Close up imaging simulation of low-altitude ENA emission during geomagnetic substorm

The low altitude ENA emission generated by the precipitation ions of the ring current located at magnetic latitude 50 °~60 °, 1500~3000 km altitude. Low-orbit sun-synchronous satellites are the closest spacecraft to the ENA emission sources. Utilizing sun-synchronous orbit satellite on boat of a two-dimensional neutral atom-coded aperture imager was simulated, which can realize all-weather and all-orbital conjugate continuous monitoring of low-altitude ENA radiation sources without dead angles. Simulation studies show that: (1) The low orbit the sun synchronous satellite can approach ENA emission source on both inside and outside of radiation belts, remote sensing of neutral atoms image with the temporal resolution about 5s, it helps to analyze precipitation and injection of energetic ions of the ring current, and the causal sequence with the environment field, identify if “the energetic ions come from the solar wind”; (2)Using the high-energy particle spectrum data of the semiconductor detector to confirm the causal sequence between the changes of ion flux in the inner radiation belt and cosmic rays, as well as the corresponding solar proton events, so as to provide the exploration basis for solving the mystery of "particle source in the inner radiation belt"; (3)Due to the north-south conjugate imaging and monitoring characteristics of the neutral atom imager on the low-orbit satellite, it can realize the south and north comparative observation of the ion flux distribution in the South Atlantic anomaly, providing the exploration basis for the study of "the south Atlantic anomaly" ; (4)Due to proximity to ENA emission source, the neutral atom imager will respond to medium-and small-magnitude signals of geomagnetic substorm activity, which will help realize continuous collection and statistical analysis of massive data of geomagnetic activity without missing, and provide important data support for the creation of new space-based weather forecasts.

This study was supported by the National Natural Science Foundation of China (Grant Nos. 41574152)