This is a collection of articles relating to a question about the mechanism whereby excitation of plasma in ionosphere transfers energy back to earth (to possibly induce earthquakes) via ionosphere/atmosphere/lithosphere coupling.
Title: Preseismic Lithosphere-Atmosphere-Ionosphere Coupling
Authors: Kamogawa, Masashi
Publication: 40th COSPAR Scientific Assembly. Held 2-10 August 2014, in Moscow, Russia, Abstract C2.2-58-14. Publication Date: 00/2014
Preseismic atmospheric and ionospheric disturbances besides preseismic geo-electric potential anomalies and ultra-low-frequency (ULF) geomagnetic variations observed on the ground have been reported. Both the phenomena have been found since the 1980s and a number of papers have been published. Since most of the reported phenomena transiently appear with accompanying quiescence before the mainshock, this prevents us to intuitively recognize a correlation between the anomaly appearance and the earthquake occurrence.
Some of them, however, showed that anomalies monotonically grew into the mainshock, of which a variation supports the concept of seismic nucleation process under the pre-earthquake state. For example, Heki [GRL, 2011] reported that ionospheric electron density monotonically enhanced tens of minutes prior to the subduction mega-earthquake. However, this preseismic enhancement is apparent variation attributed to tsunamigenic ionospheric hole [Kakinami and Kamogawa et al, GRL, 2012], namely wide and long-duration depression of ionospheric electron after tsunami-excited acoustic waves reach the ionosphere. Since the tsunamigenic ionospheric hole could be simulated [Shinagawa et al., GRL, 2013], the reported variations are high-possibly pseudo phenomena [Kamogawa and Kakinami, JGR, 2013]. Thus, there are barely a few reports which show the preseismic monotonic variation supported by the concept of the seismic nucleation process.
As far as we discuss the preseismic geoelectromagnetical and atmospheric-ionospheric anomalies, preseismic transient events from a few weeks to a few hours prior to the mainshock are paid attention to for the precursor study. In order to identify precursors from a number of anomalies, one has to show a statistical significance of correlation between the earthquake and the anomalies, to elucidate the physical mechanism, or to conduct both statistical and physical approach. Since many speculation of the physical mechanism have been hardly verified so far, a statistical approach has been unique way to promote the research. After the 2000s, several papers showing robust statistical results have arisen. In this paper, we focus on publications satisfying the following identification criteria: 1) A candidate of precursor, namely anomaly, is quantitatively defied. 2) Two time-series of anomalies and earthquake are constructed within the fixed thresholds such as a minimum magnitude, a region, and a lead-time. 3) To obtain a statistical correlation, a statistical process which includes four relations considering all combination among earthquake – no earthquake versus anomaly and no anomalies is applied, e. g., phi correlation. 4) For correlations under various thresholds the results keep consistency. 5) Large anomalies appear before large earthquakes.
One of papers based on the identification criteria, which concerns preseismic geoelectrically anomalies, is introduced as an educative example. VAN method in Greece, i. e., Geo-electric potential difference measurement for precursor study in Greece, has been often discussed in the point of view of success and failure performance for practical prediction [Varotsos et al, Springer, 2011] to show a correlation and then less number of papers shows the statistical correlation with satisfying the identification criteria [Geller (ed.), GRL, 1996], so that the phenomena had been controversial. However, recent related study in Kozu-Island, Japan which satisfied the criteria showed the robust correlation [Orihara and Kamogawa et al., PNAS, 2012]. Therefore, the preseismic geoelectric anomalies are expected to be a precursor.
Preseismic lithosphere-atmosphere-ionosphere coupling has been intensively discussed [Kamogawa, Eos, 2006]. According to review based on the identification criteria with considering recent publications, plausible precursors have been found, which are tropospheric anomaly [Fujiwara and Kamogawa, GRL, 2004], daytime electron depletion in F region [Liu et al, JGR, 2006], nighttime decrease of background intensity of VLF electromagnetic waves possibly attributed to ionospheric disturbance in D region [Nemec et al., GRL, 2008; Nemec et al., JGR, 2009; Pisa et al, JGR, 2013]. Although these reported anomalies are plausible from a statistical correlation mostly satisfying the above criteria. In this presentation, I review recent studies of preseismic atmospheric-ionospheric coupling and introduce the plausible mechanisms.
Generation of ELF and ULF electromagnetic waves by modulated heating of the ionospheric F2 region / Eliasson, B.; Chang, C.-L.; Papadopoulos, K.
AA(Institute for Theoretical Physics, Ruhr-University Bochum, Bochum, Germany), AB(Technology Solutions, BAE Systems, Arlington, Virginia, USA), AC(Technology Solutions, BAE Systems, Arlington, Virginia, USA)
Journal of Geophysical Research, Volume 117, Issue A10, CiteID A10320 (JGRA Homepage). Publication Date: 10/2012
Ionosphere: Active experiments, Ionosphere: Ionospheric dynamics, Ionosphere: Wave propagation
We present a theoretical and numerical study of the generation of extremely low frequency (ELF) and ultra-low frequency (ULF) waves by the modulation of the electron pressure at the F2-region with an intense high-frequency electromagnetic wave. The study is based on a cold plasma Hall-MHD model, including electron-neutral and ion-neutral collisions, which governs the dynamics of magnetostatic waves and their propagation through the ionospheric layers. Magnetosonic waves generated in the F2 region are propagating isotropically and are channeled in the ionospheric waveguide, while shear Alfvén waves are propagating along the magnetic field.
To penetrate the ionosphere from the F2 peak at 300 km to the ground, the magnetostatic waves first propagate as magnetosonic or shear Alfvén waves that encounter a diffusive layer from about 150 km to 120 km where the Pedersen conductivity dominates, and then as helicon (whistler-like) mode waves from about 120 km to 80 km where the ions are collisionally glued to the neutrals and the Hall conductivity dominates. By performing numerical simulations and studying the dispersive properties of the wave modes, we investigate the dynamics and penetration of ELF/ULF waves through the ionospheric layers to the ground and along the geomagnetic field lines to the magnetosphere. Realistic profiles of the ionospheric profiles of conductivity and density are used, together with different configurations of the geomagnetic field, relevant for both the high, mid and equatorial latitudes. Some of the results are compared with recent HAARP experiments.
Title: Shear Alfven Wave Injection in the Magnetosphere by Ionospheric Modifications in the Absence of Electrojet Currents
Authors: Papadopoulos, K.; Eliasson, B.; Shao, X.; Labenski, J.; Chang, C.
Affiliation: AA(Physics & Astronomy, Univ of Maryland, College Park, MD, USA; firstname.lastname@example.org), AB(Physics & Astronomy, Univ of Maryland, College Park, MD, USA; email@example.com), AC(Physics & Astronomy, Univ of Maryland, College Park, MD, USA; firstname.lastname@example.org), AD(2000 N. 15th Street, Technology Solutions, BAE Systems, Arlington, Germany; email@example.com), AE(2000 N. 15th Street, Technology Solutions, BAE Systems, Arlington, Germany; firstname.lastname@example.org) / Publication:American Geophysical Union, Fall Meeting 2011, abstract #SM34A-01; Publication Date:12/2011
2403 IONOSPHERE / Active experiments, 2431 IONOSPHERE / Ionosphere/magnetosphere interactions, 2447 IONOSPHERE / Modeling and forecasting, 2487 IONOSPHERE / Wave propagation
A new concept of generating ionospheric currents in the ULF/ELF range with modulated HF heating using ground-based transmitters even in the absence of electrojet currents is presented.
The new concept relies on using HF heating of the F-region to modulate the electron temperature and has been given the name Ionospheric Current Drive (ICD). In ICD, the pressure gradient associated with anomalous or collisional F-region electron heating drives a local diamagnetic current that acts as an antenna to inject mainly Magneto-Sonic (MS) waves in the ionospheric plasma.
The electric field associated with the MS wave drives Hall currents when it reaches the E region of the ionosphere. The Hall currents act as a secondary antenna that inject waves in the Earth-Ionosphere Waveguide (EIW) below and shear Alfven waves or EMIC waves upwards towards the conjugate regions.
The paper presents: (i) Theoretical results using a cold Hall MHD model to study ICD and the generation of ULF/ELF waves by the modulation of the electron pressure at the F2-region with an intense HF electromagnetic wave. The model solves equations governing the dynamics of the shear Alfven and magnetosonic modes, of the damped modes in the diffusive Pedersen layer, and of the weakly damped helicon wave mode in the Hall-dominated E-region. The model incorporates realistic profile of the ionospheric conductivities and magnetic field configuration. We use the model to simulate propagation and dynamics of the low-frequency waves and their injection into the magnetosphere from the HAARP and Arecibo ionospheric heaters. (ii) Proof of principle experiments using the HAARP ionospheric heater in conjunction with measurements by the DEMETER satellite This work is supported by ONR MURI grant and DARPA BRIOCHE Program.
International Journal of Geophysics March 2011
Electrodynamical Coupling of Earth’s Atmosphere and Ionosphere: An Overview
A. K. Singh, Devendraa Siingh, R. P. Singh, and Sandhya Mishra
Department of Physics, University of Lucknow, Lucknow 226007, India
Indian Institute of Tropical Meteorology, Pune 411-008, India
Physics Department, Banaras Hindu University, Varanasi 221005, India
Electrical processes occurring in the atmosphere couple the atmosphere and ionosphere, because both DC and AC effects operate at the speed of light. The electrostatic and electromagnetic field changes in global electric circuit arise from thunderstorm, lightning discharges, and optical emissions in the mesosphere. The precipitation of magnetospheric electrons affects higher latitudes. The radioactive elements emitted during the earthquakes affect electron density and conductivity in the lower atmosphere. In the present paper, we have briefly reviewed our present understanding of how these events play a key role in energy transfer from the lower atmosphere to the ionosphere, which ultimately results in the Earth’s atmosphere-ionosphere coupling.
The atmosphere of the Earth is a layer of gases surrounding the Earth that is retained by Earth’s gravity. The atmosphere protects life on the Earth by absorbing the ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect), and reducing temperature extremes between day and night. Based on temperature distribution, atmosphere is divided into the troposphere, stratosphere, mesosphere, and thermosphere. The temperature in the thermosphere remains almost constant (Figure 1) . The stratosphere and mesosphere regions are also grouped as the middle atmosphere. The region above the middle atmosphere is called the upper atmosphere where solar radiation and other sources ionize the neutral constituents forming plasma of ions and electrons. The region extending from the mesosphere to the thermosphere is called ionosphere where plasma dynamics is controlled by the collisions between the ionized particles and neutrals as well as between the ionized particles themselves. The region above the ionosphere is known as the magnetosphere. In this region, charged particles dynamics is controlled by the Earth’s magnetic field because the density collision frequency is very low. There is no sharp boundary between the upper ionosphere and the lower magnetosphere region.
The ionosphere system is mainly controlled by various external sources of forcing and number of mechanisms operative in the system to convert, transport, and redistribute the input energy. Solar extreme ultraviolet (EUV) radiation and particle energy from the sun in the form of precipitating solar wind plasma energetic particle influence from the above, while tides, planetary waves, gravity waves, electromagnetic waves in wide frequency range, turbulence, convection, and so forth from the below. Even processes taking place below/on/above the surface of the Earth also affect the ionosphere and its processes. In fact, lower atmosphere/middle atmosphere/upper atmosphere (ionosphere)/magnetosphere acts as a multi-coupled system. The coupling occurs mainly through the dynamical, chemical, and electrical processes.
The ionosphere reacts to various phenomena such as lightening discharges, functioning of high-power transmitters, high-power explosion, earthquakes, volcano eruptions, and typhoons through a chain of interconnected processes in the lithosphere-atmosphere-ionosphere interaction system.
Thunderstorms play a major role in transferring energy from the atmosphere to the ionosphere  and in establishing electrical coupling between atmosphere and ionosphere through the global electric circuit (GEC). The Earth’s surface has a net negative charge, and there is an equal and opposite positive charge distributed throughout the atmosphere above the surface. The electrical structures of the lower atmosphere, GEC, and conductivity profile shown in Figure 1 are deeply influenced by cosmic ray flux , high-power transmitted waves [5–7], and earthquakes . Lightening-generated whistler mode waves scatter radiation belt trapped electrons which precipitate into the lower ionosphere and result into the additional ionization and formation of ionospheric inhomogeneities [9, 10]. The powerful high-frequency transmitted waves produce ionospheric heating which, in turn, causes generation of ultra-low-frequency (ULF) and extremely low-frequency (ELF) waves , the formation of very low-frequency (VLF) ducts and other types of inhomogeneities [12, 13], the acceleration of ions, and the excitation of atmospheric emissions in different spectral bands . The effects of these processes on the GEC (including the ionosphere) are not yet fully understood.
…The generation of transient mesospheric electric field needs detailed study as it provides a basis for developing coupled troposphere-mesosphere-ionosphere electrodynamic models under disturbed conditions. In fact, numerous phenomena that occur in the upper atmosphere of the Earth are caused by the sources located in the lower atmosphere and on the ground such as thunderstorms, typhoons, dust storms, earthquakes, volcanic eruptions, and radioactive emissions from the nuclear power plants. All these phenomena affect the electrical conductivity from the Earth’s surface to the lower ionosphere. Variation of conductivity and external current in the lower atmosphere lead to the perturbation of electric current flowing in the GEC and to the associated DC electric field perturbations both on the Earth’s surface and in the ionosphere and hence affect the electrodynamic coupling of the Earth’s atmosphere and the ionosphere.
Atmosphere Above Japan Heated Rapidly Before M9 Earthquake
Infrared emissions above the epicenter increased dramatically in the days before the devastating earthquake in Japan, say scientists.
May 18, 2011
…Dimitar Ouzounov at the NASA Goddard Space Flight Centre in Maryland and a few buddies present the data from the Great Tohoku earthquake which devastated Japan on 11 March. Their results, although preliminary, are eye-opening. They say that before the M9 earthquake, the total electron content of the ionosphere increased dramatically over the epicentre, reaching a maximum three days before the quake struck. At the same time, satellite observations showed a big increase in infrared emissions from above the epicentre, which peaked in the hours before the quake. In other words, the atmosphere was heating up. These kinds of observations are consistent with an idea called the Lithosphere-Atmosphere-Ionosphere Coupling mechanism. The thinking is that in the days before an earthquake, the great stresses in a fault as it is about to give cause the releases large amounts of radon. The radioactivity from this gas ionises the air on a large scale and this has a number of knock on effects. Since water molecules are attracted to ions in the air, ionisation triggers the large scale condensation of water.
Explanation of Lithosphere-Atmosphere-Ionosphere Coupling System …
by MK Kachakhidze – 2014 /Tbilisi, Georgia
Physical mechanisms of mentioned phenomena are explained on the basis of the model of generation of electromagnetic emission detected before earthquake, where a … Since the above listed Lithisphere-Atmosphere-Ionosphere (LAI) system … propagate through the crust and reach the Earth’s surface (Sasai and …
Magnetospheric ULF waves driven by external sources
NASA Astrophysics Data System (ADS)
Agapitov, O. V.; Cheremnykh, O. K. / 2013-08-01
The multi-spacecraft missions (Cluster and THEMIS) observations allowed to collect large data base for Ultra Low Frequency (ULF) waves properties, their localization, and sources. Here we focused mainly on these recent results. Studies of the source and characteristics of ULF waves can help in the understanding of the interaction and energy transport from the solar wind to the magnetosphere. In the presented paper peculiarities of the ULF waves are presented in depends of their generation source: surface magnetopause instabilities, magnetospheric cavity modes, and solar wind sudden impulses (SI). Permanent observations of the ULF waves involve existence of the permanent source and, as the previous studies showed, the contributions to Pc4-Pc5 ULF wave power from the external sources are larger than the contribution from internal magnetosphere sources.
The Kelvin-Helmholtz instability (KHI) can generate classical ULF resonant waves with spatially localized amplitude maximum on the magnetosphere flanks. As observations show the constraint satisfaction of KHI development is quite rare. SI in the solar wind dynamic pressure generate ULF waves with different polarization and frequency close to the frequency of the local field line resonance (FLR). Wide range of temporal and amplitude characteristics of the solar wind dynamics can generate magnetosphere cavity modes and magnetosonic perturbations which penetrate through the magnetosphere and can couple with the local FLR modes. The observed dependence of ULF waves properties on their localization corresponds well to these sources and their occurrence.
Sample records for ULF electromagnetic fields
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