Hi all, this is more of a scientific question than anything computational. I'm looking at the Hack scheme, which I know is no longer the default from CAM 5 onwards, but is the version I'm building off.
I'm confused about which of the dry static enthalpy
Specifically, in the equations
is defined as a conserved quantity.
Is there something I'm missing? Either something silly in terms of when the quantities are evaluated, or some counter-intuitive reason that the maths is set up this way? Is the liquid water meant to evaporate straight back into the plume? Or is it assumed that the latent heat release from condensation goes to the environment and not the plume?
Thank you!
I'm confused about which of the dry static enthalpy
s, moist static enthalpy h, and 'liquid water static energy' s_l are meant to be conserved at the plume rises. The written documentation and definitions seem at odds with the equations printed (4.86-4.111, CAM 4 docs) and the code as written, and I'd love some help in reconciling the two from anyone familiar with the scheme.Specifically, in the equations
s is conserved, as it shouldn't be: in moist convection latent heat release should warm the parcel. h is conserved, as it should be, the reduction in water vapour is compensated by the latent heat release). s_l is not, even though it should be: s_l = s + Ll (L is latent heat of vapourisation, l is liquid water). The Ll component changes during the plume (as the plume starts off with no liquid water then hits saturation) and s is constant, so the total changes when s_lis defined as a conserved quantity.
Is there something I'm missing? Either something silly in terms of when the quantities are evaluated, or some counter-intuitive reason that the maths is set up this way? Is the liquid water meant to evaporate straight back into the plume? Or is it assumed that the latent heat release from condensation goes to the environment and not the plume?
Thank you!