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1. Atmospheric convection and turbulent diffusion. 2. G ravitational sedimentation.

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1. Atmospheric convection and turbulent diffusion. 2. G ravitational sedimentation.

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  1. The 1st CSES Satellite Workshop, November 13-16, 2014, Beijing, ChinaLAI coupling caused by the seismic-related disturbances of electric current in the global circuit V.M. Sorokin Puskov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation (IZMIRAN), Russian Academy of Sciences, Troitsk, Moscow, 142190, RUSSIA. This report presents a model for LAI coupling by disturbances of electric current in the global circuit and a brief description of the formation mechanisms of electromagnetic and plasma disturbances in near-Earth space at the preparatory phase of earthquakes (EQs). Spatial distribution of this field has a horizontal scale of 100 – 1000 km and the temporal scale of field is (1 – 10) days. Sorokin and Hayakawa, Modern Applied Science, 2013; 2014

  2. Variation of electric current in the global circuit is occurred by appearance of EMF in this circuit. The external current of EMF is excited in a process of vertical atmospheric convection and gravitational sedimentation of charged aerosols. Aerosols are injected into the atmosphere due to intensified soil gas elevation in the lithosphere during the enhancement of seismic activity. Constancy of total current results in growth of conductivity current depends on altitude in the atmosphere because external current of EMF is reduced with altitude. 1. Atmospheric convection and turbulent diffusion. 2. Gravitational sedimentation. 3. Atmospheric radioactivity. 4. Soil gases. 5. Conduction electric current. 6. Electromotive force.

  3. Feedback formation between external current and vertical component ofelectric field on the Earth surface results in limitation of electric fieldSorokin et al., JASTP, 2005 1 - Positive charged aerosols. 2 - Negative charged aerosols. 3 - Elevated soil gases. 4 - The Earth surface. This feedback is produced by the potential barrier for charged particle at its transfer from ground to the atmosphere Value of electric field on the Earth’ surface has to be in the following limits: is the ionosphere potential, is the atmosphere conductivity, is the limit field,

  4. Schema of DC electric field generation in the ionosphere by seismic-related Electro Motive Force (EMF) in the lower atmosphere 1. Earth surface 2. Conductive layer of the ionosphere 3. External electric current in the lower atmosphere 4. Conductivity electric current in the atmosphere – ionosphere circuit 5. DC electric field in the ionosphere 6. Field - aligned electric current 7. Charged aerosols injected into the atmosphere by soil gases

  5. Equivalent circuit of DC electric field formation in the ionosphere over a region of EMF occurring in the surface atmosphere. Black color illustrates the global circuit. Red color denotes the part of circuit over a region of EMF generation.

  6. Example of calculation results of the spatial distribution of horizontal electric field in the ionosphere, vertical component of electric field in the troposphere and near the Earth surface over the ellipsoidal fault Sorokin et al., Nat. Haz. Earth Sys. Sci.,2005Sorokin et al., JASTP, 2011

  7. Theory results • Charged aerosols injection in the atmosphere forms EMF in the near ground level. • Including EMF in the global circuit leads to growth of electric current in this circuit. At the same time value of quasi-static electric field can attain 10 mV/m in the ionosphere, breakdown value in the troposphere but it does not exceed the background value ~100 V/m. Key features of model which was discovered by our theory • The mechanism of electric current growth depends on altitude in the atmosphere. • The mechanism of electric field limitation on the Earth’s surface at charged aerosols injection in the atmosphere.

  8. Theory confirmation by experimental data • Satellite direct measuring of DC electric field in an area of the order of several hundred km in diameter over an EQ region during from hours to 10 days before EQs. Chmyrev et al., Phys. Earth Planet. Inter. 1989; Sorokin et al., J. Atmos. Solar-Terr. Phys. 2005; Gousheva et al., Nat. Haz. Earth Syst. Sci. 2008, 2009. • Computer simulation shows that pre-seismic TEC variations occur by a quasi-static electric field disturbance in the ionosphere with amplitude (3 – 9) mV/m . Zolotov et al., 7th International Conference "Problems of Geocosmos" 2008 Namgaladze et al., Geomagn. Aeron. 2009 Klimenko et al., Adv. Space Res. 2011; 2012 • Pre-earthquake VHF electromagnetic radiation is generated by electric discharges in the troposphere at altitudes (1 – 10) km over the EQ zone. Vallianatos and Nomicos, Phys. Chem. Earth 1998; Ruzhin et al., Proc. 15th Wroclaw EMC Symposium 2000; Ruzhin and Nomicos, Nat. Hazards 2007.

  9. (continuation) • Quasi-static electric fields on the Earth surface in an EQ epicenter area do not exceed the background value ~100 V/m. The spike of electric field reaching (1 – 10) kV/m in the local area has a duration over 10 min. Jianguo, Acta Seismol. Sin., 1989 Vershinin et al., Atmos. Ionosph. Elect.-Magn. Phenom., 1999 Nikiforova and Michnovski, IUGG XXI General Assem. 1995 Hao et al., J. Earthquake Pred. Res., 2000 Rulenko, Vulcanology and Seismology, 2000 • Lithosphere activity stimulates the processes of active substances injection in the atmosphere during days and weeks before EQs. Number density of charged aerosols enhancement of one – two order. Atmosphere radioactivity level is increased by radon and other radioactive elements in several times. King, J. Geophys. Res., 1986 Alekseev and Alekseeva, Nucl. Geophys., 1992 Virk and Singh, Geophys. Res. Lett., 1994 Heinke et al., Geophys. Res. Lett., 1994 Voitov and Dobrovolsky, Izvestiya AN SSSR, Fizika Zemli, 1994 Igarashi et al., Science, 1995 Pulinets et al., Adv. Space Res. 1997 Boyarchuk, Proceed. of RAS, Afmos. Ocean. Phys. 1997 Yasuoka et al., Appl. Geochem 2006; Omori et al., Nat. Hzards Earth Syst. Sci. 2007

  10. Application of electrodynamic LAI coupling model for interpretation of experimental data. • Below it is presented the examples of calculation of plasma and electromagnetic effects occurring by charged aerosols injection in the atmosphere during growth of seismic activity using our theory. Perturbation of electric current in the global circuit leads to following effects: • 1. Small-scale ionospheric irregularities. • 1.1. Formation of irregularities by AGW instability in electric field. • 1.2. VLF/ELF electromagnetic effects. • 1.3. ULF electromagnetic effects. • 2. Large-scale irregularities of the ionosphere. • 2.1. D layer of the ionosphere. • 2.2. E layer of the ionosphere. • 2.3 F layer of the ionosphere. • 3. Breakdown electric field in the troposphere. • 3.1. Self-radiation of random discharges. • 3.2. Scattering of the VHF transmitter radiation on the random discharges.

  11. Small-scale ionospheric irregularities.Formation of irregularities by AGW instability in electric fieldThe formation of large enough DC electric field in the ionosphere exceeding a definite threshold value leads to an instability of acoustic-gravity waves, form of horizontal vortex chains and associated plasma density and electric conductivity disturbances in the ionosphere. Sorokin et al., JASTP, 1998; Chmyrev and Sorokin, JASTP, 2010 Condition of vortex formation is The frequency dependence of the refraction indexand the absorption coefficientof acoustic-gravity wave in the ionosphere in the presence of an external electric field.

  12. Formation of field-aligned currents, plasma irregularities and ELF electromagnetic emissions in the upper ionosphere The excitation of horizontal spatial structure of conductivity in the lower ionosphere results in the formation of magnetic field- aligned currents and plasma layers stretched along the geomagnetic field. Sorokin et al., 1998 • Irregularities of the ionosphere conductivity. • DC electric field in the ionosphere. • Field – aligned electric current. • Plasma layers stretched along geomagnetic field. • Thunderstorms. • Lightning electromagnetic emission. • ELF electromagnetic radiation.

  13. Examples of satellite observations of ULF magnetic field oscillations, electron number density fluctuations and ELF electromagnetic emissions caused by the formation of the ionosphere conductivity irregularitiesChmyrev et al., Phys. Earth Planet. Inter., 1989; Chmyrev et al., JASTP, 1997 1. Earthquake. 2. Irregularities of the ionosphere conductivity. 3. Field-aligned currents and irregularities of electron number density. 4. Satellite trajectory crossing the disturbed region. ULF magnetic field. Electron number density fluctuations. ELF electromagnetic emissions

  14. The generation mechanism of electromagnetic ELF wave precursors to EQs. Excitation of horizontal small-scale irregularities of electric conductivity in the lower ionosphere is a key factor for ELF wave radiation to the ionosphere. Borisov et al., JASTP, 2001 These waves are generated by an interaction of thunderstorm related EM radiation with small-scale plasma irregularities excited in the lower ionosphere before EQs.

  15. ULF electromagnetic effectsGyro-tropic waves generation in the lower ionosphere by polarization currents which occurs due to interaction of background electromagnetic noise and conductivity irregularities. Sorokin et al., JASTP, 2003.Sorokin and Pokhotelov, JASTP, 2005.Sorokin and Hayakawa, JGR, 2008

  16. Examples of applications of the model for gyro-tropic waves generation in the lower ionosphere. • Observation of the narrow-band ULF electromagnetic and magnetic fields associated with seismic and volcanic natural activity. • Rauscher and Van Bise, 1999. • Interpretation in terms of gyro-tropic waves of Schumann-resonance-like anomalous line emissions observed before earthquakes. • Hayakawa et al., IEEJ, 2011

  17. Large-scale irregularities of the ionosphereExample of calculation of electron density in D layer by perturbation of electric current in the global circuit. Laptukhov et al., Geomagn. Aeronom., 2009 Theory show that the transportation of electrons downward by electric current leads to an increase in the plasma density at heights below 70 km. It happens because the electrons have no time to attach to neutral molecules at lower altitudes.

  18. Scheme of formation of the inhomogeneity in the lower ionosphere caused by perturbation of the electric current in the global circuit due to charged aerosols injection to the atmosphere in the epicentral zone. • Injection of the charged aerosols by the soil gazes. • The region of the convective transport of the charged aerosols and formation of the EMF. • Perturbation of the conductive electric current. • Electric current in the ionosphere. • Ionospheric conductive layer. • Plasma inhomogeneity in the lower ionosphere.

  19. Calculation results of electron density in the ionospheric E - region associated with perturbation of electric current in the global circuit. Sorokin et al., JASTP, 2006 Theory show that positive ions of the atmospheric electric current flowing into the ionosphere are compensated by electrons of the field-aligned current flowing from magnetosphere. These currents lead to formation of the plasma layer in the lower ionosphere. The results can be applied to the interpretation of observation data of the lower-ionospheric perturbations over seismic regions, typhoons obtained by VLF/LF technic.

  20. Model for the VLF/LF radio signal anomalies formation associated with earthquakes • Quasi-static electric field. • Lower ionosphere. • Background AGW without scattering. • Scattered AGW. Growth of electric field leads to formation of filtering properties in the ionosphere concerning background AGW. The waves with specified periods are not affected by this field. However, the influence of field on AGW with other periods results in their scattering. This leads to predominant growth of the amplitude of the perturbations with discrete spectrum, period of which satisfies such a condition. Sorokin and Pokhotelov, ASR, 2013.

  21. The values of periods corresponding to spectrum maximums of oscillations caused by enhancement of electric current in the lower ionosphere . The increase of the Ampere’s force due to the electric field of seismic origin results in the appearance in the spectrum of ionosphere oscillations of maximums with short periods of the order 10 and 22 min. Sorokin and Pokhotelov, ASR, 2013. Circles – the electric field is zero. Squares – the electric field equals 9 mV/m.

  22. Seismic related large-scale modification of the ionosphere F layer The total TEC variations caused by two following processes:• Plasma drifts by electric field in the ionosphere, • Ionosphere modification by electric current heating. Ruzhin et al., Geomagn. and aeronomy, 2013. • 1. Earth’s surface. 2. Conducting layer of the ionosphere. 3. Charged aerosols injection by soil gases. 4. Region of EMF formation in the near ground atmosphere. 5. Perturbation of electric current in the global circuit. TEC disturbance due to heating of the ionosphere by electric current. TEC disturbance due to plasma drift in the electric field.

  23. Horizontal distribution of charged aerosols number density in the near ground level. Horizontal distribution of zonal electric field in the ionosphere. Example of TEC calculation formed by plasma drift and ionosphere heating over seismic region associated with charged aerosols injection in the atmosphere . The combination of these effects allows explain existence of two types of TEC disturbances both bipolar and like-sign ones. Horizontal distributions of the relative TEC disturbances. Horizontal distribution of the ionosphere temperature.

  24. Examples of experimental confirmation of theory. VLF/LF radio signal anomalies associated with earthquakes Specificvariationsoftheamplitudeandphaseof VLF signalswereobservedthetracesofwhichwereclosetotheepicentresoftheforthcomingearthquakes. Thetransmittersand receivers of these waves ((20 – 50) kHz) propagating in the Earth-ionosphere waveguide were located on the ground. Biagiet al., 2004;; Hayakawa 2007 During a few days prior the earthquakes there were anomalies in the form of the decreases of the amplitude and phase of the VLF signals. In the spectra of quiet as well as disturbed days the main maximums correspond to the period of 30-35 min. Moreover, during seismic activity there is an evidence of appearance of maximums with 20-25 min and 10-12 min. Rozhnoi et al., 2005, 2007

  25. Effects of breakdown electric field in the tropospherePre-EQ DC electric field reaching the breakdown value initiates numerous chaotic electrical discharges and related phenomena in the lower atmosphereSorokin et al., The Frontier of Earthquake Prediction Studies, 2012 • Chaotic electric discharges. • Heating of the atmosphere in the discharge region and the generation of outgoing long wave (8-12 μm) radiation. • Broadband electromagnetic VHF emission. • Airglow in visible range of wavelengths. • Refraction and scattering of VHF radio waves in the troposphere providing the over-horizon reception of ground-based VHF transmitter signals.

  26. Calculated spectrum of VHF electromagnetic radiation by random discharges in the troposphere at distance 300 km from the epicenter of disturbed area. The radiation source is modeled by the disk-like random discharges region with radius 40 km and thickness 1 km located at 6 km altitude in the atmosphere. Two vertical lines on the curve in figure show the spectral densities observed in experiment (Ruzhin and Nomicos, 2007). Sorokin et al., JASTP, 2011 Calculated amplitude at a frequency 50 MHz. depends on distance. Calculated spectrum at distance 300 km from epicenter.

  27. Seismic related VHF emissions are observed during several days before earthquakes and the source region lies in the atmosphere at the altitudes about several km above the earthquake center that gives a possibility for over-horizon observation of these emissions. Vallianatos and Nomicos (1998), Ruzhin et al. (2000), Hayakawa et al. (2006), Ruzhin and Nomicos (2007)

  28. Schema of the over horizon transmitter wave propagation due to scattering one on electric discharges in the troposphere.Sorokin et al., JASTP, 2014 • 1. Transmitter. 2. Receiver. 3. Disturbed region of troposphere with electric discharges. 4. Line of sight. 5. Incident wave. 6. Scattered wave.

  29. Calculation results of the over horizon spatial distribution of mean value of scattered electric field. The transmitter monochromatic wave is scattered on the random electric discharges. These discharges are occurred in the region of troposphere in which electric field reaches breakdown value. Axially symmetric scattering region Ellipsoidal scattering region 100km X 100km 100km X 600km

  30. Scheme of registration of VHF signals on the satellite. 1. Transmitter, 2. Receiver, 3. Satellite, 4. Direct signal, 5. Scattered signal, 6. Electric discharges.

  31. VHF observations onboard the satellite could be an effective tool for detection and locating the seismically modified atmospheric regions of anomalously strong (breakdown) DC electric field. It could be reached through simultaneous registration of broad band VHF radiation from the ‘discharge’ region and electromagnetic waves from the ground VHF transmitters, both direct and scattered signals. Using of the direction finding technique with highly sensitive onboard VHF receivers could allow to locate the source of emission and scattering in the atmosphere and therefore to make applicable an additional type of the precursor signals in space. Principally this task can be realized through installation of a pair of magnetic loop antennas and appropriate electric antenna on the micro satellite platform.

  32. Conclusion. Aerosols injection in the atmosphere leads to perturbation of electric current in the global circuit. Calculation shown that quasi-static electric field associated with current attain 10 mV/m in the ionosphere, breakdown value in the troposphere and it do not exceed background value 100 V/m in the near-ground atmosphere. Growth of electric field in the global circuit stimulates plasma and electromagnetic effects. Our theory allows us to make calculations of measured parameters of plasma and electromagnetic precursors. Presented results can be considered by two part of following review: Sorokin V.M., Hayakawa M. Generation of seismic-related DC electric fields and lithosphere-atmosphere-ionosphere coupling // Modern Applied Science. 2013, V.7, No6, P.1-25. Sorokin V.M., Hayakawa M. Plasma and electromagnetic effects caused by the seismic-related disturbances of electric current in the global circuit // Modern Applied Science. 2014, V.8, P.61-83.

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