Satellite Measured Ionospheric Magnetic Field Variations over Natural Hazards Sites

Abstract

Processes and threats related to natural hazards play an important role in the evolution of the Earth and in human history. The purpose of this study is to investigate magnetic field variations measured at low Earth orbit (LEO) altitudes possibly associated with earthquakes, volcanic eruptions, and artificial outbursts. We focus on two missions with well equipped magnetometer packages, the China Seismo-Electromagnetic Satellite (CSES) and ESA’s three spacecraft Swarm fleet. After a natural hazards survey in the context of this satellites, and consideration of external magnetospheric and solar influences, together with spacecraft interferences, wavelet analysed spatio-temporal patterns in ionospheric magnetic field variations related to atmospheric waves are examined in detail. We provide assessment of the links between specific lithospheric or near surface sources and ionospheric magnetic field measurements. For some of the diverse events the achieved statistical results show a change in the pattern between pre- and post-event periods, we show there is an increase in the fluctuations for the higher frequency (smaller scales) components. Our results are relevant to studies which establish a link between space based magnetic field measurements and natural hazards.

Potential Earthquake Proxies from Remote Sensing Data

“…In Ref. [69], the authors inspected magnetic field variations from earthquakeassociated satellites, utilizing the China Seismo-Electromagnetic Satellite (CSES) and ESA's three spacecraft Swarm fleet. The study accessed links between specific lithospheric or near-surface sources and ionospheric magnetic field measurements, revealing increased fluctuations in higher-frequency components.…”

Case study of radio emission beam associated to very low frequency signal recorded onboard CSES satellite

“…The high-precision magnetometer and search coil magnetometer (Schirninger et al, 2021) and Electric Field Detector (Zhang et al, 2020) perform electromagnetic measurements. EFD experiment is part of the eight scientific payloads and is devoted to a continuous survey of the electric field fluctuations at the altitudes of CSES satellite.…”

“…Such solar flares increase the ionospheric electron density where propagate the VLF radio signal, and generate phase and amplitude anomalies. The interest to the solar effect on the Earth's ionosphere increases, since few years, by the developing of VLF network towards a better spatial coverage as performed in Europe (Biagi et al, 2019;Schwingenschuh et al, 2011). Other solar indexes were considered, like sunspots and solar radio flux, in investigating VLF radio propagation in periods of high solar activity.…”