"State variables" refer to measurable properties or characteristics of a system that can fully describe its current condition or state. They are used to determine and predict how the system will behave or change over time. Full definition
This is the file name from where the initial ice state variables are set. (hannahlab.org)
From the initial definitions of this article it follows that there no such thing as a separate «statistical model» but statistically - processed outputs from actual state variables of the running «physical» model. (realclimate.org)
They extract just those three state variables from the CMIP data and the same downscaling model projects that down to the local level. (judithcurry.com)