New perspectives in the study of the Earth's magnetic field and climate connection: the use of transfer entropy

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

A first insight into the Marsili volcanic seamount (Tyrrhenian Sea, Italy): results from ORION-GEOSTAR3 experiment

The Marsili Seamount is the largest European underwater volcano. It is Plio-Pleistocenic in age, rising up to more than 3000m from the seafloor in the SE Tyrrhenian basin (Central Mediterranean), a back arc basin which began progressively opening 10 Ma ago (Kastens et al., 1988). The seamount lies in a key area for understanding the evolution of the Tyrrhenian region, characterized by high values of heat flow (Della Vedova et al., 2001) and low values of Moho isobaths (Locardi and Nicolich, 1988). In spite of the large dimensions of the Marsili seamount, we still have limited knowledge of its present activity. Ocean exploration is dependent on available technology and infrastructure, which started to develop strongly only after the 1980s. In fact, from its discovery in the 1920s, very little was known of the Marsili Seamount until the late 1990s when new techniques such as multibeam acoustic bathymetry were developed allowed to reveal at least the morphology. Some dedicated expeditions then obtained the first morpho-bathimetric map of the entire Tyrrhenian seafloor, based on multibeam swath-mapping together with seismic, gravimetric and magnetometric data (e.g. Marani and Gamberi, 2004). Although these data have greatly contributed to our understanding, the necessarily short measurement time limits the extent to which they reflect short- to medium-term geophysical processes in the Tyrrhenian basin. New technologies, such as multiparameter seafloor observatories, provide long-term continuous time-series in deep ocean waters, which are the basis for an original approach in ocean exploration. The observation of phenomena variability over time is key to understanding many Earth processes, among which we recall hydrothermal activity, active tectonics, and ecosystem life cycles. The development in Europe of multidisciplinary seafloor observatories has been pioneered under the EC Framework Programmes, specifically in the GEOSTAR projects (Beranzoli et al., 1988, 2000). From 2003 to 2005, long-term geophysical and oceanographic monitoring was conducted within the EC ORION-GEOSTAR3 project with two multiparameter observatories deployed on the seafloor 3320m below sea level (b.s.l.) in the vicinity of the Marsili Seamount. The two observatories were equipped with a set of sensors providing long-term continuous time-series of various physical measurements. The acquired time series are the longest continuous data record of the Marsili Basin available so far. This chaper intends to provide the main information on this experiment and present some results of the processing of the corresponding time-series, adding new valuable information on the still poorly explored activity of the volcano seamount. This chapter is organized as follows: The next section will provide the geological setting to understanding the importance of the Marsili Seamount and its basin; the ORION-GEOSTAR3 experiment is described in Section 24.3; some results from this unprecedented seismic, magnetic and gravimetric data analyses are shown in Section 24.4; and finally, in the last section we present our discussion with the main conclusions.Published623-6413A. Geofisica marina e osservazioni multiparametriche a fondo mar

Magnetic Field and Electron Density Data Analysis from Swarm Satellites Searching for Ionospheric Effects by Great Earthquakes: 12 Case Studies from 2014 to 2016

We analyse Swarm satellite magnetic field and electron density data one month before and one month after 12 strong earthquakes that have occurred in the first 2.5 years of Swarm satellite mission lifetime in the Mediterranean region (magnitude M6.1+) or in the rest of the world (M6.7+). The search for anomalies was limited to the area centred at each earthquake epicentre and bounded by a circle that scales with magnitude according to the Dobrovolsky’s radius. We define the magnetic and electron density anomalies statistically in terms of specific thresholds with respect to the same statistical quantity along the whole residual satellite track (|geomagnetic latitude| ≤ 50°, quiet geomagnetic conditions). Once normalized by the analysed satellite tracks, the anomalies associated to all earthquakes resemble a linear dependence with earthquake magnitude, so supporting the statistical correlation with earthquakes and excluding a relationship by chance.PublishedID 3711A. Geomagnetismo e PaleomagnetismoJCR Journa

NEMO-SN1 Abyssal Cabled Observatory in the Western Ionian Sea

The NEutrinoMediterranean Observatory—Submarine Network 1 (NEMO-SN1) seafloor observatory is located in the central Mediterranean Sea, Western Ionian Sea, off Eastern Sicily (Southern Italy) at 2100-m water depth, 25 km from the harbor of the city of Catania. It is a prototype of a cabled deep-sea multiparameter observatory and the first one operating with real-time data transmission in Europe since 2005. NEMO-SN1 is also the first-established node of the European Multidisciplinary Seafloor Observatory (EMSO), one of the incoming European large-scale research infrastructures included in the Roadmap of the European Strategy Forum on Research Infrastructures (ESFRI) since 2006. EMSO will specifically address long-term monitoring of environmental processes related to marine ecosystems, marine mammals, climate change, and geohazards

Repeat-station surveys: implications from chaos and ergodicity of the recent geomagnetic field

The present geomagnetic field is chaotic and ergodic: chaotic because it can no longer be predicted beyond around 6 years; and ergodic in the sense that time averages correspond to phase-space averages. These properties have already been deduced from complex analyses of observatory time series in a reconstructed phase space and from global predicted and definitive models of differences in the time domain. These results imply that there is a strong necessity to make repeat-station magnetic surveys more frequently than every 5 years. This, in turn, will also improve the geomagnetic field secular variation models. This report provides practical examples and case studies.

Swarm Langmuir probes' data quality validation and future improvements

Swarm is the European Space Agency (ESA)'s first Earth observation constellation mission, which was launched in 2013 to study the geomagnetic field and its temporal evolution. Two Langmuir probes aboard each of the three Swarm satellites provide in situ measurements of plasma parameters, which contribute to the study of the ionospheric plasma dynamics. To maintain a high data quality for scientific and technical applications, the Swarm products are continuously monitored and validated via science-oriented diagnostics. This paper presents an overview of the data quality of the Swarm Langmuir probes' measurements. The data quality is assessed by analysing short and long data segments, where the latter are selected to be sufficiently long enough to consider the impact of the solar activity. Langmuir probe data have been validated through comparison with numerical models, other satellite missions, and ground observations. Based on the outcomes from quality control and validation activities conducted by ESA, as well as scientific analysis and feedback provided by the user community, the Swarm products are regularly upgraded. In this paper, we discuss the data quality improvements introduced with the latest baseline, and how the data quality is influenced by the solar cycle. In particular, plasma measurements are more accurate in day-side regions during high solar activity, while electron temperature measurements are more reliable during night side at middle and low latitudes during low solar activity. The main anomalies affecting the Langmuir probe measurements are described, as well as possible improvements in the derived plasma parameters to be implemented in future baselines

Swarm Langmuir probes' data quality validation and future improvements

Swarm is the European Space Agency (ESA)'s first Earth observation constellation mission, which was launched in 2013 to study the geomagnetic field and its temporal evolution. Two Langmuir probes aboard each of the three Swarm satellites provide in situ measurements of plasma parameters, which contribute to the study of the ionospheric plasma dynamics. To maintain a high data quality for scientific and technical applications, the Swarm products are continuously monitored and validated via science-oriented diagnostics. This paper presents an overview of the data quality of the Swarm Langmuir probes' measurements. The data quality is assessed by analysing short and long data segments, where the latter are selected to be sufficiently long enough to consider the impact of the solar activity. Langmuir probe data have been validated through comparison with numerical models, other satellite missions, and ground observations. Based on the outcomes from quality control and validation activities conducted by ESA, as well as scientific analysis and feedback provided by the user community, the Swarm products are regularly upgraded. In this paper, we discuss the data quality improvements introduced with the latest baseline, and how the data quality is influenced by the solar cycle. In particular, plasma measurements are more accurate in day-side regions during high solar activity, while electron temperature measurements are more reliable during night side at middle and low latitudes during low solar activity. The main anomalies affecting the Langmuir probe measurements are described, as well as possible improvements in the derived plasma parameters to be implemented in future baselines. Astrodynamics & Space Mission