8:30am - 8:45am
Swarm Satellite Data Analysis For Earthquake Preparatory Phase Studies
1Istituto Nazionale di Geofisica e Vulcanologia, Italy; 2Universidad Complutense de Madrid, Spain; 3Planetek Italia spa
The primary goal of the Swarm three-satellite mission is to measure the magnetic signals from the Earth, in order to better monitor and study with greatest detail its planetary magnetic field. One of the STSE Swarm + Innovation ESA funded project, SAFE (Swarm for Earthquake study), aims at applying the new approach of geosystemics to the analysis of Swarm magnetic and electron density data for investigating the preparatory phase of earthquakes as seen from space, with integration of ground based (ionosonde and GPS/GNSS) data. The main objective is to explore the possible link between magnetic/ionospheric anomalies and large earthquakes. This contribution shows the importance of this novel approach for several earthquake case studies. Finally, in the framework of the SAFE project, a web exploitation platform has also been developed, in order to show, demonstrate and help scientific stakeholders in understanding and analyzing the possible relations between Swarm, in situ and ancillary data and possible earthquake precursors
8:45am - 9:00am
The Search of the Cross Correlation Between the Ground Based and Swarm Registration of the Thunderstorms and TLE’s Effects
1Space Research Centre PAS, Warsaw, Poland; 2OBSEE, Warsaw, Poland; 3AGH University of Science and Technology, Cracow, Poland; 4ESTEC, Noordwijk, Netherland
The main goal of this presentation is discussion of the cross correlation between the ground based and Swarm registration of the effects related to the thunderstorm and TLE’s. The brief review of the expected effects is given as an introduction. The simple model of the connection between ground effects and satellite registration in given in next part. Further the main results are presented. Ground-based observations of atmospheric discharges in the ELF range are carried out using broadband low noise magnetometers currently operated in three ELF stations. The Hylaty ELF station is located in Poland, near the Bieszczady National Park, Hugo station, installed in May 2015, is located in Colorado, USA and the Patagonia station, installed in March 2016, is located in southern Patagonia, Argentina. The three stations form the WERA system (World ELF Radiolocation Array) that enable us to observe very strong atmospheric discharges occurring anywhere on Earth. 430 lightning discharges with charge moment 1000 [Ckm] has been identified as potential candidates for the cross-analysis with the Swarm measurements. Spatial distribution of these events is presented. The Swarm data are variations of the magnetic field with sampling frequency 50Hz and electron density from Langmuir probe with sampling 1Hz. Steps distinguished in the magnetic data processing chain are as follows: δBi residuals retrieval from the measured signal for three B components, FFT transformation applied to the δBi residuals, generation of time-frequency spectrograms for δBi along the orbit in the frequency range up to 25Hz, integration of lightning‘s database with derived Swarm δBi spectra. Identification of signals generated by strong electric discharges is based on the analysis of time-frequency spectrograms for the wave data. The response of Swarm to sequence of sprites documented with ground based optical sensor is presented. The event registered on August 17, 2016 at 21:40:57.8 took place in Croatia eastwards from Novigrad 45.35 N 13.75E.
9:00am - 9:15am
Lightning-Generated Whistlers Observed during ASM Burst Mode Sessions
1Institut de Physique du Globe de Paris, Sorbonne Paris Cité, Université Paris Diderot, CNRS, F-75005 Paris, France; 2British Geological Survey, Murchison House, West Mains Road, EH9 3LA, Edinburgh, UK; 3CEA, LETI, MINATEC Campus, F-38054 Grenoble, France
Lighting-released energy covers a wide band of the electromagnetic spectrum. The propagation of the corresponding electromagnetic signal is not limited to the neutral atmosphere, and specific whistler-modes of propagation can enter the ionosphere, thus allowing their detection by LEO satellites. Though most of the whistler energy is released between 1 and 10 kHz, part of it appears to be also released in the frequency band 10-125 Hz detectable by the Swarm Absolute Scalar Magnetometers (ASM) operated in burst mode (250 Hz).
Several hundreds of whistler events were indeed recorded in this way when a few burst-mode sessions were operated during the commissioning phase of the Swarm mission, at the beginning of 2014. These events have been unambiguously correlated with strong lightning strikes detected and located on ground by the World Wide Lightning Location Network (WWLLN). We developed a simple ray-tracing software to understand the propagation properties of these low-frequency whistlers. It uses the Appleton refraction index through the ionosphere plasma in the Earth magnetic field and solves the Haselgrove equations of propagation. We have thus been able to recover satisfyingly the propagation time and dispersion relation observed in the Swarm data.
9:15am - 9:30am
The Contribution of CSES Mission to Study Lithosphere-Atmosphere-Ionosphere Coupling Phenomena Through the Analysis of Combined Missions Data and Ground Measurements
1Agenzia Spaziale Italiana, Italy; 2INFN - Sezione Roma 2, Rome, Italy; 3INFN - TIFPA, Trento, Italy; 4INFN - Sezione of Bologna, Bologna, Italy; 5INFN - LNF, Frascati, Italy; 6INFN - Sezione of Napoli, Napoli, Italy; 7INFN - Sezione of Perugia, Perugia, Italy; 8University of Bologna, Bologna, Italy; 9University of Perugia,Perugia, Italy; 10University of Tor Vergata, Roma, Italy; 11University of Trento, Trento, Italy; 12Uninettuno University, Rome, Italy; 13INAF-IAPS, Rome, Italy; 14INGV, Rome, Italy; 15Fondazione Bruno Kessler, Trento, Italy; 16CEA, Beijing, China; 17National Research Nuclear University MEPhI, Moscow, Russia
We present the CSES (China Seismo-Electromagnetic Satellite) mission that aims at investigating electromagnetic field, plasma and particles in the near-Earth environment in order to study: seismic precursors, particles fluxes (from Van Allen belts, cosmic rays, solar wind, etc.), anthropogenic electromagnetic emissions and more in general the atmosphere-ionosphere-magnetosphere coupling mechanisms that can also affect the climate changes. CSES – the first of two twin missions developed by the CNSA (China National Space Agency) together with the ASI (Italian Space Agency) – will be launched by the summer of 2017 on a polar orbit, at about 500 km, for a lifespan greater than 5 years. Several studies (such as the DEMETER analyses, the SAFE (SwArm For Earthquake study) project funded by the ESA, etc.) have shown that LEO satellite observations of electromagnetic fields, plasma parameters and particle fluxes can be able to investigate electromagnetic emissions possibly associated to earthquakes of medium and high magnitude. Although the earthquakes forecasting is not possible today, it is certainly a major challenge for science in the near future. The claims that the reported anomalies are seismic precursors are still intensely debated and analyses for confirming correlations are still lacking. In fact, in order to identify seismo-associated perturbations, it is needed to reject the “normal” background effects of the e.m. emissions due to: geomagnetic storms, tropospheric phenomena, and artificial sources (such as power lines, VLF transmitters, HF stations, etc.). Currently, the largest available database for studies of seismo-associated phenomena is that collected by the DEMETER satellite and by observations executed by some other space missions, non-dedicated to this purpose. The CSES satellite aims at continuing the exploration started by DEMETER with advanced multi-parametric measurements. In order to execute observations of energetic particle fluxes, ionospheric plasma parameters and electromagnetic fields - in a wide range of energy and frequencies – CSES is equipped with several instruments: HEPD (High Energy Particle Detector); HEPP (Low Energy Particle Detector); LP (Langmuir Probes); IDM (Ion Drift Meter); ICM (Ion Capture Meter); RPA (Retarding Potential Analyzer); EFD (Electric Field Detectors) with 4 probes installed on 4 deployable booms; HPM (High Precision Magnetometer); and SCM (Search-Coil Magnetometer). The SWARM satellites and CSES will be flying in the same time, at a similar altitude/inclination, by executing measurements of several similar parameters. The observations executed by CSES (and by its twin CSES-2) can complement those performed by SWARM increasing the monitoring capability and the range of observations. On the other side, the CSES multi-instruments payload includes two particles detectors and an electric-field detector (not installed on SWARM satellites) that can improve the capability to study the top side ionosphere giving an important contribution in monitoring the solar-terrestrial interactions. Finally, CSES will be the only satellite, with these characteristics, flying in the near future simultaneously with the SWARM mission. In this framework, we will discuss the CSES mission, its complementarity and differences with SWARM, as well as the possible overlap between the scientific investigations performed by the two missions.
9:30am - 9:45am
How Swarm Can Help Solve the Mystery of Extremely Fast Ultra-Relativistic Electron Loss in the Outer Van Allen Radiation Belt.
1University of Alberta, Canada; 2NASA Goddard Space Flight Centre, Greenbelt, Maryland, USA
Understanding the dynamics of the relativistic electrons in the Earth’s Van Allen radiation belts remains one of the most important and fundamental challenges in space physics. One of the major challenges is the fact that the dynamics of the outer radiation belt are controlled by a delicate balance between electron acceleration and loss processes. Enhancements in the outer radiation belt flux can be caused by multiple different processes which may occur at the same time during magnetic storms, such as local acceleration of the electrons by chorus waves and inward ULF wave radial diffusion. Geomagnetic storms are also times of electron loss from the potential action of multiple possible processes. For example, enhanced outward radial diffusion and magnetopause shadowing can cause the loss of electrons through the magnetopause, whilst pitch-angle scattering of the electrons into the loss cone can cause electron loss to the atmosphere by wave-particle interactions with waves such as chorus, hiss and EMIC waves. Several observations of rapid decreases in the flux of ultra-relativistic electrons in the outer radiation belt measured with the Van Allen probes during geomagnetic storms will be presented. Simulations of the electron flux dynamics during these geomagnetic storms will also be presented obtained using our radiation belt model. These simulation results illustrate that an additional loss process is required in our radiation belt model to reproduce the observed rapid electron flux decrease. Using Swarm measurements we show that EMIC waves were present during the rapid decreases in the flux of ultra-relativistic electrons, and show that once the effects of EMIC wave scattering of electrons into the atmosphere are included in our model, then the electron flux dynamics observed by the Van Allen probes during these geomagnetic storms can be accurately reproduced by our model. The results highlight the importance of the Swarm probes for detecting short duration (<2 hour) EMIC waves and for determining the range of L-shells where these waves are occurring.
9:45am - 10:00am
10-year Time Series of GNSS Daily Solutions, Geomagnetic Storms and Biggest Earthquakes
1University of Latvia, Latvia; 2Riga Technical university
10-year GNSS daily solutions performed at the University of Latvia by using Bernese software, EUREF recommended methodology and IGS/EPN reference network. The daily solutions were performed for continuously operating GNSS RTK reference network stations in Latvia. The graphs are designed for 10-year time series where the information of both each year 50 strongest geomagnetic storms and earthquakes in the world of magnitude 6.0 and stronger, correspondingly. The effect of small earthquakes in surrounding counties is analysed. Some statistics has been summarized on the relation of computed daily coordinates and both space weather and earthquakes in the world.