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Radar Observations of 8.3-m Scale Equatorial Spread F Irregulariti...

By: R. Sridharan; K. S. Viswanathan; A. K. Patra; C. V. Devasia; K. S. V. Subbarao; D. Tiwari; N. Jyoti

Description: Space Physics Laboratory, Vikram Sarabhai Space Center Trivandrum, 695022, India. In this paper, we present observations of equatorial spread F (ESF) irregularities made using a newly installed 18MHz radar located at Trivandrum. We characterize the morphology and the spectral parameters of the 8.3-m ESF irregularities which are found to be remarkably different from that observed so extensively at the 3-m scale size. We also present statistical results of...

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Multi-scale Analysis of Turbulence in the Earth's Current Sheet : ...

By: T. L. Zhang; W. Baumjohann; R. Nakamura; M. Volwerk; H. Rème; A. Runov; K.-h. Glassmeier; B. Klecker; A. Balogh; R. A. Treumann; Z. Vörös

Description: IWF, ÖAW, Graz, Austria. A multi-scale analysis of magnetotail turbulence in the Earth's tail current sheet is presented based on Cluster magnetometer observations. Both Fourier and wavelet analysis is used to describe the spectral index and scaling indices of the turbulence for different frequency regions. Flows in the tail are very important for driving the observed turbulence. There is a strong correlation between the maximum perpendicular flow veloc...

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Plasma and Wave Phenomena Induced by Neutral Gas Releases in the S...

By: J.-g. Trotignon; P. Janhunen; R. Grard; H. Laakso

Description: ESA Space Science Department, Noordwijk, The Netherlands. We investigate plasma and wave disturbances generated by nitrogen (N2) gas releases from the cooling system of an IR-camera on board the Vega 1 and Vega 2 spacecraft, during their flybys of comet Halley in March 1986. N2 molecules are ionized by solar UV radiation at a rate of ~ 7 · 10-7 s-1 and give rise to a plasma cloud expanding around the spacecraft. Strong disturb...

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Remote Sensing of the Proton Aurora Characteristics from Image-fuv...

By: H. U. Frey; M. Meurant; J.-c. Gérard; V. I. Shematovich; S. B. Mende; D. V. Bisikalo

Description: Institute of Astronomy, RAS, Moscow, Russia. The combination of simultaneous global images of the north polar region obtained with the IMAGE-FUV imaging system makes it possible to globally map the properties of the electron and proton auroral precipitation. The SI12 imager, which observes the Doppler-shifted Lyman-a emission, provides a global snapshot of the proton aurora every 2 min. These images may be combined with t...

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The Measurements of Light High-energy Ions in Nina-2 Experiment : ...

By: J. Cabrera; P. Picozza; S. Benck; M. Cyamukungu; M. Casolino; M. Ricci; A. Galper; A. Leonov; M. P. De Pascale; S. Koldashov; R. Sparvoli; P. Leleux; V. Mikhailov; Gh. Grégoire; S. Voronov; A. Bakaldin

Description: Center for Space Radiations (CSR); Chemin du Cyclotron 2, 1348 Louvain-la-Neuve, Belgium. The flux of energetic light ions at low altitude is both an important input and output for self-consistent calculations of albedo particles resulting from the interaction of trapped and cosmic ray particles, with the upper atmosphere. In addition, data on the flux of light ions are needed to evaluate radiation damages on space-borne instruments and on space mission ...

Adams, J. H., Silberberg R., and Tsao C. H.: Cosmic Ray Effects on Microelectronics, Part I: The Near-Earth Particle Environment, NRL Memorandum Report 4506, Naval Research Laboratory, Washington D.C. 20375-5000, USA, 1981.; Bakaldin, A., Galper, A., Koldashov, S., et al.: Geomagnetically trapped light isotopes observed with the detector NINA, J. Geophys. Res., 107, A8, 81, 2002a.; Bakaldin, A., Galper, A., Koldashov, S., et al.: Light isotope abundances in solar energet...

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A 22-year Cycle in the F Layer Ionization of the Ionosphere : Volu...

By: E. Feichter; R. Leitinger

Description: Institut für Meteorologie und Geophysik, Universität Graz, Halbärthgasse 1, A-8010 Graz, Austria Tel: +43 316 380 5257; Fax: +43 316 384091;
e-mail: leitinger@bkfung.kfunigraz.ac.at. The double-sunspot-cycle variation in terrestrial magnetic activity has been well known for about 30 years. In 1990 we examined and compared the low-solar-activity (LSA) part of two consecutive cycles and predicted from this database and from published results the existen...

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Comparison of the Open-closed Field Line Boundary Location Inferre...

By: S. E. Milan; O. Amm; T. Pitkänen; A. T. Aikio; K. Kauristie; B. Hubert; S. W. H. Cowley; J.-c. Gérard

Description: Laboratory for Planetary and Atmospheric Physics, University of Liège, Liège, Belgium. We compare the location of the polar cap boundary (PCB) determined using two different techniques, and use them as proxies for the open-closed field line boundary (OCB). Electron temperatures from observations of the EISCAT radar facility are used to estimate the latitude of the PCB along the meridian of the EISCAT VHF beam. The second method utilizes global images of ...

Aikio, A. T., Pitkänen, T., Kozlovsky, A., and Amm, O.: Method to locate the polar cap boundary in the nightside ionosphere and application to a substorm event, Ann. Geophys., 24, 1905–1917, 2006.; Aikio, A. T., Pitkänen, T., Fontaine, D., Dandouras, I., Amm, O., Kozlovsky, A., Vaivdas, A., and Fazakerley, A.: EISCAT and Cluster observations in the vicinity of the dynamical polar cap boundary, Ann. Geophys., 26, 87–105, 2008.; Blanchard, G. T., Lyons, L. R., and de la Be...

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Infrasound - the Cause of Strong Polar Mesosphere Winter Echoes? :...

By: E. Belova; M. Rietveld; P. Chilson; P. Dalin; W. Singer; I. Häggström; S. Kirkwood

Description: Swedish Institute of Space Physics, Box 812, 98128 Kiruna, Sweden. The ESRAD 52-MHz and the EISCAT 224-MHz radars in northern Scandinavia observed thin layers of strongly enhanced radar echoes from the mesosphere (Polar Mesosphere Winter Echoes - PMWE) during a solar proton event in November 2004. Using the interferometric capabilities of ESRAD it was found that the scatterers responsible for PMWE show very high horizontal travel speeds, up to 500 ms

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Corrigendum to Ulf Geomagnetic Pulsations at Different Latitudes i...

By: M. De Lauretis; M. Vellante; U. Villante; A. Piancatelli; P. Francia

Description: Dipartimento di Fisica, Università di L'Aquila, Italy. No abstract available.

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Cluster and Tc-1 Observation of Magnetic Holes in the Plasma Sheet...

By: H. Reme; Q. G. Zong; C. L. Tang; A. Fazakerley; Q. Q. Shi; T. Xiao; Z. Y. Pu; A. P. Walsh; W. J. Sun; M. W. Dunlop; C. Carr; S. Y. Fu; E. Lucek

Description: Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, School of Space Science and Physics, Shandong University at Weihai, Weihai, China. Magnetic holes with relatively small scale sizes, detected by Cluster and TC-1 in the magnetotail plasma sheet, are studied in this paper. It is found that these magnetic holes are spatial structures and they are not magnetic depressions generated by the flapping movement of the magn...

Ashour-Abdalla, M., Zhou, M., Schriver, D., El-Alaoui, M., Deng, X., Richard, R. L., Walker, R. J., and Sergeev, V. A.: Electron acceleration during substroms, American Geophysical Union, Fall Meeting, America, available at: http://adsabs.harvard.edu/abs/2009AGUFMSM53B1373A, 14–18 December 2009.; Balogh, A., Carr, C. M., Acuña, M. H., Dunlop, M. W., Beek, T. J., Brown, P., Fornacon, K.-H., Georgescu, E., Glass...

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Electromagnetic Oscillations of the Earth's Upper Atmosphere (Revi...

By: T. D. Kaladze; A. Ishimaru; G. V. Jandieri; A. G. Khantadze; Zh. M. Diasamidze

Description: Metrology and Hydrology Department, Tbilisi State University, Chavchavadze Avenue, 1, 0128, Tbilisi, Georgia. A complete theory of low-frequency MHD oscillations of the Earth's weakly ionized ionosphere is formulated. Peculiarities of excitation and propagation of electromagnetic acoustic-gravity, MHD and planetary waves are considered in the Earth's ionosphere. The general dispersion equation is derived for the magneto-acoustic, magneto-gravity and ele...

Aburjania, G. D., Jandieri, G. V., and Khantadze, A. G.: Self – organization of planetary electromagnetic waves in E–region of the ionosphere, J. Atmos. Solar-Terr. Phys., 65(6), 661–671, 2003.; Aburjania, G. D., Chargazia, K. Z., Jandieri, G. V., Khantadze, A. G., and Kharshiladze, O. A.: On the new modes of planetary-scale electromagnetic waves in the ionosphere, Ann. Geophys., 22, 1203–1211, doi:10.5194/angeo-22-1203-2004, 2004.; Aburjania, G. D., Chargazia, Kh. Z., J...

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Response of the Convecting High-latitude F Layer to a Powerful Hf ...

By: G. I. Mingaleva; V. S. Mingalev

Description: Polar Geophysical Institute, Fersman Str. 14, Apatity, Murmansk Region 184200, Russia. A numerical model of the high-latitude ionosphere, which takes into account the convection of the ionospheric plasma, has been developed and utilized to simulate the F-layer response at auroral latitudes to high-power radio waves. The model produces the time variations of the electron density, positive ion velocity, and ion and electron temperature profiles within a m...

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Imaging and Eiscat Radar Measurements of an Auroral Prebreakup Eve...

By: T. Turunen; W. Lyatsky; J. Manninen; V. Safargaleev; A. Kozlovsky

Description: Polar Geophysical Institute, Fersman St. 14, 184200 Apatity, Russia. The results of coordinated EISCAT and TV-camera observations of a prebreakup event on 15 November 1993 have been considered. The variations of the luminosity of two parallel auroral arcs, plasma depletion on the poleward edge of one of these arcs as well as electron and ion temperatures in front of a westward travelling surge were studied. It was found that a short-lived brightening of...

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The Spatial Relationship Between Active Regions and Coronal Holes ...

By: D. Rojas; J. A. L. Cruz-abeyro; S. Bravo

Description: Instituto de Geofísica, Universidad Nacional Autónoma de México, Coyoacán D.F., 04510, México. We study the annual frequency of occurrence of intense geomagnetic storms (Dst < –100 nT) throughout the solar activity cycle for the last three cycles and find that it shows different structures. In cycles 20 and 22 it peaks during the ascending phase, near sunspot maximum. During cycle 21, however, there is one peak in the ascending phase and a second...

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Comparison of Birkeland Current Observations During Two Magnetic C...

By: M. Wiltberger; B. J. Anderson; J. G. Lyon; H. Korth

Description: The Johns Hopkins University, Applied Physics Laboratory, Laurel, MD, USA. Low altitude field-aligned current densities obtained from global magnetospheric simulations are compared with two-dimensional distributions of Birkeland currents at the topside ionosphere derived from magnetic field observations by the constellation of Iridium satellites. We present the analysis of two magnetic cloud events, 17–19 August 2003 and 19–21 March 2001, where the int...

Anderson, B J., Takahashi, K., and Toth, B A.: Sensing global Birkeland currents with Iridium engineering magnetometer data, Geophys. Res. Lett., 27, 4045–4048, 2000.; Anderson, B J., Takahashi, K., Kamei, T., Waters, C L., and Toth, B A.: Birkeland currents sytem key parameters derived from Iridium observations: Method and initial validation results, J. Geophys. Res., 107, 1079, \doi10.1029/2001JA000080, 2002.; Baker, K B. and Wing, S.: A new magnetic coordinate system ...

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Spatial Dependence of Magnetopause Energy Transfer: Cluster Measur...

By: E. A. Lucek; T. I. Pulkkinen; C. R. Anekallu; M. Palmroth; I. Dandouras; M. Dunlop; T. V. Laitinen

Description: Finnish Meteorological Institute, Helsinki, Finland. We investigate the spatial variation of magnetopause energy conversion and transfer using Cluster spacecraft observations of two magnetopause crossing events as well as using a global magnetohydrodynamic (MHD) simulation GUMICS-4. These two events, (16 January 2001, and 26 January 2001) are similar in all other aspects except for the sign of the interplanetary magnetic field (IMF) y-component that has...

Rosenqvist, L., Buchert, S., Opgenoorth, H., Vaivads, A., and Lu, G.: Magnetospheric energy budget during huge geomagnetic activity using Cluster and ground-based data, J. Geophys. Res., 111, A10211, doi:10.1029/2006JA011608, 2006.; Rosenqvist, L., Opgenoorth, H. J., Rastaetter, L., Vaivads, A., and Dandouras, I.: Comparison of local energy conversion estimates from Cluster with global MHD simulations, Geophys. Res., Let...

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Efficient Data Assimilation Into a Complex, 3-d Physical-biogeoche...

By: G. Petihakis; G. Triantafyllou; I. Hoteit

Description: Scripps Institution of Oceanography, La Jolla, CA, USA. Advanced Kalman filtering techniques were used to assimilate pseudo ocean color and profile data into a complex, three-dimensional coupled physical (POM)-biogeochemical (ERSEM) model of the Cretan Sea ecosystem. The assimilation schemes, the Singular Evolutive Partially-Local Extended Kalman (SEPLEK) filter and its variant called SFPLEK, are based on the standard SEEK filter in which the Kalman c...

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Stormtime Dynamics of the Global Thermosphere and Equatorial Ionos...

By: R. D. Sharma; C. Y. Huang; W. J. Burke

Description: Space Vehicles Directorate, Air Force Research Laboratory, Hanscom AFB, MA, USA. During magnetic storms the development of equatorial plasma bubbles (EPBs) and distributions of thermospheric densities are strongly influenced by the histories of imposed magnetospheric electric (ΕM) fields. Periods of intense EPB activity driven by penetration ΕM fields in the main phase are followed by their worldwide absence during recovery. A new ...

Blanc, M. and Richmond, A. D.: The ionospheric disturbance dynamo, J. Geophys. Res., 85, 1669–1686, 1980.; Bowman, B. R., Tobiska, W. K., and Marcos, F. A.: A new empirical thermospheric density model JB2006 using new solar indices, AIAA 2006-6166, AIAA Astrodynamics Conference, Keystone, CO, 2006.; Bowman, B. R., Tobiska, W. K., Marcos, F. A., Huang, C. Y., Lin, C. S., and Burke, W. J.: A new empirical thermospheric density model JB2008 using solar and geomagnetic indic...

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Variability of Ionospheric Scintillation Near the Equatorial Anoma...

By: S. Chatterjee; S. K. Chakraborty

Description: Department of Physics, Raja Peary Mohan College, Uttarpara, Hooghly, Pin-712258, India. Multistation observations of ionosphere scintillation at VHF (250 MHz) and GNSS L1 frequency from three locations – (i) Bokkhali (BOK) (geographic 21.6° N, 88.2° E, dip 31.48°, (ii) Raja Peary Mohan College Centre (RPMC) (geographic 22.66° N, 88.4° E, dip 33.5°) and (iii) Krishnath College Centre (KNC), Berhampore (geographic 24.1° N, 88.3° E, dip 35.9°) – at ~ 1° la...

Basu, S. and Basu, Su.: Equatorial scintillations – a review, J. Atmos. Terr. Phys., 43, 473–489, 1981.; Aarons, J., Whitney, H. E., MacKenzie E., and Basu, S.: Microwave equatorial scintillation intensity during solar maximum, Radio Sci., 16, 939–945, 1981.; Abdu, M. A., de Medeiros, R. T., Sobral, J. H. A., and Bittencourt, J. A.: Spread F plasma bubble vertical rise velocities determined from spaced ionosonde observations, J. Geophys. Res., 88, 9197–9204, 1983.; Alex,...

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Long-term Variations and Trends in the Simulation of the Middle At...

By: M. Deushi; K. Shibata

Description: Meteorological Research Institute, Tsukuba, Ibaraki 305-0052, Japan. A middle-atmosphere simulation of the past 25 years (from 1980 to 2004) has been performed with a chemistry-climate model (CCM) of the Meteorological Research Institute (MRI) under observed forcings of sea-surface temperature, greenhouse gases, halogens, volcanic aerosols, and solar irradiance variations. The dynamics module of MRI-CCM is a spectral global model truncated triangularly ...

Randel, W. J. and Wu, F.: Cooling of the arctic and antarctic polar stratospheres due to ozone depletion, J. Climate, 12, 1467–1479, 1999.; Andrews, D. G., Holton, J. R., and Leovy, C. B.: Middle Atmosphere Dynamics, International Geophysics Series, 40, Academic Press, Orlando, USA, 1987.; Austin, J. and Wilson, R. J.: Ensemble simulations of the decline and recovery of stratospheric ozone, J. Geophys. Res., 111, doi:10.1029/2005JD006907, 2006.; Austin, J.,~Shindell, D.,...

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