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The ESA Swarm mission, launched on 22 November 2013, consists of three spacecraft each equipped with a Micro Advanced Stellar Compass (μ ASC) from the Technical University of Denmark (DTU). Each μ ASC features three Camera Head Units (CHUs) orientated orthogonally to optimize system accuracy performance and avoid simultaneous blinding. The image sensors inside the CHUs are sensitive to ionizing radiation. When an energetic particle impacts the image sensor, electrons are liberated along the particle's ionizing track and appear on the source image as white dots dubbed 'energetic particle detection' (EPD) events. For star tracker applications EPDs are normally supressed to support nominal attitude operation. However, in early 2018 software was uploaded to the μ ASCs on-board Swarm, which on top of using the EPD measurements to improve the image for star tracking, is reporting the EPD count to the telemetry to ground. This added functionality enables detection and monitoring of high energy particles. By taking advantage of the sample rates (1-2 Hz), the orientation of the camera heads and simultaneous measurements from all three spacecraft spatial derivatives of the EDP aligned to electric and magnetic fields can be determined. Furthermore, since the Swarm spacecraft are in circular, near-polar orbits at an altitude of 450-510 km the spacecraft continuously monitor and map high energy particles at the South Atlantic Anomaly (SAA) of relevance for future mission planning as well as provide detailed time-radiation relations from charge injections processes from e.g. Coronal Mass Ejections (CMEs). In this work we present processes and analysis of four years of high energy radiation data obtained from the Micro Advanced Stellar Compass (μ ASC) on board ESA's Swarm mission, from February 2018 to February 2022. [ABSTRACT FROM AUTHOR]

The debated question on the possible relation between the Earth’s magnetic field and climate has been usually focused on direct correlations between different time series representing both systems. However, the physical mechanism able to potentially explain this connection is still an open issue. Finding hints about how this connection could work would suppose an important advance in the search of an adequate physical mechanism. Here, we propose an innovative information-theoretic tool, i.e. the transfer entropy, as a good candidate for this scope because is able to determine, not simply the possible existence of a connection, but even the direction in which the link is produced. We have applied this new methodology to two real time series, the South Atlantic Anomaly (SAA) area extent at the Earth’s surface (representing the geomagnetic field system) and the Global Sea Level (GSL) rise (for the climate system) for the last 300 years, to measure the possible information flow and sense between them. This connection was previously suggested considering only the long-term trend while now we study this possibility also in shorter scales. The new results seem to support this hypothesis, with more information transferred from the SAA to the GSL time series, with about 90% of confidence level. This result provides new clues on the existence of a link between the geomagnetic field and the Earth’s climate in the past and on the physical mechanism involved because, thanks to the application of the transfer entropy, we have determined that the sense of the connection seems to go from the system that produces geomagnetic field to the climate system. Of course, the connection does not mean that the geomagnetic field is fully responsible for the climate changes, rather that it is an important driving component to the variations of the climate. [ABSTRACT FROM AUTHOR]

The article presents a study which uses spectral analysis to analyze geomagnetic field time-series. It mentions the proposed algorithm used in the detection of the geomagnetic jerks in time-series that occur mainly in the Eastern part of the geomagnetic field. It states that the method resulted to understanding of spatial evolution of changes in the geomagnetic field.

The article presents a study that uses two spectral techniques in terms of Fourier and wavelet analysis to detect geometric jerks time series. It suggests that the analysis allows researchers to depict the most important space-time features of the geomagnetic jerks on global scale. It reveals that the spherical harmonic analysis of the secular acceleration power spectrum brings new insights in understanding the rapid changes of the geomagnetic field and their origin.

Abstract: The geomagnetic field is a fundamental property of our planet: its study would allow us to understand those processes of Earth’s interior, which act in its outer core and produce the main field. Knowledge of whether the field is ergodic, i.e. whether time averages correspond to phase space averages, is an important question since, if this were true, it would point out a strong spatio-temporal coupling amongst the components of the dynamical system behind the present geomagnetic field generation. Another consequence would be that many computations, usually undertaken with many difficulties in the phase space, can be made in the conventional time domain. We analyse the temporal behaviour of the deviation between predictive and definitive geomagnetic global models for successive intervals from 1965 to 2010, finding a similar exponential growth with time. Also going back in time (at around 1600 and 1900 by using the GUFM1 model) confirms the same findings. This result corroborates previous chaotic analyses made in a reconstructed phase space from geomagnetic observatory time series, confirming the chaotic character of the recent geomagnetic field with no reliable prediction after around 6years from definitive values, and disclosing the potentiality of estimating important entropic quantities of the field by time averages. Although more tests will be necessary, some of our analyses confirm the efforts to improve the representation of the geomagnetic field with more detailed secular variation and acceleration. [Copyright &y& Elsevier]

Direct measurements of the geomagnetic field have been made for more than 400 years, beginning with individual determinations of the angle between geographic and magnetic North. This was followed by the start of continuous time series of full vector measurements at geomagnetic observatories and the beginning of geomagnetic repeat stations surveys in the 19th century. In the second half of the 20th century, true global coverage with geomagnetic field measurements was accomplished by magnetometer payloads on low-Earth-orbiting satellites. This article describes the procedures and instruments for magnetic field measurements on ground and in space and covers geomagnetic observatories, repeat stations, automatic observatories, satellites and historic observations. Special emphasis is laid on the global network of geomagnetic observatories. [ABSTRACT FROM AUTHOR]

Abstract: We present a review of our work on data acquired by GEOSTAR-class (GEophysical and Oceanographic STation for Abyssal Research) observatories deployed at three EMSO (European Multidisciplinary Seafloor and water-column Observatory; http://www.emso-eu.org) sites in southern European waters where strong geo-hazards are present: the Western Iberian Margin, the Western Ionian Sea, the Marmara Sea, and the Marsili basin in the Tyrrhenian Sea. A procedure for multiparameter data quality control is described. Then we explain why the seafloor is an interesting observation point for geophysical parameters and how it differs from land sites. We consider four interesting geophysical phenomena found at the EMSO sites that are related to geo-hazard. In the first case, we show how unknown seismicity and landslides in the Western Ionian Sea were identified and roughly localised through a single-sensor analysis based on the seismometer. In the second case, we concentrate on the problem of near-coast tsunami generation and describe a Tsunami Early Warning Detection (TEWD) system, tested in the Western Iberian Margin and currently operating in real time at the Western Ionian site. In the third case, we consider two large volcanoes in the central Mediterranean area, Mt. Etna and the Marsili seamount. Signals from the seismometer and gravimeter recorded at the seafloor at 2100m b.s.l. show various phases of Mt. Etna's 2002–2003 eruption. For the less-known Marsili we illustrate how several indicators coming from different sensors point to hydrothermal activity. A vector magnetometer at the two volcanic sites helps identify the magnetic lithospheric depth. In the fourth and final case, we present a multiparameter analysis which was focused on finding possible correlations between methane seepage and seismic energy release in the Gulf of Izmit (Marmara Sea). [Copyright &y& Elsevier]