Two representative polar projections of Jupiter’s northern UV aurora obtained by the HST at different CMLS on day 351, in 2000 and on day 13, in 2001, respectively. The CML of each image is aligned toward the bottom of each image, such that dawn is to the left, dusk to the right, and midnight to the top. The intensity scale is logarithmic and saturated at 250 kR. The red dashed line indicates the statistical reference oval from Grodent et al. (2003a). A 10° × 10° jovigraphic grid is overlaid. The auroras correspond to rarefaction and compression of solar wind conditions. Adapted from Nichols et al. (2007).