See Guillaumin (2021) 2.2, 2.3.
We use the CM2.6 dataset hosted on the Pangeo Cloud Datastore, which is simulation output from the CM2.6 climate model. Though public, the data is not freely available, due to the data being in a Requester Pays bucket on Google Cloud Platform (GCP). Reading data from the bucket requires you to have Google Cloud access credentials configured with billing access; bandwidth charges are then charged to that account i.e. you.
A guide for configuring GCP credentials is over here on the Pangeo Cloud
Datastore: Working with requester pays
data.
Alternatively, if you have a JSON credentials file (downloaded from GCP after
creating a service account), place it at
~/.config/gcloud/application_default_credentials
.