User-friendly magnetosheath model and its validation for the LEXI and SMILE mission support

Upcoming LEXI and SMILE missions will visualize the Earths dayside magnetosheath and its dynamic response to solar wind using the innovative soft X-ray imaging techniques. Soft X-rays are emitted in the magnetosheath when heated solar wind ions interact with terrestrial hydrogens. Magnetosheath plasma density, velocity, and temperatures are important parameters to calculate the soft X-ray images expected from LEXI and SMILE, and thus to support their data analysis. This presentation introduces a user-friendly and computationally inexpensive magnetosheath model based on MagnetoHydroDynamics (MHD) and its validation efforts with the THEMIS and Cluster observations. Our model uses a normalized magnetosheath coordinates with 11 radial grids between the magnetopause and the bow shock, 91 latitudinal grids, and 181 longitudinal grids. Latitudinal and longitudinal grids are 1 degree apart each other in the GSE coordinates, covering the dayside magnetosheath from north to south and from 6 to 18 MLT. Our model uses the MHD results obtained from the Open Geospace General Circulation Model (OpenGGCM) simulations at the normalized magnetosheath coordinates under 14 different solar wind (SW) and interplanetary magnetic field (IMF) conditions. As users provide the SW/IMF conditions and the magnetosheath location of their interest, our magnetosheath model determine a magnetopause and bow shock location using Shue et al. (1999) and Jerab et al. (2005), and then provides plasma density, velocity, temperature, and magnetic field vector that are linearly interpolated based on the input conditions. Our model also allows users to select other magnetosheath models available in previous literature such a gas-dynamic magnetosheath model of Spreiter et al. (1966), a magnetosheath flow model of Soucek and Escoubet (2012), and a magnetosheath magnetic field model of Romashets et al. (2019). Our magnetosheath model is validated with the THEMIS statistical magnetosheath data and the two magnetosheath crossing events of Cluster and THEMIS, which shows good data-model agreement. Our model will be publicly available through Github and can be used to quickly produce soft X-ray images from various vantage points under different SW/IMF conditions and thus to support the LEXI and SMILE data analysis.