The fate of O+ ions observed in the plasma mantle - forward tracing code and Cluster observations
Ion escape is of particular interest for studying the evolution of the atmosphere on geological time scales. Previously, using Cluster-CODIF data, we investigated the oxygen ion outflow from the plasma mantle for different solar wind conditions (clock angle, EUV, SW dynamic pressure) and geomagnetic activity (Kp). We found significant correlations between IMF, SW dynamic pressure, Kp and the O+ outflow contrary to EUV. Additionally, during extreme geomagnetic storms, the O+ outflow is increased by approximately a factor 30. We believe that these O+ ions observed in the plasma mantle have enough energy and velocity to escape the magnetosphere and be lost in the solar wind or in the distant magnetotail. The analysis of the data supports this hypothesis but in order to confirm it, we numerically calculate the trajectories of O+ using a tracing code. This code consists of a magnetic field model (Tsyganenko) and an ionospheric potential model (Weimer) in which particles initiated in the plasma mantle are launched and traced forward in time. The simulated trajectories give the fate of the ions. This study aims to provide statistics on the fate of the plasma mantle ions based on Cluster observations.
Created 2018-11-09 10:52:36 by Mats HolmstrÃ¶m Last changed 2019-08-27 13:12:07 by Uwe Raffalski