84 research outputs found

    Ionospheric disturbances generated by different natural processes and by human activity in Earth plasma environment

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    The magnetosphere-ionosphere-thermosphere subsystem is strongly coupled via the electric field, particle precipitation, heat flows and small scale interaction. Satellites in situ measurements and ground based complex diagnostics can provide comprehensive coverage of both time and geomagnetic place effects. Human activity also can perturb Earth s environment, but few are connected with controlled experiments in the ionosphere and are transient. Most of them are related to industrial activity and have increased in recent years. The most important power sources are broadcasting transmitters, power stations, power lines and heavy industry. At ionospheric altitude some disturbances and physical processes are related to seismic activity, thunderstorm activity and some global changes in the Earth environment such as ozone holes. Various natural and artificial indicators can affect satellite telecommunication quality. The aim of this presentation is to report progress in understanding the physical processes in the ionosphere described above and to assess the application of these considerations to the study of plasma effects on Earth-space and satellite-to-satellite communication

    Super fast plasma streams as drivers of transient and anomalous magnetospheric dynamics

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    Abstract. We present multi spacecraft measurements in the magnetosheath (MSH) and in the solar wind (SW) by Interball, Cluster and Polar, demonstrating that coherent structures with magnetosonic Mach number up to 3 – Supermagnetosonic Plasma Streams (SPS) – generate transient and anomalous boundary dynamics, which may cause substantial displacements of the magnetospheric boundaries and the riddling of peripheral boundary layers. In this regard, for the first time, we describe a direct plasma penetration into the flank boundary layers, which is a candidate for being the dominant transport mechanism for disturbed MSH periods. Typically SPS's have a ram pressure exceeding by several times that of the SW and lead to long-range correlations between processes at the bow shock (BS) and at the magnetopause (MP) on one side and between MSH and MP boundary layers on the other side. We demonstrate that SPS's can be observed both near the BS and near the MP and argue that they are often triggered by hot flow anomalies (HFA), which represent local obstacles to the SW flow and can induce the SPS generation as a means for achieving a local flow balance. Finally, we also discuss other causes of SPS's, both SW-induced and intrinsic to the MSH. SPS's appear to be universal means for establishing a new equilibrium between flowing plasmas and may also prove to be important for astrophysical and fusion applications

    Experimental study of nonlinear interaction of plasma flow with charged thin current sheets: 1. Boundary structure and motion

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    We study plasma transport at a thin magnetopause (MP), described hereafter as a thin current sheet (TCS), observed by Cluster at the southern cusp on 13 February 2001 around 20:01 UT. The Cluster observations generally agree with the predictions of the Gas Dynamic Convection Field (GDCF) model in the magnetosheath (MSH) up to the MSH boundary layer, where significant differences are seen. We find for the MP a normal roughly along the GSE x-axis, which implies a clear departure from the local average MP normal, a ~90 km thickness and an outward speed of 35 km/s. Two populations are identified in the MSH boundary layer: the first one roughly perpendicular to the MSH magnetic field, which we interpret as the &quot;incident&quot; MSH plasma, the second one mostly parallel to <b>B</b>. Just after the MP crossing a velocity jet is observed with a peak speed of 240 km/s, perpendicular to <b>B</b>, with <i>M<sub>A</sub></i>=3 and &beta;>10 (peak value 23). The magnetic field clock angle rotates by 70&deg; across the MP. <i>E<sub>x</sub></i> is the main electric field component on both sides of the MP, displaying a bipolar signature, positive on the MSH side and negative on the opposite side, corresponding to a ~300 V electric potential jump across the TCS. The <i>E</i>&times;<i>B</i> velocity generally coincides with the perpendicular velocity measured by CIS; however, in the speed jet a difference between the two is observed, which suggests the need for an extra flow source. We propose that the MP TCS can act locally as an obstacle for low-energy ions (&lt;350 eV), being transparent for ions with larger gyroradius. As a result, the penetration of plasma by finite gyroradius is considered as a possible source for the jet. The role of reconnection is briefly discussed. The electrodynamics of the TCS along with mass and momentum transfer across it are further discussed in the companion paper by Savin et al. (2006)

    An evaluation of the exposure in nadir observation of the JEM-EUSO mission

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    We evaluate the exposure during nadir observations with JEM-EUSO, the Extreme Universe Space Observatory,on-board the Japanese Experiment Module of the International Space Station. Designed as a mission to explore the extreme energy Universe from space, JEM-EUSO will monitor the Earth's nighttime atmosphere to record the ultraviolet light from tracks generated by extensive air showers initiated by ultra-high energy cosmic rays. In the present work, we discuss the particularities of space-based observation and we compute the annual exposure in nadir observation. The results are based on studies of the expected trigger aperture and observational duty cycle, as well as, on the investigations of the effects of clouds and different types of background light. We show that the annual exposure is about one order of magnitude higher than those of the presently operating ground-based observatories.Fil: Adams, J. H.. University of Alabama in Huntsville; Estados UnidosFil: Ahmad, S.. Universite Paris Sud; FranciaFil: Albert, J. N..Fil: Allard, D.. Universite Paris Diderot - Paris 7; FranciaFil: Ambrosio, M.. Istituto Nazionale di Fisica Nucleare; ItaliaFil: Anchordoqui, L.. Medical College Of Wisconsin; Estados UnidosFil: Anzalone, A.. INAF; ItaliaFil: Arai, Y.. High Energy Accelerator Research Organization (KEK); JapónFil: Aramo, C..Fil: Asano, K.. Interactive Research Center of Science, Tokyo Institute of Technology; JapónFil: Ave, M.. Universidad de Santiago de Compostela; EspañaFil: Barrillon, P.. Universite de Paris; FranciaFil: Batsch, T.. National Centre for Nuclear Research; PoloniaFil: Bayer, J.. University of Tubingen; AlemaniaFil: Belenguer, T.. j Instituto Nacional de Técnica Aeroespacial (INTA); EspañaFil: Bellotti, R.. Universita’ degli Studi di Bari Aldo Moro and INFN; ItaliaFil: Berlind, A. A.. Vanderbilt University; Estados UnidosFil: Bertaina, M.. Universita di Torino; ItaliaFil: Biermann, P. L.. Karlsruhe Institute of Technology (KIT); AlemaniaFil: Biktemerova,. Joint Institute for Nuclear Research; RusiaFil: Blaksley, C.. Universite de la Sorbona Nouvelle; FranciaFil: Blecki, J.. Space Research Centre of the Polish Academy of Sciences (CBK); PoloniaFil: Blin-Bondil, S.. Universite de Paris; FranciaFil: Blumer, J.. Karlsruhe Institute of Technology (KIT),; AlemaniaFil: Bobik, P.. Institute of Experimental Physics; EslovaquiaFil: Bogomilov, M.. St. Kliment Ohridski University of Sofia; BulgariaFil: Bonamente, M.. University of Alabama in Huntsville; Estados UnidosFil: Briz, S.. Universidad Carlos III de Madrid,; EspañaFil: Supanitsky, Alberto Daniel. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentin

    Science of atmospheric phenomena with JEM-EUSO

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    The main goal of the JEM-EUSO experiment is the study of Ultra HighEnergy Cosmic Rays (UHECR, 10^19 - 10^21 eV ), but the method which will be used (detection of the secondary light emissions induced by cosmic rays in the atmosphere) allows to study other luminous phenomena. The UHECRs will be detected through the measurement of the emission in the range between 290 and 430 m, where some part of Transient Luminous Events (TLEs) emission also appears. This work discusses the possibility of using the JEM-EUSO Telescope to get new scientific results on TLEs. The high time resolution of this instrument allows to observe the evolution of TLEs with great precision just at the moment of their origin. Thepaper consists of four parts: review of the present knowledge on the TLE, presentation of the results of the simulations of the TLE images in the JEM-EUSO telescope, results of the Russian experiment Tatiana-2 and discussion of the possible progress achievable in this field with JEM-EUSO as well as possible cooperation with other space projects devoted to the study of TLE-TARANIS and ASIM. In atmospheric physics, the study of TLEs became one of the main physical subjects of interest after their discovery in 1989. In the years 1992 - 1994 detection was performed fromsatellite, aircraft and space shuttle and recently from the International Space Station. These events have short duration (milliseconds) and small scales (km to tens of km) and appear at altitudes 50 - 100 km. Their nature is still not clear and each new experimental data can be useful for a better understanding of these mysterious phenomena.Fil: Adams, J. H.. University of Alabama in Huntsville; Estados UnidosFil: Ahmad, S.. Ecole Polytechnique; FranciaFil: Albert, J. N.. Univ Paris-Sud; FranciaFil: Allard, D.. Univ Paris Diderot; FranciaFil: Anchordoqui, L.. University of Wisconsin-Milwaukee; Estados UnidosFil: Andreev, V.. University of California; Estados UnidosFil: Anzalone, A.. INAF - Istituto di Astrofisica Spaziale e Fisica Cosmica di Palermo; ItaliaFil: Arai, Y.. High Energy Accelerator Research Organization (KEK); JapónFil: Asano, K.. Tokyo Institute of Technology; JapónFil: Ave Pernas, M.. Universidad de Alcala (UAH); EspañaFil: Barrillon, P.. Univ Paris-Sud; FranciaFil: Batsch, T.. Skobeltsyn Institute of Nuclear Physics; RusiaFil: Bayer, J.. University of Tubingen; AlemaniaFil: Bechini, R.. Universita’ di Torino; ItaliaFil: Belenguer, T.. Instituto Nacional de Tecnica Aeroespacial (INTA); EspañaFil: Bellotti, R.. Istituto Nazionale di Fisica Nucleare; ItaliaFil: Belov, K.. University of California; Estados UnidosFil: Berlind, A. A.. Vanderbilt University; Estados UnidosFil: Bertaina, M.. Istituto Nazionale di Fisica Nucleare; ItaliaFil: Biermann, P. L.. Karlsruhe Institute of Technology (KIT); AlemaniaFil: Biktemerova, S.. Joint Institute for Nuclear Research; RusiaFil: Blaksley, C.. Univ Paris Diderot; FranciaFil: Blanc, N.. Swiss Center for Electronics and Microtechnology (CSEM); SuizaFil: Blecki, J.. Space Research Centre of the Polish Academy of Sciences (CBK; PoloniaFil: Blin-Bondil, S.. Ecole Polytechnique; FranciaFil: Blumer, J.. Karlsruhe Institute of Technology (KIT),; AlemaniaFil: Bobik, P.. Institute of Experimental Physics; EslovaquiaFil: Bogomilov, M.. University of Sofia; BulgariaFil: Bonamente, M.. University of Alabama in Huntsville; Estados UnidosFil: Supanitsky, Alberto Daniel. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: The JEM-EUSO Collaboration

    The atmospheric science of JEM-EUSO

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    An Atmospheric Monitoring System (AMS) is critical suite of instruments for JEM-EUSO whose aim is to detect Ultra-High Energy Cosmic Rays (UHECR) and (EHECR) from Space. The AMS comprises an advanced space qualified infrared camera and a LIDAR with cross checks provided by a ground-based and airborne Global Light System Stations. Moreover the Slow Data Mode of JEM-EUSO has been proven crucial for the UV background analysis by comparing the UV and IR images. It will also contribute to the investigation of atmospheric effects seen in the data from the GLS or even to our understanding of Space Weather
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