increment postprocessing #1136
Description
Currently at EMC we're postprocessing increment/analyses in two different steps:
- postprocess ocean increment using a custom gdas application
- postprocess ice analysis using convertstate with Soca2Cice variable change.
I'd like to bring those two together in one app, for computational (less I/O), code maintenance (everything in one place, done similarly) and future feature development (e.g. optional postprocessing for sst under ice) reasons.
As part of bringing them together, I plan to refactor the ice postprocessing to use background + analysis increment (instead of background + analysis as now). It may seem like a trivial computation (increment = analysis - background), but in our workflow it's not (background used for computing analysis is in the middle of the window, while background passed to the ice postprocessing is at the beginning of the window).
Since with this change Soca2Cice code will no longer fit well into VariableChange infrastructure, I plan to move it to the postprocessing code, and remove Soca2Cice from VariableChanges. All the features will remain the same for everyone who currently uses Soca2Cice to postprocess ice increment in a ConvertState application (yamls will likely change slightly). I don't know if anyone is using Soca2Cice in any other way; please let me know if you do.
Tagging @guillaumevernieres, @travissluka, @Dooruk for awareness.