EPP

The Langmuir probe (LAP), onboard the China seismic electromagnetic satellite (CSES), has been designed for in situ measurements of bulk parameters of the ionosphere plasma, the first Chinese application of in-situ measurement technology in the field of space exploration. The two main parameters measured by LAP are electron density and temperature. In this paper, a brief description of the LAP and its work mode are provided. Based on characteristics of the LAP, and assuming an ideal plasma environment, we introduce in detail a method used to invert the I-V curve; the data products that can be accessed by users are shown. Based on the LAP data available, this paper reports that events such as earthquakes and magnetic storms are preceded and followed by obvious abnormal changes. We suggest that LAP could provide a valuable data set for studies of space weather, seismic events, and the ionospheric environment.

Four levels of the data from the search coil magnetometer (SCM) onboard the China Seismo-Electromagnetic Satellite (CSES) are defined and described. The data in different levels all contain three components of the waveform and spectrum of the induced magnetic field around the orbit in the frequency range of 10 Hz to 20 kHz; these are divided into an ultra-low-frequency band (ULF, 10–200 Hz), an extremely low frequency band (ELF, 200–2200 Hz), and a very low frequency band (VLF, 1.8–20 kHz). Examples of data products for Level-2, Level-3, and Level-4 are presented. The initial results obtained in the commission test phase demonstrated that the SCM was in a normal operational status and that the data are of high enough quality to reliably capture most space weather events related to low-frequency geomagnetic disturbances.

High energy particles are the main target of satellite space exploration; particle storm events are closely related to solar activity, cosmic ray distribution, and magnetic storms. The commonly seen energetic particle (electron) precipitation anomalous structures include mainly the inner and outer Van Allen radiation belts, the South Atlantic anomaly, and the anomalous stripes excited by artificial electromagnetic waves. The China Seismo-Electromagnetic Satellite (CESE), launched in February of 2018, provides a platform for studying ionospheric particle disturbances. This paper reports the first studies of electron precipitation phenomenon based on high energy particle data from the CSES satellite. We find that the global distribution of electrons in the low energy band (0.1–3 MeV) can relatively well reflect the structure of the anomalous precipitation belt, which is consistent with results based on data from the DEMETER satellite, indicating that the quality of the low-energy band data from the energetic particle instrumentation of the CSES satellite is good. In addition, this paper makes an in-depth study of the electron precipitation belt excited by the NWC artificial VLF electromagnetic wave transmitter located in Australia, which appears as a typical wisp structure on the energy spectrum. The magnetic shell parameter L corresponding to the precipitation belt ranges from 1.44 to 1.74, which is close to the L value (~1.45) of the Australian NWC transmitter; the energy of the precipitation electrons is between 100 keV and 361.57 keV, among which the precipitation of 213.73 keV electrons is most conspicuous.