JapaneseGEMSIS-Magnetosphere
Study of O+ Supply Processes to the Ring Current
It is well known that the singly-charged oxygen ions (O+ ions), which originate from Earth’s atmosphere, contribute significantly to the ring current during large geospace storms, while the quiet-time ring current mainly consists of protons of solar wind/ionospheric origin. In order to understand the mechanisms of this drastic change in the ring current composition, we conducted detailed analysis of the velocity distribution function and the field data obtained from in-situ observations of geospace plasma. The main results include (1) the relationship between the O+ supply to the ring current and variations in the solar wind dynamic pressure as well as the spatial distribution of O+ inflow into/outflows from the inner magnetosphere and (2) effects of specific solar wind structures to the ring current variations.
Outputs from the data analysis studies will be also used as the boundary conditions of the GEMSIS-RC model.
References: Yao et al., JGR, 2008a; Yao et al., JGR, 2008b