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Magnetopause Mapping to the Ionosphere for Northward Imf : Volume ...

By: S. Yu. Bobrovnikov; E. S. Belenkaya; V. V. Kalegaev; I. I. Alexeev; J. A. Cumnock; L. G. Blomberg

Description: Skobeltsyn Institute of Nuclear Physics, Moscow State University, Moscow, Russia. We study the topological structure of the magnetosphere for northward IMF. Using a magnetospheric magnetic field model we study the high-latitude response to prolonged periods of northward IMF. For forced solar wind conditions we investigate the location of the polar cap region, the polar cap potential drop, and the field-aligned acceleration potentials, depending on the s...

Alexeev, I. I.: The penetration of interplanetary magnetic and electric fields into the magnetosphere, J. Geomagn. Geoelectr., 38, 1199–1221, 1986.; Alexeev, I. I.: What define the polar cap and auroral oval diameter?, in: The Inner Magnetosphere: Physics and Modeling, edited by: Pulkkinen, T. I., Tsyganenko, N. A., and Friedel, R. H. W.: Geophysical Monograph Series, Volume 155, 313 pp., 257–262, ISBN 0-87590-420-3, AGU Code GM1554203, 2005.; Alekseyev, I. I. and Belenk...

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Missing Data and the Accuracy of Magnetic-observatory Hour Means :...

By: J. J. Love

Description: Geomagnetism Program, US Geological Survey, Denver, CO, USA. Analysis is made of the accuracy of magnetic-observatory hourly means constructed from definitive minute data having missing values (gaps). Bootstrap sampling from different data-gap distributions is used to estimate average errors on hourly means as a function of the number of missing data. Absolute and relative error results are calculated for horizontal-intensity, declination, and vertical-...

Barkhatov, N A., Levitin, A E., and Sakharov, S Y.: The method of artificial neuron networks as a procedure for reconstructing gaps in records of individual magnetic observatories from the data at other stations, Geomag. Aeron., 42, 187–190, 2002.; Brooke, C.: On the automatic registration of magnetometers, and other meteorological instruments, by photography, Phil. Trans. R. Soc. Lond., 137, 69–77, 1847.; Bulmer, M G.: Principles of Statistics, Dover Publications, New Y...

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A Comparative Study of Winds and Tidal Variability in the Mesosphe...

By: N. J. Mitchell; A. G. Beard; P. Mukhtarov; H. G. Muller; D. Pancheva

Description: Geophysical Institute, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria. Meteor radars located in Bulgaria and the UK have been used to simultaneously measure winds in the mesosphere/lower-thermosphere region near 42.5°N, 26.6°E and 54.5°N, 3.9°W, respectively, over the period January 1991 to June 1992. The data have been used to investigate planetary waves and diurnal and semidiurnal tidal variability over the two sites. The tidal amplitudes at each...

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Solar Flux Dependence of Coherence Scales in Scintillation Pattern...

By: K. Jeeva; A. Bhattacharyya; K. U. Nair; B. Engavale

Description: Indian Institute of Geomagnetism, Kalamboli Highway, Kalamboli - 410 218 New Panvel, India. The coherence scale length, defined as the 50% decorrelation scale length along the magnetic east-west direction, in the ground scintillation pattern obtained at a dip equatorial location, due to scattering of VHF radio waves by equatorial spread F (ESF) irregularities, is calculated, using amplitude scintillation data recorded by two spaced receivers. The averag...

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Mid-latitude Summer Nighttime Anomaly (Msna) – Observations and Mo...

By: N. Balan; C. Lin; H. Liu; M. Yamamoto; S. V. Thampi

Description: Research Institute for Sustainable Humanosphere (RISH), Kyoto University, 611-0011, Japan. In this paper, we present model simulations of the Mid-latitude Summer Nighttime Anomaly (MSNA) in the Northern Hemisphere, which is characterized by noon-time dip and evening maximum in the diurnal variation of the ionospheric density. The simulations are carried out using SUPIM (Sheffield University Plasmasphere Ionosphere Model) for solar minimum at 135° E long...

Balan, N. and Rao, P. B.: Latitudinal Variations of Nighttime Enhancements in Total Electron Content, J. Geophys. Res., 92(A4), 3436–3440, 1987.; Anthes, R. A., Bernhardt, P. A., Chen, Y., Cucurull, L., Dymond, K. F., Ector, D., Healy, S. B., Ho, S.-P., Hunt, D. C., Kuo, Y.-H., Liu, H., Manning, K., Mccormick, C., Meehan, T. K., Randel, W. J., Rocken, C., Schreiner, W. S., Sokolovskiy, S. V., Syndergaard, S., Thompson, D. C., Trenberth, K. E., Wee, T.-K., Yen, N. L., and...

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Several Notes on the Oh&Ast; Layer : Volume 33, Issue 7 (27/07/2015)

By: M. Grygalashvyly

Description: Leibniz Institute of Atmospheric Physics at the University of Rostock in Kühlungsborn, Schloss-Str. 6, 18225 Ostseebad Kühlungsborn, Germany. This brief note introduces several analytical approaches to OH* layer parameters. The number density and height of the OH* layer peak are determined by the distributions of atomic oxygen and temperature, and by corresponding vertical gradients. The theory can be applied to satellite-borne and ground-based a...

Adler-Golden, S.: Kinetic parameters for OH nightglow modeling consistent with recent laboratory measurements, J. Geophys. Res., 102, 19969–19976, doi:10.1029/97JA01622, 1997.; Baker, D. J., Thurgood, B. K., Harrison, W. K., Mlynczak, M. G., and Russell, J. M.: Equatorial enhancement of the nighttime OH mesospheric infrared airglow, Phys. Scripta, 75, 615–619, doi:10.1088...

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Seasonal Variation of the Ion Upflow in the Topside Ionosphere Dur...

By: H. Wang; H. Lühr

Description: Dept. of Space Physics, School of Electronic Information, Wuhan University, Wuhan 430072, China. A statistical study has been performed by using two years of DMSP (Defense Meteorological Satellite Program) plasma observations to investigate the seasonal effect of SAPS (subauroral polarization stream) on the ion upflow in the duskside ionosphere of the Northern Hemisphere. There are obvious upflows occurring in the topside ionosphere around the SAPS regi...

Pollock, C. J., Chandler, M. O., Moore, T. E., Chappell, C. R., and Waite Jr., J. H.: A survey of upwelling ion event characteristics, J. Geophys. Res., 95, 18969–18980, doi:10.1029/JA095iA11p18969, 1990.; Retterer, J. M., Chang, T., and Jasperse, J. R.: Plasma simulation of ion acceleration by lower hybrid waves in the suprauroral region, in: Ion Acceleration in the Magnetosphere and Ionosphere; Proceedings of the AG...

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Eddy Diffusion Coefficients and Their Upper Limits Based on Applic...

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

Description: School of Electrical and Computer Engineering, Cornell University, Ithaca, New York, USA. The equation for the diffusion velocity in the mesosphere and the lower thermosphere (MLT) includes the terms for molecular and eddy diffusion. These terms are very similar. For the first time, we show that, by using the similarity theory, the same formula can be obtained for the eddy diffusion coefficient as the commonly used formula derived by Weinstock (1981). Th...

Bishop, R. L., Larsen, M. F., Hecht, J. H., Liu, A. Z., and Gardner, C. S.: TOMEX: Mesospheric and lower thermospheric diffusivity and instability layers, J. Geophys. Res., 109, D02S03, doi:10.1029/2002JD003079, 2004.; Hecht, J. H., Liu, A. Z., Walterscheid, R. L., Roble, R. G., Larsen, M. F., and Clemmons, J. H.: Airglow emissions and oxygen mixing ratios from the photometer experiment on the Turbulent Oxygen Mixing Exp...

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Quantitative Magnetotail Characteristics of Different Magnetospher...

By: V. A. Sergeev; N. P. Dmitrieva; M. A. Shukhtina

Description: V. A. Fock Institute of Physics, St.-Petersburg State University, St.-Petersburg, Russia. Quantitative relationships allowing one to compute the lobe magnetic field, flaring angle and tail radius, and to evaluate magnetic flux based on solar wind/IMF parameters and spacecraft position are obtained for the middle magnetotail, X=(–15,–35)RE, using 3.5 years of simultaneous Geotail and Wind spacecraft observations. For the first time it...

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A Self-consistent Derivation of Ion Drag and Joule Heating for Atm...

By: J. B. H. Baker; J.-h. Yee; E. R. Talaat; X. Zhu

Description: The Johns Hopkins University, Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723-6099, USA. The thermosphere is subject to additional electric and magnetic forces, not important in the middle and lower atmosphere, due to its partially ionized atmosphere. The effects of charged particles on the neutral atmospheric dynamics are often parameterized by ion drag in the momentum equations and Joule heating in the energy equation. Presented ...

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New Method in Computer Simulations of Electron and Ion Densities a...

By: A. V. Pavlov

Description: Institute of Terrestrial Magnetism, Ionosphere and Radio-Wave Propagation, Russia Academy of Science (IZMIRAN), Troitsk, Moscow Region, 142190, Russia. A new theoretical model of the Earth’s low- and mid-latitude ionosphere and plasmasphere has been developed. The new model uses a new method in ionospheric and plasmaspheric simulations which is a combination of the Eulerian and Lagrangian approaches in model simulations. The electron and ion continui...

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Evidence of Meso-scale Structure in the High-latitude Thermosphere...

By: E. Griffin; A. L. Aruliah

Description: Atmospheric Physics Laboratory, University College London, 67–73, Riding House Street, London W1P 7PP, England. There is a widely held assumption that the thermospheric neutral gas is slow to respond to magnetospheric forcing owing to its large inertia and therefore, may be treated as a steady state background medium for the more dynamic ionosphere. This is shown to be over simplistic. The data presented here compare direct measurements of the thermosph...

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Structure of the Low-latitude Magnetopause: Magion-4 Observations ...

By: A. Fedorov; J. Safrankova; G. Zastenker; Z. Nemecek

Description: Faculty of Mathematics and Physics of Charles University, Prague, Czech Republic. The aims of this paper are (1) briefly to describe the plasma devices onboard the MAGION-4 satellite, launched on 3 August 1995, of the INTERBALL project, and (2) to discuss first observations made near the magnetopause region. During the presented boundary crossings the MAGION-4 observed quasi-periodic pulses of magnetosheath-like plasma in a region of low plasma density....

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Lhr Effects in Nonducted Whistler Propagation – New Observations a...

By: D. R. Shklyar; P. Třiska; F. Jiřiček

Description: Institute of Atmospheric Physics, Acad. Sci. Czech Republic, Boční II, 141 31 Prague 4, Czech Republic. VLF-ELF broadband measurements onboard the MAGION 4 and 5 satellites at heights above 1 Re in plasmasphere provide new data on various known phenomena related to ducted and nonducted whistler wave propagation. Two examples are discussed: magnetospherically reflected (MR) whistlers and lower hybrid resonance (LHR) noise band. We present examples of rat...

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Determining Characteristics of Hf Communications Links Using Super...

By: R. J. Barnes; R. A. Greenwald; W. A. Bristow; J. M. Hughes

Description: Geophysical Institute, University of Alaska Fairbanks, Fairbanks, AK, USA. Space weather effects can strongly influence high-frequency (HF) communications by changing the ionospheric environment through which the radio waves propagate. Since many systems utilize HF communications, the ability to make real-time assessments of propagation conditions is an important part of space weather monitoring systems. In this paper, we present new techniques for...

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Comparing Jupiter and Saturn: Dimensionless Input Rates from Plasm...

By: V. M. Vasyliūnas

Description: Max-Planck-Institut für Sonnensystemforschung, 37191 Katlenburg-Lindau, Germany. The quantitative significance for a planetary magnetosphere of plasma sources associated with a moon of the planet can be assessed only by expressing the plasma mass input rate in dimensionless form, as the ratio of the actual mass input to some reference value. Traditionally, the solar wind mass flux through an area equal to the cross-section of the magnetosphere has been ...

Delamere, P A., Bagenal, F., Dols, V., and Ray, L C.: Saturn's neutral torus versus Jupiter's plasma torus, Geophys. Res. Lett., 34, L09105, doi:10.1029/2007GL029437, 2007.; Hill, T W.: Inertial limit on corotation, J. Geophys. Res., 84, 6554–6558, 1979a.; Dougherty, M K., Khurana, K K., Neubauer, F M., Russell, C T., Saur, J., Leisner, J S., and Burton, M E.: Identification of a dynamic atmosphere at Enceladus with the Cassini magnetometer, Science, 311, 1406–1409, doi:...

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A Study Into the Effect of the Diurnal Tide on the Structure of th...

By: A. D. Aylward; N. F. Arnold; M. J. Harris

Description: Atmospheric Physics Laboratory, University College London, 67–73, Riding House Street, London W1P 7PP, UK. A new coupled middle atmosphere and thermosphere general circulation model has been developed, and some first results are presented. An investigation into the effects of the diurnal tide upon the mean composition, dynamics and energetics was carried out for equinox conditions. Previous studies have shown that tides deplete mean atomic oxygen i...

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Ulf Fluctuations of the Geomagnetic Field and Ionospheric Sounding...

By: I. Cholakov; A. Meloni; T. L. Zhang; B. Zolesi; M. Förster; M. Vellante; U. Villante; M. Pezzopane; P. Francia; M. De Lauretis; V. Wesztergom; P. Palangio; P. Nenovski; W. Magnes

Description: Consorzio Area di Ricerca in Astrogeofisica, L’Aquila, Italy. We present an analysis of ULF geomagnetic field fluctuations at low latitudes during the first CAWSES campaign (29 March-3 April 2004). During the whole campaign, mainly in the prenoon sector, a moderate Pc3-4 pulsation activity is observed, clearly related to interplanetary upstream waves. On 3 April, in correspondence to the Earth's arrival of a coronal mass ejection, two SIs are observed w...

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The Relationship Between Electric Fields, Conductances and Current...

By: M. Lester; J. A. Davies

Description: Radio and Space Plasma Physics Group, Department of Physics and Astronomy, University of Leicester, University Road, Leicester, LE1 7RH, UK. The relationship between electric fields, height-integrated conductivities and electric currents in the high-latitude nightside electrojet region is known to be complex. The tristatic nature of the EISCAT UHF radar facility provides an excellent means of exploring this interrelationship as it enables simultaneous es...

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Spectral Characteristics of Spring Arctic Mesosphere Dynamics : Vo...

By: C. E. Meek; A. H. Manson; C. M. Hall

Description: The Auroral Observatory, Department of Physics, University of Tromsø, 9037 Tromsø, Norway
e-mail chris.hall@phys.uit.no. The spring of 1997 has represented a stable period of operation for the joint University of Tromsø / University of Saskatchewan MF radar, being between refurbishment and upgrades. We examine the horizontal winds from the February to June inclusive and also include estimates of energy dissipation rates derived from signal fading time...

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