Prognostic cloud scheme

[nfeldl]

It would be great to have an option for an interactive cloud scheme in a single-column RCM. From the documentation for the MIT single column model, it looks like they use the Bony and Emanuel (2001) layer cloud parametrization, which predicts cloud fraction and water content based on a pdf of total water concentration whose mean is the predicted specific humidity in the column and whose variance is proportional to the difference between that mean and the total water content inside the cumulus clouds at the level in question. How difficult would it be to implement a simple parametrization like this in climlab? Does anyone have thoughts or suggestions for an alternative cloud scheme that would be better?

References

MIT Single-Column Model https://ocw.mit.edu/courses/earth-atmospheric-and-planetary-sciences/12-340-global-warming-science-spring-2012/tools/

Bony, S., and K. A. Emanuel, 2001: A parameterization of the cloudiness associated with cumulus convection: evaluation using TOGA COARE data. J. Atmos. Sci., 58, 3158‐3183.

[brian-rose]

Nice! I wasn't familiar with this work but Bony and Emanuel paper is here

Glancing briefly through this, my impression is that this is totally doable. It may require a small modification to the wrapper for the Emanuel convection scheme, because currently Cloud Liquid Water is computed internally by the scheme but not passed back as a diagnostic.

[brian-rose]

Another source of inspiration for simple interactive cloud schemes may be the SPEEDY model: https://www.ictp.it/research/esp/models/speedy.aspx