Example cell of the 3D staggered grid adopted in ECLIPS3D, based on Thuburn et al. (2002). i discretises the longitudinal variable λ, j the latitude ϕ, and k the radial variable r. Here, u and v are staggered in latitude, with v running from the south to north pole and thereby having an additional latitude point. Also, p is staggered in height with w and θ with the latter two variables running from the bottom to the top of the atmosphere resulting in an additional height point.