资源环境科技发展态势分析平台

We have quantified the O+ transports in the plasma sheet and lobes (-20 < X-GSM < -10R(E)) and their dependencies on geomagnetic activity, Kp, using Cluster data. We found that they have similar behavior as the polar region O+ outflow as well as the O+ fluxes in the plasma mantle and high-latitude dayside magnetosheath, in their response to geomagnetic activity. The sum of the total O+ fluxes in the lobes, plasma sheet, plasma mantle, and high-latitude magnetosheath equals the O+ outflow above the polar regions for any geomagnetic condition. It can be argued that there are no hidden O+ populations for Cluster, in the sense that there are no significant amounts of O+ with energies outside the energy range of the ion spectrometer, Composition Distribution Function, and/or below the spacecraft potential. Therefore, we have obtained a complete picture of the O+ circulation (and escape) in the outer magnetosphere and its dependence on geomagnetic activity.