Revision of section 2.12 (Lake Model) in technical note for CLM6#3997
Revision of section 2.12 (Lake Model) in technical note for CLM6#3997nmizukami wants to merge 5 commits into
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The changes make sense to me. And cover the things talked about. Removal of the section about updates since the previous version is good.
@nmizukami changed so that equations have equation before it, which makes sense to me. He questioned if that's a good change. But, I think we should go with it. It might be something to look at later for consistency between chapters.
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@nmizukami , during my review of and changes to the Surface Albedo chapter, I found that the description of lake albedos was outdated (it referred to the prescribed lake albedos from LSM). So I changed this in the Surface Albedo chapter to follow the current code for lake albedo. I'd suggest then to simply refer to the Surface Albedo chapter (specifically Section 2.3.2 Ground Albedos) in the lake chapter. That way we don't duplicate the text/equations. I think the Ground Albedo section is appropriate since it describes albedos for the different surface types. |
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@nmizukami this failed the checker in regard to curly quotes (since Sphynx will handle this). So you'll need to fix that before it can be merged. This should be straightforward, but I can show you if you have any questions. |
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You can see the offending curlies here. I'm removing myself as reviewer since this isn't my bailiwick. |
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Thanks for this @nmizukami . My review consists mostly of identifying orphaned equations, which were there before your modifications. See also my comment about lake albedos.
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| #. Saturated specific humidity :math:`q_{sat}^{T_{g} }` and its derivative :math:`\frac{dq_{sat}^{T_{g} } }{dT_{g} }` are updated for :math:`T_{g}^{n+1}` (section :numref:`Monin-Obukhov Similarity Theory`). | |||
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Is there a way to have this next step (saturated specific humidity...) follow the numbering convention as the previous steps? Here it is starting over as step 1, when it should be step 14. I assume this is happening because there is a sentence in between (where the last term....).
| #. Heat of vaporization / sublimation :math:`\lambda` \ (:eq:`12.8`) | ||
| #. Heat of vaporization / sublimation :math:`\lambda` \ (equation :eq:`12.8`) | ||
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| #. Thermal conductivity :math:`\lambda _{T}` \ (above) |
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Not sure what "above" means here. It's probably referring to earlier text that describes the thermal conductivity but doesn't have any equations that can be referenced. Regardless, maybe we could say "(described above after equation :eq:12.13)". I think that is correct...
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| Thermal conductivities include additional eddy diffusivity, beyond the :ref:`Hostetler and Bartlein (1990)<HostetlerBartlein1990>` formulation, due to unresolved processes (:ref:`Fang and Stefan 1996<FangStefan1996>`; :ref:`Subin et al. (2012a) <Subinetal2012a>`). Lake water is now allowed to freeze by an arbitrary fraction for each layer, which releases latent heat and changes thermal properties. Convective mixing occurs for all lakes, even if frozen. Soil and bedrock are included beneath the lake. The full snow model is used if the snow thickness exceeds a threshold; if there are resolved snow layers, radiation transfer is predicted by the snow-optics submodel (Chapter :numref:`rst_Surface Albedos`), and the remaining radiation penetrating the bottom snow layer is absorbed in the top layer of lake ice; conversely, if there are no snow layers, the solar radiation penetrating the bottom lake layer is absorbed in the top soil layer. The lakes have variable depth, and all physics is assumed valid for arbitrary depth, except for a depth-dependent enhanced mixing (section :numref:`Eddy Diffusivity and Thermal Conductivities`). Finally, a previous sign error in the calculation of eddy diffusivity (specifically, the Brunt-Väisälä frequency term; eq. ) was corrected. | ||
| where :math:`\tilde{c}_{v,j} (t)`\ is the volumetric heat capacity of the *j*\ th layer (section :numref:`Heat Capacities Lake`), :math:`L_{j} (t)`\ is the latent heat of fusion per unit volume of the *j*\ th layer (proportional to the mass of liquid water present), and the right-hand side represents the net influx of energy to the lake system. Note that :math:`\tilde{c}_{v,j} (t)` can only change due to phase change (except for changing snow layer mass, which, apart from energy required to melt snow, represents an untracked energy flux in the land model, along with advected energy associated with water flows in general), and this is restricted to occur at :math:`T_{j} =T_{f}` \ in the snow-lake-soil system, allowing eq. to be precisely enforced and justifying the exclusion of :math:`c_{v,j}` from the time derivative in eq.. |
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| where :math:`\tilde{c}_{v,j} (t)`\ is the volumetric heat capacity of the *j*\ th layer (section :numref:`Heat Capacities Lake`), :math:`L_{j} (t)`\ is the latent heat of fusion per unit volume of the *j*\ th layer (proportional to the mass of liquid water present), and the right-hand side represents the net influx of energy to the lake system. Note that :math:`\tilde{c}_{v,j} (t)` can only change due to phase change (except for changing snow layer mass, which, apart from energy required to melt snow, represents an untracked energy flux in the land model, along with advected energy associated with water flows in general), and this is restricted to occur at :math:`T_{j} =T_{f}` \ in the snow-lake-soil system, allowing eq. to be precisely enforced and justifying the exclusion of :math:`c_{v,j}` from the time derivative in eq.. | |
| where :math:`\tilde{c}_{v,j} (t)`\ is the volumetric heat capacity of the *j*\ th layer (section :numref:`Heat Capacities Lake`), :math:`L_{j} (t)`\ is the latent heat of fusion per unit volume of the *j*\ th layer (proportional to the mass of liquid water present), and the right-hand side represents the net influx of energy to the lake system. Note that :math:`\tilde{c}_{v,j} (t)` can only change due to phase change (except for changing snow layer mass, which, apart from energy required to melt snow, represents an untracked energy flux in the land model, along with advected energy associated with water flows in general), and this is restricted to occur at :math:`T_{j} =T_{f}` \ in the snow-lake-soil system, allowing equation :eq:`12.27` to be precisely enforced and justifying the exclusion of :math:`c_{v,j}` from the time derivative in equation :eq:`12.27' |
But please check my equation references here.
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| N^{2} =\frac{g}{\rho _{i} } \frac{\partial \rho }{\partial z} | ||
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| and :math:`g` is the acceleration due to gravity (m s\ :sup:`-2`) (:numref:`Table Physical Constants`), :math:`\rho _{i}` is the density of water (kg m\ :sup:`-3`), and :math:`\frac{\partial \rho }{\partial z}` is approximated as :math:`\frac{\rho _{i+1} -\rho _{i} }{z_{i+1} -z_{i} }`. Note that because here, *z* is increasing downwards (unlike in :ref:`Hostetler and Bartlein (1990)<HostetlerBartlein1990>`), eq. contains no negative sign; this is a correction from CLM4. The density of water is (:ref:`Hostetler and Bartlein (1990)<HostetlerBartlein1990>`) |
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| and :math:`g` is the acceleration due to gravity (m s\ :sup:`-2`) (:numref:`Table Physical Constants`), :math:`\rho _{i}` is the density of water (kg m\ :sup:`-3`), and :math:`\frac{\partial \rho }{\partial z}` is approximated as :math:`\frac{\rho _{i+1} -\rho _{i} }{z_{i+1} -z_{i} }`. Note that because here, *z* is increasing downwards (unlike in :ref:`Hostetler and Bartlein (1990)<HostetlerBartlein1990>`), equation :eq:`12.33` contains no negative sign; this is a correction from CLM4. The density of water is (:ref:`Hostetler and Bartlein (1990)<HostetlerBartlein1990>`) |
But please check my equation reference.
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| K_{ed} =1.04\times 10^{-8} \left(N^{2} \right)^{-0.43} ,N^{2} \ge 7.5\times 10^{-5} {\rm s}^{2} | ||
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| where :math:`N^{2}` \ is calculated as in eq. except for the minimum value imposed in. |
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| where :math:`N^{2}` \ is calculated as in equation :eq:`12.33` except for the minimum value imposed in. |
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| K_{ed} =1.04\times 10^{-8} \left(N^{2} \right)^{-0.43} ,N^{2} \ge 7.5\times 10^{-5} {\rm s}^{2} | ||
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| where :math:`N^{2}` \ is calculated as in eq. except for the minimum value imposed in. |
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I'm not sure how this sentence is supposed to finish. "except for the minimum value imposed in...". In what? Do you know?
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| M=\max \left\{-M_{liq} ,\frac{Q_{avail} }{H_{fus} } \right\} | ||
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| where :math:`M_{liq}` is the mass of water in the layer: :math:`\left(1-I_{i} \right)\rho _{liq} \Delta z_{i}` for a lake body layer, or the soil / snow water content state variable (:math:`w_{liq}` ). The heat remainder :math:`Q_{rem}` is given by eq. and will be negative or zero. Finally, :math:`M_{liq}` is adjusted downwards by :math:`-M` and the temperature is reset according to eq.. |
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| where :math:`M_{liq}` is the mass of water in the layer: :math:`\left(1-I_{i} \right)\rho _{liq} \Delta z_{i}` for a lake body layer, or the soil / snow water content state variable (:math:`w_{liq}` ). The heat remainder :math:`Q_{rem}` is given by equation :eq:`12.49` and will be negative or zero. Finally, :math:`M_{liq}` is adjusted downwards by :math:`-M` and the temperature is reset according to equation :eq:`12.50` |
But please check my equation references.
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Description of changes
After review, I made a few minor edits and various corrections e.g., links, equations. etc. I did not change anything on roughness length update made by @olyson.
Specific changes I made:
Specific notes
Contributors other than yourself, if any:
CTSM Issues Fixed (include github issue #): Resolve #3858
Are answers expected to change (and if so in what way)? N/A
Any User Interface Changes (namelist or namelist defaults changes)? N/A
Does this create a need to change or add documentation? Did you do so? Yes, This PR is for documentation change.
Testing performed, if any:
Built documentation on Casper (NCAR HPC) following the working with documentation guide, no errors.