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2015
Authors: Korotova G. I., Sibeck D G, Tahakashi K., Dai L., Spence H E, et al.
Title: Van Allen Probe observations of drift-bounce resonances with Pc 4 pulsations and wave–particle interactions in the pre-midnight inner magnetosphere
Abstract: We present Van Allen Probe B observations of azimuthally limited, antisymmetric, poloidal Pc 4 electric and magnetic field pulsations in the pre-midnight sector of the magnetosphere from 05:40 to 06:00 UT on 1 May 2013. Oscillation periods were similar for the magnetic and electric fields and proton fluxes. The flux of energetic protons exhibited an energy-dependent response to the pulsations. Energetic proton variations were anticorrelated at medium and low energies. Although we attribute the pulsations to a drift-bounce resonance, we demonstrate that the energy-dependent response of the ion fluxes results from pulsation-associated velocities sweeping energy-dependent radial ion flux gradients back and forth past the spacecraft.
Date: 01/2015 Publisher: Annales Geophysicae Pages: 955 - 964 DOI: 10.5194/angeo-33-955-2015 Available at: http://www.ann-geophys.net/33/955/2015/angeo-33-955-2015.pdf
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Authors: Liu Si, Xiao Fuliang, Yang Chang, He Yihua, Zhou Qinghua, et al.
Title: Van Allen Probes observations linking radiation belt electrons to chorus waves during 2014 multiple storms
Abstract: During 18 February to 2 March 2014, the Van Allen Probes encountered multiple geomagnetic storms and simultaneously observed intensified chorus and hiss waves. During this period, there were substantial enhancements in fluxes of energetic (53.8 − 108.3 keV) and relativistic (2 − 3.6 MeV) electrons. Chorus waves were excited at locations L = 4 − 6.2 after the fluxes of energetic were greatly enhanced, with a lower frequency band and wave amplitudes ∼ 20 − 100 pT. Strong hiss waves occurred primarily in the main phases or below the location L = 4 in the recovery phases. Relativistic electron fluxes decreased in the main phases due to the adiabatic (e.g., the magnetopause shadowing) or non-adiabatic (hiss-induced scattering) processes. In the recovery phase. . .
Date: 01/2015 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2014JA020781 Available at: http://doi.wiley.com/10.1002/2014JA020781
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2014
Authors: O'Brien T.P.
Title: The activity and radial dependence of anomalous diffusion by pitch-angle scattering on split magnetic drift shells
Abstract: Asymmetries in the magnetospheric magnetic field produce drift shell splitting, which causes the radial (drift shell) invariant to sometimes depend on pitch angle. Where drift shell splitting is significant, pitch angle scattering leads to diffusion in all three invariants of the particle's motion, including cross diffusion. We examine the magnitude of drift shell splitting-related anomalous diffusion for outer zone electrons compared to conventional diffusion in the absence of drift shell splitting. We assume the primary local scattering process is wave-particle interactions with chorus. We find that anomalous radial diffusion can exceed that of conventional drift resonant radial diffusion for particles with energies near 0.1 MeV at all radial distances outside the plasmasphere during q. . .
Date: 12/2014 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2014JA020422 Available at: http://doi.wiley.com/10.1002/2014JA020422
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Authors: Jaynes A. N., Li X, Schiller Q. G., Blum L. W., Tu W., et al.
Title: Evolution of relativistic outer belt electrons during an extended quiescent period
Abstract: To effectively study steady loss due to hiss-driven precipitation of relativistic electrons in the outer radiation belt, it is useful to isolate this loss by studying a time of relatively quiet geomagnetic activity. We present a case of initial enhancement and slow, steady decay of 700 keV - 2 MeV electron populations in the outer radiation belt during an extended quiescent period from ~15 December 2012 - 13 January 2013. We incorporate particle measurements from a constellation of satellites, including the Colorado Student Space Weather Experiment (CSSWE) CubeSat, the Van Allen Probes twin spacecraft, and THEMIS, to understand the evolution of the electron populations across pitch angle and energy. Additional data from calculated phase space density (PSD), as well as hiss and chorus w. . .
Date: 12/2014 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2014JA020125 Available at: http://doi.wiley.com/10.1002/2014JA020125
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Authors: Takahashi Kazue, Denton Richard E, Kurth William, Kletzing Craig, Wygant John, et al.
Title: Externally driven plasmaspheric ULF waves observed by the Van Allen Probes
Abstract: We analyze data acquired by the Van Allen Probes on 8 November 2012, during a period of extended low geomagnetic activity, to gain new insight into plasmaspheric ultra-low-frequency (ULF) waves. The waves exhibited strong spectral power in the 5–40 mHzband and included multiharmonic toroidal waves visible up to the 11th harmonic, unprecedented in the plasmasphere. During this wave activity, the interplanetary magnetic field cone angle was small, suggesting that the waves were driven by broadband compressional ULF waves originating in the foreshock region. This source mechanism is supported by the tailward propagation of the compressional magnetic field perturbations at a phase velocity of a few hundred kilometers per second that is determined bythe cross phase analysis of data from the t. . .
Date: 12/2014 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2014JA020373 Available at: http://doi.wiley.com/10.1002/2014JA020373
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Authors: Summers Danny, Omura Yoshiharu, Nakamura Satoko, and Kletzing Craig A.
Title: Fine structure of plasmaspheric hiss
Abstract: Plasmaspheric hiss has been widely regarded as a broadband, structureless, incoherent emission. In this study, by examining burst-mode vector waveform data from the Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) instrument on the Van Allen Probes mission, we show that plasmaspheric hiss is a coherent emission with complex fine structure. Specifically, plasmaspheric hiss appears as discrete rising tone and falling tone elements. Our study comprises the analysis of two one-hour samples within which a total of 8 one-second samples were analyzed. By means of waveform analysis on two samples we identify typical amplitudes, phase profiles, and sweep rates of the rising and falling tone elements. The exciting new observations reported here can be expected to fuel a . . .
Date: 12/2014 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2014JA020437 Available at: http://doi.wiley.com/10.1002/2014JA020437
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Authors: Li Zan, Millan Robyn M., Hudson Mary K, Woodger Leslie A., Smith David M., et al.
Title: Investigation of EMIC wave scattering as the cause for the BARREL January 17, 2013 relativistic electron precipitation event: a quantitative comparison of simulation with observations
Abstract: Electromagnetic ion cyclotron (EMIC) waves were observed at multiple observatory locations for several hours on 17 January 2013. During the wave activity period, a duskside relativistic electron precipitation (REP) event was observed by one of the BARREL balloons, and was magnetically mapped close to GOES-13. We simulate the relativistic electron pitch-angle diffusion caused by gyroresonant interactions with EMIC waves using wave and particle data measured by multiple instruments on board GOES-13 and the Van Allen Probes. We show that the count rate, the energy distribution and the time variation of the simulated precipitation all agree very well with the balloon observations, suggesting that EMIC wave scattering was likely the cause for the precipitation event. The event reported here is . . .
Date: 12/2014 Publisher: Geophysical Research Letters DOI: 10.1002/2014GL062273 Available at: http://doi.wiley.com/10.1002/2014GL062273
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Authors: Su Zhenpeng, Zhu Hui, Xiao Fuliang, Zheng Huinan, Wang Yuming, et al.
Title: Quantifying the relative contributions of substorm injections and chorus waves to the rapid outward extension of electron radiation belt
Abstract: We study the rapid outward extension of the electron radiation belt on a timescale of several hours during three events observed by RBSP and THEMIS satellites, and particularly quantify the contributions of substorm injections and chorus waves to the electron flux enhancement near the outer boundary of radiation belt. A comprehensive analysis including both observations and simulations is performed for the first event on 26 May 2013. The outer boundary of electron radiation belt moved from L = 5.5 to L > 6.07 over about 6 hours, with up to four orders of magnitude enhancement in the 30 keV-5 MeV electron fluxes at L = 6. The observations show that the substorm injection can cause 100% and 20% of the total subrelativistic (~0.1 MeV) and relativistic (2-5 MeV) electron . . .
Date: 12/2014 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2014JA020709 Available at: http://doi.wiley.com/10.1002/2014JA020709
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Authors: Wang Chih-Ping, Xing Xiaoyan, Nakamura T. K. M., Lyons Larry R., and Angelopoulos Vassilis
Title: Source and structure of bursty hot electron enhancements in the tail magnetosheath: Simultaneous two-probe observation by ARTEMIS
Abstract: Bursty enhancements of hot electrons (≳0.5 keV) with duration of minutes sometimes occur in the tail magnetosheath. In this study we used the unique simultaneous measurements from the two Acceleration Reconnection Turbulence and Electrodynamics of Moon's Interaction with the Sun probes to investigate the likely sources, spatial structures, and responsible processes for these hot electron enhancements. The enhancements can be seen at any distance across the magnetosheath, but those closer to the magnetopause are more often accompanied by magnetosheath density and flow magnitudes changing to more magnetosphere-like values. From simultaneous measurements with the two probes being on either side of magnetopause or both in the magnetosheath, it is evident that these hot electrons come from . . .
Date: 12/2014 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2014JA020603 Available at: http://doi.wiley.com/10.1002/2014JA020603
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Authors: Betz Eric O.
Title: Trapping waves in Earth's plasmasphere
Abstract: Earth's magnetic field traps donut-shaped bands of radiation in a belt around the planet that react to solar eruptions by growing and shrinking. The Van Allen belts consist of two rings filled with particles from the solar wind and cosmic rays. Within the outer ring of the Van Allen belt sits the plasmasphere, which is the innermost part of the planet's magnetic field and home to low-energy charged particles.
Date: 12/2014 Publisher: Eos, Transactions American Geophysical Union Pages: 472 - 472 DOI: 10.1002/2014EO490016 Available at: http://doi.wiley.com/10.1002/eost.v95.49http://doi.wiley.com/10.1002/2014EO490016
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Authors: Boardsen S. A., Hospodarsky G B, Kletzing C A, Pfaff R. F., Kurth W S, et al.
Title: Van Allen Probe Observations of Periodic Rising Frequencies of the Fast Magnetosonic Mode
Abstract: Near simultaneous periodic dispersive features of fast magnetosonic mode emissions are observed by both Van Allen Probes spacecraft while separated in magnetic local time by ~5 hours: Probe A at 15 and Probe B at 9–11 hours. Both spacecraft see similar frequency features, characterized by a periodic repetition at ~180 s. Each repetition is characterized by a rising frequency. Since no modulation is observed in the proton shell distribution, the plasma density, or in the background magnetic field at either spacecraft we conclude that these waves are not generated near the spacecraft but external to both spacecraft locations. Probe A while outside the plasmapause sees the start of each repetition ~40 s before probe B while deep inside the plasmasphere. We can qualitatively reproduce . . .
Date: 12/2014 Publisher: Geophysical Research Letters DOI: 10.1002/2014GL062020 Available at: http://doi.wiley.com/10.1002/2014GL062020
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Authors: Taubenschuss Ulrich, Khotyaintsev Yuri V., ík Ondrej, Vaivads Andris, Cully Christopher M., et al.
Title: Wave normal angles of whistler-mode chorus rising and falling tones
Abstract: We present a study of wave normal angles (θk) of whistler mode chorus emission as observed by Time History of Events and Macroscale Interactions during Substorms (THEMIS) during the year 2008. The three inner THEMIS satellites THA, THD, and THE usually orbit Earth close to the dipole magnetic equator (±20°), covering a large range of L shells from the plasmasphere out to the magnetopause. Waveform measurements of electric and magnetic fields enable a detailed polarization analysis of chorus below 4 kHz. When displayed in a frequency-θk histogram, four characteristic regions of occurrence are evident. They are separated by gaps at f/fc,e≈0.5 (f is the chorus frequency, fc,e is the local electron cyclotron frequency) and at θk∼40°. Below θk∼40°, the average value for θk is pre. . .
Date: 12/2014 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2014JA020575 Available at: http://doi.wiley.com/10.1002/2014JA020575
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Authors: Mourenas D., Artemyev A. V., Agapitov O.V., Krasnoselskikh V., and Li W
Title: Approximate analytical solutions for the trapped electron distribution due to quasi-linear diffusion by whistler-mode waves
Abstract: The distribution of trapped energetic electrons inside the Earth's radiation belts is the focus of intense studies aiming at better describing the evolution of the space environment in the presence of various disturbances induced by the solar wind or by an enhanced lightning activity. Such studies are usually performed by means of comparisons with full numerical simulations solving the Fokker-Planck quasi-linear diffusion equation for the particle distribution function. Here, we present for the first time approximate but realistic analytical solutions for the electron distribution, which are shown to be in good agreement with exact numerical solutions in situations where resonant scattering of energetic electrons by whistler-mode hiss, lightning-generated or chorus waves, is the dominant p. . .
Date: 11/2014 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2014JA020443 Available at: http://doi.wiley.com/10.1002/2014JA020443
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Authors: Zhao H., Li X, Blake J B, Fennell J. F., Claudepierre S G, et al.
Title: Characteristics of pitch angle distributions of 100 s keV electrons in the slot region and inner radiation belt
Abstract: The pitch angle distribution (PAD) of energetic electrons in the slot region and inner radiation belt received little attention in the past decades due to the lack of quality measurements. Using the state-of-art pitch-angle-resolved data from the Magnetic Electron Ion Spectrometer (MagEIS) instrument onboard the Van Allen Probes, a detailed analysis of 100 s keV electron PADs below L = 4 is performed, in which the PADs is categorized into three types: normal (flux peaking at 90∘), cap (exceedingly peaking narrowly around 90∘) and 90∘-minimum (lower flux at 90∘) PADs. By examining the characteristics of the PADs of ~460 keV electrons for over a year, we find that the 90∘-minimum PADs are generally present in the inner belt (L < 2), while normal PADs dominate at .L ~3.5. . .
Date: 11/2014 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2014JA020386 Available at: http://doi.wiley.com/10.1002/2014JA020386
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Authors: Whittaker Ian C., Clilverd Mark A., and Rodger Craig J.
Title: Characteristics of precipitating energetic electron fluxes relative to the plasmapause during geomagnetic storms
Abstract: n this study we investigate the link between precipitating electrons from the Van Allen radiation belts and the dynamical plasmapause. We consider electron precipitation observations from the Polar Orbiting Environmental Satellite (POES) constellation during geomagnetic storms. Superposed epoch analysis is performed on precipitating electron observations for the 13 year period of 1999 to 2012 in two magnetic local time (MLT) sectors, morning and afternoon. We assume that the precipitation is due to wave-particle interactions and our two MLT sectors focus on chorus (outside the plasmapause) and plasmaspheric hiss (inside the plasmapause) waves. We generate simple expressions based on the geomagnetic index, Dst, which reproduce the chorus-driven observations for the >30 keV precipitating ele. . .
Date: 11/2014 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2014JA020446 Available at: http://doi.wiley.com/10.1002/2014JA020446
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Authors: Kellerman A. C., Shprits Y Y, Makarevich R. A., Spanswick E., Donovan E., et al.
Title: Characterization of the energy-dependent response of riometer absorption
Abstract: Ground based riometers provide an inexpensive means to continuously remote sense the precipitation of electrons in the dynamic auroral region of Earth's ionosphere. The energy-dependent relationship between riometer absorption and precipitating electrons is thus of great importance for understanding the loss of electrons from the Earth's magnetosphere. In this study, statistical and event-based analyses are applied to determine the energy of electrons to which riometers chiefly respond. Time-lagged correlation analysis of trapped to precipitating fluxes shows that daily averaged absorption best correlates with ~ 60 keV trapped electron flux at zero-time lag, although large variability is observed across different phases of the solar cycle. High-time resolution statistical cross-correlati. . .
Date: 11/2014 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2014JA020027 Available at: http://doi.wiley.com/10.1002/2014JA020027
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Authors: Mauk B H
Title: Comparative Investigation of the Energetic Ion Spectra Comprising the Magnetospheric Ring Currents of the Solar System
Abstract: Investigated here are factors that control the intensities and shapes of energetic ion spectra that make up the ring current populations of the strongly magnetized planets of the solar system, specifically those of Earth, Jupiter, Saturn, Uranus, and Neptune. Following a previous and similar comparative investigation of radiation belt electrons, we here turn our attention to ions. Specifically, we examine the possible role of the differential ion Kennel-Petschek limit, as moderated by Electromagnetic Ion Cyclotron (EMIC) waves, as a standard for comparing the most intense ion spectra within the strongly magnetized planetary magnetospheres. In carrying out this investigation, the substantial complexities engendered by the very different ion composition distributions of these diverse magneto. . .
Date: 11/2014 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2014JA020392 Available at: http://doi.wiley.com/10.1002/2014JA020392
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Authors: Ripoll J.-F., Albert J M, and Cunningham G. S.
Title: Electron lifetimes from narrowband wave-particle interactions within the plasmasphere
Abstract: This paper is devoted to the systematic study of electron lifetimes from narrowband wave-particle interactions within the plasmasphere. It relies on a new formulation of the bounce-averaged quasi-linear pitch angle diffusion coefficients parameterized by a single frequency, ω, and wave normal angle, θ. We first show that the diffusion coefficients scale with ω/Ωce, where Ωce is the equatorial electron gyrofrequency, and that maximal pitch angle diffusion occurs along the line α0 = π/2–θ, where α0 is the equatorial pitch angle. Lifetimes are computed for L shell values in the range [1.5, 3.5] and energies, E, in the range [0.1, 6] MeV as a function of frequency and wave normal angle. The maximal pitch angle associated with a given lifetime is also given, revealing the frequen. . .
Date: 11/2014 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2014JA020217 Available at: http://doi.wiley.com/10.1002/2014JA020217
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Authors: Kersten Tobias, Horne Richard B, Glauert Sarah A, Meredith Nigel P, Fraser Brian J., et al.
Title: Electron losses from the radiation belts caused by EMIC waves
Abstract: Electromagnetic Ion Cyclotron (EMIC) waves cause electron loss in the radiation belts by resonating with high-energy electrons at energies greater than about 500 keV. However, their effectiveness has not been fully quantified. Here we determine the effectiveness of EMIC waves by using wave data from the fluxgate magnetometer on CRRES to calculate bounce-averaged pitch angle and energy diffusion rates for L*=3.5–7 for five levels of Kp between 12 and 18 MLT. To determine the electron loss, EMIC diffusion rates were included in the British Antarctic Survey Radiation Belt Model together with whistler mode chorus, plasmaspheric hiss, and radial diffusion. By simulating a 100 day period in 1990, we show that EMIC waves caused a significant reduction in the electron flux for energies greater t. . .
Date: 11/2014 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2014JA020366 Available at: http://doi.wiley.com/10.1002/2014JA020366
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Authors: Zhou Qinghua, Xiao Fuliang, Yang Chang, Liu Si, Kletzing C A, et al.
Title: Excitation of nightside magnetosonic waves observed by Van Allen Probes
Abstract: During the recovery phase of the geomagnetic storm on 30-31 March 2013, Van Allen Probe A detected enhanced magnetosonic (MS) waves in a broad range of L =1.8-4.7 and MLT =17-22 h, with a frequency range ~10-100 Hz. In the meanwhile, distinct proton ring distributions with peaks at energies of ~10 keV, were also observed in L =3.2-4.6 and L =5.0-5.6. Using a subtracted bi-Maxwellian distribution to model the observed proton ring distribution, we perform three dimensional ray tracing to investigate the instability, propagation and spatial distribution of MS waves. Numerical results show that nightside MS waves are produced by proton ring distribution and grow rapidly from the source location L =5.6 to the location L =5.0, but remain nearly stable at locations L <5.0 Moreover, waves launched. . .
Date: 11/2014 Publisher: Journal of Geophysical Research: Space Physics Pages: n/a - n/a DOI: 10.1002/2014JA020481 Available at: http://doi.wiley.com/10.1002/2014JA020481
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Authors: McKenna-Lawlor Susan
Title: Feasibility study of astronaut standardized career dose limits in LEO and the outlook for BLEO
Abstract: Cosmic Study Group SG 3.19/1.10 was established in February 2013 under the aegis of the International Academy of Astronautics to consider and compare the dose limits adopted by various space agencies for astronauts in Low Earth Orbit. A preliminary definition of the limits that might later be adopted by crews exploring Beyond Low Earth Orbit was, in addition, to be made. The present paper presents preliminary results of the study reported at a Symposium held in Turin by the Academy in July 2013. First, an account is provided of exposure limits assigned by various partner space agencies to those of their astronauts that work aboard the International Space Station. Then, gaps in the scientific and technical information required to safely implement human missions beyond the shielding provided. . .
Date: 11/2014 Publisher: Acta Astronautica Pages: 565 - 573 DOI: 10.1016/j.actaastro.2014.07.011 Available at: http://linkinghub.elsevier.com/retrieve/pii/S0094576514002549http://api.elsevier.com/content/article/PII:S0094576514002549?httpAccept=text/xmlhttp://api.elsevier.com/content/article/PII:S0094576514002549?httpAccept=text/plain
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Authors: Fu H. S., Cao J. B., Zhima Z., Khotyaintsev Y. V., Angelopoulos V, et al.
Title: First observation of rising-tone magnetosonic waves
Abstract: Magnetosonic (MS) waves are linearly polarized emissions confined near the magnetic equator with wave normal angle near 90° and frequency below the lower hybrid frequency. Such waves, also termed equatorial noise, were traditionally known to be “temporally continuous” in their time-frequency spectrogram. Here we show for the first time that MS waves actually have discrete wave elements with rising-tone features in their spectrogram. The frequency sweep rate of MS waves, ~1 Hz/s, is between that of chorus and electromagnetic ion cyclotron (EMIC) waves. For the two events we analyzed, MS waves occur outside the plasmapause and cannot penetrate into the plasmasphere; their power is smaller than that of chorus. We suggest that the rising-tone feature of MS waves is a consequence of nonl. . .
Date: 11/2014 Publisher: Geophysical Research Letters Pages: 7419 - 7426 DOI: 10.1002/grl.v41.2110.1002/2014GL061867 Available at: http://doi.wiley.com/10.1002/grl.v41.21http://doi.wiley.com/10.1002/2014GL061867
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Authors: Baker D N, Jaynes A. N., Hoxie V C, Thorne R M, Foster J. C., et al.
Title: An impenetrable barrier to ultrarelativistic electrons in the Van Allen radiation belts
Abstract: Early observations1, 2 indicated that the Earth’s Van Allen radiation belts could be separated into an inner zone dominated by high-energy protons and an outer zone dominated by high-energy electrons. Subsequent studies3, 4 showed that electrons of moderate energy (less than about one megaelectronvolt) often populate both zones, with a deep ‘slot’ region largely devoid of particles between them. There is a region of dense cold plasma around the Earth known as the plasmasphere, the outer boundary of which is called the plasmapause. The two-belt radiation structure was explained as arising from strong electron interactions with plasmaspheric hiss just inside the plasmapause boundary5, with the inner edge of the outer radiation zone corresponding to the minimum plasmapause location6. Re. . .
Date: 11/2014 Publisher: Nature Pages: 531 - 534 DOI: 10.1038/nature13956 Available at: http://www.nature.com/doifinder/10.1038/nature13956
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Authors: Gerrard Andrew, Lanzerotti Louis, Gkioulidou Matina, Mitchell Donald, Manweiler Jerry, et al.
Title: Initial Measurements of O-ion and He-ion Decay Rates Observed from the Van Allen Probes RBSPICE Instrument
Abstract: H-ion (~45-keV to ~600-keV), He-ion (~65-keV to ~520-keV), and O-ion (~140-keV to ~1130-keV) integral flux measurements, from the Radiation Belt Storm Probe Ion Composition Experiment (RBSPICE) instrument aboard the Van Allan Probes spacecraft B, are reported. These abundance data form a cohesive picture of ring current ions during the first nine months of measurements. Furthermore, the data presented herein are used to show injection characteristics via the He-ion/H-ion abundance ratio and the O-ion/H-ion abundance ratio. Of unique interest to ring current dynamics are the spatial-temporal decay characteristics of the two injected populations. We observe that He-ions decay more quickly at lower L-shells, on the orderof ~0.8-day at L-shells of 3–4, and decay more slowly with higher L-she. . .
Date: 11/2014 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2014JA020374 Available at: http://doi.wiley.com/10.1002/2014JA020374
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Authors: Ripoll J.-F., Chen Y., Fennell J, and Friedel R
Title: On long decays of electrons in the vicinity of the slot region observed by HEO3
Abstract: Long decay periods of electron counts, which follow abrupt rises and last from weeks to months, have been observed by the HEO3 spacecraft in the vicinity of the slot region between the years 1998 and 2007. During the most stable decay periods as selected, e-folding timescales are extracted and statistically analyzed from observations as a function of L-shell and electron energy. A challenge is to reproduce the observed timescales from simulations of pitch angle diffusion by three acting waves–the plasmaspheric hiss, lightning-generated whistlers, and VLF transmitter waves. We perform full numerical simulations to accurately compute electron lifetimes. We choose to use the method and wave parameters proposed by Abel & Thorne [1998] with the goal to assess whether they can reproduce lifeti. . .
Date: 11/2014 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2014JA020449 Available at: http://doi.wiley.com/10.1002/2014JA020449
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Authors: Rodriguez Juan V., Onsager Terrance G., Heynderickx Daniel, and Jiggens Piers T. A.
Title: Meeting Report: Solar Energetic Particle Measurements Intercalibration Workshop, 11 April 2014, Boulder, Colorado
Abstract: Following the conclusion of the 2014 Space Weather Week in Boulder, Colorado, the NOAA National Geophysical Data Center and Space Weather Prediction Center cohosted a 1 day workshop on the intercalibration of solar energetic particle (SEP) measurements. The overall purpose of this workshop was to discuss the intercalibration of SEP measurements from different instruments and different spacecraft, to foster new cooperative intercalibration efforts, and to identify a path forward for establishing a set of intercalibration guidelines. The detailed objectives of this workshop were described by Rodriguez and Onsager [2014]. Ten talks were given at the workshop (available at ftp://ftp.ngdc.noaa.gov/STP/publications/spe_intercal/), interspersed with extensive discussions. One outcome of these . . .
Date: 11/2014 Publisher: Space Weather Pages: 613 - 615 DOI: 10.1002/swe.v12.1110.1002/2014SW001134 Available at: http://doi.wiley.com/10.1002/swe.v12.11
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Authors: Degeling A W, Rankin R, and Zong Q.-G.
Title: Modeling radiation belt electron acceleration by ULF fast mode waves, launched by solar wind dynamic pressure fluctuations
Abstract: We investigate the magnetospheric MHD and energetic electron response to a Storm Sudden Commencement (SSC) and subsequent magnetopause buffeting, focusing on an interval following an SSC event on 25 November 2001. We find that the electron flux signatures observed by LANL, Cluster, and GOES spacecraft during this event can largely be reproduced using an advective kinetic model for electron phase space density, using externally prescribed electromagnetic field inputs, (herein described as a “test-kinetic model”) with electromagnetic field inputs provided by a 2-D linear ideal MHD model for ULF waves. In particular, we find modulations in electron flux phase shifted by 90° from the local azimuthal ULF wave electric field (Eφ) and a net enhancement in electron flux after 1.5 h for energ. . .
Date: 11/2014 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2013JA019672 Available at: http://doi.wiley.com/10.1002/2013JA019672
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Authors: Lee Justin H., and Angelopoulos Vassilis
Title: Observations and modeling of EMIC wave properties in the presence of multiple ion species as function of magnetic local time
Abstract: Electromagnetic ion cyclotron (EMIC) wave generation and propagation in Earth's magnetosphere depend on readily measurable hot (a few to tens of keV) plasma sheet ions, elusive plasmaspheric or ionospheric cold (sub-eV to a few eV) ions, and partially heated warm ions (tens to hundreds of eV). Previous work has assumed all low-energy ions are cold and not considered possible effects of warm ions. Using measurements by multiple Time History of Events and Macroscale Interactions during Substorms spacecraft, we analyze four typical EMIC wave events in the four magnetic local time sectors and consider the properties of both cold and warm ions supplied from previous statistical studies to interpret the wave observations using linear theory. As expected, we find that dusk EMIC waves grow due to . . .
Date: 11/2014 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2014JA020469 Available at: http://doi.wiley.com/10.1002/2014JA020469
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Authors: Albert J
Title: Radial diffusion simulations of the 20 September 2007 radiation belt dropout
Abstract: This is a study of a dropout of radiation belt electrons, associated with an isolated solar wind density pulse on 20 September 2007, as seen by the solid-state telescopes (SST) detectors on THEMIS (Time History of Events and Macroscale Interactions during Substorms). Omnidirectional fluxes were converted to phase space density at constant invariants M = 700 MeV G−1 and K = 0.014 RE G1/2, with the assumption of local pitch angle α ≈ 80° and using the T04 magnetic field model. The last closed drift shell, which was calculated throughout the time interval, never came within the simulation outer boundary of L* = 6. It is found, using several different models for diffusion rates, that radial diffusion alone only allows the data-driven, time-dependent boundary values at Lmax = 6 and Lmin =. . .
Date: 11/2014 Publisher: Annales Geophysicae Pages: 925 - 934 DOI: 10.5194/angeo-32-925-2014 Available at: http://www.ann-geophys.net/32/925/2014/http://www.ann-geophys.net/32/925/2014/angeo-32-925-2014.pdf
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Authors: Gao X., Li W, Thorne R M, Bortnik J, Angelopoulos V, et al.
Title: Statistical results describing the bandwidth and coherence coefficient of whistler mode waves using THEMIS waveform data
Abstract: The bandwidths and coherence coefficients of lower band whistler mode waves are analyzed using Time History of Events and Macroscale Interactions during Substorms (THEMIS) waveform data for rising tones, falling tones, and hiss-like emissions separately. We also evaluate their dependences on the spatial location, electron density, the ratio of plasma frequency to local electron gyrofrequency (fpe/fce), and the wave amplitude. Our results show that the bandwidth normalized by the local electron gyrofrequency (fce) of rising and falling tones is very narrow (~0.01 fce), smaller than that of the hiss-like emissions (~0.025 fce). Meanwhile, the normalized bandwidth of discrete emissions gradually decreases with increasing wave amplitude, whereas that of hiss-like emissions increases slowly. Th. . .
Date: 11/2014 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2014JA020158 Available at: http://doi.wiley.com/10.1002/2014JA020158
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Authors: Ozaki Mitsunori, Yagitani Satoshi, Takahashi Ken, Imachi Tomohiko, Koji Hiroki, et al.
Title: Equivalent Circuit Model for the Electric Field Sensitivity of a Magnetic Search Coil of Space Plasma
Abstract: Magnetic search coils (MSCs) are sensitive to both magnetic and electric fields, but detecting electric fields is unnecessary for magnetic observations of plasma waves. However, it is important to evaluate both sensitivities for different geometries and electrostatic shields to avoid electric field pickup. An equivalent circuit model for the electric field sensitivity of an MSC in a collisionless isotropic cold plasma is developed here using electrical coupling through a sheath capacitance. That sensitivity is defined by a relationship between the MSC impedance and the sheath capacitance. To confirm the validity of the circuit model, the sensitivity to an electric field is measured by imposing an external electric field using charged parallel metallic plates in laboratory experiments. The . . .
Date: 10/2014 Publisher: IEEE Sensors Journal Pages: 1 - 1 DOI: 10.1109/JSEN.2014.2365495 Available at: http://ieeexplore.ieee.org/lpdocs/epic03/wrapper.htm?arnumber=6937067
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Authors: Zanetti L. J., Mauk B H, Fox N.J., Barnes R.J., Weiss M, et al.
Title: The Evolving Space Weather System - Van Allen Probes Contribution
Abstract: The overarching goal and purpose of the study of space weather is clear - to understand and address the issues caused by solar disturbances on humans and technological systems. Space weather has evolved in the past few decades from a collection of concerned agencies and researchers to a critical function of the National Weather Service of NOAA. The general effects have also evolved from the well-known telegraph disruptions of the mid-1800’s to modern day disturbances of the electric power grid, communications and navigation, human spaceflight and spacecraft systems. The last two items in this list, and specifically the effects of penetrating radiation, were the impetus for the space weather broadcast implemented on NASA’s Van Allen Probes’ twin pair of satellites, launched in August . . .
Date: 10/2014 Publisher: Space Weather DOI: 10.1002/2014SW001108 Available at: http://doi.wiley.com/10.1002/2014SW001108
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Authors: Hao Y. X., Zong Q.-G., Wang Y. F., Zhou X.-Z., Zhang Hui, et al.
Title: Interactions of energetic electrons with ULF waves triggered by interplanetary shock: Van Allen Probes observations in the magnetotail
Abstract: We present in situ observations of a shock-induced substorm-like event on 13 April 2013 observed by the newly launched Van Allen twin probes. Substorm-like electron injections with energy of 30–500 keV were observed in the region from L∼5.2 to 5.5 immediately after the shock arrival (followed by energetic electron drift echoes). Meanwhile, the electron flux was clearly and strongly varying on the ULF wave time scale. It is found that both toroidal and poloidal mode ULF waves with a period of 150 s emerged following the magnetotail magnetic field reconfiguration after the interplanetary (IP) shock passage. The poloidal mode is more intense than the toroidal mode. The 90° phase shift between the poloidal mode Br and Ea suggests the standing poloidal waves in the Northern Hemisphere. F. . .
Date: 10/2014 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2014JA020023 Available at: http://doi.wiley.com/10.1002/2014JA020023
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Authors: Ozeke Louis G., Mann Ian R., Turner Drew L, Murphy Kyle R., Degeling Alex W., et al.
Title: Modeling cross L shell impacts of magnetopause shadowing and ULF wave radial diffusion in the Van Allen belts
Abstract: We present simulations of the outer electron radiation belt using a new ULF wave-driven radial diffusion model, including empirical representations of loss due to chorus and plasmaspheric hiss. With an outer boundary condition constrained by in situ electron flux observations, we focus on the impacts of magnetopause shadowing and outward radial diffusion in the heart of the radiation belt. Third invariant conserving solutions are combined to simulate the L shell and time dependence of the differential flux at a fixed energy. Results for the geomagnetically quiet year of 2008 demonstrate not only remarkable cross L shell impacts from magnetopause shadowing but also excellent agreement with the in situ observations even though no internal acceleration source is included in the model. Our mod. . .
Date: 10/2014 Publisher: Geophysical Research Letters Pages: 6556 - 6562 DOI: 10.1002/2014GL060787 Available at: http://doi.wiley.com/10.1002/grl.v41.19http://doi.wiley.com/10.1002/2014GL060787
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Authors: Li Zhao, Hudson Mary, Jaynes Allison, Boyd Alexander, Malaspina David, et al.
Title: Modeling Gradual Diffusion Changes in Radiation Belt Electron Phase Space Density for the March 2013 Van Allen Probes Case Study
Abstract: March 2013 provided the first equinoctial period when all of the instruments on the Van Allen Probes spacecraft were fully operational. This interval was characterized by disturbances of outer zone electrons with two timescales of variation, diffusive and rapid dropout and restoration [Baker et al., 2014]. A radial diffusion model was applied to the month-long interval to confirm that electron phase space density is well described by radial diffusion for the whole month at low first invariant ≤400 MeV/G, but peaks in phase space density observed by the ECT instrument suite at higher first invariant are not reproduced by radial transport from a source at higher L. The model does well for much of the month-long interval, capturing three of four enhancements in phase space density which e. . .
Date: 10/2014 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2014JA020359 Available at: http://doi.wiley.com/10.1002/2014JA020359
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Authors: Powers Nicole
Title: A Parametric Approach to NASA Mission Operations Costing
Abstract: Quantifying the cost of mission operations can be problematic. Currently few tools exist to estimate these costs and fewer that utilize a parametric approach. This paper begins the process of developing a parametric model for estimating mission operation costs. We hypothesize that the costs of mission operations are determined by the duration and type of operation activity. For the purposes of this paper operation activities fall into the following four categories: hibernated cruise, standard cruise, flyby, and high intensity operations. Hypothesis tests were conducted on each of the aforementioned categories and the results are based on data from APL’s historical missions. Those results will be used to develop a Cost Estimating Relationship (CER) to better predict missio. . .
Date: 10/2014 Publisher: American Institute of Aeronautics and Astronautics DOI: 10.2514/MSPACE1410.2514/6.2014-4398 Available at: http://arc.aiaa.org/doi/abs/10.2514/6.2014-4398
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Authors: Pakhotin I. P., Drozdov A. Y., Shprits Y Y, Boynton R. J., Subbotin D. A., et al.
Title: Simulation of high-energy radiation belt electron fluxes using NARMAX-VERB coupled codes
Abstract: This study presents a fusion of data-driven and physics-driven methodologies of energetic electron flux forecasting in the outer radiation belt. Data-driven NARMAX (Nonlinear AutoRegressive Moving Averages with eXogenous inputs) model predictions for geosynchronous orbit fluxes have been used as an outer boundary condition to drive the physics-based Versatile Electron Radiation Belt (VERB) code, to simulate energetic electron fluxes in the outer radiation belt environment. The coupled system has been tested for three extended time periods totalling several weeks of observations. The time periods involved periods of quiet, moderate, and strong geomagnetic activity and captured a range of dynamics typical of the radiation belts. The model has successfully simulated energetic electron fluxes . . .
Date: 10/2014 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2014JA020238 Available at: http://doi.wiley.com/10.1002/2014JA020238
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Authors: Spasojevic M.
Title: Statistical analysis of ground-based chorus observations during geomagnetic storms
Abstract: Chorus observations from two ground-based, Antarctic receiving stations are analyzed for a set of geomagnetic storms from 2000 to 2010. Superposed epoch analysis is performed together with statistical hypothesis testing to determine whether the observed quantities (geomagnetic indices, outer belt energetic electron fluxes, and chorus properties) are statistically significantly different as functions of storm phase, storm size, and storm type. Waves generated in the outer dayside magnetosphere and observed on the ground at South Pole Station are suppressed during main phase and are statistically unchanged from random intervals during recovery phase. Waves generated in the inner magnetosphere and observed on the ground at Palmer Station are significantly enhanced during storm main phase and . . .
Date: 10/2014 Publisher: Journal of Geophysical Research: Space Physics Pages: 8299 - 8317 DOI: 10.1002/jgra.v119.1010.1002/2014JA019975 Available at: http://doi.wiley.com/10.1002/jgra.v119.10http://doi.wiley.com/10.1002/2014JA019975
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Authors: Menietti J. D., Averkamp T. F., Groene J. B., Horne R B, Shprits Y Y, et al.
Title: Survey analysis of chorus intensity at Saturn
Abstract: In order to conduct theoretical studies or modeling of pitch angle scattering of electrons by whistler mode chorus emission at Saturn, a knowledge of chorus occurrence and magnetic intensity levels, PB, as well as the distribution of PB relative to frequency and spatial parameters is essential. In this paper an extensive survey of whistler mode magnetic intensity levels at Saturn is carried out, and Gaussian fits of PB are performed. We fit the spectrum of wave magnetic intensity between the lower hybrid frequency and fceq/2 and for frequencies in the interval fceq/2 < f < 0.9 fceq, where fceq is the cyclotron frequency mapped to the equator. Saturn chorus is observed over most local times, but is dominant on the nightside in the range of 4.5 < L <7.5, with minimum power at t. . .
Date: 10/2014 Publisher: Journal of Geophysical Research: Space Physics Pages: 8415 - 8425 DOI: 10.1002/jgra.v119.1010.1002/2014JA020523 Available at: http://doi.wiley.com/10.1002/jgra.v119.10http://doi.wiley.com/10.1002/2014JA020523
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Authors: Califf S., Li X, Blum L., Jaynes A., Schiller Q., et al.
Title: THEMIS measurements of quasi-static electric fields in the inner magnetosphere
Abstract: We use four years of THEMIS double-probe measurements to offer, for the first time, a complete picture of the dawn-dusk electric field covering all local times and radial distances in the inner magnetosphere based on in situ equatorial observations. This study is motivated by the results from the CRRES mission, which revealed a local maximum in the electric field developing near Earth during storm times, rather than the expected enhancement at higher L shells that is shielded near Earth as suggested by the Volland-Stern model. The CRRES observations were limited to the dusk side, while THEMIS provides complete local time coverage. We show strong agreement with the CRRES results on the dusk side, with a local maximum near L =4 for moderate levels of geomagnetic activity and evidence of stro. . .
Date: 10/2014 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2014JA020360 Available at: http://doi.wiley.com/10.1002/2014JA020360
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Authors: Osmane A., and Pulkkinen T. I.
Title: On the threshold energization of radiation belt electrons by double layers
Abstract: Using a Hamiltonian approach, we quantify the energization threshold of electrons interacting with radiation belts' double layers discovered by Mozer et al. (2013). We find that double layers with electric field amplitude E0 ranging between 10 and 100 mV/m and spatial scales of the order of few Debye lengths are very efficient in energizing electrons with initial velocities v∥ ≤ vth to 1 keV levels but are unable to energize electrons with E ≥ 100 keV. Our results indicate that the localized electric field associated with the double layers are unlikely to generate a seed population of 100 keV necessary for a plethora of relativistic acceleration mechanisms and additional transport to higher energetic levels.
Date: 10/2014 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2014JA020236 Available at: http://doi.wiley.com/10.1002/2014JA020236
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Authors: Murphy Kyle R., Mann Ian R., and Ozeke Louis G.
Title: A ULF wave driver of ring current energization
Abstract: ULF wave radial diffusion plays an important role in the transport of energetic electrons in the outer radiation belt, yet similar ring current transport is seldom considered even though ions satisfy a nearly identical drift resonance condition albeit without the relativistic correction. By examining the correlation between ULF wave power and the response of the ring current, characterized by Dst, we demonstrate a definite correlation between ULF wave power and Dst. Significantly, the lagged correlation peaks such that ULF waves precede the response of the ring current and Dst. We suggest that this correlation is the result of enhanced radial transport and energization of ring current ions through drift resonance and ULF wave radial diffusion of ring current ions. An analysis and compariso. . .
Date: 10/2014 Publisher: Geophysical Research Letters Pages: 6595 - 6602 DOI: 10.1002/grl.v41.1910.1002/2014GL061253 Available at: http://doi.wiley.com/10.1002/grl.v41.19http://doi.wiley.com/10.1002/2014GL061253
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Authors: Yang Xiao C., Zhu Guang W., Zhang Xiao X., Sun Yue Q., Liang Jin B., et al.
Title: An unusual long-lived relativistic electron enhancement event excited by sequential CMEs
Abstract: An unusual long-lived intense relativistic electron enhancement event from July to August 2004 is examined using data from Fengyun-1, POES, GOES, ACE, the Cluster Mission and geomagnetic indices. During the initial 6 days of this event, the observed fluxes in the outer zone enhanced continuously and their maximum increased from 2.1 × 102 cm-2·sr-1·s-1 to 3.5 × 104 cm-2·sr-1·s-1, the region of enhanced fluxes extended from L = 3.5-6.5 to L = 2.5-6.5, and the flux peak location shifted inward from L ~ 4.2 to L ~ 3.3. During the following 7 days, without any locational movement, the flux peak increased slowly and exceeded the pre-storm fluxes by about 4 orders of magnitude. Subsequently, the decay rate of relativistic electrons is so slow that the peak re. . .
Date: 10/2014 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2014JA019797 Available at: http://doi.wiley.com/10.1002/2014JA019797
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Authors: Fu Xiangrong, Cowee Misa M., Friedel Reinhard H., Funsten Herbert O, Gary Peter, et al.
Title: Whistler Anisotropy Instabilities as the Source of Banded Chorus: Van Allen Probes Observations and Particle-in-Cell Simulations
Abstract: Magnetospheric banded chorus is enhanced whistler waves with frequencies ωr < Ωe, where Ωe is the electron cyclotron frequency, and a characteristic spectral gap at ωr ≃ Ωe/2. This paper uses spacecraft observations and two-dimensional particle-in-cell (PIC) simulations in a magnetized, homogeneous, collisionless plasma to test the hypothesis that banded chorus is due to local linear growth of two branches of the whistler anisotropy instability excited by two distinct, anisotropic electron components of significantly different temperatures. The electron densities and temperatures are derived from HOPE instrument measurements on the Van Allen Probes A satellite during a banded chorus event on 1 November 2012. The observations are consistent with a three-component electron mod. . .
Date: 10/2014 Publisher: Journal of Geophysical Research: Space Physics DOI: 10.1002/2014JA020364 Available at: http://doi.wiley.com/10.1002/2014JA020364
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Authors: Fok M.-C., Buzulukova N. Y., Chen S.-H., Glocer A., Nagai T., et al.
Title: The Comprehensive Inner Magnetosphere-Ionosphere Model
Abstract: Simulation studies of the Earth's radiation belts and ring current are very useful in understanding the acceleration, transport, and loss of energetic particles. Recently, the Comprehensive Ring Current Model (CRCM) and the Radiation Belt Environment (RBE) model were merged to form a Comprehensive Inner Magnetosphere-Ionosphere (CIMI) model. CIMI solves for many essential quantities in the inner magnetosphere, including ion and electron distributions in the ring current and radiation belts, plasmaspheric density, Region 2 currents, convection potential, and precipitation in the ionosphere. It incorporates whistler mode chorus and hiss wave diffusion of energetic electrons in energy, pitch angle, and cross terms. CIMI thus represents a comprehensive model that considers the effects of the r. . .
Date: 09/2014 Publisher: Journal of Geophysical Research: Space Physics Pages: 7522 - 7540 DOI: 10.1002/jgra.v119.910.1002/2014JA020239 Available at: http://doi.wiley.com/10.1002/jgra.v119.9http://doi.wiley.com/10.1002/2014JA020239
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Authors: Wang X., Malaspina D. M., Hsu H.-W., Ergun R. E., and M. Horányi.
Title: The effects of magnetic fields on photoelectron-mediated spacecraft potential fluctuations
Abstract: Previously, we have experimentally studied photoelectron-mediated spacecraft potential fluctuations associated with time-dependent external electric fields. In this paper, we investigate the effects of magnetic fields on such spacecraft potential fluctuations. A magnetic field is created above the UV-illuminated surface of a spacecraft model to alter the escape rate of photoelectrons. The packet of the observed potential oscillations becomes less positive with increasing magnetic field strength because more of the emitted photoelectrons are returned to the surface. As a result, the photoelectric charging time is increased, corresponding to a decrease in the response frequency of the photoemitting surface. The amplitude of the potential oscillations decreases when the response frequency bec. . .
Date: 09/2014 Publisher: Journal of Geophysical Research: Space Physics Pages: 7319 - 7326 DOI: 10.1002/jgra.v119.910.1002/2014JA019923 Available at: http://doi.wiley.com/10.1002/jgra.v119.9http://doi.wiley.com/10.1002/2014JA019923
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Authors: Shiokawa Kazuo, Yokoyama Yu, Ieda Akimasa, Miyoshi Yoshizumi, Nomura Reiko, et al.
Title: Ground-based ELF/VLF chorus observations at subauroral latitudes-VLF-CHAIN Campaign
Abstract: We report observations of very low frequency (VLF) and extremely low frequency (ELF) chorus waves taken during the ELF/VLF Campaign observation with High-resolution Aurora Imaging Network (VLF-CHAIN) of 17–25 February 2012 at subauroral latitudes at Athabasca (L=4.3), Canada. ELF/VLF waves were measured continuously with a sampling rate of 100 kHz to monitor daily variations in ELF/VLF emissions and derive their detailed structures. We found quasiperiodic (QP) emissions whose repetition period changes rapidly within a period of 1 h without corresponding magnetic pulsations. QP emissions showed positive correlation between amplitude and frequency sweep rate, similarly to rising-tone elements. We found an event of nearly simultaneous enhancements of QP emissions and Pc1/electromagnetic ion. . .
Date: 09/2014 Publisher: Journal of Geophysical Research: Space Physics Pages: 7363 - 7379 DOI: 10.1002/jgra.v119.910.1002/2014JA020161 Available at: http://doi.wiley.com/10.1002/jgra.v119.9http://doi.wiley.com/10.1002/2014JA020161
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Authors: Fuselier S. A., Lewis W. S., Schiff C., Ergun R., Burch J L, et al.
Title: Magnetospheric Multiscale Science Mission Profile and Operations
Abstract: The Magnetospheric Multiscale (MMS) mission and operations are designed to provide the maximum reconnection science. The mission phases are chosen to investigate reconnection at the dayside magnetopause and in the magnetotail. At the dayside, the MMS orbits are chosen to maximize encounters with the magnetopause in regions where the probability of encountering the reconnection diffusion region is high. In the magnetotail, the orbits are chosen to maximize encounters with the neutral sheet, where reconnection is known to occur episodically. Although this targeting is limited by engineering constraints such as total available fuel, high science return orbits exist for launch dates over most of the year. The tetrahedral spacecraft formation has variable spacing to determine the optimum se. . .
Date: 09/2014 Publisher: Space Science Reviews DOI: 10.1007/s11214-014-0087-x Available at: http://link.springer.com/content/pdf/10.1007/s11214-014-0087-x
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Authors: Gamayunov K. V., Engebretson M. J., Zhang M., and Rassoul H. K.
Title: Model of electromagnetic ion cyclotron waves in the inner magnetosphere
Abstract: The evolution of He+-mode electromagnetic ion cyclotron (EMIC) waves is studied inside the geostationary orbit using our global model of ring current (RC) ions, electric field, plasmasphere, and EMIC waves. In contrast to the approach previously used by Gamayunov et al. (2009), however, we do not use the bounce-averaged wave kinetic equation but instead use a complete, nonbounce-averaged, equation to model the evolution of EMIC wave power spectral density, including off-equatorial wave dynamics. The major results of our study can be summarized as follows. (1) The thermal background level for EMIC waves is too low to allow waves to grow up to the observable level during one pass between the “bi-ion latitudes” (the latitudes where the given wave frequency is equal to the O+–He+ bi-io. . .
Date: 09/2014 Publisher: Journal of Geophysical Research: Space Physics Pages: 7541 - 7565 DOI: 10.1002/jgra.v119.910.1002/2014JA020032 Available at: http://doi.wiley.com/10.1002/jgra.v119.9http://doi.wiley.com/10.1002/2014JA020032
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Authors: Bergeot Nicolas, Chevalier Jean-Marie, Bruyninx Carine, Pottiaux Eric, Aerts Wim, et al.
Title: Near real-time ionospheric monitoring over Europe at the Royal Observatory of Belgium using GNSS data
Abstract: Various scientific applications and services increasingly demand real-time information on the effects of space weather on Earth’s atmosphere. In this frame, the Royal Observatory of Belgium (ROB) takes advantage of the dense EUREF Permanent GNSS Network (EPN) to monitor the ionosphere over Europe from the measured delays in the GNSS signals, and provides publicly several derived products. The main ROB products consist of ionospheric vertical Total Electron Content (TEC) maps over Europe and their variability estimated in near real-time every 15 min on 0.5° × 0.5° grids using GPS observations. The maps are available online with a latency of ~3 min in IONEX format at ftp://gnss.oma.be and as interactive web pages at www.gnss.be. This paper presents the method used in the ROB-IONO softwa. . .
Date: 09/2014 Publisher: Journal of Space Weather and Space Climate Pages: A31 DOI: 10.1051/swsc/2014028 Available at: http://www.swsc-journal.org/10.1051/swsc/2014028
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