[MIS09-05] The ULF waves possibly related to earthquakes in geomagnetic field from CSES and SWARM satellites
★Invited Papers
キーワード：CSES satellite, ULF waves, geomagnetic field
The China Seismo-Electromagnetic satellite (CSES, also named as Zhangheng-1 or ZH-1) is the first Chinese space-borne platform dedicated to geophysical field exploration and earthquake research by monitoring the space electromagnetic environment. It was launched on February 2, 2018, with the operating duration time near to 2 years until now. The CSES is a 3-axes-stablished satellite, with a circular Sun-synchronous orbit at the altitude of 507km and inclination about 97.4º, ascending and descending node at LT02:00 and LT14:00 respectively. Eight scientific payloads are installed onboard CSES, including high precision magnetometer (HPM), Search-coil magnetometer (SCM), Electric field detector (EFD), GNSS radio occultation receiver (GOR), High energetic particle package (HEP), Langmuir probe (LAP), Plasma analyzer package (PAP), and Tri-band beacon (TBB). Three main products are obtained, consisting of vector and scalar electromagnetic field, in-situ plasma parameters, and electron density profiles. All payloads are designed to work in the region within latitude of ±65º, and the burst mode will be automatically switched on over all of China and the Circum-Pacific and Eurasia seismic belts. Here we will mainly introduce some new earthquake results from HPM of CSES. SWARM satellite was launched in Nov. 2013 with three ones at different altitudes, continuously longer than 6 years. Its scientific objective mainly focused on the geomagnetic field model, so the geomagnetic field observation data is the main product from the Vector Field Magnetometer (VFM) and Absolute Scalar Magnetometer (ASM) on this satellite.
During 2018 to 2019, there took place three earthquakes with magnitude around 6.0 in west China, including the Mojiang Ms 5.9 earthquake on Sep. 12 2018 in Yunnan province, Motuo Ms6.2 on Apr. 24 2019 in Tibet Autonomous Region, Changning Ms6.0 on Jun. 17 2019 in Sichuan Province. Here we mainly analyzed the geomagnetic field observations on CSES and SWARM. Firstly we select the CSES and SWARM orbits within the seismic preparation region by the equation of ρ=10^0.43M. Secondly the geomagnetic disturbances were distinguished by removing the multi-point smoothing average data. Thirdly the spectra were calculated to confirm the frequency characteristics of these ULF waves. It is found that before these three earthquakes, some ULF disturbances were clearly detected by satellites near the epicenter. By comparison the multi-satellite observations, the spatial and temporal distributions of these ULF waves in geomagnetic field were studied, and mainly ULF disturbances occurred at dayside, which is greatly different with those nighttime perturbations in plasma parameters from DEMETER and other satellites. The construction and propagation processes of ULF waves were discussed to explain these phenomena finally with multi satellites in different time and altitude of the topside ionosphere, to help us further understanding the seismo-ionospheric coupling mechanism.
This paper is supported by ISSI-BJ (IT2019-33) and National Key R&D Program of China (2018YFC1503506).
During 2018 to 2019, there took place three earthquakes with magnitude around 6.0 in west China, including the Mojiang Ms 5.9 earthquake on Sep. 12 2018 in Yunnan province, Motuo Ms6.2 on Apr. 24 2019 in Tibet Autonomous Region, Changning Ms6.0 on Jun. 17 2019 in Sichuan Province. Here we mainly analyzed the geomagnetic field observations on CSES and SWARM. Firstly we select the CSES and SWARM orbits within the seismic preparation region by the equation of ρ=10^0.43M. Secondly the geomagnetic disturbances were distinguished by removing the multi-point smoothing average data. Thirdly the spectra were calculated to confirm the frequency characteristics of these ULF waves. It is found that before these three earthquakes, some ULF disturbances were clearly detected by satellites near the epicenter. By comparison the multi-satellite observations, the spatial and temporal distributions of these ULF waves in geomagnetic field were studied, and mainly ULF disturbances occurred at dayside, which is greatly different with those nighttime perturbations in plasma parameters from DEMETER and other satellites. The construction and propagation processes of ULF waves were discussed to explain these phenomena finally with multi satellites in different time and altitude of the topside ionosphere, to help us further understanding the seismo-ionospheric coupling mechanism.
This paper is supported by ISSI-BJ (IT2019-33) and National Key R&D Program of China (2018YFC1503506).