Questions about setting up DYCOMS verification experiment

[ali-ramadhan]

The basic state for RF01 was compiled from all of the measurements and is idealized as a quasi-two-layer structure in liquid water potential temperature θₗ and total-water specific humidity qₜ...

1. For the n-density model I'm guessing we want to add a second gas for water vapor with water vapor density ρₗ and water vapor total energy eₗ?

We specify geostrophic winds of U = 7 m/s and V = 5.5 m/s, which produce winds within the PBL near 6 and 4.25 m/s"

2. How do we best impose this? Presumably you specify the geostrophic winds and expect a small shear to develop? Two ideas from CliMA.jl include geostrophic forcing and Rayleigh damping.

For the sea surface temperature we specify a value of 292.5 K, which is 2.1 K warmer than the surface air temperature. Given a bulk aerodynamic drag coefficient, CD = CH =
CQ = 0.0011, this should correspond to a surface sensible heat flux near 15 W/m² and a surface latent heat flux of approximately 115 W/m².

To test the degree to which the assumption of fixed fluxes masked differences among the simulations, additional simulations were performed by most groups for which surface temperatures were held fixed and surface fluxes were computed interactively. However, these simulations did not differ substantially from those with surface fluxes fixed at the above values, and so the results reported on below are from simulations with specified fluxes.

3. Should be easy enough to enforce a couple of fluxes but I'm not super sure how to enforce them. Is the latent heat flux converted into a water vapor energy flux? And the sensible heat flux is converted into a total energy flux?

4. The radiative cooling is converted into an appropriate energy flux?

[ali-ramadhan]

Modeling groups were also asked to standardize their thermodynamic calculations so that the initial state corresponded to a cloud layer between 600 and 800 m with qₗ ≈ 0.45 g/kg at cloud top.

Hmmm, how do we impose or diagnose this?

[ali-ramadhan]

Also not sure what rₗ is in equation (4)

[ali-ramadhan]

After discussing with @thabbott:

1. We'll add a second gas but it'll be condensible so it'll enter the energy equation a little differently. For now we can add a non-condensible water density. Then you diagnose water vapor from the saturation vapor pressure. There should be an equation for diagnosing liquid water potential temperature.

2. Separate u = U + u` and add forcing terms to the momentum equation.

3. Add both fluxes as energy fluxes, and add latent heat flux to water density.

4. Radiative flux is added like (F_in - F_out) / dz.

5. ρrₗ might be liquid water path which we can diagnose.

[ali-ramadhan]