Current Status and Main Scientific Outcomes of the CSES Mission
Abstract: This report briefly introduces the current status of the CSES (China Seismo-Electromagnetic Satellite) mission which includes the first satellite CSES 01 in-orbit (launched in February 2018), and the second satellite CSES 02 (will be launched in 2023) under development. The CSES 01 has been steadily operating in orbit for over four years, providing abundant global geophysical field data, including the background geomagnetic field, the electromagnetic field and wave, the plasma (in-situ and profile data), and the energetic particles in the ionosphere. The CSES 01 platform and the scientific instruments generally perform well. The data validation and calibration are vital for CSES 01, for it aims to monitor earthquakes by extracting the very weak seismic precursors from a relatively disturbing space electromagnetic environment. For this purpose, we are paying specific efforts to validate data quality comprehensively. From the CSES 01 observations, we have obtained many scientific results on the ionosphere electromagnetic environment, the seismo-ionospheric disturbance phenomena, the space weather process, and the Lithosphere-Atmosphere-Ionosphere coupling mechanism.
Figure 2. ELF/VLF QP waves recorded by CSES satellite in the high-latitude upper ionosphere on 26 February 2018. (a)(b) Power Spectral Density values (PSD) of the magnetic field and the electric field. (c)(d) Density of H+ and He +. (e) Drifting velocity of ions. (f) Density of electron. Data are displayed as a function of Universal Time (UT), geomagnetic longitude (mlon), geomagnetic latitude (mlat) and L shell, respectively
Figure 3. Global distributions of Ne at 02:00 LT of CSES (up panels) and Swarm (bottom panels) under the quiet geomagnetic conditions. From left to right: Ne measurements during 12–19 July 2018, 18–27 November 2018, and 7–16 April 2019, corresponding to roughly at the summer solstice, winter solstice, and spring equinox, respectively. For CSES observations, Ne value range from 0 to 2.5×1010 or 3×1010 m–3, while for Swarm one, Ne is mainly from 0 to 2.5×1011 m–3
Figure 5. MERRA-2 AOD at 18:00 UTC 2013 in the region of EQ epicenter (indicated by a star in the maps). Grey lines indicate main seismic faults in the research area; on the 49–53th, 78–80th days, respectively, with the value on 23th (20 February 2013) subtracted. Latitude (North) and longitude (East) are in degrees
Figure 6. (a)(b) is a comparison between a simulated EM field at CSES altitude from an M6 earthquake with different source depths and sensitivity of CSES EM sensors (10 km, 15 km; lithospheric conductivity is 10–4 S·m–1); (c)(d) is comparison under different lithospheric conductivity and sensitivity of CSES EM sensors (source depth is 15 km; lithospheric conductivity is 10–4 S·m–1 and 10–5 S·m–1)
Figure 7. Lithospheric magnetic anomaly map over China and surrounding regions at average 507 km altitude (a) derived from CSES data and (b) given by the CHAOS-7 model. Abbreviations: TMA, Tarim magnetic high anomaly; SCMA, Sichuan magnetic high anomaly; SGMA, Songliao-Greater Khingan magnetic high anomaly; HMLA, Himalayan-Tibetan magnetic low anomaly
Figure 9. Proton evolution during the large magnetic storm of August 2018 observed by HEPP-H onboard CSES satellite. The outer boundary of the inner radiation belt are denoted by red dotted lines before 26 August (quiet time) and black dotted lines after 26 August (storm time). The flux enhancement within the region of L > 2.5 appearing from 26 August could come from the high-energy electron contamination
Table 1. Possible seismo-ionospheric disturbances recorded by the CSES during the shallow strong EQs
No. Place UTC Lat./
1 Mexico 16 Feb. 2018 23:39:38 16.6 –97.75 7.1 10 The abnormal emissions in frequency 155.5 Hz and 1.405 kHz.
The electron density and ion (O+) density increased two days before the mainshock
2 Papua New Guinea 25 Feb. 2018 17:44:42 –6.19 142.77 7.5 20 The magnetic field enhancement in the frequency 155 Hz nearest the epicenter 7 and 3 days before the mainshock.
The electron/ion disturbed 7, 6, 5, and 2 days before mainshock
3 Loyalty Islands Region 29 Aug. 2018 03:51:54 –21.95 170.1 7.1 20 The electron density increased; the PSD values of the electromagnetic field in ELF frequency increase; the energetic particle flux in the 0.1–3 MeV increased during the mainshock 4 Indonesia 28 Sept. 2018 10:02:44 –0.25 119.9 7.4 10 The electron density significantly increased on 12 and 2 days before the mainshock 5 Papua New Guinea 10 Oct. 2018 20:48:18 –5.70 151.25 7.1 20 The abnormal emissions in ULF/ELF/VLF frequency 9 and 4 days before the mainshock.
The electron density, and energetic particle flux were disturbed 5,and 2 days before and on the mainshock day
6 Kmadek islands, New Zealand 15 Jun. 2019 22:55:00 –30.80 –178.10 7.2 20 The in-situ and occultation electron density abnormally increased within one week before the mainshock 7 Southern waters
28 Jan. 2020 19:10:22 19.46 –78.79 7.7 10 The electron density increased over the conjugate area on January 27 and the epicenter area on January 28 8 Mexico 23 Jun. 2020 15:29:04 16.14 –95.75 7.4 10 The electron density got disturbed 3 days before the mainshock 9 Sumatra island, Indonesia 18 Aug. 2020 22:29:21 –4.31 101.15 7.0 10 The electron density significantly increased 10 days before the mainshock 10 Maduo County, Qinghai, China 21 May. 2021 18:04:11 34.59 98.34 7.4 17 The electron density, and the electromagnetic field in ULF/ELF band observed simultaneous increases 8 days before the mainshock.
The energetic electron in the energy level 0.1 to 3 MeV increased 7 days and 6 days before the mainshock.
The electric field intensity in the VLF band increased one day before the mainshock
11 Near Alaska Peninsula 29 Jul. 2021 06:15:46 55.40 –158.00 8.1 10 The abnormal ULF wave appeared on 10, 2 days before the mainshock.
The Infrared hyperspectral methane, OLR, aerosol, and other long-term observation data observed anomalies more than a month before the earthquake.
12 South water of Alaska 14 Aug. 2021 11:57:42 55.30 –157.75 7.0 10 The abnormal ULF emissions occurred on 12,4 days before and on the mainshock day 13 Haiti region 14 Aug. 2021 12:29:07 18.35 –73.45 7.3 10 The electromagnetic field intensity in the ULF/ELF band increased on August 9, 8, 4 days, and one day before the mainshock.
The energetic particle flux in 100 to 200 keV increased 4 and 3 days before the mainshock
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