ESCOMP
Add modifications to ZM convection to enable deeper convection
What is the feature/what would you like to discuss?
I hope to make an initial implementation of options for ZM deep convection that will enable convection to reach to greater altitude than we saw in CESM2 and that we currently see in CESM3 beta simulations.
Option 1: Consider the test convective plume from a total energy perspective rather than the existing potential energy/CAPE perspective Setting 1a: Prescribe parcel initial kinetic energy and energy conversion efficiency as namelist constants Setting 1b: Prescribe parcel energy conversation efficiency as a constant, but derive initial parcel kinetic energy from the time varying TKE provided by CLUBB.
Option 2: Specify test parcel entrainment with linear height variation. This requires two parameters specifying lower tropospheric and upper tropospheric entrainment and pressure levels to determine the transition height between these two values.
These are not necessarily intended as a feature for CESM3, but it could provide a more fine control on tuning efforts if needed. A further benefit is being evaluated for improved vertical transport of chemical species near the tropopause. The impacts of these changes on the stratosphere (e.g., QBO, tape recorder) are unknown at this point.
All these changes are namelist controlled and so it should be BFB for out of the box settings. The majority of code modifications will be in a PR for ESCOMP/atmospheric_physics.
Is there anyone in particular you want to be part of this conversation?
@JulioTBacmeister @adamrher @PeterHjortLauritzen
Will this change (regression test) answers?
No
Will you be implementing this enhancement yourself?
Yes
Somewhat minimal changes in rainfall, but with significant deepening of deep convective tops (below).
Hi @swrneale, as part of recent changes for CCPPizing Hack shallow convection (https://github.com/ESCOMP/atmospheric_physics/pull/195) I had to move ZM namelist options in atmospheric_physics for CAM-SIMA to a separate module, zm_conv_options (existing CAM code to read namelists is not affected). If you run into issues locating the places to make edits please feel free to let me know and I am happy to assist. Thanks!
Thanks for the heads up @jimmielin. Is your best bet that and automatic merge won't work that great then?