Gyroscopic coefficients of an ocean basin of angular radius θ₀ = 130° (i.e. θ_c = 50°) for various values of the colatitude of the ocean’s centre. Top: (polar ocean). Middle: (mid-latitude ocean). Bottom: (equatorial ocean). The gyroscopic coefficients are computed from the expressions given by Eqs. (G.9–G.12) with the truncation degree set to L = 4. The basis functions of indices k and j are sorted in ascending order of orders (m = −4, −3,…, 3, 4), with degrees (l ≥ |m|) grouped together. For convenience, the minimum and maximum of the colour bar are set to 6 in absolute value although the maximum values reached by gyroscopic coefficients are around ~15 in this case.