CSES High Precision Magnetometer Data Products and Example Study of an Intense Geomagnetic Storm

International audienceProviding accurate measurement of the magnetic field intensity and its vector components is one of the primary objectives of the China Seismo Electromagnetic Satellite (CSES). The high precision magnetometer (HPM) payload assembled on CSES is designed to achieve this goal. In this study, the data format, naming convention, and content of the CSES HPM Level 2 scientific data products are introduced, as a reference for users who are interested in this data set. In particular, flags for potential magnetic field disturbances from the platform and payloads are discussed. Possible scientific applications are also outlined. A preliminary validation of the data is conducted through comparison with magnetic data from the ESA's Swarm constellation, and the result demonstrates that the HPM data of CSES are of good quality. Taking the intense geomagnetic storm that occurred on August 25-26, 2018 as an example, the magnetic field variations and the expansion of the field aligned currents (FACs) during this storm are discussed. We finally show that the CSES HPM data can be used to derive a satellite derived index equivalent to the Dst index, which agrees well to the index during this event. Our analysis thus suggests a high scientific potential of the HPM data