@georgyfalster We do have a tutorial which includes a section on doing precisely this. Once your account is added to the ACCESS-Community-Hub organisation, first follow the steps under Authorise with Github here, which will authorise your Github account on Gadi. I think the following stuff under Perturbation is stuff you’ve already done.
Once you’ve done that, follow the steps under Push to repo here. It looks like you have multiple branches for the different SST variability scenarios, so you’ll want to use git push <repo_name> --all. Note that the name you set for the remote is the name you’ll have to sub in for <repo_name>. Once this is done, it should be available for others to clone and fork on Github.
If there are any issues, please ping me and I’ll take a look.