Fig. 18From: The science case for the EISCAT_3D radarBoth hydrogen ion (H+) and oxygen ion (O+) upflows in the topside polar ionosphere were recently observed with the ESR radar in the vicinity of the cusp. On closed field lines, the H+ became the larger contributor to the upward flux above about 550Â km (see Ogawa et al. 2009)Back to article page