GEM and with that CRCM-GEM is using both, horizontal and vertical staggering. 

In the horizontal, the Arakawa-C grid is used. In the vertical, the Charney-Phillips grid - see graphic below.

The horizontal wind components are on full levels, also called "momentum levels" and the scalar fields (like temperature, humidity, hydrometeors and passive tracers) as well as the vertical velocity component are on half levels, also called "thermodynamic levels". They are alternating with the lowest model level being a thermodynamic level, the highest a momentum level. See also wiki about model levels.

For more information have a look at the following publication:
    Girard, C., A. Plante et al., 2014: Staggered Vertical Discretization of the Canadian Environmental Multiscale (GEM) Model Using a Coordinate of the Log-Hydrostatic-Pressure Type. Monthly Weather Review, DOI: 10.1175/MWR-D-13-00255.1