The Experts below are selected from a list of 585 Experts worldwide ranked by ideXlab platform
Janusz Mlynarczyk - One of the best experts on this subject based on the ideXlab platform.
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subtraction of correlated noise in global networks of gravitational wave interferometers
Classical and Quantum Gravity, 2016Co-Authors: Michael W. Coughlin, Rosario De Rosa, Irene Fiori, Andrzej Kulak, N Christensen, Mark Golkowski, Melissa A Guidry, J Harms, Jerzy Kubisz, Janusz MlynarczykAbstract:The recent discovery of merging black holes suggests that a stochastic gravitational-wave background is within reach of the advanced detector network operating at design sensitivity. However, correlated magnetic noise from Schumann resonances threatens to contaminate observation of a stochastic background. In this paper, we report on the first effort to eliminate intercontinental correlated noise from Schumann resonances using Wiener filtering. Using magnetometers as proxies for gravitational-wave detectors, we demonstrate as much as a factor of two reduction in the coherence between magnetometers on different continents. While much work remains to be done, our results constitute a proof-of-principle and motivate follow-up studies with a dedicated array of magnetometers.
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analytical modeling of schumann resonance and elf propagation parameters on mars with a multi layered ground
Planetary and Space Science, 2015Co-Authors: Joanna Kozakiewicz, Andrzej Kulak, Janusz MlynarczykAbstract:Abstract Two electrically conductive planetary spheres, the ionosphere and the ground, form a spherical waveguide. Within such a planetary cavity a phenomenon called Schumann resonance (SR) can occur. It is a resonance of extremely low frequency (ELF) electromagnetic waves. The resonance parameters are strongly related to the electromagnetic properties of the cavity. On Mars, as there is no liquid water at the planetary surface, the ground has a low conductivity. In such a situation, ELF waves penetrate into the planetary subsurface up to many kilometers depth. To examine the influence of low-conductivity grounds on ELF propagation, we have introduced a recently developed analytical method, which enables to estimate the propagation parameters and explicate their dependence of the ground properties. Since the presented model is fully analytical, it is computationally efficient and can be very useful in finding inverse solutions. To demonstrate the potential of the method, we present the relationship between individual ground properties and the parameters of Schumann resonance. The obtained results indicate that Martian exploration performed by one ELF station located at the planetary surface can reveal, along with the properties of the ionosphere, the existence of liquid water under the Martian surface.
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novel analysis of a sudden ionospheric disturbance using schumann resonance measurements
Journal of Geophysical Research, 2015Co-Authors: M Dyrda, Andrzej Kulak, Janusz Mlynarczyk, M OstrowskiAbstract:A spherical cavity between Earth and the lower ionosphere forms a global resonator for Extremely Low Frequency electromagnetic waves. Constant thunderstorm activity leads to the formation of a resonance field in the cavity, known as the Schumann resonance. Solar flare generated Sudden Ionospheric Disturbances (SID) modify the ionosphere affecting the ground-based radio communication systems. They are also expected to modify radiowave propagation in the cavity. In this paper, the Schumann Resonance spectral decomposition method is used for the first time to study the cavity resonance frequencies during the SID accompanying a strong X2.1 solar flare. We analyzed rapid changes in the frequencies and Q factors of the first five resonance modes using a 5 min timescale. The observed frequency shifts were compared to the ionizing solar flare fluxes in the UV, X-ray, and high-energy γ rays.
Andrzej Kulak - One of the best experts on this subject based on the ideXlab platform.
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subtraction of correlated noise in global networks of gravitational wave interferometers
Classical and Quantum Gravity, 2016Co-Authors: Michael W. Coughlin, Rosario De Rosa, Irene Fiori, Andrzej Kulak, N Christensen, Mark Golkowski, Melissa A Guidry, J Harms, Jerzy Kubisz, Janusz MlynarczykAbstract:The recent discovery of merging black holes suggests that a stochastic gravitational-wave background is within reach of the advanced detector network operating at design sensitivity. However, correlated magnetic noise from Schumann resonances threatens to contaminate observation of a stochastic background. In this paper, we report on the first effort to eliminate intercontinental correlated noise from Schumann resonances using Wiener filtering. Using magnetometers as proxies for gravitational-wave detectors, we demonstrate as much as a factor of two reduction in the coherence between magnetometers on different continents. While much work remains to be done, our results constitute a proof-of-principle and motivate follow-up studies with a dedicated array of magnetometers.
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analytical modeling of schumann resonance and elf propagation parameters on mars with a multi layered ground
Planetary and Space Science, 2015Co-Authors: Joanna Kozakiewicz, Andrzej Kulak, Janusz MlynarczykAbstract:Abstract Two electrically conductive planetary spheres, the ionosphere and the ground, form a spherical waveguide. Within such a planetary cavity a phenomenon called Schumann resonance (SR) can occur. It is a resonance of extremely low frequency (ELF) electromagnetic waves. The resonance parameters are strongly related to the electromagnetic properties of the cavity. On Mars, as there is no liquid water at the planetary surface, the ground has a low conductivity. In such a situation, ELF waves penetrate into the planetary subsurface up to many kilometers depth. To examine the influence of low-conductivity grounds on ELF propagation, we have introduced a recently developed analytical method, which enables to estimate the propagation parameters and explicate their dependence of the ground properties. Since the presented model is fully analytical, it is computationally efficient and can be very useful in finding inverse solutions. To demonstrate the potential of the method, we present the relationship between individual ground properties and the parameters of Schumann resonance. The obtained results indicate that Martian exploration performed by one ELF station located at the planetary surface can reveal, along with the properties of the ionosphere, the existence of liquid water under the Martian surface.
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novel analysis of a sudden ionospheric disturbance using schumann resonance measurements
Journal of Geophysical Research, 2015Co-Authors: M Dyrda, Andrzej Kulak, Janusz Mlynarczyk, M OstrowskiAbstract:A spherical cavity between Earth and the lower ionosphere forms a global resonator for Extremely Low Frequency electromagnetic waves. Constant thunderstorm activity leads to the formation of a resonance field in the cavity, known as the Schumann resonance. Solar flare generated Sudden Ionospheric Disturbances (SID) modify the ionosphere affecting the ground-based radio communication systems. They are also expected to modify radiowave propagation in the cavity. In this paper, the Schumann Resonance spectral decomposition method is used for the first time to study the cavity resonance frequencies during the SID accompanying a strong X2.1 solar flare. We analyzed rapid changes in the frequencies and Q factors of the first five resonance modes using a 5 min timescale. The observed frequency shifts were compared to the ionizing solar flare fluxes in the UV, X-ray, and high-energy γ rays.
F. Simões - One of the best experts on this subject based on the ideXlab platform.
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Schumann resonance: a tool to study planetary atmospheric electricity and the origin and evolution of the solar system
2012Co-Authors: Michel Hamelin, F. Simões, Jean-jacques Berthelier, William M. Farrell, Robert F. Pfaff, Christian Béghin, Phillip C. Chamberlin, Henry Freudenreich, Réjean Grard, Jeffrey KlenzingAbstract:Investigation of extremely low frequency electromagnetic waves produced by lightning activity has been used to assist the characterization of a variety of phenomena related to atmospheric electricity in the Earth environment. Detection of Schumann Resonance spectral features of the earth-ionosphere cavity from outside the cavity offers new remote sensing capabilities to assess tropospheric-space weather connections, namely periodic patterns observed in a variety of tropospheric, ionospheric, and magnetospheric processes. A link between the water mixing ratio and atmospheric electrical conductivity makes Schumann resonance a suitable tool to assess volatile abundance of the outer planets, offering new capabilities to constrain thermodynamic parameters of the protosolar nebula from which the solar system evolved. In this work we discuss a technique and associated instrumentation to detect Schumann resonance signatures of planetary environments and subsequently to infer the fraction of volatiles and to investigate weather patterns in the gaseous envelopes of the giant planets.
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satellite observations of schumann resonances in the earth s ionosphere
Geophysical Research Letters, 2011Co-Authors: F. Simões, Robert F. Pfaff, Henry FreudenreichAbstract:[1] Using electric field measurements gathered on the C/NOFS satellite, we report, Schumann resonance signatures detected in space, well beyond the upper boundary of the resonant cavity formed by the earth's surface and the lower edge of the ionosphere. The resonances are routinely observed in the satellite ELF data during nighttime conditions within the altitude region of 400–850 km sampled by the satellite. They exhibit the distinctive frequency patterns predicted for Schumann resonances and are consistent with the corresponding frequency characteristics of ground-based observations of this phenomenon. The observations of Schumann resonances in space support a leaky cavity interpretation of the ionosphere and call for revisions of models of extremely low frequency wave propagation in the ionosphere. They suggest new remote sensing capabilities for investigating atmospheric electricity on Earth and other planets.
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Comment on "Evidence of electrical activity on Titan drawn from the Schumann resonances sent by Huygens probe" by J.A. Morente, J.A. Portí, A. Salinas, E.A. Navarro [doi: 10.1016/j.icarus.2008.02.004]
Icarus, 2009Co-Authors: Michel Hamelin, Jean-jacques Berthelier, Christian Béghin, R. Grard, J.j. López-moreno, K. Schwingenschuh, F. SimõesAbstract:Morente et al. [J.A. Morente, J.A. Portí, A. Salinas, E.A. Navarro, 2008. Icarus, doi: 10.1016/j.icarus.2008.02.004] have recently presented a new analysis of the Permittivity, Wave and Altimetry (PWA) measurements made during the descent of the Huygens Probe through the atmosphere of Titan. They claimed the identification of several Schumann resonance harmonics and concluded in favor of a lightning activity on Titan. We report here several reasons for not endorsing this paper.
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a schumann like resonance on titan driven by saturn s magnetosphere possibly revealed by the huygens probe
Icarus, 2007Co-Authors: Christian Béghin, F. Simões, Jean-jacques Berthelier, Michel Hamelin, C Bettanini, R. Grard, K. Schwingenschuh, V Krasnoselskikh, Bruno P Besser, J J LopezmorenoAbstract:The low-frequency data collected with the antenna of the Permittivity, Wave and Altimetry experiment on board the Huygens Probe that landed on Titan on 14 January 2005 have been thoroughly analyzed considering different possible natural and artificial effects. Although a definite conclusion is still subject to the outcome of complementary inquiries, it results from our analysis that the observations can be explained, for the most part, in term of natural phenomena rather than being artifacts. Extremely-low frequency waves generated in the ionosphere of Titan, driven by the corotating Saturn's frozen plasma flow, are assumed to be the most likely source for the observation of the second eigenmode of a Schumann-like resonance at around 36 Hz in the moon-ionosphere cavity. This particular mode is thought to be enhanced with respect to other harmonics because of the particular location of the landing site with respect to that of the supposed sources. The power budget of the observed wave amplitude seems to be consistent with a rough model of the global current of the wake-ionosphere circuit. Broadband low-frequency noise events which are observed sporadically during the descent are probably due to shot noise on the antenna when the Probe is crossing aerosol clouds, an interpretation supported by post-flight ground tests. Contrary to the situation encountered on Earth, atmospheric lightning does not appear to be the source of a conventional Schumann resonance on Titan.
Henry Freudenreich - One of the best experts on this subject based on the ideXlab platform.
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Schumann resonance: a tool to study planetary atmospheric electricity and the origin and evolution of the solar system
2012Co-Authors: Michel Hamelin, F. Simões, Jean-jacques Berthelier, William M. Farrell, Robert F. Pfaff, Christian Béghin, Phillip C. Chamberlin, Henry Freudenreich, Réjean Grard, Jeffrey KlenzingAbstract:Investigation of extremely low frequency electromagnetic waves produced by lightning activity has been used to assist the characterization of a variety of phenomena related to atmospheric electricity in the Earth environment. Detection of Schumann Resonance spectral features of the earth-ionosphere cavity from outside the cavity offers new remote sensing capabilities to assess tropospheric-space weather connections, namely periodic patterns observed in a variety of tropospheric, ionospheric, and magnetospheric processes. A link between the water mixing ratio and atmospheric electrical conductivity makes Schumann resonance a suitable tool to assess volatile abundance of the outer planets, offering new capabilities to constrain thermodynamic parameters of the protosolar nebula from which the solar system evolved. In this work we discuss a technique and associated instrumentation to detect Schumann resonance signatures of planetary environments and subsequently to infer the fraction of volatiles and to investigate weather patterns in the gaseous envelopes of the giant planets.
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Using Schumann resonance measurements for constraining the water abundance on the giant planets - Implications for the solar system's formation
The Astrophysical Journal, 2012Co-Authors: Fernando Sim Oes, Jean-jacques Berthelier, Michel Hamelin, Christian Béghin, Henry Freudenreich, Réjean Grard, Jeffrey Klenzing, Robert Pfaff, Kenneth Bromund, Jean-pierre LebretonAbstract:The formation and evolution of the solar system is closely related to the abundance of volatiles, namely water, ammonia, and methane in the protoplanetary disk. Accurate measurement of volatiles in the solar system is therefore important for understanding not only the nebular hypothesis and origin of life but also planetary cosmogony as a whole. In this work, we propose a new remote sensing technique to infer the outer planets' water content by measuring Tremendously and Extremely Low Frequency (TLF–ELF) electromagnetic wave characteristics (Schumann resonances) excited by lightning in their gaseous envelopes. Schumann resonance detection can be potentially used for constraining the uncertainty of volatiles of the giant planets, mainly Uranus and Neptune, because such TLF–ELF wave signatures are closely related to the electric conductivity profile and water content. Key words: planets and satellites: composition – planets and satellites: formation – planets and satellites: physical evolution – protoplanetary disks – space vehicles: instruments – waves Online-only material: color figures
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satellite observations of schumann resonances in the earth s ionosphere
Geophysical Research Letters, 2011Co-Authors: F. Simões, Robert F. Pfaff, Henry FreudenreichAbstract:[1] Using electric field measurements gathered on the C/NOFS satellite, we report, Schumann resonance signatures detected in space, well beyond the upper boundary of the resonant cavity formed by the earth's surface and the lower edge of the ionosphere. The resonances are routinely observed in the satellite ELF data during nighttime conditions within the altitude region of 400–850 km sampled by the satellite. They exhibit the distinctive frequency patterns predicted for Schumann resonances and are consistent with the corresponding frequency characteristics of ground-based observations of this phenomenon. The observations of Schumann resonances in space support a leaky cavity interpretation of the ionosphere and call for revisions of models of extremely low frequency wave propagation in the ionosphere. They suggest new remote sensing capabilities for investigating atmospheric electricity on Earth and other planets.
Alexandre Eyries - One of the best experts on this subject based on the ideXlab platform.
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philippe aldrin nicolas hube caroline ollivier yaniv jean michel
2015Co-Authors: Alexandre EyriesAbstract:Depuis sa creation au lendemain de la Seconde Guerre mondiale, le 9 mai 1950 a l’initiative de Maurice Schumann, ministre francais des Affaires etrangeres, dans une perspective de reconstruction et de paix apres la barbarie, l’Europe n’a cesse d’etre a la fois un enjeu pour les dirigeants des partis membres, une nebuleuse pour les citoyens des differents pays composant l’Union europeenne (ue) et une entite complexe tres proche et pourtant le plus souvent inaccessible. A la lueur d’une histoir...
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philippe aldrin nicolas hube caroline ollivier yaniv jean michel utard coords les mediations de l europe politique strasbourg presses universitaires de strasbourg 2014 372 pages
Questions de communication, 2015Co-Authors: Alexandre EyriesAbstract:Depuis sa creation au lendemain de la Seconde Guerre mondiale, le 9 mai 1950 a l’initiative de Maurice Schumann, ministre francais des Affaires etrangeres, dans une perspective de reconstruction et de paix apres la barbarie, l’Europe n’a cesse d’etre a la fois un enjeu pour les dirigeants des partis membres, une nebuleuse pour les citoyens des differents pays composant l’Union europeenne (ue) et une entite complexe tres proche et pourtant le plus souvent inaccessible. A la lueur d’une histoir...