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Preface C/Nofs Results and Equatorial Ionospheric Dynamics : Volum...

By: J. Retterer; L. C. Gentile; R. A. Stoneback; O. De La Beaujardière; F. S. Rodrigues; J. Klenzing
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Substorm Onset Identification Using Neural Networks and Pi2 Pulsat...

By: P. R. Sutcliffe

Description: Hermanus Magnetic Observatory, P.O. Box 32, Hermanus 7200, South Africa. The pattern recognition capabilities of artificial neural networks (ANNs) have for the first time been used to identify Pi2 pulsations in magnetometer data, which in turn serve as indicators of substorm onsets and intensifications. The pulsation spectrum was used as input to the ANN and the network was trained to give an output of +1 for Pi2 signatures and -1 for non-Pi2 signatures...

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Evaluation of Energetic Particle Parameters in the Near-earth Magn...

By: Q. G. Zong; R. H. W. Friedel; A. Korth; A. Roux; Z. X. Chen; Z. Y. Pu; S. Perraut

Description: Max-Planck-Institut für Aeronomie, D-37191 Katlenburg-Lindau, Germany. The flux asymmetries measured by spectrometers on board spacecraft contain information on particle parameters. The net flux intensity (NFI) method provides a tool to evaluate these parameters. The NFI method is valid when both the spin period of the spacecraft and the time resolution of the particle spectrometers are much shorter than the characteristic time-scale of the particle flu...

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Artificial Optical Emissions at Haarp for Pump Frequencies Near th...

By: J. Hughes; T. Pedersen; R. Marshall; A. Senior; F. T. Djuth; D. Sentman; E. Gerken; M. J. Kosch; M. McCarrick

Description: Space Vehicles Directorate, Air Force Research Laboratory, Hanscom AFB, Massachusetts, USA. High-power high-frequency radio waves beamed into the ionosphere cause plasma turbulence, which can accelerate electrons. These electrons collide with the F-layer neutral oxygen causing artificial optical emissions identical to natural aurora. Pumping at electron gyro-harmonic frequencies has special significance as many phenomena change their character. In parti...

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Cluster Peace Observations of Electrons During Magnetospheric Flux...

By: I. C. Krauklis; A. N. Fazakerley; G. Watson; R. J. Wilson; S. Szita; C. J. Owen; A. J. Coates; P. J. Carter; M. G. G. T. Taylor; M. W. Dunlop; A. Balogh; P. Travnicek

Description: Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking, Surrey, UK. During the first quarter of 2001 the apogees of the Cluster spacecraft quartet precessed through midday local times. This provides the first opportunity for 4 spacecraft studies of the bow shock, magnetosheath and the dayside magnetopause current layer and boundary layers. In this paper, we present observations of electrons in the energy range ~ 10 ...

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Use of Coupled Ozone Fields in a 3-d Circulation Model of the Midd...

By: W. Kouker; R. Ruhnke; T. Reddmann

Description: Institut für Meteorologie und Klimaforschung, Forschungszentrum Karlsruhe, Postfach 3640, 76021 Karlsruhe, Germany. With a detailed chemistry scheme for the middle atmosphere up to 70 km which has been added to the 3-D Karlsruhe simulation model of the middle atmosphere (KASIMA), the effects of coupling chemistry and dynamics through ozone are studied for the middle atmosphere. An uncoupled version using an ozone climatology for determining heating rates...

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Climatology of the Inter-hemispheric Field-aligned Current System ...

By: K. W. Min; H. Lühr; J. Park

Description: GFZ, German Research Center for Geosciences, Potsdam, Germany. From geomagnetic field observations of CHAMP during 2001–2009 we extracted characteristic signatures of inter-hemispheric field-aligned currents (IHFACs) in the equatorial ionosphere. The results are in general agreement with previous observations. Nighttime IHFACs are negligibly small. Solstitial IHFACs flow from the summer to winter (from winter to summer) hemisphere at dawn (around noon)....

Abdu, M. A., Batista, I. S., Carrasco, A. J., and Brum, C. G. M.: South Atlantic magnetic anomaly ionization: A review and a new focus on electrodynamic effects in the equatorial ionosphere, J. Atmos. Solar Terr. Phys., 67, 1643–1657, 2005.; Campbell, H. W.: Introduction to Geomagnetic Fields, Cambridge Univ. Press, New York, 1997.; Chapman, S. and Bartels, J.: Geomagnetism, Oxford Univ. Press, London, 1940.; Chulliat, A., Blanter, E., Le-Mouël, J.-L., and Shnirman, M.: ...

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Analysis and Parameterisation of Ionic Reactions Affecting Middle ...

By: P. T. Verronen; R. Lehmann

Description: Finnish Meteorological Institute, Helsinki, Finland. In the polar regions, precipitation of solar high-energy protons and electrons affects the neutral composition of the middle atmosphere. Here we use the Sodankylä Ion and Neutral Chemistry model to calculate ionic production and loss rates of neutral HOx and NOy species, imposed by particle precipitation, for a range of atmospheric conditions and levels of ionization. We also ana...

Damiani, A., Funke, B., Marsh, D. R., López-Puertas, M., Santee, M. L., Froidevaux, L., Wang, S., Jackman, C. H., von Clarmann, T., Gardini, A., Cordero, R. R., and Storini, M.: Impact of January 2005 solar proton events on chlorine species, Atmos. Chem. Phys., 12, 4159–4179, doi:10.5194/acp-12-4159-2012, 2012.; Funke, B., López-Puertas, M., Garcia-Comas, M., Stiller, G. P., von Clarmann, T., and Glatthor, N.: Mesosp...

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First Hf Radar Measurements of Summer Mesopause Echoes at Sura : V...

By: Y. V. Shlyugaev; V. I. Abramov; I. F. Belov; I. V. Berezin; A. N. Karashtin; E. B. Eryshev; G. P. Komrakov; V. V. Bychkov

Description: Radiophysical Research Institute (NIRFI), 25 B. Pecherskaya, Nizhny Novgorod 603600, Russia, e-mail: tolk@nir®.sci-nnov.ru. HF sounding of the mesosphere was first carried out at SURA in summer 1994 at frequencies in the range 8–9 MHz using one of the sub-arrays of the SURA heating facility. The observations had a range resolution of 3 km. Almost all measurements indicated the presence of strong radar returns from altitudes between 83 and 90 km with feat...

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A Diagnostic Study of Monsoon Energetics for Two Contrasting Years...

By: A. Sravani; V. Brahmananda Rao; S. S. V. S. Ramakrishna; N. Vijaya Saradhi; G. Harikishan

Description: Department of Meteorology & Oceanography, Andhra University, Visakhapatnam-530003, India. In the present study we made an attempt to explain the behavior of the southwest monsoon for two contrasting years, from the view point of energetics. As a test case we selected 2002 and 2003, which were weak and strong monsoon years, respectively, based on rainfall. The energy terms KΨ, KΧ and APE and the conversion terms f∇Ψ. ∇Χ,

Awade, S. T., Totagi, M. Y., and Bawiskar, S. H.: Wave to wave and wave to zonal mean flow kinetic energy exchanges during contrasting monsoon years, Pure Appl. Geophys., 120(3), 463–482, 1982.; Bordoni, S. and Schneider, T.: Monsoons as eddy-mediated regime transitions of the tropical overturning circulation, Nature Geosci., 1, 515–519, 2008.; Chen, T. C.: Global water flux and maintenance during FGGE, Mon. Weather Rev., 113, 1801–1819, 1985.; De, U. S. and Mukhopadhyay...

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A Study of Phase-steepened Alfvén Waves in a High-speed Stream at ...

By: P. Alexander

Description: Departmento de Físcia, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Argentina. This work performs a search of phase-steepened Alfvén waves under a priori ideal conditions: a high-speed solar wind stream observed in one of the closest approaches to the Sun by any spacecraft (Helios 2). Five potential candidates were initially found following procedures established in earlier work. The observed cases exhibited arc-like or elliptic...

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Energetics of Small Scale Turbulence in the Lower Stratosphere fro...

By: C. Sidi; F. Dalaudier; R. Wilson; J. Dole

Description: Service d’Aéronomie, Université Pierre et Marie Curie, Paris, France. Very high resolution radar measurements were performed in the troposphere and lower stratosphere by means of the PROUST radar. The PROUST radar operates in the UHF band (961 MHz) and is located in St. Santin, France (44°39’ N, 2°12’ E). A field campaign involving high resolution balloon measurements and the PROUST radar was conducted during April 1998. Under the classical hypothe...

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The Auroral and Ionospheric Flow Signatures of Dual Lobe Reconnect...

By: B. Hubert; S. M. Imber; S. E. Milan

Description: Department of Physics and Astronomy, University of Leicester, Leicester, UK. We present the first substantial evidence for the occurrence of dual lobe reconnection from ionospheric flows and auroral signatures. The process of dual lobe reconnection refers to an interplanetary magnetic field line reconnecting with lobe field lines in both the northern and southern hemispheres. Two bursts of sunward plasma flow across the noon portion of the open/closed f...

Baker, K. B., Dudeney, J. R., Greenwald, R. A., Pinnock, M., Newell, P. T., Rodger, A. S., Mattin, N., and Meng, C.-I.: HF radar signatures of the cusp and low-latitude boundary layer, J. Geophys. Res., 100, 7671–7695, 1995.; Carlson, C. W., Pfaff, R. F., and Watzin, J. G.: The Fast Auroral Snapshot mission, Geophys. Res. Lett., 25, 2013–2016, 1998.; Balogh, A., Dunlop, M. W., Cowley, S. W. H., Southwood, D. J., Thomlinson, J. G., Glassmeier, K. H., Musmann, G., Luhr, H....

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Orientation of the Cross-field Anisotropy of Small-scale Ionospher...

By: E. D. Tereshchenko; A. V. Koustov; N. Yu. Romanova

Description: Polar Geophysical Institute of Russian Academy of Sciences, 15 Khalturina, 183 010 Murmansk, Russia. The relationship between the orientation of the small-scale ionospheric irregularity anisotropy in a plane perpendicular to the geomagnetic field and the direction of plasma convection in the F region is investigated. The cross-field anisotropy of irregularities is obtained by fitting theoretical expectations for the amplitude scintillations of satellite...

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The Statistical Studies of the Inner Boundary of Plasma Sheet : Vo...

By: H. Reme; Z. X. Liu; I. Dandouras; M. Dunlop; W. Z. Ding; J. Y. Yang; J. B. Cao

Description: Beijing University of Aeronautics and Astronautics, 100190, Beijing, China. The penetration of plasma sheet ions into the inner magnetosphere is very important to the inner magnetospheric dynamics since plasma sheet ions are one of the major particle sources of ring current during storm times. However, the direct observations of the inner boundary of the plasma sheet are fairly rare due to the limited number of satellites in near equatorial orbits outsi...

Carr, C., Brown, P., Zhang, T. L., Gloag, J., Horbury, T., Lucek, E., Magnes, W., O'Brien, H., Oddy, T., Auster, U., Austin, P., Aydogar, O., Balogh, A., Baumjohann, W., Beek, T., Eichelberger, H., Fornacon, K.-H., Georgescu, E., Glassmeier, K.-H., Ludlam, M., Nakamura, R., and Richter, I.: The Double Star magnetic field investigation: instrument design, performance and highlights of the first year's observations, Ann. Geophys., 23, 2713–2732,

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Proton-electron Precipitation Effects on the Electron Production a...

By: M. Galand; J. Lilensten

Description: SGEP-CEPHAG, BP 46, 38402 St Martin d'Hres cedex, France. The suprathermal particles, electrons and protons, coming from the Sun and precipitating into the high-latitude atmosphere are an energy source for the Earth's ionosphere. They interact with the ambient thermal gas through inelastic and elastic collisions. Most of the physical quantities perturbed by the precipitation, such as the electron production rate, may be evaluated by solving the stationa...

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Velocity Shear and Current Driven Instability in a Collisional F-r...

By: J.-p. St.-maurice; J.-m. A. Noël; P. J. G. Perron

Description: Department of Physics, Royal Military College of Canada, Kingston, Ontario, Canada. We have studied how the presence of collisions affects the behavior of instabilities triggered by a combination of shears and parallel currents in the ionosphere under a variety of ion to electron temperature ratios. To this goal we have numerically solved a kinetic dispersion relation, using a relaxation model to describe the effects of ion and electron collisions. We h...

Agrimson, E., D'Angelo, N., and Merlino, R L.: Excitation of Ion-Acoustic-Like Waves by Subcritical Currents in a Plasma Having Equal Electron and Ion Temperatures, Phys. Rev. Lett., 86, 5282–5285, 2001.; Basu, B. and Coppi, B.: Velocity shear and fluctuations in the auroral regions of the ionosphere., J. Geophys. Res., 94, 5316–5326, 1989.; Cerisier, J C., Machard, C., and Pottelette, R.: MHD turbulence generated by time-varying field-aligned currents., J. Geophys. Res....

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Naturally Enhanced Ion-line Spectra Around the Equatorial 150-km R...

By: M. A. Milla; R. F. Woodman; E. Kudeki; J. L. Chau

Description: Radio Observatorio de Jicamarca, Instituto Geofísico del Perú, Lima. For many years strong radar echoes coming from 140–170 km altitudes at low latitudes have been associated to the existence of field-aligned irregularities (FAIs) (the so called 150-km echoes). In this work, we present frequency spectra as well as angular distribution of 150-km echoes. When the 150-km region is observed with beams perpendicular to the magnetic field (B) the obser...

Chau, J L.: Unexpected Spectral Characteristics of VHF Radar Signals from 150-Km Region over Jicamarca, Geophys Res Lett., 31, L23803, doi:10.1029/2004GL021620, 2004.; Anderson, D N., Anghel, A., Chau, J L., and Veliz, O.: Daytime, Vertical ExB Drift Velocities Inferred from Ground-Based Magnetometer Observations at Low Latitudes, Space Weather, 2, S11001, doi:10.1029/2004SW000095, 2004.; Bahcivan, H., Cosgrove, R B., and Tsunoda, R T.: Parallel electron streaming in the...

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Estimates of Eddy Turbulence Consistent with Seasonal Variations o...

By: M. C. Kelley; M. N. Vlasov

Description: School of Electrical and Computer Engineering, Cornell University, Ithaca, NY, USA. According to current understanding, adiabatic cooling and heating induced by the meridional circulation driven by gravity waves is the major process for the cold summer and warm winter polar upper mesosphere. However, our calculations show that the upward/downward motion needed for adiabatic cooling/heating of the summer/winter polar mesopause simultaneously induces a se...

Akmaev, R. A.: On the energetics of mean-flow interactions with thermally dissipating gravity waves, J. Geophys. Res., 112, D11125, doi:10.1029/2006JD007908, 2007.; Becker, E.: Direct heating rates associated with gravity wave saturation, J. Atmos. Solar-Terr. Phys., 66(6–9), 683–696, 2004.; Becker, E. and McLandress, C.: Consistent scale interaction of gravity waves in the Doppler spread parameterization, J. Atmos. Sci., 66, 1434–1449, 2009.; Banks, P. M. and Kockarts, ...

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The Occurrence Frequency of Auroral Potential Structures and Elect...

By: H. Laakso; A. Olsson; P. Janhunen

Description: Finnish Meteorological Institute, Geophysical Research, Helsinki, Finland. The aim of the paper is to study how auroral potential structures close at high altitude. We analyse all electric field data collected by Polar on auroral field lines in 1996–2001 by integrating the electric field along the spacecraft orbit to obtain the plasma potential, from which we identify potential minima by an automatic method. From these we estimate the associated effecti...

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