Comparison between the 2D temperature maps of hot Jupiter GCMs in the upper row (Perna et al. 2012), and the 2D temperature maps represented with the h_mℓ basis in the middle and lower rows with ℓ_max = 1 and 50, respectively. The horizontal axis is longitude, the vertical axis is latitude, and the center of each map is the substellar point. For model input parameters see Table 1; for an outline of the linear algorithm used to fit maps with ℓ_max = 50, see Appendix A.