Setting heterogeneous scaling factor to 1 before NorESM2.3 release

[oyvindseland]

I had a discussion meeting with Trude Storelvmo and Astrid Gjelsvik last Friday. Due to time limits on the project and getting out articles they want to do development in NorESM2.3
If possible they prefer if secondary ice deformation is default on, i.e. included in the tuning. Given the behavior of this parameterisation e.g. for aerosol ERF, I presume this may well happen anyway.
Also, if possible they asked if it was possible to remove the 0.01 factor for scaling the heterogeneous freezing. This was a very ad hoc and not very physical solution to get more water in mixed phase cloud. The other tuning factors can be defended and will be modified in their development later on.
The problem is of course to do so this late in the process. Is it possible to run a test with this setting. @DirkOlivie @gold2718
I can do the simulation although since Dirk has done a fairly large ensemble already, it will be faster if he can do the test.
Or do you think we should just respond that it is too late?

[gold2718]

I will defer to @DirkOlivie as he has been doing all the tuning studies.
I am happy to help ensuring that the settings we decide on are set correctly for supported NorESM2.3 cases.

[DirkOlivie]

@oyvindseland @gold2718
I will set up a N1850 simulations with the suggested modification (possibly also a NF1850norbc and NF1850norbc_aer2014 to see the impact on the aerosol ERF). Øyvind, can you let me know what parameter I should change?
Best regards, Dirk

[oyvindseland]

It was easier than I remembered since it has actually been included as a namelist variable. So the only change needed is to set
hetfrz_aer_scalfac = 1.0D0

in user_nl_cam