to gravity > g=dP/dz (m s-2). This could have eastward, northward and upward derivatives > dg/dx=d2P/dxdz, dg/dy=d2P/dydz, dg/dz=d2P/dz2. By northward upward derivative, > for instance, do you mean d2g/dydz=d3P/dydz2? Or perhaps by Tij you mean > d2P/dx_i dx_j in my notation? In that case the northward upward derivative > is d2P/dydz=dg/dy, which is the northward derivative of the acceleration due > to gravity. Txz Tyz Tzz are then the three derivatives of g, and Txx Tyy Txy > are Iward_Jward_derivative_of_geopotential. To be consistent we could name > all six of them in this second form, as second derivatives of geopotential. > > Best wishes > > Jonathan > > ----- Forwarded message from Napoleon Cornejo <[email protected]> ----- > > > Date: Tue, 20 Jan 2015 17:23:20 +0100 > > From: Napoleon Cornejo <[email protected]> > > To: Jonathan Gregory <[email protected]> > > CC: [email protected] > > Subject: Re: [CF-metadata] Standard Names for: Ocean Kinetic Energy and > > Relative Vorticity > > > > Hi Jonathan, > > > > Since these quantities will be calculated in Local North Oriented Frame > > (LNOF), I would like to submit these names for the gradients: > > > > northward_derivative_of_acceleration_due_to_gravity (Txx) > > westward_derivative_of_acceleration_due_to_gravity (Tyy) > > upward_derivative_of_acceleration_due_to_gravity (Tzz) > > northward_upward_derivative_of_acceleration_due_to_gravity (Txz) > > northward_westward_derivative_of_acceleration_due_to_gravity (Txy) > > westward_upward_derivative_of_acceleration_due_to_gravity (Tyz) > > > > Let me know if these seem appropriate. All with unit: s-2. > > > > Regards, > > > > On Wed, 2014-12-17 at 13:34 +0000, Jonathan Gregory wrote: > > > > > Dear Napoleon > > > > > > > Is it the convention to include the direction in the name? We will be > > > > calculating the gradient in more then one axis (Txy, Txz, etc, for a > > > > total of 6 quantities). > > > > > > Yes, it is the convention. There are not many tensor quantities named but > > > it > > > is not unpredented e.g. downward_eastward_momentum_flux_in_air. As you > > > see, > > > both sign and direction are indicated. > > > > > > Best wishes > > > > > > Jonathan > > > _______________________________________________ > > > CF-metadata mailing list > > > [email protected] > > > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata > > > > > > -- > > N.E. Cornejo, Msc. > > Engineering, Space & Science > > http://www.stcorp.nl > > s[&]t > > > > > > ----- End forwarded message ----- > _______________________________________________ > CF-metadata mailing list > [email protected] > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata -- -- N.E. Cornejo, Msc. Engineering, Space & Science http://www.stcorp.nl s[&]t
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