PIC Modeling of Ionospheric Plasma Diagnostics by Hemispherical Probes: Study of the LAP-CSES at Magnetic Conjugates

We present particle-in-cell simulations to simulate current-voltage characteristics of the Langmuir probe (LAP), onboard the China Seismo-Electromagnetic Satellite (CSES). For this purpose, three-dimensional kinetic simulations that account for several important physical processes are used to compute probe collected currents under realistic plasma environment conditions. In simulations, we used plasma parameters and background magnetic fields that are representative of the equatorial zone and the two magnetically conjugate mid-latitude sites in the Northern and Southern hemisphere. These sites are: the Millstone Hill (in North) and the Rothera (in South). The International Reference Ionosphere (IRI) and the International Geomagnetic Reference Field (IGRF) models are used to obtain the plasma parameters and the magnetic fields at the three locations. The simulation results illustrate the effect of magnetic field and the plasma environment on the current collection of the LAP. To compare the in-situ measurements of CSES along the Orbit-026610 with the calculated current-voltage characteristics at steady state, the Pearson’s correlation coefficient is calculated for each case. This comparative analysis is used to evaluate the accuracy of inferences derived from Orbit Motion Limited or other semi-empirical expressions.