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Sample records for plasmaspheric hiss interactions

  1. Plasmaspheric hiss.

    NASA Technical Reports Server (NTRS)

    Thorne, R. M.; Burton, R. K.; Holzer, R. E.; Smith, E. J.

    1973-01-01

    A relatively steady band of ELF hiss has been detected by the OGO 5 search coil magnetometer on almost every passage through the plasmasphere; except for an anomalous region of the dayside at high geomagnetic latitudes, the emissions terminate abruptly at the plasmapause and are therefore referred to as 'plasmaspheric hiss.' A preliminary statistical study of the properties of the observed whistler mode turbulence has yielded the following characteristics: the waves are band limited with a sharp lower-frequency cutoff and a more diffuse upper-frequency cutoff; power spectra show a well-defined maximum near a few hundred hertz, the peak intensities generally ranging between 10 to the minus 7th power and 0.00001 gamma squared/Hz; the wave energy is spread over a bandwidth of a few hundred hertz, and corresponding wideband amplitudes are 5 to 50 milligamma; the waves are highly turbulent in nature and show little tendency toward definite polarization.

  2. Fine Structure of Plasmaspheric Hiss

    NASA Astrophysics Data System (ADS)

    Summers, D.; Omura, Y.; Nakamura, S.; Kletzing, C.

    2014-12-01

    Plasmaspheric hiss plays a key role in controlling the structure and dynamics of Earth's radiation belts.The quiet time slot region between the inner and outer belts can be explained as a steady-state balance between earthward radial diffusion and pitch-angle scattering loss of energetic electrons to the atmosphere induced by plasmaspheric hiss. Plasmaspheric hiss can also induce gradual precipitation loss of MeV electrons from the outer radiation belt. Plasmaspheric hiss has been widely regarded as a broadband,structureless,incoherent emission. Here, by examining burst-mode vector waveform data from the 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. By means of waveform analysis we identify typical amplitudes,phase profiles,and sweep rates of the rising and falling tone elements. The new observations reported here can be expected to fuel a re-examination of the properties of plasmaspheric hiss, including a further re-analysis of the generation mechanism for hiss.

  3. Interaction of ring current and radiation belt protons with ducted plasmaspheric hiss. 1: Diffusion coefficients and timescales

    NASA Technical Reports Server (NTRS)

    Kozyra, J. U.; Rasmussen, C. E.; Miller, R. H.; Lyons, L. R.

    1994-01-01

    Protons that are convected into the inner magnetosphere in response to enhanced magnetic activity can resonate with ducted plasmaspheric hiss in the outer plasmasphere via an anomalous Doppler-shifted cyclotron resonance. Plasmaspheric hiss is a right-hand-polarized electromagnetic emission that is observed to fill the plasmasphere on a routine basis. When plasmaspheric hiss is confined within field-aligned ducts or guided along density gradients, wave normal angles remain largely below 45 deg. This allows resonant interactions with ions at typical ring current and radiation belt energies to take place. Such field-aligned ducts have been observed both within the plasmasphere and in regions outside of the plasmasphere. Wave intensities are estimated using statistical information from studies of detached plasma regions. Diffusion coefficients are presented for a range of L shells and proton energies for a fixed wave distribution. Harmonic resonances in the range N = +/-100 are considered in order to include interactions between hiss at 100 Hz to 2 kHz frequencies, and protons in the energy range between approximately 10 keV and 1000 keV. Diffusion timescales are estimated to be of the order of tens of days and comparable to or shorter than lifetimes for Coulomb decay and charge exchange losses over most of the energy and spatial ranges of interest.

  4. Guided Plasmaspheric Hiss Interactions with Superthermal Electrons. Part 1; Resonance Curves and Timescales

    NASA Technical Reports Server (NTRS)

    Liemohn, M. W.; Khazanov, G. V.; Kozyra, J. U.

    1997-01-01

    Under the proper conditions, guided plasmaspheric hiss is shown to be more efficient than Coulomb collisions at scattering electrons in the superthermal energy range of 50 to 500 eV. Broadband, whistler mode hiss becomes guided by plasma density gradients, intensifying the wave energy densities and focusing the wave normal angles. These waves are shown to interact through Cherenkov (Landau) resonance with electrons below 500 eV, and the presented equatorial plane timescales for pitch angle, energy, and mixed diffusion are shown to be faster than Coulomb collision timescales for typical values at the inner edge of the plasmapause and in detached plasma regions. In the latter case, energy diffusion timescales of less than 100 s for small pitch angle electrons between 250 and 500 eV indicate that these waves have the potential to dramatically change the distribution function.

  5. Interaction of ring current and radiation belt protons with ducted plasmaspheric hiss. 2. Time evolution of the distribution function

    NASA Astrophysics Data System (ADS)

    Kozyra, J. U.; Rasmussen, C. E.; Miller, R. H.; Villalon, E.

    1995-11-01

    The evolution of the bounce-averaged ring current/radiation belt proton distribution is simulated during resonant interactions with ducted plasmaspheric hiss. The plasmaspheric hiss is assumed to be generated by ring current electrons and to be damped by the energetic protons. Thus energy is transferred between energetic electrons and protons using the plasmaspheric hiss as a mediary. The problem is not solved self-consistently. During the simulation period, interactions with ring current electrons (not represented in the model) are assumed to maintain the wave amplitudes in the presence of damping by the energetic protons, allowing the wave spectrum to be held fixed. Diffusion coefficients in pitch angle, cross pitch angle/energy, and energy were previously calculated by Kozyra et al. (1994) and are adopted for the present study. The simulation treats the energy range, E>=80 keV, within which the wave diffusion operates on a shorter timescale than other proton loss processes (i.e., Coulomb drag and charge exchange). These other loss processes are not included in the simulation. An interesting result of the simulation is that energy diffusion maximizes at moderate pitch angles near the edge of the atmospheric loss cone. Over the simulation period, diffusion in energy creates an order of magnitude enhancement in the bounce-averaged proton distribution function at moderate pitch angles. The loss cone is nearly empty because scattering of particles at small pitch angles is weak. The bounce-averaged flux distribution, mapped to ionospheric heights, results in elevated locally mirroring proton fluxes. OGO 5 observed order of magnitude enhancements in locally mirroring energetic protons at altitudes between 350 and 1300 km and invariant latitudes between 50° and 60° (Lundblad and Soraas, 1978). The proton distributions were highly anisotropic in pitch angle with nearly empty loss cones. The similarity between the observed distributions and those resulting from this

  6. Hiss Energy Flow in the Plasmasphere

    NASA Astrophysics Data System (ADS)

    Kletzing, C.; Christopher, I.; Santolik, O.; Kurth, W. S.; Hospodarsky, G. B.; Bounds, S. R.

    2016-12-01

    The measured wave properties of plasmaspheric hiss are important to constrain models of the generation of hiss as well as its propagation and amplification. Local generation or amplification of plasmaspheric hiss within the plasmasphere should produce a signature of waves propagating away from the source region. Additionally, the scattering of energetic particles into the loss cone transfers energy from the particles to the waves. By examining the statistical characteristics of the Poynting flux of plasmaspheric hiss, we can determine the properties of wave energy flow in the plasmasphere. We report on the statistics of observations from the Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) Waves instrument on the Van Allen Probes for periods when the spacecraft is inside the plasmasphere. We find that near the plasmapause, the energy carried by the waves Poynting flux typically does, indeed, flow away from the equator, and, the energy flow steadily increases with a scale height (as measured from the equatorial plane) that is frequency dependent: 1.25 RE for 70-700 Hz and dropping to 0.6 RE for higher frequencies of 700-2000 Hz. However, deeper within the plasmasphere and often at radial distances less than 3.5 RE, the energy carried by the waves reverses direction and the energy flow is towards the equator with a scale height of 0.6-1.3 RE. In this region, the energy deposition rate can exceed 0.1 eV per particle per hour for the cold population, suggesting that whistler-mode plasmaspheric hiss may be a significant source of energy for heating the inner plasmasphere.

  7. Characteristic energy range of electron scattering due to plasmaspheric hiss

    NASA Astrophysics Data System (ADS)

    Ma, Q.; Li, W.; Thorne, R. M.; Bortnik, J.; Reeves, G. D.; Kletzing, C. A.; Kurth, W. S.; Hospodarsky, G. B.; Spence, H. E.; Baker, D. N.; Blake, J. B.; Fennell, J. F.; Claudepierre, S. G.; Angelopoulos, V.

    2016-12-01

    We investigate the characteristic energy range of electron flux decay due to the interaction with plasmaspheric hiss in the Earth's inner magnetosphere. The Van Allen Probes have measured the energetic electron flux decay profiles in the Earth's outer radiation belt during a quiet period following the geomagnetic storm that occurred on 7 November 2015. The observed energy of significant electron decay increases with decreasing L shell and is well correlated with the energy band corresponding to the first adiabatic invariant μ = 4-200 MeV/G. The electron diffusion coefficients due to hiss scattering are calculated at L = 2-6, and the modeled energy band of effective pitch angle scattering is also well correlated with the constant μ lines and is consistent with the observed energy range of electron decay. Using the previously developed statistical plasmaspheric hiss model during modestly disturbed periods, we perform a 2-D Fokker-Planck simulation of the electron phase space density evolution at L = 3.5 and demonstrate that plasmaspheric hiss causes the significant decay of 100 keV-1 MeV electrons with the largest decay rate occurring at around 340 keV, forming anisotropic pitch angle distributions at lower energies and more flattened distributions at higher energies. Our study provides reasonable estimates of the electron populations that can be most significantly affected by plasmaspheric hiss and the consequent electron decay profiles.

  8. Parameterizing Plasmaspheric Hiss Wave Power by Plasmapause Location

    NASA Astrophysics Data System (ADS)

    Malaspina, D.; Jaynes, A. N.; Boule, C.; Bortnik, J.; Thaller, S. A.; Ergun, R.; Kletzing, C.; Wygant, J. R.

    2016-12-01

    Plasmaspheric hiss is a superposition of electromagnetic whistler-mode waves largely confined within the plasmasphere, the cold plasma torus surrounding Earth. Hiss plays an important role in radiation belt dynamics by pitch angle scattering electrons for a wide range of electron energies (10's of keV to > 1 MeV) which can result in their loss to the atmosphere. This interaction is often included in predictive models of radiation belt dynamics using statistical hiss wave power distributions derived from observations. However, the traditional approach to creating these distributions parameterizes hiss power by L-parameter (e.g. MacIlwain L, dipole L, or L*) and a geomagnetic index (e.g. DST or AE). Such parameterization introduces spatial averaging of dissimilar wave power radial profiles, resulting in heavily smoothed wave power distributions. This work instead parameterizes hiss wave power distributions using plasmapause location and distance from the plasmapause. Using Van Allen Probes data and these new parameterizations, previously unreported and highly repeatable features of the hiss wave power distribution become apparent. These features include: (1) The highest amplitude hiss wave power is concentrated over a narrower range of L than previous studies have indicated, and (2) the location of the peak in hiss wave power is determined by the plasmapause location, occurring at a consistent standoff distance Earthward of the plasmapause. Based on these features, parameterizing hiss using the plasmapause location and distance from the plasmapause may shed new light on hiss generation and propagation physics, as well as serve to improve the parameterization of hiss in predictive models of the radiation belts.

  9. Mid-latitude hiss and plasmaspheric notch

    NASA Astrophysics Data System (ADS)

    Masson, A.; Inan, U.; Laakso, H.; Décréau, P.; Santolik, O.

    2004-12-01

    A newly identified whistler mode ELF/VLF emission, observed by the Cluster satellites, will be presented. In the vicinity of the plasmapause, around the geomagnetic equator, the four Cluster satellites often observe banded hiss-like electromagnetic emissions (BHE). Their frequency bandwidth is always in between the lower hybrid resonance and the electron gyrofrequency, from 2 kHz to 10 kHz. Based on two years of data measured by three waves experiments on Cluster (WHISPER, STAFF and WBD), the following properties of the BHE waves have been deduced: (i) their location is strongly correlated with the position of the plasmapause, (ii) no MLT dependence has been found, (iii) their spectral width is generally 1 to 2 kHz, and (iv) the central frequency of their emission band varies from 2 kHz to 10 kHz. All these features suggest that BHE are in fact mid-latitude hiss emissions (MLH). MLH have been rarely observed on a regular basis at such altitude. Based on this survey, the central frequency of mid-latitude hiss is shown to be correlated with the Kp index. This suggests either that these banded emissions are generated in a given f/fce range, or that there is a Kp dependent Doppler shift between the satellites and a possible moving source of the MLH Mid-latitude hiss case events observed within density depletion known as plasmaspheric notch (observed by the EUV instrument on IMAGE) will be presented. A recent study showed that plasmaspheric notch plays a crucial role in the generation of higher frequency emissions such as kilometric continuum. The role of plasmaspheric notch in the generation and/or the amplification of mid-latitude hiss will be addressed.

  10. Evidence for Significant Local Generation of Plasmaspheric Hiss

    NASA Astrophysics Data System (ADS)

    Kletzing, C.; Kurth, W. S.; Bounds, S. R.; Hospodarsky, G. B.; Santolik, O.; Wygant, J. R.; Bonnell, J. W.; Omura, Y.; Summers, D.

    2014-12-01

    The source of plasmaspheric hiss has been an outstanding problem in inner magnetospheric radiation belt physics since the discovery of this whistler-mode emission. The generation mechanism for plasmaspheric hiss has been suggested to come from one of three possible mechanisms: 1) local generation and amplification, 2) whistlers from lightning, and 3) chorus emissions which have refracted into the plasmasphere. The latter two mechanisms are external sources which produce an incoherent hiss signature as the original waves mix in a stochastic manner, propagating in both directions along the background magnetic field. In contrast, local generation of plasmaspheric hiss within the plasmasphere should produce a signature of waves propagating away from the source region. We report observations from the Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) Waves insturment on the Van Allen Probes that clearly indicate that the Poynting flux associated with plasmaspheric hiss is frequently propagating away from the equator in the outer region of the plasmasphere. Initial statistics suggest that for more than 40% of the orbits of the Van Allen Probes, the plasmaspheric hiss is generated by a local source within the plasmasphere. We present examples of the signature of locally generated plasmaspheric hiss and show additional statistics of locally generated hiss occurrence.

  11. Relationship between Chorus and Plasmaspheric Hiss Waves

    NASA Astrophysics Data System (ADS)

    Bortnik, J.; Chen, L.; Li, W.; Thorne, R. M.; Nishimura, Y.; Angelopoulos, V.; Kletzing, C. A.

    2016-02-01

    This chapter focuses on the origin of the plasmaspheric hiss (PH) emission, and in particular, considers whether chorus could be the embryonic source of PH. It describes the ray-tracing model used to study chorus wave propagation. The chapter mainly focuses on more recent observations that still raise puzzling questions regarding the origin of PH. It then shows that PH has a lower frequency boundary, and that, at least in some instances, chorus could not be the source of the PH power and that it would necessarily need to be excited locally. The chapter also shows a coincident observation between THEMIS-E and one of the newly launched Van Allen Probes (RB-B) that showed simultaneous chorus and hiss emissions. These emissions were very well correlated but occurred at much higher L-shells than predicted by our ray-tracing model.

  12. Joint observations by RBSP and THEMIS satellites on the disappearance of plasmaspheric hiss following interplanetary impulsive disturbances

    NASA Astrophysics Data System (ADS)

    Liu, N.; Su, Z.; Zheng, H.

    2016-12-01

    Plasmaspheric hiss is an important whistler-mode emission controlling the evolution of radiation belt electrons, whose generation mechanism is still under debate. Here we present two events of plasmaspheric hiss disappearance following interplanetary impulsive disturbances jointly observed by Van Allen Probes (RBSP) and Time history of events and macroscale interactions during substorm (THEMIS) satellites on 12 February 2014 and 27 February 2014. The origination of plasmaspheric hiss from plasmatrough chorus is suggested to be an appropriate prerequisite to explain these events. In the first event, the magnetosphere expanded following the impulsive decrease of solar wind pressure. The change in background plasma conditions increased the minimum resonat energy of chorus and then prevented the generation of chorus. In the second event, the magnetopause was compressed earthward by an interplanetary shock and the pre-existing source region of chorus waves became outside the magnetopause. The disappearance of plasmatrough chours resulted in the disappearance of plasmaspheric hiss in both events.

  13. Observational evidence of the nonlinear wave growth theory of plasmaspheric hiss

    NASA Astrophysics Data System (ADS)

    Omura, Y.; Nakamura, S.; Summers, D.; Kletzing, C.

    2016-12-01

    Recently, it has been revealed by measurements from the Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) instrument on the Van Allen Probes mission that plasmaspheric hiss is a coherent emission containing discrete rising tone and falling tone elements [1]. Here, we test the recently developed nonlinear wave growth theory of plasmaspheric hiss [2] against EMFISIS observations of hiss. Wave forms of the hiss emissions at different frequencies are extracted from the EMFISIS burst-mode data by means of band-pass filters. From the phase variation of the waveforms we calculate the instantaneous frequencies and wave amplitudes. We obtain parameters of the energetic electrons by fitting the theoretical optimum wave amplitude as a function of frequency at the equator where hiss elements are generated. Through the propagation process from the equator to the observation point, the wave packet of the hiss element undergoes convective wave growth due to the nonlinear interaction with energetic electrons. The frequency sweep rate of the hiss element at a higher latitude is modified by the variation of the group velocity as a function of the frequency. We obtain the theoretical relation between the wave amplitude and frequency sweep rates at the observation point by applying the convective growth rates and dispersion factors to the known relation at the equator. By plotting the theoretical relation over scatter plots of the wave amplitudes and the frequency sweep rates for rising-tone elements, we find good agreement between the hiss observations and the nonlinear theory. We also find that the duration periods of the hiss elements are in good agreement with the nonlinear transition time necessary for the formation of a resonant current through coherent nonlinear wave-particle interactions. [1] Summers, D., Y. Omura, S. Nakamura, and C. A. Kletzing (2014), Fine structure of plasmaspheric hiss, J. Geophys. Res. Space Physics, 119, 9134-9149, doi:10

  14. Global-scale coherence modulation of radiation-belt electron loss from plasmaspheric hiss.

    PubMed

    Breneman, A W; Halford, A; Millan, R; McCarthy, M; Fennell, J; Sample, J; Woodger, L; Hospodarsky, G; Wygant, J R; Cattell, C A; Goldstein, J; Malaspina, D; Kletzing, C A

    2015-07-09

    Over 40 years ago it was suggested that electron loss in the region of the radiation belts that overlaps with the region of high plasma density called the plasmasphere, within four to five Earth radii, arises largely from interaction with an electromagnetic plasma wave called plasmaspheric hiss. This interaction strongly influences the evolution of the radiation belts during a geomagnetic storm, and over the course of many hours to days helps to return the radiation-belt structure to its 'quiet' pre-storm configuration. Observations have shown that the long-term electron-loss rate is consistent with this theory but the temporal and spatial dynamics of the loss process remain to be directly verified. Here we report simultaneous measurements of structured radiation-belt electron losses and the hiss phenomenon that causes the losses. Losses were observed in the form of bremsstrahlung X-rays generated by hiss-scattered electrons colliding with the Earth's atmosphere after removal from the radiation belts. Our results show that changes of up to an order of magnitude in the dynamics of electron loss arising from hiss occur on timescales as short as one to twenty minutes, in association with modulations in plasma density and magnetic field. Furthermore, these loss dynamics are coherent with hiss dynamics on spatial scales comparable to the size of the plasmasphere. This nearly global-scale coherence was not predicted and may affect the short-term evolution of the radiation belts during active times.

  15. Statistical Properties of Plasmaspheric Hiss from Van Allen Probes Observations

    NASA Astrophysics Data System (ADS)

    Hartley, D.; Kletzing, C.; Santolik, O.; Bounds, S. R.; Kurth, W. S.; Hospodarsky, G. B.

    2016-12-01

    Plasmaspheric hiss wave properties are investigated using Van Allen Probes observations of both electric and magnetic wave field power spectra. The analysis reveals that at L-shells greater than 3.5, the wave normal vector is predominantly field aligned. However, at L-shells less than 3.5 the wave normal angle may be significantly more oblique, particularly at frequencies greater than 1 kHz. Analysis of this region (L < 3.5) reveals two populations of the plasmaspheric hiss wave mode; i) a population with wave normal angles less than approximately 50° containing power in both the electric and magnetic field (electromagnetic) and, ii) a population at very oblique wave normal angles (θk > 70°) with a weak magnetic component and strong electric component (more electrostatic). The distribution of these two populations are presented both as a function of magnetic local time and geomagnetic activity, with their distinguishing features identified and discussed.

  16. Modeling the evolution of chorus waves into plasmaspheric hiss

    NASA Astrophysics Data System (ADS)

    Bortnik, J.; Chen, L.; Li, W.; Thorne, R. M.; Horne, R. B.

    2011-08-01

    Plasmaspheric hiss (PH) is a band-limited, incoherent whistler mode emission found predominantly in the plasmasphere or high-density plasma regions in the near-Earth space environment. Since its discovery in the late 1960s, PH has been recognized as playing an important role in shaping the structure and dynamics of the Earth's electron radiation belts and creating the slot region that separates the inner and outer belts. However, the origin of PH has been a topic of intense debate for over four decades. Here we present a model for the origin of PH that involves the evolution of chorus waves into the PH spectrum. We perform extensive ray tracing using the HOTRAY code and calculate Landau damping using newly developed suprathermal flux maps from THEMIS observations, that are L and magnetic local time dependent, for both inside and outside the plasmasphere. Our results show remarkable consistency with the observed statistical characteristics of hiss, including the day/night asymmetry in wave power, frequency spectrum, geomagnetic control of PH, quasi-parallel equatorial wave normal angles, and confinement within the plasmasphere. Our model also reproduces ancillary features such as exohiss and extremely low frequency (ELF) hiss and might be related to a previously reported phenomenon called lower hybrid resonance duct trapping in the ionosphere. A detailed analysis of ray morphologies shows a separation into four distinct groups, which correspond to (1) rays that are trapped at the plasmapause, (2) PH rays, (3) ELF hiss rays, and (4) rays that represent the bulk of the chorus ray power.

  17. Evolution of chorus emissions into plasmaspheric hiss observed by Van Allen Probes

    NASA Astrophysics Data System (ADS)

    Zhou, Qinghua; Xiao, Fuliang; Yang, Chang; Liu, Si; He, Yihua; Wygant, J. R.; Baker, D. N.; Spence, H. E.; Reeves, G. D.; Funsten, H. O.

    2016-05-01

    The two classes of whistler mode waves (chorus and hiss) play different roles in the dynamics of radiation belt energetic electrons. Chorus can efficiently accelerate energetic electrons, and hiss is responsible for the loss of energetic electrons. Previous studies have proposed that chorus is the source of plasmaspheric hiss, but this still requires an observational confirmation because the previously observed chorus and hiss emissions were not in the same frequency range in the same time. Here we report simultaneous observations form Van Allen Probes that chorus and hiss emissions occurred in the same range ˜300-1500 Hz with the peak wave power density about 10-5 nT2/Hz during a weak storm on 3 July 2014. Chorus emissions propagate in a broad region outside the plasmapause. Meanwhile, hiss emissions are confined inside the plasmasphere, with a higher intensity and a broader area at a lower frequency. A sum of bi-Maxwellian distribution is used to model the observed anisotropic electron distributions and to evaluate the instability of waves. A three-dimensional ray tracing simulation shows that a portion of chorus emission outside the plasmasphere can propagate into the plasmasphere and evolve into plasmaspheric hiss. Moreover, hiss waves below 1 kHz are more intense and propagate over a broader area than those above 1 kHz, consistent with the observation. The current results can explain distributions of the observed hiss emission and provide a further support for the mechanism of evolution of chorus into hiss emissions.

  18. Propagation characteristics of plasmaspheric hiss: Van Allen Probe observations and global empirical models

    NASA Astrophysics Data System (ADS)

    Yu, J.; Li, L. Y.; Cao, J. B.; Chen, L.; Wang, J.; Yang, J.

    2017-04-01

    Based on the Van Allen Probe A observations from 1 October 2012 to 31 December 2014, we develop two empirical models to respectively describe the hiss wave normal angle (WNA) and amplitude variations in the Earth's plasmasphere for different substorm activities. The long-term observations indicate that the plasmaspheric hiss amplitudes on the dayside increase when substorm activity is enhanced (AE index increases), and the dayside hiss amplitudes are greater than the nightside. However, the propagation angles (WNAs) of hiss waves in most regions do not depend strongly on substorm activity, except for the intense substorm-induced increase in WNAs in the nightside low L-region. The propagation angles of plasmaspheric hiss increase with increasing magnetic latitude or decreasing radial distance (L-value). The global hiss WNAs (the power-weighted averages in each grid) and amplitudes (medians) can be well reproduced by our empirical models.

  19. Evolution of chorus emissions into plasmaspheric hiss observed by Van Allen Probes

    DOE PAGES

    Zhou, Qinghua; Xiao, Fuliang; Yang, Chang; ...

    2016-05-09

    The two classes of whistler mode waves (chorus and hiss) play different roles in the dynamics of radiation belt energetic electrons. Chorus can efficiently accelerate energetic electrons, and hiss is responsible for the loss of energetic electrons. Previous studies have proposed that chorus is the source of plasmaspheric hiss, but this still requires an observational confirmation because the previously observed chorus and hiss emissions were not in the same frequency range in the same time. In this paper, we report simultaneous observations form Van Allen Probes that chorus and hiss emissions occurred in the same range ~300–1500 Hz with themore » peak wave power density about 10-5 nT2/Hz during a weak storm on 3 July 2014. Chorus emissions propagate in a broad region outside the plasmapause. Meanwhile, hiss emissions are confined inside the plasmasphere, with a higher intensity and a broader area at a lower frequency. A sum of bi-Maxwellian distribution is used to model the observed anisotropic electron distributions and to evaluate the instability of waves. A three-dimensional ray tracing simulation shows that a portion of chorus emission outside the plasmasphere can propagate into the plasmasphere and evolve into plasmaspheric hiss. Moreover, hiss waves below 1 kHz are more intense and propagate over a broader area than those above 1 kHz, consistent with the observation. Finally, the current results can explain distributions of the observed hiss emission and provide a further support for the mechanism of evolution of chorus into hiss emissions.« less

  20. Evolution of chorus emissions into plasmaspheric hiss observed by Van Allen Probes

    SciTech Connect

    Zhou, Qinghua; Xiao, Fuliang; Yang, Chang; Liu, Si; He, Yihua; Wygant, J. R.; Baker, D. N.; Spence, H. E.; Reeves, Geoffrey D.; Funsten, Herbert O.

    2016-05-09

    The two classes of whistler mode waves (chorus and hiss) play different roles in the dynamics of radiation belt energetic electrons. Chorus can efficiently accelerate energetic electrons, and hiss is responsible for the loss of energetic electrons. Previous studies have proposed that chorus is the source of plasmaspheric hiss, but this still requires an observational confirmation because the previously observed chorus and hiss emissions were not in the same frequency range in the same time. In this paper, we report simultaneous observations form Van Allen Probes that chorus and hiss emissions occurred in the same range ~300–1500 Hz with the peak wave power density about 10-5 nT2/Hz during a weak storm on 3 July 2014. Chorus emissions propagate in a broad region outside the plasmapause. Meanwhile, hiss emissions are confined inside the plasmasphere, with a higher intensity and a broader area at a lower frequency. A sum of bi-Maxwellian distribution is used to model the observed anisotropic electron distributions and to evaluate the instability of waves. A three-dimensional ray tracing simulation shows that a portion of chorus emission outside the plasmasphere can propagate into the plasmasphere and evolve into plasmaspheric hiss. Moreover, hiss waves below 1 kHz are more intense and propagate over a broader area than those above 1 kHz, consistent with the observation. Finally, the current results can explain distributions of the observed hiss emission and provide a further support for the mechanism of evolution of chorus into hiss emissions.

  1. Evolution of chorus emissions into plasmaspheric hiss observed by Van Allen Probes

    SciTech Connect

    Zhou, Qinghua; Xiao, Fuliang; Yang, Chang; Liu, Si; He, Yihua; Wygant, J. R.; Baker, D. N.; Spence, H. E.; Reeves, Geoffrey D.; Funsten, Herbert O.

    2016-05-09

    The two classes of whistler mode waves (chorus and hiss) play different roles in the dynamics of radiation belt energetic electrons. Chorus can efficiently accelerate energetic electrons, and hiss is responsible for the loss of energetic electrons. Previous studies have proposed that chorus is the source of plasmaspheric hiss, but this still requires an observational confirmation because the previously observed chorus and hiss emissions were not in the same frequency range in the same time. In this paper, we report simultaneous observations form Van Allen Probes that chorus and hiss emissions occurred in the same range ~300–1500 Hz with the peak wave power density about 10-5 nT2/Hz during a weak storm on 3 July 2014. Chorus emissions propagate in a broad region outside the plasmapause. Meanwhile, hiss emissions are confined inside the plasmasphere, with a higher intensity and a broader area at a lower frequency. A sum of bi-Maxwellian distribution is used to model the observed anisotropic electron distributions and to evaluate the instability of waves. A three-dimensional ray tracing simulation shows that a portion of chorus emission outside the plasmasphere can propagate into the plasmasphere and evolve into plasmaspheric hiss. Moreover, hiss waves below 1 kHz are more intense and propagate over a broader area than those above 1 kHz, consistent with the observation. Finally, the current results can explain distributions of the observed hiss emission and provide a further support for the mechanism of evolution of chorus into hiss emissions.

  2. CIMI simulations with recently developed multi-parameter chorus and plasmaspheric hiss models

    NASA Astrophysics Data System (ADS)

    Aryan, Homayon; Sibeck, David; Kang, Suk-bin; Balikhin, Michael; Fok, Mei-ching

    2017-04-01

    Simulation studies of the Earth's radiation belts are very useful in understanding the acceleration and loss of energetic particles. The Comprehensive Inner Magnetosphere-Ionosphere (CIMI) model considers the effects of the ring current and plasmasphere on the radiation belts. CIMI was formed by merging the Comprehensive Ring Current Model (CRCM) and the Radiation Belt Environment (RBE) model to solves for many essential quantities in the inner magnetosphere, including radiation belt enhancements and dropouts. It incorporates chorus and plasmaspheric hiss wave diffusion of energetic electrons in energy, pitch angle, and cross terms. Usually the chorus and plasmaspheric hiss models used in CIMI are based on single-parameter geomagnetic index (AE). Here we integrate recently developed multi-parameter chorus and plasmaspheric hiss wave models based on geomagnetic index and solar wind parameters. We then perform CIMI simulations for different storms and compare the results with data from the Van Allen Probes and the Two Wide-angle Imaging Neutral-atom Spectrometers and Akebono satellites. We find that the CIMI simulations with multi-parameter chorus and plasmaspheric hiss wave models are more comparable to data than the single-parameter wave models.

  3. Hiss induced radiation belt electron loss timescales in the plasmasphere based on ray tracings of wave propagation angle

    NASA Astrophysics Data System (ADS)

    Zhou, C.; Ni, B.; Li, W.; Bortnik, J.; Gu, X.; Zhao, Z.

    2015-12-01

    Plasmaspheric hiss plays an important role in driving resonant scattering losses of radiation belt electrons and thereby largely controls the lifetimes of electrons in the plasmasphere. Besides the spectral information of waves, an accurate investigation of hiss induced radiation belt electron loss timescales requires the details of wave normal angle distribution during propagation along the field line, which however is difficult to obtain directly from in situ measurements but can be reasonably evaluated from ray tracing of hiss propagation on basis of reasonable setups of background field and plasma density. By assuming a nominal and suitable plasmapause location at L = 4.5, we report the ray tracing results of hiss wave propagation angles for various hiss wave frequencies at various L-shells in the plasmasphere. Subsequently, we construct the improved model of hiss wave normal angle distribution with dependence on both wave frequency, magnetic latitude and L-shell, which is used to compute the quasi-linear bounce-averaged rates of electron scattering due to plasmaspheric hiss and perform the pure pitch angle diffusion simulations. Hiss induced radiation belt electron loss timescales are then determined from the simulated temporal evolution of electron fluxes after reaching the equilibrium state, as a function of electron kinetic energy and L-shell, which is of importance for incorporation into future simulations of the radiation belt electron dynamics under various geomagnetic conditions to comprehend the exact contribution of plasmaspheric hiss.

  4. Competition between outer zone electron scattering by plasmaspheric hiss and magnetosonic waves

    NASA Astrophysics Data System (ADS)

    Ni, Binbin; Hua, Man; Zhou, Ruoxian; Yi, Juan; Fu, Song

    2017-04-01

    We quantify the electron scattering effects of simultaneous plasmaspheric hiss and magnetosonic waves that occurred in two neighboring time intervals but with distinct wave intensity profiles on 21 August 2013. Their combined scattering is found capable of causing electron distribution variations largely distinguishable from the consequences of individual waves. The net effect of electron diffusion relies strongly on the relative dominance of the two wave intensities, which also controls the relative contribution of each wave mode. In combination, MS waves slow down the hiss-induced loss of 100 keV electrons, and hiss efficiently inhibits the electron butterfly distribution caused by MS waves to produce a gradual acceleration process. Our results strongly suggest that comprehensive simulations of the radiation belt electron dynamics should carefully incorporate the combined scattering and complex competition resulting from simultaneous occurrences of various magnetospheric emissions, including, but not limited to, plamaspheric hiss and magnetosonic waves.

  5. Simultaneous disappearances of plasmaspheric hiss, exohiss, and chorus waves triggered by a sudden decrease in solar wind dynamic pressure

    NASA Astrophysics Data System (ADS)

    Liu, Nigang; Su, Zhenpeng; Gao, Zhonglei; Zheng, Huinan; Wang, Yuming; Wang, Shui; Spence, H. E.; Reeves, G. D.; Baker, D. N.; Blake, J. B.; Funsten, H. O.; Wygant, J. R.

    2017-01-01

    Magnetospheric whistler mode waves are of great importance in the radiation belt electron dynamics. Here on the basis of the analysis of a rare event with the simultaneous disappearances of whistler mode plasmaspheric hiss, exohiss, and chorus triggered by a sudden decrease in the solar wind dynamic pressure, we provide evidences for the following physical scenarios: (1) nonlinear generation of chorus controlled by the geomagnetic field inhomogeneity, (2) origination of plasmaspheric hiss from chorus, and (3) leakage of plasmaspheric hiss into exohiss. Following the reduction of the solar wind dynamic pressure, the dayside geomagnetic field configuration with the enhanced inhomogeneity became unfavorable for the generation of chorus, and the quenching of chorus directly caused the disappearances of plasmaspheric hiss and then exohiss.

  6. Simultaneous disappearances of plasmaspheric hiss, exohiss, and chorus waves triggered by a sudden decrease in solar wind dynamic pressure

    DOE PAGES

    Liu, Nigang; Su, Zhenpeng; Gao, Zhonglei; ...

    2016-12-29

    Magnetospheric whistler mode waves are of great importance in the radiation belt electron dynamics. In this paper, on the basis of the analysis of a rare event with the simultaneous disappearances of whistler mode plasmaspheric hiss, exohiss, and chorus triggered by a sudden decrease in the solar wind dynamic pressure, we provide evidences for the following physical scenarios: (1) nonlinear generation of chorus controlled by the geomagnetic field inhomogeneity, (2) origination of plasmaspheric hiss from chorus, and (3) leakage of plasmaspheric hiss into exohiss. Finally, following the reduction of the solar wind dynamic pressure, the dayside geomagnetic field configuration withmore » the enhanced inhomogeneity became unfavorable for the generation of chorus, and the quenching of chorus directly caused the disappearances of plasmaspheric hiss and then exohiss.« less

  7. Simultaneous disappearances of plasmaspheric hiss, exohiss, and chorus waves triggered by a sudden decrease in solar wind dynamic pressure

    SciTech Connect

    Liu, Nigang; Su, Zhenpeng; Gao, Zhonglei; Zheng, Huinan; Wang, Yuming; Wang, Shui; Spence, H. E.; Reeves, G. D.; Baker, D. N.; Blake, J. B.; Funsten, H. O.; Wygant, J. R.

    2016-12-29

    Magnetospheric whistler mode waves are of great importance in the radiation belt electron dynamics. In this paper, on the basis of the analysis of a rare event with the simultaneous disappearances of whistler mode plasmaspheric hiss, exohiss, and chorus triggered by a sudden decrease in the solar wind dynamic pressure, we provide evidences for the following physical scenarios: (1) nonlinear generation of chorus controlled by the geomagnetic field inhomogeneity, (2) origination of plasmaspheric hiss from chorus, and (3) leakage of plasmaspheric hiss into exohiss. Finally, following the reduction of the solar wind dynamic pressure, the dayside geomagnetic field configuration with the enhanced inhomogeneity became unfavorable for the generation of chorus, and the quenching of chorus directly caused the disappearances of plasmaspheric hiss and then exohiss.

  8. Resonant scattering and resultant pitch angle evolution of relativistic electrons by plasmaspheric hiss

    NASA Astrophysics Data System (ADS)

    Ni, B.; Bortnik, J.; Thorne, R. M.; Ma, Q.; Chen, L.

    2013-12-01

    Adopting several realistic models for the wave distribution and ambient plasmaspheric density, we perform a comprehensive analysis to evaluate hiss-induced scattering coefficients, the relative role of each resonant harmonic, and the overall effect of hiss scattering on the pitch angle evolution and associated decay (loss) processes of relativistic electrons. The results show that scattering by the equatorial, highly oblique component of the hiss emission is negligible. A quasi-parallel propagating wave model of hiss emissions provides a good approximation for evaluation of scattering rates of ≤ 2 MeV electrons. However, realistic wave propagation angles as a function of latitude along the field line must be taken into account to accurately quantify the rates of hiss scattering above 2 MeV. Ambient plasma density is also a critical parameter that can influence hiss scattering rates and resultant pitch angle evolution of electron flux. While the first order cyclotron and the Landau resonances are dominant for hiss-induced scattering of less than 2 MeV electrons, higher order resonances become important and even dominant at intermediate equatorial pitch angles for ultra-relativistic (≥ 3 MeV) electrons. Hiss induced electron pitch angle evolution consistently shows a relatively rapid initial transport of electrons from high to lower pitch angles, with a gradual approach towards an equilibrium shape, and a final state where the entire distribution decays exponentially with time. Although hiss scattering rates near the loss cone control the pitch angle evolution and the ultimate loss of ultra-relativistic electrons, the presence of a scattering bottleneck (a pronounced drop in diffusion rate at intermediate pitch angles) significantly affects the loss rate and leads to characteristic top hat shaped pitch angle distributions at energies below ~1 MeV. Decay timescales are determined to be on the order of a few days, tens of days, and > 100 days for 500 keV, 2 Me

  9. Initial survey of the wave distribution functions for plasmaspheric hiss observed by ISEE 1

    NASA Technical Reports Server (NTRS)

    Storey, L. R. O.; Lefeuvre, F.; Parrot, M.; Cairo, L.; Anderson, R. R.

    1991-01-01

    The generation mechanism of hiss observed by ISEE 1 satellite in the earth magnetosphere is investigated by analyzing the ELF/VLF wave data obtained from four passes of ISEE 1, all of which occurring during magnetically quiet periods. The results of these measurements, together with those published earlier, indicate that the generation mechanisms proposed by Kennel alnd Petschek (1966), by Thorne et al. (1979), and by Solomon et al. (1988, 1989) are all physically possible and can come into action whenever the necessary conditions exist. However, plasmaspheric hiss was observed by ISEE even when the conditions for any of these mechanisms existed; under these conditions, hiss appears to be generated near the equatorial plane over a wide range of L values, with the wave normals at large angles to the field. The generation mechanism that applies in such cases is still unknown.

  10. Wave Distribution Functions of Plasmaspheric Hiss and their Effects on Radiation Belt Dynamics

    NASA Astrophysics Data System (ADS)

    Santolik, O.; Ripoll, J. F.; Kurth, W. S.; Hospodarsky, G. B.; Kletzing, C.

    2015-12-01

    Plasmaspheric hiss is formed by whistler-mode waves which play an important role in the dynamics the Earth's radiation belts, specifically in connection with the slot region between the inner and outer Van Allen belts. The origin of plasmaspheric hiss is still a subject of discussions and these waves are known for their complex propagation properties. They are often far from a single plane wave approximation, forming a continuous distribution of the wave energy density with respect to the wave vector direction (wave distribution function). Analysis of polarization and propagation parameters of these waves provides us with inputs for modeling of radiation belt dynamics. We use the data of the Waves instrument of Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) onboard the Van Allen Probes spacecraft, to analyze simultaneous measurements of all electric and magnetic field components, together with measurements of the plasma density based on the determination of the upper hybrid resonance frequency. Using this unique data set we estimate the wave distribution functions of plasmaspheric hiss and we model the effects of these waves on the decay rates of radiation belt electrons through quasilinear pitch angle diffusion.

  11. Two sources of dayside intense, quasi-coherent plasmaspheric hiss: A new mechanism for the slot region?

    NASA Astrophysics Data System (ADS)

    Falkowski, Barbara J.; Tsurutani, Bruce T.; Lakhina, Gurbax S.; Pickett, Jolene S.

    2017-02-01

    A study of dayside plasmaspheric hiss at frequencies from 22 Hz to 1.0 kHz was carried out by using 1 year of Polar data. It is shown that intense, dayside plasmaspheric hiss is correlated with solar wind pressure with P > 2.5 nPa. The dayside effect is most prominent in the 300 to 650 Hz range. Intense dayside waves are also present during SYM-H < -5 nT. The latter is centered at local noon, with the greatest intensities in the L = 2 to 3 region. Assuming drift of 25 keV electrons from midnight to the wave magnetic local time, plasmaspheric hiss is shown to be highly correlated with precursor AE* and SYM-H* indices, indicating that the hiss is associated with substorms and small injection events. Our hypothesis is that both sets of waves originate as outer zone (L = 6 to 10) chorus and then propagate into the plasmasphere. Fourteen high-intensity dayside plasmaspheric hiss events were analyzed to identify the wave k, polarization, and the degree of coherency. The waves are found to be obliquely propagating, elliptically polarized and quasi-coherent ( 0.5 to 0.8 correlation coefficient). It is hypothesized that the dayside plasmaspheric hiss is quasi-coherent because the chorus has been recently generated in the outer magnetosphere and have propagated directly into the plasmasphere. It is possible that the quasi-coherency of the dayside hiss at L = 2 to 3 may be an alternate explanation for the generation of the energetic particle slot region.

  12. Whistlers and plasmaspheric hiss: Wave directions and three-dimensional propagation

    SciTech Connect

    Draganov, A.B.; Inan, U.S.; Sonwalkar, V.S.; Bell, T.F.

    1993-07-01

    Wave data from the DE 1 satellite showing simultaneously nonducted whistlers and hiss are analyzed to determine wave propagation directions. At L = 3.8 and a geographic latitude of {lambda}{sub g} = 12{degrees}S, the average wave normal directions of discrete whistlers are measured to be {approximately}51{degrees} for f = 4.5 kHz and {approximately}60{degrees} for f = 3.5 kHz, forming a small (<20{degrees}) angle with the magnetic meridional plane. Hiss wave normal angles are determined as {approximately}70{degrees} and {approximately}77{degrees} for f = 3.5 kHz and f = 2.5 kHz, respectively, with the wave vector being almost perpendicular to the meridional plane. While the measured wave normal angles of whistlers and hiss are consistent with generation of hiss by magnetospheric whistlers, existence of a significant azimuthal component indicates that further assessment of this connection must be based on three-dimensional ray tracing. A new approximate analytical formulation of three-dimensional propagation of whistler waves is developed and used to model the drift of magnetospherically reflected whistlers in azimuth. The results show that depending on initial parameters, the time of arrival of whistler rays at a fixed observation point can differ by 10-20 s, with signals from different magnetospherically reflected whistlers overlapping to evolve into a hiss like signal. The total azimuthal drift of whistler rays is found to not exceed {approximately}30{degrees}, so that plasmaspheric hiss may be produced by nonducted whistlers at longitudes correlated with the location of thunderstorm activity. 22 refs., 11 figs.

  13. Initial survey of the wave distribution functions for plasmaspheric hiss observed by ISEE 1

    SciTech Connect

    Storey, L.R.O. ); Lefeuvre, F.; Parrot, M.; Cairo, L. ); Anderson, R.R. )

    1991-11-01

    Multicomponent ELF/VLF wave data from the ISEE 1 satellite have been analyzed with the aim of identifying the generation mechanism of plasmaspheric hiss, and especially of determining whether it involves wave propagation of cyclic trajectories. The data were taken from four passes of the satellite, of which two were close to the geomagnetic equatorial plane and two were farther from it; all four occurred during magnetically quiet periods. The principal method of analysis was calculation of the wave distribution functions. The waves appear to have been generated over a wide range of altitudes within the plasmasphere, and most, though not all, of them were propagating obliquely with respect to the Earth's magnetic field. On one of the passes near the equator, some wave energy was observed at small wave normal angles, and these waves may have been propagating on cyclic trajectories. Even here, however, obliquely propagating waves were predominant, a finding that is difficult to reconcile with the classical quasi-linear generation mechanism or its variants. The conclusion is that another mechanism, probably nonlinear, must have been generating most of the hiss observed on these four passes.

  14. Study of /sup 12/C interactions at HISS

    SciTech Connect

    Crawford, H.J.

    1982-12-01

    Single-particle inclusive measurements in high-energy nuclear physics have provided the foundation for a number of models of interacting nuclear fluids. Such measurements yield information on the endpoints of the evolution of highly excited nuclear systems. However, they suffer from the fact that observed particles can be formed in a large number of very different evolutionary paths. To learn more about how interactions proceed we have performed a series of experiments in which all fast nuclear fragments are analyzed for each individual interaction. These experiments were performed at the LBL Bevalac HISS (Heavy Ion Spectrometer System) facility where we studied the interaction of 1 GeV/nuc 12C nuclei with targets of C, CH/sub 2/, Cu, and U. In this paper we describe HISS and present some preliminary results of the experiment.

  15. Interaction of substorm injections with the plasmasphere: A turbulent plasmaspheric boundary layer

    NASA Astrophysics Data System (ADS)

    Maggiolo, R.; Maes, L.; De Keyser, J.; Haaland, S.; Echim, M.

    2014-12-01

    In-situ measurements of plasma, fields, and waves around the plasmasphere's boundary in the evening sector during substorm injection events are presented. The data reveal that the cold plasma short-circuits substorm-injected hot plasma jets when the cold plasma density exceeds a critical value of 5-10 c.c. The substorm-injected hot electrons stop at the pre-substorm plasmapause, thereby providing a natural explanation of the long-known dispersionless auroral precipitation boundary. A turbulent plasmaspheric boundary layer forms initially near the pre-substorm plasmapause due to interactions between the injected and plasmaspheric populations. The main sources of the greatly-enhanced wave activity are the so-called modified two-stream instability driven by the hot electron diamagnetic drift in the entry layer, ion-ring instability driven by the highly-anisotropic hot ion distribution in the central part, and the diamagnetic drift of hot ions near the inner edge. Enhanced plasma turbulence leads to heating of the cold plasma and to acceleration of suprathermal electron tails, thereby enhancing the downward heat transport and concomitant heating of the ionospheric electrons observed by the DMSP satellites.

  16. Interaction of substorm injections with the plasmasphere: A turbulent plasmaspheric boundary layer

    NASA Astrophysics Data System (ADS)

    Mishin, E. V.

    2015-12-01

    In-situ measurements of plasma, fields, and waves around the plasmasphere's boundary in the evening sector during substorm injection events are presented. The data reveal that the cold plasma short-circuits substorm-injected hot plasma jets when the cold plasma density exceeds a critical value of 5-10 c.c. The substorm-injected hot electrons stop at the pre-substorm plasmapause, thereby providing a natural explanation of the long-known dispersionless auroral precipitation boundary. A turbulent plasmaspheric boundary layer forms initially near the pre-substorm plasmapause due to interactions between the injected and plasmaspheric populations. The main sources of the greatly-enhanced wave activity are the so-called modified two-stream instability driven by the hot electron diamagnetic drift in the entry layer, ion-ring instability driven by the highly-anisotropic hot ion distribution in the central part, and the diamagnetic drift of hot ions near the inner edge. Enhanced plasma turbulence leads to heating of the cold plasma and to acceleration of suprathermal electron tails, thereby enhancing the downward heat transport and concomitant heating of the ionospheric electrons observed by the DMSP satellites.

  17. Anisotropic proton instability magnetospheric /APIM/ hiss - An introduction

    NASA Technical Reports Server (NTRS)

    Parady, B. K.

    1974-01-01

    Plasmaspheric hiss is broadband ELF noise between 100 and 2000 Hz generally occurring inside the plasmasphere. It is proposed that some plasmaspheric ELF hiss is generated by ring current protons. The mechanism by which waves are generated is the anisotropic proton instability magnetospheric (APIM) hiss mechanism. APIM hiss (with a frequency close to the lower hybrid resonance frequency) is a loss-cone, flute instability arising from proton velocity space anisotropies. The energy driving the waves comes from the free energy of the 'inverted population' of the proton loss-cone distribution. The APIM hiss mechanism predicts the bandwidth, center frequency, source location, and wave normal angle of some types of plasmaspheric hiss. APIM hiss is suggested as a possible additional loss mechanism for ring current protons.

  18. Statistical modeling of in situ hiss amplitudes using ground measurements

    NASA Astrophysics Data System (ADS)

    Golden, D. I.; Spasojevic, M.; Li, W.; Nishimura, Y.

    2012-05-01

    Plasmaspheric hiss is a naturally occurring extremely low frequency electromagnetic emission that is often observed within the Earth's plasmasphere. Plasmaspheric hiss plays a major role in the scattering and loss of electrons from the Earth's radiation belts, thereby contributing to the maintenance of the slot region between the inner and outer electron belt. Traditionally, in situ satellite observations have been the measurement modality of choice for studies of plasmaspheric hiss due to their ability to directly measure the hiss source region. However, satellite studies are relatively short-lived and very few satellite receivers remain operational for an entire 11-year solar cycle. Ground stations, in contrast, may collect multiple solar cycles' worth of data during their lifetime, yet they cannot directly measure the hiss source region. This study aims to determine the extent to which measurements of hiss at midlatitude ground stations may be used to predict the mean amplitude of in situ measurements of plasmaspheric hiss. We use coincident measurements between Palmer Station, Antarctica (L = 2.4, 50°S invariant latitude) and the THEMIS spacecraft from June 2008 through May 2010, during solar minimum. Using an autoregressive multiple regression model, we show that in the local time sector from 00 < MLT < 12, when the ionosphere above Palmer Station is in darkness and hiss is observed at Palmer, the amplitude of plasmaspheric hiss observed by the THEMIS spacecraft is 1.4 times higher than when hiss is not observed at Palmer. In the same local time sector when the ground station is in daylight and hiss is observed, the THEMIS observed amplitudes are not significantly different from those when hiss is not observed on the ground. A stronger relationship is found in the local time sector from 12 < MLT < 24 where, when Palmer is in daylight and hiss is observed, THEMIS plasmaspheric hiss amplitudes are 2 times higher compared to when hiss is not observed at Palmer

  19. Wave-particle interaction at the plasmasphere-ring current interface

    NASA Technical Reports Server (NTRS)

    Roth, Ilan; Hudson, Mary K.

    1992-01-01

    During the plasmasphere filling process following geomagnetic storms, an outward density decrease of the cold plasma at L = 3-4 is typically observed. When this structure overlaps with the sharp inner edge of the ring current, wave activity is detected at linearly stable phase velocities. The excitation of these waves around the lower hybrid frequency and their effects on the heating of thermal ions is analyzed. It is found that lower hybrid drift waves are most effective at heating lower mass ions, e.g. plasmaspheric H(+), versus He(+), which may be heated more effectively by electromagnetic ion cyclotron waves driven unstable by the ring current loss cone.

  20. Electron Lifetimes from Narrowband Wave-Particle Interactions within the Plasmasphere

    NASA Astrophysics Data System (ADS)

    Ripoll, J. F.; Albert, J.; Cunningham, G.

    2014-12-01

    This work is devoted to the systematic study of electron lifetimes from narrowband wave-particle interactions in the plasmasphere. It relies on a new formulation of the bounce-averaged quasi-linear pitch angle diffusion coefficients parameterized by a single frequency, w, and wave-normal angle, theta [Albert, 2012]. We first show that the diffusion coefficients scale with w/Wce, where Wce is the equatorial electron gyrofrequency, and that maximal pitch angle diffusion occurs along the line alpha0=pi/2-theta, where alpha0 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 lifetimes are relatively independent of frequency and wave-normal angle after taking into consideration the scaling law, with a weak dependence on wave-normal angle up to 60-70°, increasing to infinity as the wave-normal angle approaches the resonance cone. We identify regions in the (L, E) plane in which a single wave type (hiss, VLF transmitters, or lightning-generated waves) is dominant relative to the others. We find that VLF waves dominate the lifetime for 0.2-0.4 MeV at L~2 and for 0.5-0.8 MeV at L~1.5, while hiss dominates the lifetime for 2-3 MeV at L=3-3.5. The influence of lightning-generated waves is always mixed with the other two and cannot be easily differentiated. Limitations of the method for addressing effects due to restricted latitude or pitch angle domains are also discussed. Finally, for each (L, E) we search for the minimum lifetime and find that the "optimal" frequency that produces this lifetime increases as L diminishes. Restricting the search to very oblique waves, which could be emitted during the DSX satellite mission, we find that the optimal frequency is always close to 0.16Wce.

  1. On the Origin of Whistler Mode Radiation in the Plasmasphere

    NASA Technical Reports Server (NTRS)

    Green, James L.; Boardsen, Scott; Garcia, Leonard; Taylor, W. W. L.; Fung, Shing F.; Reinisch, B. W.

    2004-01-01

    The origin of whistler mode radiation in the plasmasphere is examined from three years of plasma wave observations from the Dynamics Explorer and three years from the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) spacecraft. These data are used to construct plasma wave intensity maps of whistler mode radiation in the plasmasphere. The highest average intensities of the radiation in the wave maps show source locations and/or sites of wave amplification. Each type of emission is classified based on its magnetic latitude and longitude rather than any spectral feature. Equatorial electromagnetic (EM) emissions (approx. 30-330 Hz), plasmaspheric hiss (approx. 330 Hz - 3.3 kHz), chorus (approx. 2 kHz - 6 kHz), and VLF transmitters (approx. 10-50 kHz) are the main types of waves that are clearly delineated in the plasma wave maps. Observations of the equatorial EM emissions show that the most intense region is on or near the magnetic equator in the afternoon sector and that during times of negative B(sub z) (interplanetary magnetic field),the maximum intensity moves from L values of 3 to less than 2. These observations are consistent with the origin of this emission being particle-wave interactions in or near the magnetic equator. Plasmaspheric hiss shows high intensity at high latitudes and low altitudes (L shells from 2 to 4) and in the magnetic equator over L values from 2 to 3 in the early afternoon sector. The longitudinal distribution of the hiss intensity (excluding the enhancement at the equator) is similar to the distribution of lightning: stronger over continents than over the ocean, stronger in the summer than winter, and stronger on the dayside than nightside. These observations strongly support lightning as the dominant source for plasmaspheric hiss, which through particle-wave interactions, maintains the slot region in the radiation belts. The enhancement of hiss at the magnetic equator is consistent with particle-wave interactions. The chorus

  2. HISS spectrometer

    SciTech Connect

    Greiner, D.E.

    1984-11-01

    This talk describes the Heavy Ion Spectrometer System (HISS) facility at the Lawrence Berkeley Laboratory's Bevalac. Three completed experiments and their results are illustrated. The second half of the talk is a detailed discussion of the response of drift chambers to heavy ions. The limitations of trajectory measurement over a large range in incident particle charge are presented.

  3. Resonant scattering of energetic electrons by unusual low-frequency hiss

    NASA Astrophysics Data System (ADS)

    Ni, Binbin; Li, Wen; Thorne, Richard M.; Bortnik, Jacob; Ma, Qianli; Chen, Lunjin; Kletzing, Craig A.; Kurth, William S.; Hospodarsky, George B.; Reeves, Geoffrey D.; Spence, Harlan E.; Bernard Blake, J.; Fennell, Joseph F.; Claudepierre, Seth G.

    2014-03-01

    We quantify the resonant scattering effects of the unusual low-frequency dawnside plasmaspheric hiss observed on 30 September 2012 by the Van Allen Probes. In contrast to normal (~100-2000 Hz) hiss emissions, this unusual hiss event contained most of its wave power at ~20-200 Hz. Compared to the scattering by normal hiss, the unusual hiss scattering speeds up the loss of ~50-200 keV electrons and produces more pronounced pancake distributions of ~50-100 keV electrons. It is demonstrated that such unusual low-frequency hiss, even with a duration of a couple of hours, plays a particularly important role in the decay and loss process of energetic electrons, resulting in shorter electron lifetimes for ~50-400 keV electrons than normal hiss, and should be carefully incorporated into global modeling of radiation belt electron dynamics during periods of intense injections.

  4. Amplification of exo-hiss into low-frequency chorus following substorm injection

    NASA Astrophysics Data System (ADS)

    Gao, Z.; Su, Z.

    2016-12-01

    Whistler-mode chorus waves contribute significantly to the acceleration of radiation belt electrons. Chorus with frequency below 0.1 fce (fce is the equatorial electron gyro-frequency) has been identified as the low-frequency chorus. How such low-frequency chorus waves are generated remains an unanswered question. Here we propose a new candidate generation mechanism that exo-hiss waves can serve as the source of low-frequency chorus. Exo-hiss is usually believed to be the leaked plasmaspheric hiss from the high-density plasmasphere into the low-density plasmatrough. Both Van Allen Probes observations and linear instability analyses support that exo-hiss can be effectively amplified into low-frequency chorus by the substorm-injected anisotropic electrons at energies around 100 keV.

  5. Geocoronal structure - The effects of solar radiation pressure and the plasmasphere interaction

    NASA Technical Reports Server (NTRS)

    Bishop, J.

    1985-01-01

    The theory of planetary exospheres is extended to incorporate solar radiation pressure in a rigorous manner, and an evaporative geocoronal prototype (classical, motionless exobase) is constructed using Liouville's theorem. Model calculations for density and kinetic temperature at points along the earth-sun axis (solar and antisolar directions) reveal an extensive satellite component, comprising approximately 2/3 of the total hydrogen density near 10 earth radii, and a temperature profile suggestive of an isotropic quasi-Maxwellian velocity distribution for the bound component. A geotail is also evident as an enhancement of the density at local midnight compared to local noon that increases outward (from approximately 25 percent at 10 earth radii to over 60 percent at 20 earth radii). Additional mechanisms acting upon the geocorona alter the basic evaporative case in notable ways. Solar ionization has been included in a simple fashion; the effect is to partially deplete the density without otherwise altering the structure. Interaction with a simple plasmasphere via the Boltzmann equation results in 'heating' the geocorona and enhancing the escape flux at the expense of the density of the bound component, an effect not appreciated in earlier studies; the geotail survives this interaction.

  6. Numerical trials of HISSE

    NASA Technical Reports Server (NTRS)

    Peters, C.; Kampe, F. (Principal Investigator)

    1980-01-01

    The mathematical description and implementation of the statistical estimation procedure known as the Houston integrated spatial/spectral estimator (HISSE) is discussed. HISSE is based on a normal mixture model and is designed to take advantage of spectral and spatial information of LANDSAT data pixels, utilizing the initial classification and clustering information provided by the AMOEBA algorithm. The HISSE calculates parametric estimates of class proportions which reduce the error inherent in estimates derived from typical classify and count procedures common to nonparametric clustering algorithms. It also singles out spatial groupings of pixels which are most suitable for labeling classes. These calculations are designed to aid the analyst/interpreter in labeling patches with a crop class label. Finally, HISSE's initial performance on an actual LANDSAT agricultural ground truth data set is reported.

  7. High Resolution Spectral Analysis of Hiss and Chorus Emissions in Ground Based Data

    NASA Astrophysics Data System (ADS)

    Hosseini Aliabad, S. P.; Golkowski, M.; Gibby, A. R.

    2015-12-01

    The dynamic evolution of the radiation belts is believed to be controlled in large part by two separate but related classes of naturally occurring plasma waves: ELF/VLF chorus and hiss emissions. Although whistler mode chorus has been extensively studied since the first reports by Storey in 1953, the source mechanism and properties are still subjects of active research. Moreover, the origin of plasmaspheric hiss, the electromagnetic emission believed to be responsible for the gap between the inner and outer radiation belts, has been debated for over four decades. Although these waves can be observed in situ on spacecraft, ground-based observing stations can provide orders of magnitude higher data volumes and decades long data coverage essential for certain long-term and statistical studies of wave properties. Recent observational and theoretical works suggest that high resolution analysis of the spectral features of both hiss and chorus emissions can provide insight into generation processes and be used to validate existing theories. Application of the classic Fourier (FFT) technique unfortunately yields a tradeoff between time and frequency resolution. In additional to Fourier spectra, we employ novel methods to make spectrograms with high time and frequency resolutions, independently using minimum variance distortionless response (MVDR). These techniques are applied to ground based data observations of hiss and chorus made in Alaska. Plasmaspheric hiss has been widely regarded as a broadband, structure less, incoherent emission. We quantify the extent to which plasmaspheric hiss can be a coherent emission with complex fine structure. Likewise, to date, researchers have differentiated between hiss and chorus coherency primarily using qualitative "naked eye" approaches to amplitude spectra. Using a quantitative approach to observed amplitude and we present more rigorous classification criteria for these emissions.

  8. Simultaneous observation of chorus and hiss near the plasmapause

    NASA Astrophysics Data System (ADS)

    Delport, B.; Collier, A. B.; Lichtenberger, J.; Rodger, C. J.; Parrot, M.; Clilverd, M. A.; Friedel, R. H. W.

    2012-12-01

    On 4 August 2010 a moderate geomagnetic storm occurred with minimum Dst of -65 nT and maximum Kp of 7-. Shortly after the onset of this storm, VLF chorus was observed at Marion Island (L= 2.6). Over time the spectral structure of the chorus transformed into a hiss band spanning the same frequency range. The observation of overlapping chorus and hiss suggests that Marion Island was close to the plasmapause at the time of this event, and provides ground-based observational confirmation of the generation mechanism of plasmaspheric hiss from chorus waves outside of the plasmasphere. Chorus observations at Marion Island were not common during this period of the solar cycle and so this event was investigated in detail. The geomagnetic conditions are discussed and geosynchronous particle data and broadband data from two other stations are presented. Empirical models are employed to predict the location of the plasmapause, and its location is inferred from a knee whistler recorded at Dunedin, New Zealand. These show that Marion Island is in the vicinity of the plasmapause during the event. The event is also compared to chorus observed at similarL after the Halloween storms of 2003. The rarity of the chorus observation is quantified using DEMETER VLF data. The DEMETER data, along with the various ground based VLF measurements, allows us to infer temporal and spatial variations in the chorus source region.

  9. Modeling of the Convection and Interaction of Ring Current, Plasmaspheric and Plasma Sheet Plasmas in the Inner Magnetosphere

    NASA Technical Reports Server (NTRS)

    Fok, Mei-Ching; Chen, Sheng-Hsien; Buzulukova, Natalia; Glocer, Alex

    2010-01-01

    Distinctive sources of ions reside in the plasmasphere, plasmasheet, and ring current regions at discrete energies constitute the major plasma populations in the inner/middle magnetosphere. They contribute to the electrodynamics of the ionosphere-magnetosphere system as important carriers of the global current system, in triggering; geomagnetic storm and substorms, as well as critical components of plasma instabilities such as reconnection and Kelvin-Helmholtz instability at the magnetospheric boundaries. Our preliminary analysis of in-situ measurements shoves the complexity of the plasmas pitch angle distributions at particularly the cold and warm plasmas, vary dramatically at different local times and radial distances from the Earth in response to changes in solar wind condition and Dst index. Using an MHD-ring current coupled code, we model the convection and interaction of cold, warm and energetic ions of plasmaspheric, plasmasheet, and ring current origins in the inner magnetosphere. We compare our simulation results with in-situ and remotely sensed measurements from recent instrumentation on Geotail, Cluster, THEMIS, and TWINS spacecraft.

  10. Physics-based models of the plasmasphere

    SciTech Connect

    Jordanova, Vania K; Pierrard, Vivane; Goldstein, Jerry; Andr'e, Nicolas; Lemaire, Joseph F; Liemohn, Mike W; Matsui, H

    2008-01-01

    We describe recent progress in physics-based models of the plasmasphere using the Auid and the kinetic approaches. Global modeling of the dynamics and inAuence of the plasmasphere is presented. Results from global plasmasphere simulations are used to understand and quantify (i) the electric potential pattern and evolution during geomagnetic storms, and (ii) the inAuence of the plasmasphere on the excitation of electromagnetic ion cyclotron (ElvIIC) waves a.nd precipitation of energetic ions in the inner magnetosphere. The interactions of the plasmasphere with the ionosphere a.nd the other regions of the magnetosphere are pointed out. We show the results of simulations for the formation of the plasmapause and discuss the inAuence of plasmaspheric wind and of ultra low frequency (ULF) waves for transport of plasmaspheric material. Theoretical formulations used to model the electric field and plasma distribution in the plasmasphere are given. Model predictions are compared to recent CLUSTER and MAGE observations, but also to results of earlier models and satellite observations.

  11. Mass Loading at the Magnetopause through the Plasmaspheric Plume

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Tu, J.; Song, P.

    2015-12-01

    An investigation of the transport of the plasmaspheric plasma to the dayside magnetopause through plasmaspheric plumes under disturbed geomagnetic conditions is conducted by numerical simulations using the Dynamic Fluid-Kinetic (DyFK) model. The simulation calculates the field-aligned density distributions of multiple ion species (H+/He+/O+) in a plasmaspheric flux tube that corotates while convecting toward the dayside magnetopause. When the convection is enhanced, a plasmaspheric plume is formed and plasmaspheric plasma mass loads to the dayside magnetopause. The effect of wave-particle interactions on the density distributions is also studied.

  12. Modeling of Plasmasphere

    NASA Astrophysics Data System (ADS)

    Watanabe, Shigeto; Kumamoto, Atsushi; Kakinami, Yoshihiro

    2016-07-01

    begin{center} {bf Modeling of Plasmasphere} end{center} Electron density at altitudes below 10,000km is estimated from upper-hybrid resonance (UHR) emission observed by the plasma wave and sounder experiments (PWS) on Akebono satellite from February 22, 1989 to April 23, 2015. The electron density of plasmasphere is investigated statistically and compared with International Reference Ionosphere model. We have made an empirical model of electron density of plasmasphere at altitudes between 1000 km and 10000 km. The electron density distribution is also compared with a physical model (Plasmasphere Thermosphere model: PTM) developed in Japan. The electron densities by the Akebono satellite and the PTM show clearly density gradient change at altitude of 1500 km and plasmapause. The density gradient change at 1500 km altitude is corresponding to transition height from O+ to H+. The electron density distribution of plasmasphere shows clearly local time, latitude, season, solar activity and magnetic activity dependences.

  13. Landau damping of auroral hiss

    NASA Technical Reports Server (NTRS)

    Morgan, D. D.; Gurnett, D. A.; Menietti, J. D.; Winningham, J. D.; Burch, J. L.

    1994-01-01

    Auroral hiss is observed to propagate over distances comparable to an Earth radius from its source in the auroral oval. The role of Landau damping is investigated for upward propagating auroral hiss. By using a ray tracing code and a simplified model of the distribution function, the effect of Landau damping is calculated for auroral hiss propagation through the environment around the auroral oval. Landau damping is found to be the likely mechanism for explaining some of the one-sided auroral hiss funnels observed by Dynamics Explorer 1. It is also found that Landau damping puts a lower limit on the wavelength of auroral hiss. Poleward of the auroral oval, Landau damping is found in a typical case to limit omega/k(sub parallel) to values of 3.4 x 10(exp 4) km/s or greater, corresponding to resonance energies of 3.2 keV or greater and wavelengths of 2 km or greater. For equatorward propagation, omega/k(sub parallel) is limited to values greater than 6.8 x 10(exp 4) km/s, corresponding to resonance energies greater than 13 keV and wavelengths greater than 3 km. Independent estimates based on measured ratios of the magnetic to electric field intensity also show that omega/k(sub parallel) corresponds to resonance energies greater than 1 keV and wavelengths greater than 1 km. These results lead to the difficulty that upgoing electron beams sufficiently energetic to directly generate auroral hiss of the inferred wavelength are not usually observed. A partial transmission mechanism utilizing density discontinuities oblique to the magnetic field is proposed for converting auroral hiss to wavelengths long enough to avoid damping of the wave over long distances. Numerous reflections of the wave in an upwardly flared density cavity could convert waves to significantly increased wavelengths and resonance velocities.

  14. Landau damping of auroral hiss

    NASA Technical Reports Server (NTRS)

    Morgan, D. D.; Gurnett, D. A.; Menietti, J. D.; Winningham, J. D.; Burch, J. L.

    1994-01-01

    Auroral hiss is observed to propagate over distances comparable to an Earth radius from its source in the auroral oval. The role of Landau damping is investigated for upward propagating auroral hiss. By using a ray tracing code and a simplified model of the distribution function, the effect of Landau damping is calculated for auroral hiss propagation through the environment around the auroral oval. Landau damping is found to be the likely mechanism for explaining some of the one-sided auroral hiss funnels observed by Dynamics Explorer 1. It is also found that Landau damping puts a lower limit on the wavelength of auroral hiss. Poleward of the auroral oval, Landau damping is found in a typical case to limit omega/k(sub parallel) to values of 3.4 x 10(exp 4) km/s or greater, corresponding to resonance energies of 3.2 keV or greater and wavelengths of 2 km or greater. For equatorward propagation, omega/k(sub parallel) is limited to values greater than 6.8 x 10(exp 4) km/s, corresponding to resonance energies greater than 13 keV and wavelengths greater than 3 km. Independent estimates based on measured ratios of the magnetic to electric field intensity also show that omega/k(sub parallel) corresponds to resonance energies greater than 1 keV and wavelengths greater than 1 km. These results lead to the difficulty that upgoing electron beams sufficiently energetic to directly generate auroral hiss of the inferred wavelength are not usually observed. A partial transmission mechanism utilizing density discontinuities oblique to the magnetic field is proposed for converting auroral hiss to wavelengths long enough to avoid damping of the wave over long distances. Numerous reflections of the wave in an upwardly flared density cavity could convert waves to significantly increased wavelengths and resonance velocities.

  15. Hiss or equatorial noise? Ambiguities in analyzing suprathermal ion plasma wave resonance

    NASA Astrophysics Data System (ADS)

    Sarno-Smith, Lois K.; Liemohn, Michael W.; Skoug, Ruth M.; Santolik, Ondrej; Morley, Steven K.; Breneman, Aaron; Larsen, Brian A.; Reeves, Geoff; Wygant, John R.; Hospodarsky, George; Kletzing, Craig; Moldwin, Mark B.; Katus, Roxanne M.; Zou, Shasha

    2016-10-01

    Previous studies have shown that low-energy ion heating occurs in the magnetosphere due to strong equatorial noise emission. Observations from the Van Allen Probes Helium Oxygen Proton Electron (HOPE) instrument recently determined that there was a depletion in the 1-10 eV ion population in the postmidnight sector of Earth during quiet times at L < 3. The diurnal variation of equatorially mirroring 1-10 eV H+ ions at 2 < L < 3 is connected with similar diurnal variation in the electric field component of plasma waves ranging between 150 and 600 Hz. Measurements from the Van Allen Probes Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) data set are used to analyze waves of this frequency in near-Earth space. However, when we examine the polarization of the waves in the 150 to 600 Hz range in the equatorial plane, the majority are right-hand polarized plasmaspheric hiss waves. The 1-10 eV H+ equatorially mirroring population does not interact with right-hand waves, despite a strong statistical relationship suggesting that the two are linked. We present evidence supporting the relationship, both in our own work and the literature, but we ultimately conclude that the 1-10 eV H+ heating is not related to the strong enhancement of 150 to 600 Hz waves.

  16. Long-duration exohiss waves outside the plasmasphere: observed by Van Allen Probes

    NASA Astrophysics Data System (ADS)

    Zhu, H.; Su, Z.; Xiao, F.; Zheng, H.; Wang, Y.; He, Z.; Shen, C.; Zhang, M.; Wang, S.; Kletzing, C.; Kurth, W. S.; Hospodarsky, G. B.; Spence, H. E.; Reeves, G. D.; Funsten, H. O.; Blake, J. B.; Baker, D. N.

    2014-12-01

    We report an exohiss event in the low-density trough region observed by Van Allen Probes on 2 February 2014. These exohiss waves are discovered in the wide MLT distribution [9.1,13.4] and low magnetic latitude, with narrow-band structure and weak intensity compared with plasmaspheric hiss. Using the Continue Waveform Burst Mode data and MAG data on the EMFISIS, we analyze the normal angle, electromagnetic planarity and anti~/parallel-propagating Poynting flux of exohiss wave. The results show indicate that exohiss waves are the result of plasmaspheric hiss leakage into the trough region. The dependence of the proportion of anti~/parallel-propagating Poynting flux on MLT can be explained by Landau damping associated with suprathermal eletrons.

  17. Global MHD simulations of plasmaspheric plumes

    NASA Astrophysics Data System (ADS)

    Lyon, J.; Ouellette, J.; Merkin, V. G.

    2015-12-01

    The plasmasphere represents a separate population from the rest of themagnetosphere, generally high density but cold. When the solar windturns strongly southward this plasma is convected toward the daysidemagnetopause and affects the interaction of the solar wind with themagnetosphere. We have used multi-fluid simulations using the LFMglobal MHD code to model this interaction. The plasmasphere isinitialized as a cold (~1eV) hydrogen plasma in a quiet northward IMFstate with a density distribution appropriate for K_p = 1. Thecorotation potential from the ionosphere spins up the plasmasphereinto rough corotation. After a initialization period of hours, asouthward IMF is introduced and the enhanced convection initiates asurge of plasmaspheric density to the dayside. We discuss two aspectsof this interaction, the effects on dayside reconnection and on theKelvin-Helmholtz instability (KHI). We find that the mass loading ofmagnetospheric flux tubes slows local reconnection rates, though notas much as predicted by Borovsky et al. [2013]. We findthat the total reconnection rate is reduced, although not as much aswould be predicted by just the sub-solar reconnection rate. The KHIis somewhat reduced by the plasmaspheric loading of density in the lowlatitude boundary layer. It has been suggested that the presence ofthe plasmasphere may lead to enhanced ULF wave power in the interiorof the magnetosphere from the KHI waves. We find only a minimal effect during northward IMF. For southward IMF, the situation is complicated by the interaction of KHI with non-steady reconnection.

  18. Genetic aspects of communication during male-male competition in the Madagascar hissing cockroach: honest signalling of size.

    PubMed

    Clark, D C; Moore, A J

    1995-08-01

    Male Madagascar hissing cockroaches, Gromphadorhina portentosa, engage in agonistic contests with other males and produce audible sounds or 'hisses' during these interactions. Hisses are used to maintain, rather than to establish, social relationships among males. The agonistic hisses of males are variable and could be used as signals to communicate size or competitive ability of an individual. In this study we examined how size influences male-male competition, as well as the genetic variation and covariation of male body size and components of the agonistic hiss. We found that male size affected the outcome of agonistic interactions between pairs of males: a male that dominated in a pair was significantly larger than the male that was subordinate. However, we found no differences in the hisses produced by dominant and subordinate males after controlling for male weight. We estimated heritabilities, evolvability and genetic correlations for male size and characteristics of the hiss from a full-sib analysis of brothers. The patterns of heritabilities and evolvabilities were very similar. The heritabilities of both male weight and duration of the hiss were significantly greater than zero. There was a significant positive genetic correlation between duration of the agonistic hiss and male weight, and a significant negative genetic correlation between hiss duration and the beginning dominant frequency. There was also a positive phenotypic correlation and a negative environmental correlation between male weight and hiss duration. Thus, hiss duration can signal the present influence of the environment on male size, whereas information from hiss duration and beginning dominant frequency can signal the male's ability to transmit genetic influence for size.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Transverse eV ion heating by random electric field fluctuations in the plasmasphere

    NASA Astrophysics Data System (ADS)

    Artemyev, A. V.; Mourenas, D.; Agapitov, O. V.; Blum, L.

    2017-02-01

    Charged particle acceleration in the Earth inner magnetosphere is believed to be mainly due to the local resonant wave-particle interaction or particle transport processes. However, the Van Allen Probes have recently provided interesting evidence of a relatively slow transverse heating of eV ions at distances about 2-3 Earth radii during quiet times. Waves that are able to resonantly interact with such very cold ions are generally rare in this region of space, called the plasmasphere. Thus, non-resonant wave-particle interactions are expected to play an important role in the observed ion heating. We demonstrate that stochastic heating by random transverse electric field fluctuations of whistler (and possibly electromagnetic ion cyclotron) waves could explain this weak and slow transverse heating of H+ and O+ ions in the inner magnetosphere. The essential element of the proposed model of ion heating is the presence of trains of random whistler (hiss) wave packets, with significant amplitude modulations produced by strong wave damping, rapid wave growth, or a superposition of wave packets of different frequencies, phases, and amplitudes. Such characteristics correspond to measured characteristics of hiss waves in this region. Using test particle simulations with typical wave and plasma parameters, we demonstrate that the corresponding stochastic transverse ion heating reaches 0.07-0.2 eV/h for protons and 0.007-0.015 eV/h for O+ ions. This global temperature increase of the Maxwellian ion population from an initial Ti˜0.3 eV could potentially explain the observations.

  20. Transverse eV Ion Heating by Random Electric Field Fluctuations in the Plasmasphere

    NASA Technical Reports Server (NTRS)

    Artemyev, A. V.; Mourenas, D.; Agapitov, O. V.; Blum, L.

    2017-01-01

    Charged particle acceleration in the Earth inner magnetosphere is believed to be mainly due to the local resonant wave-particle interaction or particle transport processes. However, the Van Allen Probes have recently provided interesting evidence of a relatively slow transverse heating of eV ions at distances about 2-3 Earth radii during quiet times. Waves that are able to resonantly interact with such very cold ions are generally rare in this region of space, called the plasmasphere. Thus, non-resonant wave-particle interactions are expected to play an important role in the observed ion heating. We demonstrate that stochastic heating by random transverse electric field fluctuations of whistler (and possibly electromagnetic ion cyclotron) waves could explain this weak and slow transverse heating of H+ and O+ ions in the inner magnetosphere. The essential element of the proposed model of ion heating is the presence of trains of random whistler (hiss) wave packets, with significant amplitude modulations produced by strong wave damping, rapid wave growth, or a superposition of wave packets of different frequencies, phases, and amplitudes. Such characteristics correspond to measured characteristics of hiss waves in this region. Using test particle simulations with typical wave and plasma parameters, we demonstrate that the corresponding stochastic transverse ion heating reaches 0.07-0.2 eV/h for protons and 0.007-0.015 eV/h for O+ ions. This global temperature increase of the Maxwellian ion population from an initial Ti approx. 0.3 eV could potentially explain the observations.

  1. The Storm-Time Plasmasphere by IMAGE/EUV

    NASA Technical Reports Server (NTRS)

    Gallagher, D. L.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    With the availability of routine global images of the plasmasphere from the IMAGE Mission Extreme Ultraviolet Imager (EUV), we now have a growing body of observations that both characterize and quantify the dynamics of the plasmasphere. Direct interactions of the plasmasphere with the ring current and indirect interaction through localized electric fields appear to be the cause of a complex array of structures in the spatial distribution of thermal plasma. This presentation will show those features in detail and discuss possible mechanisms for their cause.

  2. The Storm-Time Plasmasphere by IMAGE/EUV

    NASA Technical Reports Server (NTRS)

    Gallagher, D. L.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    With the availability of routine global images of the plasmasphere from the IMAGE Mission Extreme Ultraviolet Imager (EUV), we now have a growing body of observations that both characterize and quantify the dynamics of the plasmasphere. Direct interactions of the plasmasphere with the ring current and indirect interaction through localized electric fields appear to be the cause of a complex array of structures in the spatial distribution of thermal plasma. This presentation will show those features in detail and discuss possible mechanisms for their cause.

  3. Empty Flux Tubes and Plasmasphere Refilling as Seen by IMAGE

    NASA Technical Reports Server (NTRS)

    Adrian, M. L.; Gallagher, D. L.; Sandel, B. R.; Green, J. L.; Reinish, B.; Goldstein, J.; Huegrich, T.

    2002-01-01

    When a plasmaspheric flux tube is empty, what plasma is actually missing? When a flux tube refills, where does the plasma accumulate first? How long does it take to refill a flux tube to a level that is essentially saturated? Owing to the observational difficulties of measuring the distribution of plasmaspheric plasma along a flux tube, these questions have remained unanswered over many decades of study since discovery of the plasmasphere. They are important questions, because of the role that plasmaspheric plasma plays in collisional losses of higher energy populations, in modifying instabilities for wave-particle interactions, and in influencing the transport of energy through plasma waves. The Extreme Ultraviolet Imager and the Radio Plasma Imager on the IMAGE Mission are providing new, critical observations of the dynamic outer plasmasphere where convective erosion and refilling dominate. Latitudinal density profiles along a single L-shell from BPI confirm earlier indications of a mid-latitude transition between the altitude organized structure of the ionosphere and L-shell organized plasmasphere. Emptied flux tubes often mean empty only above about 1 Re in altitude or below plus or minus 40 degrees in magnetic latitude. Refilling to nearly saturated levels is found to take much less than that previously found necessary to complete the process. The observations behind these conclusions and the new light brought to plasmaspheric refilling will be discussed.

  4. The Origin and Evolution of Deep Plasmaspheric Notches

    NASA Technical Reports Server (NTRS)

    Gallagher, D.; Adrian, M.; Liemohn, M.

    2004-01-01

    Deep plasmaspheric notches can extend over more than 2 RE and 3 hours MLT in the magnetic equatorial plane. They can last for days and exhibit varying structure. In this presentation, the low L-shell portion of the recovery-time plasmaspheric convection plume will be explored as the source for these deep evacuations in density. Interactions with the ring current will be explored as the source of features observed in these density depletions.

  5. Measurement and modeling of the refilling plasmasphere during 2001

    DOE PAGES

    Krall, J.; Huba, J. D.; Jordanova, V. K.; ...

    2016-03-18

    The Naval Research Laboratory SAMI3 (Sami3 is Also a Model of the Ionosphere) and the RAM-CPL (Ring current Atmosphere interaction Model-Cold PLasma) codes are used to model observed plasmasphere dynamics during 25 November 2001 to 1 December 2001 and 1–5 February 2001. Model results compare well to plasmasphere observations of electron and mass densities. Comparison of model results to refilling data and to each other shows good agreement, generally within a factor of 2. We find that SAMI3 plasmaspheric refilling rates and ion densities are sensitive to the composition and temperature of the thermosphere and exosphere, and to photoelectron heating.more » Furthermore, results also support our previous finding that the wind-driven dynamo significantly impacts both refilling rates and plasmasphere dynamics during quiet periods.« less

  6. Measurement and modeling of the refilling plasmasphere during 2001

    SciTech Connect

    Krall, J.; Huba, J. D.; Jordanova, V. K.; Denton, R. E.; Carranza, T.; Moldwin, M. B.

    2016-03-18

    The Naval Research Laboratory SAMI3 (Sami3 is Also a Model of the Ionosphere) and the RAM-CPL (Ring current Atmosphere interaction Model-Cold PLasma) codes are used to model observed plasmasphere dynamics during 25 November 2001 to 1 December 2001 and 1–5 February 2001. Model results compare well to plasmasphere observations of electron and mass densities. Comparison of model results to refilling data and to each other shows good agreement, generally within a factor of 2. We find that SAMI3 plasmaspheric refilling rates and ion densities are sensitive to the composition and temperature of the thermosphere and exosphere, and to photoelectron heating. Furthermore, results also support our previous finding that the wind-driven dynamo significantly impacts both refilling rates and plasmasphere dynamics during quiet periods.

  7. Unsolved problems in plasmasphere refilling

    NASA Astrophysics Data System (ADS)

    Gallagher, D. L.; Comfort, R. H.

    2016-02-01

    The plasmasphere is a cold (~1 eV) plasma at middle to low magnetic latitudes surrounding the Earth. Its shape is dominated by Earth's magnetic field and its cross-field motion is dominated by electric fields. It is a highly coupled part of the inner magnetosphere. Storm time conditions erode the outer plasmasphere, transporting that plasma into the dayside magnetosheath region, leaving behind a region of greatly reduced plasma density that will refill from ionospheric outflow. The processes involved in refilling remain incompletely understood. In this commentary, outstanding questions about plasmaspheric refilling are summarized in the context of recent publications.

  8. The enhancement of cosmic radio noise absorption due to hiss-driven energetic electron precipitation during substorms

    NASA Astrophysics Data System (ADS)

    Li, Haimeng; Yuan, Zhigang; Yu, Xiongdong; Huang, Shiyong; Wang, Dedong; Wang, Zhenzhen; Qiao, Zheng; Wygant, John R.

    2015-07-01

    The Van Allen probes, low-altitude NOAA satellite, MetOp satellite, and riometer are used to analyze variations of precipitating energetic electron fluxes and cosmic radio noise absorption (CNA) driven by plasmaspheric hiss with respect to geomagnetic activities. The hiss-driven energetic electron precipitations (at L ~ 4.7-5.3, magnetic local time (MLT) ~ 8-9) are observed during geomagnetic quiet condition and substorms, respectively. We find that the CNA detected by riometers increased very little in the hiss-driven event during quiet condition on 6 September 2012. The hiss-driven enhancement of riometer was still little during the first substorm on 30 September 2012. However, the absorption detected by the riometer largely increased, while the energies of the injected electrons became higher during the second substorm on 30 September 2012. The enhancement of CNA (ΔCNA) observed by the riometer and calculated with precipitating energetic electrons is in agreement during the second substorm, implying that the precipitating energetic electrons increase CNA to an obviously detectable level of the riometer during the second substorm on 30 September 2012. The conclusion is consistent with Rodger et al. (2012), which suggest that the higher level of ΔCNA prefers to occur in the substorms, because substorms may produce more intense energetic electron precipitation associated with electron injection. Furthermore, the combination of the observations and theory calculations also suggests that higher-energy electron (>55 keV) precipitation contributes more to the ΔCNA than the lower energy electron precipitation. In this paper, the higher-energy electron precipitation is related to lower frequency hiss.

  9. Properties of electron flux spectra around the plasmapause in the chorus and hiss regions using POES.

    NASA Astrophysics Data System (ADS)

    Whittaker, Ian; Rodger, Craig; Clilverd, Mark

    2014-05-01

    The European FP7 PLASMON project aims to provide observations of plasmaspheric densities, and link the plasmaspheric variations to relativistic electron precipitation from the radiation belts. This is intended to assist in the estimation and prevent damage of space assets from space weather events as well as to improve forecasting (http://plasmon.elte.hu). As part of the PLASMON project, electron fluxes from the POES series of satellites are being used to determine the link between energetic electron precipitation energy spectra and magnitude to the position of the plasmapause. The MEPED instrument onboard POES measures electron flux from 90° (trapped particles) and 0° (losscone) telescopes, in 3 integral energy channels (>30, >100 and >300 keV). These fluxes have been compared to the DEMETER/IDP instrument to confirm that published geometric factor corrections (Yando et al. 2011) can be accurately applied to the POES data to produce as accurate as possible fluxes. These global fluxes have then been separated into regions in which Chorus (23:00-11:00 MLT) and Hiss (11:00-16:00 MLT) whistler mode waves are expected to occur, in 0.2 L-shell bins with a 20 minute temporal resolution. The plasmapause locations have been determined from the O'Brien and Moldwin (2003) models based on Kp, Ae and Dst peaks. We are currently comparing the POES spectral gradient and flux magnitude with plasmapause location and geomagnetic activity for the locations in which chorus and hiss are known to occur. This presentation will focus on the electron flux spectral gradient behaviour either side of the plasmapause, a value that is difficult to measure from ground based techniques.

  10. The Roles of Transport and Wave-Particle Interactions on Radiation Belt Dynamics

    NASA Technical Reports Server (NTRS)

    Fok, Mei-Ching; Glocer, Alex; Zheng, Qiuhua

    2011-01-01

    Particle fluxes in the radiation belts can vary dramatically during geomagnetic active periods. Transport and wave-particle interactions are believed to be the two main types of mechanisms that control the radiation belt dynamics. Major transport processes include substorm dipolarization and injection, radial diffusion, convection, adiabatic acceleration and deceleration, and magnetopause shadowing. Energetic electrons and ions are also subjected to pitch-angle and energy diffusion when interact with plasma waves in the radiation belts. Important wave modes include whistler mode chorus waves, plasmaspheric hiss, electromagnetic ion cyclotron waves, and magnetosonic waves. We investigate the relative roles of transport and wave associated processes in radiation belt variations. Energetic electron fluxes during several storms are simulated using our Radiation Belt Environment (RBE) model. The model includes important transport and wave processes such as substorm dipolarization in global MHD fields, chorus waves, and plasmaspheric hiss. We discuss the effects of these competing processes at different phases of the storms and validate the results by comparison with satellite and ground-based observations. Keywords: Radiation Belts, Space Weather, Wave-Particle Interaction, Storm and Substorm

  11. Kinetic Framework for the Magnetosphere-Ionosphere-Plasmasphere-Polar Wind System: A UnifiedApproach for Studying Hot and Cold Plasma Interactions

    NASA Astrophysics Data System (ADS)

    Karimabadi, H.; Omelchenko, Y.; Schunk, R. W.; Barakat, A. R.; Gardner, L. C.; Khazanov, G. V.; Glocer, A.; Kistler, L. M.

    2013-12-01

    The Magnetosphere-Ionosphere-Plasmasphere-Polar Wind System is complex; it varies on a wide range in spatial and temporal scales, exhibits relatively thin ion-scale boundaries (e.g., bow shock, magnetopause, magnetotail), contains hot and cold particle populations, and the particle distribution functions are typically non-Maxwellian. The existing space weather frameworks are based on global fluid models and therefore cannot address many important issues concerning particle, momentum, and energy coupling in the system. To remedy this situation, we have formed a multi-disciplinary team to create a new kinetic modeling framework. The new framework will include kinetic electron and ion formulations for the ionosphere, plasmasphere, and polar wind domains, and kinetic ions and fluid electrons for the magnetosphere. The proposed methodology is expected to lead to breakthroughs in studying numerous problems/issues, including the self-consistent formation of the ring current, the self-consistent formation of ion scale turbulence and waves, the calculation of appropriate reconnection rates, the effect that multiple species and ion outflows from the ionosphere have on the development and evolution of storms/substorms, among others. The presentation will focus on the current state and capabilities of the global kinetic models that form the framework for the Magnetosphere-Ionosphere-Plasmasphere-Polar Wind Model.

  12. ``Hiss, clicks and pops'' - The enigmatic sounds of meteors

    NASA Astrophysics Data System (ADS)

    Finnegan, J. A.

    2015-04-01

    The improbability of sounds heard simultaneously with meteors allows the phenomenon to remain on the margins of scientific interest and research. This is unjustified, since these audibly perceived electric field effects indicate complex, inconsistent and still unresolved electric-magnetic coupling and charge dynamics; interacting between the meteor; the ionosphere and mesosphere; stratosphere; troposphere and the surface of the earth. This paper reviews meteor acoustic effects, presents illustrating reports and hypotheses and includes a summary of similar and additional phenomena observed during the 2013 February 15 asteroid fragment disintegration above the Russian district of Chelyabinsk. An augmenting theory involving near ground, non uniform electric field production of Ozone, as a stimulated geo-physical phenomenon to explain some hissing `meteor sounds' is suggested in section 2.2. Unlike previous theories, electric-magnetic field fluctuation rates are not required to occur in the audio frequency range for this process to acoustically emit hissing and intermittent impulsive sounds; removing the requirements of direct conversion, passive human transduction or excited, localised acoustic `emitters'. Links to the Armagh Observatory All-sky meteor cameras, electrophonic meteor research and full construction plans for an extremely low frequency (ELF) receiver are also included.

  13. Thermal Plasma Flow During Plasmaspheric Erosion

    NASA Technical Reports Server (NTRS)

    Gallagher, D. L.

    2006-01-01

    Our picture of plasmaspheric erosion is dominated by a simple model of corotational and enhanced convective motion and by many decades of plasmapause boundary measurement. Observational evidence for the plasma motion that lowers the outer plasmaspheric boundary has largely been unavailable. A new analysis technique for the IMAGE Mission extreme ultraviolet imager (EUV) instrument now offers to reveal motion in the plasmaspheric boundary layer as enhanced global and meso-scale convection penetrates the quite-time plasmasphere. IMAGE EUV provides good global coverage of the striking plasmaspheric erosion that took place on July 10,2000. During this erosion event divergent flows in the vicinity of the plasmapause and centered initially near 2 hours MLT have been found. Over a period of about 1 hour the center of divergent flow drifts dawnward to almost 4 hours MLT. Plasma flows during this storm and others imaged by IMAGE EUV will be discussed along with their implication for the process of plasmaspheric erosion.

  14. The dayside of the plasmasphere.

    NASA Technical Reports Server (NTRS)

    Chappell, C. R.; Harris, K. K.; Sharp, G. W.

    1971-01-01

    The concentrations of H(+) ions in the dayside region of the plasmasphere, measured from March 1968 through February 1969 by the Lockheed light-ion mass spectrometer aboard the OGO 5 satellite, are presented and analyzed. The position of the plasmapause on the dayside appears to be determined by the level of magnetic activity present during the previous corotation of the dayside sector through the formative nightside region. Observations of the buildup of H(+) density versus local time following magnetic storms indicate that H(+) ions flow from the dayside ionosphere into the plasmasphere and plasma trough. Plasmapause density profiles in the afternoon-dusk sector show the effects of the dayside filling from the ionosphere. In addition, several of the dayside profiles display a steep drop in the H(+) density of about a factor of 10 inside the plasmapause position.

  15. Trapping waves in Earth's plasmasphere

    NASA Astrophysics Data System (ADS)

    Betz, Eric O.

    2014-12-01

    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.

  16. Modeling of the thermal plasma in the outer plasmasphere - A magnetospheric heat source

    NASA Technical Reports Server (NTRS)

    Chandler, M. O.; Kozyra, J. U.; Horwitz, J. L.; Comfort, R. H.; Brace, L. H.

    1988-01-01

    A case study has been carried out using data from the Dynamics Explorer 1 and 2 spacecraft to study the effect of Coulomb interactions between ring current and suprathermal O(+) and thermal protons on the plasmasphere. Results from a one-dimensional plasmaspheric model suggest that heating due to Coulomb collisions may be sufficient to raise the ion and electron temperatures to observed values. The resultant high temperature produced enhancements in the model O(+) and O(++) densities in agreement with observations.

  17. Whistlers observed outside the plasmasphere: Correlation to plasmaspheric/plasmapause features

    NASA Astrophysics Data System (ADS)

    Adrian, M. L.; Fung, S. F.; Gallagher, D. L.; Green, J. L.

    2015-09-01

    Whistlers observed outside the plasmasphere by Cluster have been correlated with the global plasmasphere using Imager for Magnetopause-to-Aurora Global Exploration-Extreme Ultraviolet Imager (IMAGE-EUV) observations. Of the 12 Cluster-observed whistler events reported, EUV is able to provide global imaging of the plasmasphere for every event and demonstrates a direct correlation between the detection of lightning-generated whistlers beyond the plasmapause and the presence of a global perturbation of the local plasmapause. Of these 12 correlated events, seven of the Cluster-observed whistlers (or 58%) are associated with the Cluster spacecraft lying radially outward from a plasmaspheric notch. Two of the Cluster-observed whistlers (17%) are associated with the low-density region between the late afternoon plasmapause and the western wall of a plasmaspheric drainage plume. The final three Cluster-observed whistler events (25%) are associated with a nonradial, nonazimuthal depletion in plasmaspheric He+ emission that are termed "notch-like" crenulations. In one of these cases, the notch-like crenulations appear to be manifestations entrained within the plasmasphere boundary layer of a standing wave on the surface of the plasmasphere. The correlated Cluster/IMAGE-EUV observations suggest that the depleted flux tubes that connect the ionosphere to the low-density regions of plasmaspheric trough and inner magnetosphere facilitate the escape of whistler waves from the plasmasphere.

  18. Allergenicity of the Madagascar hissing cockroach.

    PubMed

    Morgan, Marjorie S; Arlian, Larry G; Bernstein, Jonathan A; Yoder, Jay A

    2007-03-01

    The Madagascar hissing cockroach (Gromphadorhina portentosa) has become popular as a pet and as an educational tool in classrooms, zoos, and museums. To determine whether proteins in G. portentosa are allergens and whether these allergens cross-react with those of other cockroach species. Sera from cockroach-sensitive individuals and control subjects were used to probe immunoblots for the presence of circulating IgE that bound to proteins present in extracts of 4 cockroach species. Serum from an individual sensitized to G portentosa had circulating IgE that bound to proteins in extracts of all 4 cockroach species. Eight of 15 Blatella germanica-sensitized patients had IgE that bound to proteins in extracts prepared from G portentosa. Rabbit antiserum to Periplaneta americana and to Bla g 1 also contained antibody that bound to proteins in G. portentosa extract, demonstrating antigenic cross-reactivity among these cockroach species. Allergists, teachers, parents, and patients should be aware that sensitization and allergic reactions to the Madagascar hissing cockroach can occur. Caution should be taken if these exotic cockroaches are used in educational exercises in schools, museums, and zoos to protect predisposed individuals.

  19. Imagers for the magnetosphere, aurora, and plasmasphere (IMAP)

    NASA Astrophysics Data System (ADS)

    Frank, Louis A.; Williams, Donald J.; Roelof, Edmond C.

    1993-07-01

    We propose a small Explorer (SMEX) IMAP mission to provide the first global magnetospheric images that will allow a systematic study of major regions of the magnetosphere, their dynamics and their interactions. The mission objective is to obtain simultaneous images of the inner magnetosphere (ring current and trapped particles), the plasmasphere, the aurora, and auroral upflowing ions. The four IMAP instruments are (1) a Low Energy Neutral Particle Imager (LENPI) for imaging H and O atoms, separately, in the energy range of approximately 1 - 30 keV, in several energy passbands, (2) an Energetic Neutral Particle Imager (ENPI) for imaging H atoms in the energy range approximately 15 keV - 200 keV and, separately, O atoms in the energy range approximately 60 keV - 200 keV, each in several energy passbands, (3) an Extreme-Ultraviolet Imager (EUVI) to obtain images of the plasmasphere (the distribution of cold He(superscript +)) using He(superscript +) (30.4-nm) emissions; and (4) a Far-Ultraviolet Imaging Monochromator (FUVIM) to provide images of the aurora and the geocorona. All images will be obtained with time and spatial resolutions appropriate to the global and macroscale structures to be observed. The results expected from IMAP will provide the first large-scale visualization of the ring current, the trapped ion populations, the plasmasphere, and the upflowing auroral ion population.

  20. Statistical analysis of plasmaspheric EMIC waves

    NASA Astrophysics Data System (ADS)

    Kato, Y.; Miyoshi, Y.; Sakaguchi, K.; Kasahara, Y.; Keika, K.; Shoji, M.; Kitamura, N.; Hasegawa, S.; Kumamoto, A.; Shiokawa, K.

    2014-12-01

    Electromagnetic ion cyclotron (EMIC) waves in the inner magnetosphere are important since EMIC waves cause the pitch angle scattering of ring current ions as well as relativistic electrons of the radiation belts. Although the spatial distributions of EMIC waves have been investigated by several spacecraft such as CRRES, THEMIS and AMPTE/CCE, there have been little studies on plasmaspheric EMIC waves. We investigate statistically EMIC wave data using the Akebono/VLF measurements. The plasmaspheric EMIC waves tend to be distributed at lower L-shell region (L~2) than the slot region. There are no significant MLT dependences, which are different from the EMIC waves outside the plasmapause. The plasmaspheric EMIC wave frequencies depend on the equatorial cyclotron frequency, suggesting that the plasmaspheric EMIC waves are not propagated from high L-shell but generated near the equivalent L-shell magnetic equator. This result is consistent with the result of the dependence of resonance energy. Using the in-situ thermal plasma density measured by the Akebono satellite, we estimate the resonance energy of energetic ions, and the resonance energies of the plasmaspheric EMIC waves are few tens keV to ~ 1 MeV. The results indicate that the ring current and radiation belt ions may contribute the generation of the plasmaspheric EMIC waves.

  1. Plasmasphere Modeling with Ring Current Heating

    NASA Technical Reports Server (NTRS)

    Guiter, S. M.; Fok, M.-C.; Moore, T. E.

    1995-01-01

    Coulomb collisions between ring current ions and the thermal plasma in the plasmasphere will heat the plasmaspheric electrons and ions. During a storm such heating would lead to significant changes in the temperature and density of the thermal plasma. This was modeled using a time- dependent, one-stream hydrodynamic model for plasmaspheric flows, in which the model flux tube is connected to the ionosphere. The model simultaneously solves the coupled continuity, momentum, and energy equations of a two-ion (H(+) and O(+) quasineutral, currentless plasma. Heating rates due to collisions with ring current ions were calculated along the field line using a kinetic ring current model. First, diurnally reproducible results were found assuming only photoelectron heating of the thermal electrons. Then results were found with heating of the H(+) ions by the ring current during the recovery phase of a magnetic storm.

  2. Plasmasphere formation in arbitrarily oriented magnetospheres

    NASA Technical Reports Server (NTRS)

    Selesnick, R. S.; Richardson, J. D.

    1986-01-01

    The formation of plasmaspheres in planetary magnetospheres with arbitrary orientations of the rotation and magnetic dipole axes is investigated. A traditional plasmasphere with closed orbits inside the plasmapause and open trajectories outside it only occurs for the limiting case of aligned rotation and dipole axes. A time-variable plasmapause exists if the rotation axis is perpendicular to the solar win flow direction. In any other case, no definite plasmapause exists. Solar wind-driven convection transports plasma throughout the magnetosphere with an effectiveness which increases as the orientation goes further from one of the two limiting cases of strict plasmapause formation. The present analysis is applied to earth and Uranus using the actual orientations of the rotation and dipole axes. Particle trajectories at earth deviate only slightly from those obtained with traditional models. Uranus has no plasmasphere, and plasma convects sunwards throughout the inner magnetosphere.

  3. High Resolution Measurement of LF Auroral Hiss at South Pole

    NASA Astrophysics Data System (ADS)

    Ye, S.; Labelle, J.

    2005-05-01

    In December 2002, a Versatile Electromagnetic Wave Receiver (VIEW) and a new digitization system were deployed at South Pole station(-74° magnetic latitude). The motivation was to measure three types of auroral radio emissions: Auroral Roar, a relatively narrowband (δf/f<0.1) emission near 2 and 3 times the F region ionospheric electron cyclotron frequency (fce); Auroral Hiss, a whistler mode wave emission with frequencies lower than 1MHz; and Auroral medium frequency (MF) burst, broadband impulsive radio emissions observed at ground level during the breakup phase of auroral substorms. High resolution broad band structure of those three emissions are recorded automatically at South Pole, and are crucial to our understanding the mechanism and relations of auroral radio emissions. This experiment uses a 3×3 meter square magnetic dipole antenna, located 1.7 km away from the South Pole station. A pre-amplifier is buried right below the eastern pylon of the antenna, connected by a 1.7 km long co-axial cable to a LF-HF receiver in the station. The output of the receiver is fed into the Versatile Electromagnetic Wave Receiver (VIEW) and Windows system equipped with a digitization board. Customed software was used to digitize the selected signals at 1-2 MHz. This data acquisition system was designed so that researchers at Dartmouth College can review the data from South Pole weekly and save interesting parts according to instructions sent from Dartmouth. In the year of 2004(from Jan through September), the experiment concentrated on the auroral hiss frequency band, covering either 0-500 kHz or 0-1000 kHz. With 3-6 hours window per day, VIEW captured more than 30 GBytes data of auroral hiss waveforms. Many experiments report wave forms of VLF auroral hiss at f < 30 kHz. We focused on waveforms of LF auroral hiss, typically at 100-300 kHz. At these frequencies, the hiss shows striking fine structure. We classified our LF hiss events into three different types: standard

  4. Refilling the plasmasphere through the exospheric sieve

    NASA Astrophysics Data System (ADS)

    Krall, J.; Huba, J.; Emmert, J. T.

    2016-12-01

    The ability to compute plasmasphere densities is critical to many space weather concerns. The sensitivity of refilling to the solar cycle is compelling because, paradoxically, refilling rates are generally lowest when the ionosphere is strongest. In the past, this has been attributed to a dearth of exosphere H at solar maximum. While H is needed to supply H + O+ -> H+ + O charge exchange, recent work demonstrates a significant sensitivity to O [1]. Results will be based on preliminary model-data comparisons using in situ Van Allen Probe EMFISIS data and the SAMI3 ionosphere/plasmasphere code. We will assess the impact of atmospheric composition (i.e., O and H) and solar activity (e.g., F10.7) on plasmasphere refilling rates and density following magnetic storms. SAMI3 (Sami3 is Also a Model of the Ionosphere) is a first-principles ionosphere/plasmasphere model. SAMI3 includes 7 ion species (H+, He+, O+, N+, O2+, N2+, NO+), each treated as a separate fluid, with temperature equations being solved for H+, He+, O+ and e- [2]. SAMI3 uses the empirical MSIS thermosphere/exosphere model to specify O and H densities. SAMI3 includes scaling factors that can be used to tune MSIS densities to bring them in line with measurements of satellite drag. Key inputs for this data-driven modeling are the thermosphere oxygen (O) and hydrogen (H) densities, and the F10.7 proxy for solar ultraviolet irradiance. [1 ]Krall, J., J. T. Emmert, F. Sassi, S. E. McDonald, and J. D. Huba (2016), Day-to-day variability in the thermosphere and its impact on plasmasphere refilling, J. Geophys. Res. Space Physics, 121, doi:10.1002/2015JA022328. [2] Huba, J. and J. Krall (2013), Modeling the plasmasphere with SAMI3, Geophys. Res. Lett., 40, 6-10, doi:10.1029/2012GL054300 Research supported by NRL base funds.

  5. Image RPI Reawakens Plasmaspheric Refilling Research

    NASA Technical Reports Server (NTRS)

    Gallagher, D. L.; Smith, Z. B.

    2007-01-01

    The plasmasphere is a toroidal region of cold plasma surrounding the Earth that results from ionospheric outflow and accumulation. The physics of refilling and the dynamics of this region have been studied for nearly 50-years. During that time many models have been proposed, but little has been done to test these models due to a lack of observational information. With the launch of the IMAGE Mission in March 2000 the Radio Plasma Imager has provided true field aligned density measurements that uniquely enable the testing of these models and a final determination of the physical processes important for the plasmasphere's recovery from storm-time conditions.

  6. The Plasmasphere as "Seen" by the IMAGE Mission

    NASA Technical Reports Server (NTRS)

    Gallagher, D. L.; Green, J. L.; Fung, S. F.; Benson, R. F.; Sandel, B. R.; Carpenter, D. L.

    1999-01-01

    The Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) is the first mission designed exclusively to remotely measure the magnetosphere. As such, it will reveal the ring current, plasmasphere, polar cusp, and magnetopause as whole extended, interacting systems. For the first time, our impressions of the global magnetosphere, synthesized through many years of whistler and in situ measurement, will be replaced by images. The overall morphology of each system of plasma and the correspondence of changes between them in response to the sun and solar wind will become available. The Extreme Ultraviolet Imager (EUV) and the Radio Plasma Imager (RPI) are the two IMAGE instruments which will remotely measure and image the plasmasphere. What we expect to "see" from these instruments and how it may be interpreted is the subject of this presentation. The EUV instrument includes three optical cameras, with an almost 90 degree field of view, transverse to the spin axis. EUV is designed to see He+ ions in resonantly scatter solar light at 30.4rim. The IMAGE spacecraft will spin with a period of about 2 minutes, with its spin axis parallel to the orbit normal. The IMAGE orbit will be highly inclined, with a high latitude apogee at a geocentric distance of 8RE and perigee of about 1.2RE. The normal observing integration time of 10 minutes will easily see to the outer edge of the plasmasphere. The RPI instrument makes use of three orthoganal dipole antennas: two in the spin plane with a tip-to-tip length of 500m and one along the spin axis with a length of 20 meters. Using coded pulse transmissions, the RPI instrument will broadcast from 3kHz to 3MHz. With one minute resolution, plasma densities from about 0.1 cm(exp -3) to 100,000 cm(exp -3), along with line-of-sight bulk velocities and locations, will be obtained from all returned radio wave signals. When transmitting from the high latitude magnetospheric cavity, RPI will measure density profiles for the major plasma

  7. Analysis of Simultaneous Hiss and Chorus Ground & In Situ Observations

    NASA Astrophysics Data System (ADS)

    Hosseini, P.; Golkowski, M.

    2016-12-01

    The dynamic evolution of the radiation belts is believed to be controlled in large part by two separate but related classes of naturally occurring plasma waves: ELF/VLF chorus and hiss emissions. These waves can be observed both in situ on spacecraft and at ground-based stations. Recent observational and theoretical works suggest that high resolution analysis of the spectral features of both hiss and chorus emissions can provide insight into generation processes and be used to validate existing theories. However, ground observation are limited to the portion of magnetospheric waves that are able to propagate to low altitudes and penetrate through the ionosphere. The whistler mode wave is intrinsically right hand circularly polarized (RHCP) in the magnetosphere, and becomes more linear with increased propagation distance in the Earth-ionosphere waveguide. We use wave polarization to differentiate magnetospheric and ionospheric effects in ground based observations. Observations are compared to simulations using the finite difference time domain method to track the effect of propagation in the Earth-ionosphere waveguide on polarization. Ionospheric exit point of the emissions, have been further determined by calculating the angle of arrival, which shows a rotation of exit points along with transition of hiss to chorus emissions. Simultaneous THEMIS spacecraft data have been investigated and show agreement with the observed transitions in our ground based observations. The plasmapause is seen to erode and density structures develop, providing insight into the relationship of chorus and hiss and the plasmapause boundary.

  8. Plasmaspheric Structures Observed by the CLUSTER and IMAGE Spacecraft

    NASA Technical Reports Server (NTRS)

    Fung, S. F.; Adrian, M. L.; Benson, R. F.; Garcia, L. N.; Goldstein, M. L.; Sandel, B.

    2008-01-01

    Global EUV imaging observations by the IMAGE satellite have revealed spectacularly complex changes in plasmaspheric structures as the plasmaspheric plasmas respond to geomagnetic activity while remaining under varying degrees of influence by co-rotation, depending on the radial distance. This complex plasmaspheric plasma dynamics, with its numerous scales of variability, is clearly far from being well understood. There is now renewed interest in studying the plasmasphere due to its apparent connections with the development of the ring current and radiation belt and loss of ionospheric plasmas. Earlier in the mission, the Cluster spacecraft only crossed the plasmapause (L - 4) occasionally and made measurements of the cold plasma in the plasmasphere and plasmaspheric drainage plumes. The study by Darrouzet et al. [2006], for example, provided detailed analyses of in situ Cluster observations and IMAGE EUV imaging observations of three plasmaspheric plumes detected in April-June, 2002. Within the next couple of years, Cluster orbit will change, causing perigee to migrate to lower altitudes, and thus providing excellent opportunities to obtain more detailed measurements of the plasmasphere. In this paper, we report our analyses of the earlier Cluster-IMAGE events by incorporating the different perspectives provided by the IMAGE Radio Plasma Imager (RPI) observations through the plasmasphere. We will describe our new understanding of the Cluster-IMAGE events and their implications on plasmaspheric dynamics.

  9. A new dynamic fluid-kinetic model for plasma transport in the plasmasphere

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Tu, J.; Song, P.

    2014-12-01

    A new dynamic fluid-kinetic (DyFK) model is developed for investigating the plasma transport along a closed flux tube in the plasmasphere by coupling a truncated version of the field line interhemispheric plasma (FLIP) model at altitudes below 800 km and a generalized semi-kinetic (GSK) model above it with an overlapped boundary region (800 km-1100 km) in both hemispheres. The flux tube is allowed to move both radially away from the Earth and azimuthally around the Earth. Ion species O+ and He+ are for the first time treated as simulation particles in a numerical model for the plasmasphere. The simulation particles are subjected to the parallel electric field, magnetic mirror force, gravity, centrifugal force and Coulomb collisions, as well as possible wave-particle interaction. The effects of ionosphere-plasmasphere coupling on the day-night evolution of the plasmasphere and the relative abundance of O+ and He+ are studied. Simulations are also conducted to investigate the influence of wave-particle interaction on the field-aligned density distributions of ions (O+/ H+/ He+) and their velocity distributions.

  10. Erosion and refilling of the plasmasphere studied by neural network based three-dimensional plasmaspheric model

    NASA Astrophysics Data System (ADS)

    Chu, X.; Bortnik, J.; Li, W.; Angelopoulos, V.; Thorne, R. M.; Denton, R. E.; Menietti, J. D.; Wang, Y.

    2016-12-01

    We developed a time-dependent global plasma density model of the inner magnetosphere which uses a feedforward neural network schema with two hidden layers. As the model output, we used the electron density inferred from spacecraft potential from three THEMIS probes. As the model inputs, we took the spacecraft location (L, magnetic local time and latitude), and time series of the SYM-H, AL and F10.7 indices. The equatorial electron density is shown to be accurately reconstructed with a correlation of r 0.953 between model output and observations. The model succeeded in reconstructing the distribution and dynamics of the density, including the quiet time plasmasphere, erosion and recovery of the plasmasphere, as well as the plume formation during a storm on February 04, 2011. The model also reproduced the contraction and recovery of the plasmapause for the same event. The neural network based plasmaspheric model is then expanded to three dimensions by including more observations from both equatorial satellites and polar orbiting satellites (RBSP, CRRES, ISEE, CLUSTER, POLAR, IMAGE). We maintain the same architecture of the neural network model (two hidden layers) and the model inputs (location and time series of SYM-H, AL and F10.7 indices). The three-dimensional plasmaspheric model can reproduce almost 90% of the variation in the plasma density with a correlation of r 0.943. Using the three-dimensional plasmaspheric model, we reconstruct a time-dependent three-dimensional plasmasphere. The latitudinal profile of the plasma density is compared with those profiles from previous study. In addition, we show the evolution (erosion and refilling and plume formation) of the plasmasphere during geomagnetic storms in a three-dimensional perspective.

  11. Driving Plasmaspheric Electron Density Simulations During Geomagnetic Storms

    NASA Astrophysics Data System (ADS)

    De Pascuale, S.; Kletzing, C.; Jordanova, V.; Goldstein, J.; Wygant, J. R.; Thaller, S. A.

    2015-12-01

    We test global convection electric field models driving plasmaspheric electron density simulations (RAM-CPL) during geomagnetic storms with in situ measurements provided by the Van Allen Probes (RBSP). RAM-CPL is the cold plasma component of the ring-current atmosphere interactions suite (RAM-SCB) and describes the evolution of plasma density in the magnetic equatorial plane near Earth. Geomagnetic events observed by the RBSP satellites in different magnetic local time (MLT) sectors enable a comparison of local asymmetries in the input electric field and output densities of these simulations. Using a fluid MHD approach, RAM-CPL reproduces core plasmaspheric densities (L<4) to less than 1 order of magnitude difference. Approximately 80% of plasmapause crossings, defined by a low-density threshold, are reproduced to within a mean radial difference of 0.6 L. RAM-CPL, in conjunction with a best-fit driver, can be used in other studies as an asset to predict density conditions in locations distant from RBSP orbits of interest.

  12. Modeling the plasmasphere based on LEO satellites onboard GPS measurements

    NASA Astrophysics Data System (ADS)

    Chen, Peng; Yao, Yibin; Li, Qinzheng; Yao, Wanqiang

    2017-01-01

    The plasmasphere, which is located above the ionosphere, is a significant component of Earth's atmosphere. A global plasmaspheric model was constructed using the total electron content (TEC) along the signal propagation path calculated using onboard Global Positioning System observations from the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) and MetOp-A, provided by the COSMIC Data Analysis and Archive Center (CDAAC). First, the global plasmaspheric model was established using only COSMIC TEC, and a set of MetOp-A TEC provided by CDAAC served for external evaluation. Results indicated that the established model using only COSMIC data is highly accurate. Then, COSMIC and MetOp-A TEC were combined to produce a new global plasmaspheric model. Finally, the variational characteristics of global plasmaspheric electron content with latitude, local time, and season were investigated using the global plasmaspheric model established in this paper.

  13. Dual-spacecraft measurements of plasmasphere-ionosphere coupling

    NASA Technical Reports Server (NTRS)

    Horwitz, J. L.; Comfort, R. H.; Brace, L. H.; Chappell, C. R.

    1986-01-01

    An extensive set of plasmaspheric measurements by the DE 1 satellite and ionospheric measurements by the DE 2 satellite are presented. The developments in the ionosphere and plasmasphere during the recovery phase of a magnetospheric storm are described. Isolated profile comparisons are used to indicate some of the structural relations and complexities involving the ionosphere and plasmasphere latitudinal profiles. A transition in the ionospheric electron temperature Te from a relatively smooth profile of low Te at the base of the inner plasmasphere to enhanced and highly structured Te at higher invariant latitudes occurs near or along a plasmaspheric density gradient. Plasmaspheric enhancements of the heavy ions O(+) and O(2+) are often closely aligned with distinct ionospheric Te enhancements.

  14. The Role of Instabilities in Plasmaspheric Heating, Flux Tube Refilling, and the Development of Spatial Structures

    NASA Technical Reports Server (NTRS)

    Gallagher, D. L.; Khazanov, G. V.

    1999-01-01

    Plasma instabilities appear to play an important role in plasmasphere dynamics. Direct interactions between the plasmasphere and other plasma populations lead to energy transfer and heating, to equatorial trapping, and to changes in ionospheric outflow. Super-thermal electron and ring current populations are the dominant sources of energy for these processes. Flute (Interchange), electromagnetic lower-hybrid drift, and E x B drift instabilities can also play important roles in the distribution of thermal, plasmaspheric plasma. As our attention has returned to the remaining plasmaspheric mysteries, it has become clear that the details of plasmaspause formation and erosion and the development of localized, dense thermal plasma structures are almost completely unexplained. Radially sharp density depletions and generalized density loss are seen inside the plasmapause. Narrow and extended regions of enhanced thermal plasma density is found throughout the magnetosphere, even after extended periods of quite geomagnetic conditions. Sharp gradients are often seen on the westward edge of density enhancements, while eastward boundaries are often highly structured.

  15. What is Missing in the Modern Plasmaspheric Studies?

    NASA Astrophysics Data System (ADS)

    Khazanov, G. V.

    2015-12-01

    The inner magnetosphere space environment, where the plasmasphere is located, is a fundamentally complex system with energy flowing between its different plasma components and waves. The energy that enters that system from the Sun, are processed and redistributed through the magnetospheric regions before it either leaves the system or is finally deposited in the ionosphere-plasmasphere region. Understanding how the energy flows, get processed, redistributed, and deposited to the plasmasphere throughout the fully coupled system is a central question of fundamental importance that is missing in all modern plasmaspheric studies, and will be presented in this talk.

  16. Image-Based Empirical Modeling of the Plasmasphere

    NASA Technical Reports Server (NTRS)

    Adrian, Mark L.; Gallagher, D. L.

    2008-01-01

    A new suite of empirical models of plasmaspheric plasma based on remote, global images from the IMAGE EUV instrument is proposed for development. The purpose of these empirical models is to establish the statistical properties of the plasmasphere as a function of conditions. This suite of models will mark the first time the plasmaspheric plume is included in an empirical model. Development of these empirical plasmaspheric models will support synoptic studies (such as for wave propagation and growth, energetic particle loss through collisions and dust transport as influenced by charging) and serves as a benchmark against which physical models can be tested. The ability to know that a specific global density distribution occurs in response to specific magnetospheric and solar wind factors is a huge advantage over all previous in-situ based empirical models. The consequence of creating these new plasmaspheric models will be to provide much higher fidelity and much richer quantitative descriptions of the statistical properties of plasmaspheric plasma in the inner magnetosphere, whether that plasma is in the main body of the plasmasphere, nearby during recovery or in the plasmaspheric plume. Model products to be presented include statistical probabilities for being in the plasmasphere, near thermal He+ density boundaries and the complexity of its spatial structure.

  17. Image-Based Empirical Modeling of the Plasmasphere

    NASA Technical Reports Server (NTRS)

    Adrian, Mark L.; Gallagher, D. L.

    2008-01-01

    A new suite of empirical models of plasmaspheric plasma based on remote, global images from the IMAGE EUV instrument is proposed for development. The purpose of these empirical models is to establish the statistical properties of the plasmasphere as a function of conditions. This suite of models will mark the first time the plasmaspheric plume is included in an empirical model. Development of these empirical plasmaspheric models will support synoptic studies (such as for wave propagation and growth, energetic particle loss through collisions and dust transport as influenced by charging) and serves as a benchmark against which physical models can be tested. The ability to know that a specific global density distribution occurs in response to specific magnetospheric and solar wind factors is a huge advantage over all previous in-situ based empirical models. The consequence of creating these new plasmaspheric models will be to provide much higher fidelity and much richer quantitative descriptions of the statistical properties of plasmaspheric plasma in the inner magnetosphere, whether that plasma is in the main body of the plasmasphere, nearby during recovery or in the plasmaspheric plume. Model products to be presented include statistical probabilities for being in the plasmasphere, near thermal He+ density boundaries and the complexity of its spatial structure.

  18. The fate of the outer plasmasphere

    SciTech Connect

    Elphic, R.C.; Thomsen, M.F.; Borovsky, J.E.

    1997-02-01

    Both the solar wind and the ionosphere contribute to Earth{close_quote}s magnetospheric plasma environment. However, it is not widely appreciated that the plasmasphere is a large reservoir of ionospheric ions that can be tapped to populate the plasma sheet. We employ empirical models of high-latitude ionospheric convection and the geomagnetic field to describe the transport of outer plasmasphere flux tubes from the dayside, over the polar cap and into the magnetotail during the early phases of a geomagnetic storm. We calculate that this process can give rise to high densities of cold plasma in the magnetotail lobes and in the near-Earth plasma sheet during times of enhanced geomagnetic activity, and especially during storms. This model can help explain both polar cap ionization patches and the presence of cold flowing ions downtail.{copyright} 1997 American Geophysical Union

  19. IMAGE RPI Reawakens Plasmaspheric Refilling Research

    NASA Astrophysics Data System (ADS)

    Smith, Z. B.; Gallagher, D. L.

    2008-02-01

    Plasmaspheric refilling has received increased attention in recent years following the introduction of the introduction of innovate sensors. ``Global'' observations and single flux-tube density observations made by sensors onboard the IMAGE satellite provide data crucial to the deconfliction of previous model's refilling results. This review will serve to highlight the observational and modeling progress since the late 1950s as well as to place in context the progress to be made using the data from IMAGE, specifically the Radio Plasma Imager.

  20. Plasmaspheric Plumes Observed by the CLUSTER and IMAGE Spacecraft

    NASA Technical Reports Server (NTRS)

    Fung, S. F.; Benson, R. F.; Garcia, L. N.; Adrian, M. L.; Sandel, B.; Goldstein, M. L.

    2008-01-01

    Global IMAGE/EUV observations have revealed complex changes in plasmaspheric structures as the plasmasphere responds to geomagnetic activity while remaining under varying degrees of influence by co-rotation, depending on the radial distance. The complex plasmaspheric dynamics, with different scales of variability, is clearly far from being well understood. There is now renewed interest in the plasmasphere due to its apparent connections with the development of the ring current and radiation belt, and loss of ionospheric plasmas. Early in the mission, the Cluster spacecraft only crossed the plasmapause (L - 4) occasionally and made measurements of the outer plasmasphere and plasmaspheric drainage plumes. The study by Darrouzet et al. [2006] provided detailed analyses of in situ Cluster observations and IMAGE EUV observations of three plasmaspheric plumes detected in April-June, 2002. Within the next couple of years, Cluster orbit will change, causing perigee to migrate to lower altitudes, and thus providing excellent opportunities to obtain more detailed measurements of the plasmasphere. In this paper, we report our analyses of the earlier Cluster-IMAGE events by incorporating the different perspectives provided by the IMAGE Radio Plasma Imager (RPI) observations. We will discuss our new understanding of the structure and dynamics of the Cluster-IMAGE events.

  1. Statistical study of enhanced ion fluxes in the outer plasmasphere

    NASA Astrophysics Data System (ADS)

    Menietti, J. D.; Burch, J. L.; Williams, R. L.; Gallagher, D. L.; Waite, J. H., Jr.

    Statistical studies of outer plasmaspheric ions in the northern hemisphere have been made utilizing the High Altitude Plasma Instrument (HAPI) on board the Dynamics Explorer-1 satellite. The data were collected during equinox and winter seasons and during a period of solar maximum activity conditions. The data include approximately 40 dayside and over 50 nightside plasmaspheric passes covering a range of magnetic activities (0 < Kp < 7). A total of six magnetic storms and recovery periods and a number of quiet times are included in the sampling. The range of magnetic local times on the dayside is from about 6 hours to 12 hours, while the nightside range is from about 18 hours to 23 hours. Our results indicate a clear enhancement in the low energy (5 eV < E < 30 eV) number flux during periods of large magnetic activity in both the dayside and nightside outer plasmasphere (the inner plasmasphere was not observed). The dayside plasmaspheric fluxes were predominately upward (anti-parallel to B¯) while the nightside plasmaspheric fluxes were predominately downward (parallel to B¯). The net number fluxes sometimes reached a value of over 108cm sec-1 (assuming H+ as the predominate species). The largest flows up the field line occur in the outer plasmasphere and decrease in the plasma trough. The ion temperatures in the outer plasmasphere were typically lower than those in the plasma trough and auroral regions. Since the largest flows both parallel and anti-parallel to B¯ are observed at periods of high magnetic activity, enhanced outer plasmaspheric fluxes may be due to ionospheric ions expanding into depleted plasmaspheric flux tubes. The nightside fluxes may be due to expansion of the ionosphere in the magnetic conjugate hemisphere.

  2. The Sound and the Fury—Bees Hiss when Expecting Danger

    PubMed Central

    Galizia, C. Giovanni

    2015-01-01

    Honey bees are important model systems for the investigation of learning and memory and for a better understanding of the neuronal basics of brain function. Honey bees also possess a rich repertoire of tones and sounds, from queen piping and quacking to worker hissing and buzzing. In this study, we tested whether the worker bees’ sounds can be used as a measure of learning. We therefore conditioned honey bees aversively to odours in a walking arena and recorded both their sound production and their movement. Bees were presented with two odours, one of which was paired with an electric shock. Initially, the bees did not produce any sound upon odour presentation, but responded to the electric shock with a strong hissing response. After learning, many bees hissed at the presentation of the learned odour, while fewer bees hissed upon presentation of another odour. We also found that hissing and movement away from the conditioned odour are independent behaviours that can co-occur but do not necessarily do so. Our data suggest that hissing can be used as a readout for learning after olfactory conditioning, but that there are large individual differences between bees concerning their hissing reaction. The basis for this variability and the possible ecological relevance of the bees’ hissing remain to be investigated. PMID:25747702

  3. Chow Down! Using Madagascar Hissing Cockroaches to Explore Basic Nutrition Concepts

    ERIC Educational Resources Information Center

    Wagler, Ron

    2009-01-01

    The Madagascar hissing cockroach ("Gromphadorhina portentosa") is one of the most exciting and enjoyable animals to incorporate into your science curriculum. Madagascar hissing cockroaches (MHCs) do not bite, are easy to handle, produce little odor compared to many terrarium animals, have a fascinating social structure, are easy to breed, teach…

  4. Chow Down! Using Madagascar Hissing Cockroaches to Explore Basic Nutrition Concepts

    ERIC Educational Resources Information Center

    Wagler, Ron

    2009-01-01

    The Madagascar hissing cockroach ("Gromphadorhina portentosa") is one of the most exciting and enjoyable animals to incorporate into your science curriculum. Madagascar hissing cockroaches (MHCs) do not bite, are easy to handle, produce little odor compared to many terrarium animals, have a fascinating social structure, are easy to breed, teach…

  5. The sound and the fury--bees hiss when expecting danger.

    PubMed

    Wehmann, Henja-Niniane; Gustav, David; Kirkerud, Nicholas H; Galizia, C Giovanni

    2015-01-01

    Honey bees are important model systems for the investigation of learning and memory and for a better understanding of the neuronal basics of brain function. Honey bees also possess a rich repertoire of tones and sounds, from queen piping and quacking to worker hissing and buzzing. In this study, we tested whether the worker bees' sounds can be used as a measure of learning. We therefore conditioned honey bees aversively to odours in a walking arena and recorded both their sound production and their movement. Bees were presented with two odours, one of which was paired with an electric shock. Initially, the bees did not produce any sound upon odour presentation, but responded to the electric shock with a strong hissing response. After learning, many bees hissed at the presentation of the learned odour, while fewer bees hissed upon presentation of another odour. We also found that hissing and movement away from the conditioned odour are independent behaviours that can co-occur but do not necessarily do so. Our data suggest that hissing can be used as a readout for learning after olfactory conditioning, but that there are large individual differences between bees concerning their hissing reaction. The basis for this variability and the possible ecological relevance of the bees' hissing remain to be investigated.

  6. Density Irregularities Inside the Plasmasphere: Cluster Observations

    NASA Technical Reports Server (NTRS)

    Darrouzet, F.; Lemaire, J. F.; Decreau, P. M. E.; DeKeyser, J.; Masson, A.; Gallagher, D. L.; Santolik, O.; Trotignon, J. G.; Rauch, J. L.; LeGuirriec, E.

    2003-01-01

    The electron density profiles derived from the EFW and WHISPER instruments onboard the four Cluster spacecraft reveal small-scale density irregularities inside the plasmasphere and at its outer boundary, the plasmapause. We review statistics of the plasmapause position and thickness, as well as statistics of these density structures. We focus on a particular plasmasphere crossing on 11 April 2002, with several density irregularities, as well as two plasma tails, observed by Cluster on the legs of the inbound and outbound passes. We derive the density gradient vectors from simultaneous density measurements by the four spacecraft. We determine also the normal velocity of the surface of these irregularities, assuming they are planar boundaries, from the time delays between density structures in the four individual density profiles. These new observations yield novel insights about (1) the dimensions of plasma irregularities across and parallel to magnetic field lines, (2) the dynamics of these small-scale structures, (3) their bulk velocities, and (4) their position and distribution as a function of the magnetic local time (MLT) and the geomagnetic conditions (as determined by Kp).

  7. A New Global Core Plasma Model of the Plasmasphere

    NASA Technical Reports Server (NTRS)

    Gallagher, D. L.; Comfort, R. H.; Craven, P. D.

    2014-01-01

    The Global Core Plasma Model (GCPM) is the first empirical model for thermal inner magnetospheric plasma designed to integrate previous models and observations into a continuous in value and gradient representation of typical total densities. New information about the plasmasphere, in particular, makes possible significant improvement. The IMAGE Mission Radio Plasma Imager (RPI) has obtained the first observations of total plasma densities along magnetic field lines in the plasmasphere and polar cap. Dynamics Explorer 1 Retarding Ion Mass Spectrometer (RIMS) has provided densities in temperatures in the plasmasphere for 5 ion species. These and other works enable a new more detailed empirical model of thermal in the inner magnetosphere that will be presented.

  8. Strange VLF bursts in northern Scandinavia: case study of the afternoon "mushroom-like" hiss on 8 December 2013

    NASA Astrophysics Data System (ADS)

    Manninen, J.; Kleimenova, N. G.; Kozlovsky, A.; Kornilov, I. A.; Gromova, L. I.; Fedorenko, Y. V.; Turunen, T.

    2015-08-01

    We investigate a non-typical very low frequency (VLF) 1-4 kHz hiss representing a sequence of separated noise bursts with a strange "mushroom-like" shape in the frequency-time domain, each one lasting several minutes. These strange afternoon VLF emissions were recorded at Kannuslehto (KAN, ϕ = 67.74° N, λ = 26.27° E; L ∼ 5.5) in northern Finland during the late recovery phase of the small magnetic storm on 8 December 2013. The left-hand (LH) polarized 2-3 kHz "mushroom caps" were clearly separated from the right-hand (RH) polarized "mushroom stems" at the frequency of about 1.8-1.9 kHz, which could match the lower ionosphere waveguide cutoff (the first transverse resonance of the Earth-ionosphere cavity). We hypothesize that this VLF burst sequence could be a result of the modulation of the VLF hiss electron-cyclotron instability from the strong Pc5 geomagnetic pulsations observed simultaneously at ground-based stations as well as in the inner magnetosphere by the Time History of Events and Macroscale Interactions during Substorms mission probe (THEMIS-E; ThE). This assumption is confirmed by a similar modulation of the intensity of the energetic (1-10 keV) electrons simultaneously observed by the same ThE spacecraft. In addition, the data of the European Incoherent Scatter Scientific Association (EISCAT) radar at Tromsø show a similar quasi-periodicity in the ratio of the Hall-to-Pedersen conductance, which may be used as a proxy for the energetic particle precipitation enhancement. Our findings suggest that this strange mushroom-like shape of the considered VLF hiss could be a combined mutual effect of the magnetospheric ULF-VLF (ultra low frequency-very low frequency) wave interaction and the ionosphere waveguide propagation.

  9. Statistics of auroral hiss and relationship to auroral boundaries and upward current regions

    NASA Astrophysics Data System (ADS)

    Spasojevic, M.

    2016-08-01

    An 8 year database of VLF auroral hiss observations from South Pole station (invariant latitude of -74° with magnetic local time (MLT) = UT -3.5 h) is analyzed. There are three peaks in hiss occurrence as a function of MLT in the evening sector (19-23 MLT), afternoon sector (13-17 MLT), and morning sector (7-11 MLT). The geomagnetic and interplanetary magnetic field (IMF) drivers of hiss are examined in the three MLT sectors, and the results are interpreted using an empirical model of auroral boundaries and an empirical model of field-aligned current patterns. Auroral hiss on the dayside occurs when the auroral oval is centered near the latitude of the station, and in the afternoon sector higher disturbance levels are required. The afternoon sector favors positive By when Bz is positive and negative By when Bz is strongly negative, while the morning sector favors the complementary conditions. In each case the preference for hiss occurrence follows the pattern of upward field-aligned currents, and hiss is more likely in the configuration where the peak in the upward current is closer to the latitude of the station. IMF By does not play a role on the nightside where hiss is most likely to occur during moderately weak driving conditions as higher disturbance levels are expected to move the auroral oval and upward current systems to latitudes well equatorward of South Pole.

  10. Radio interferometer measurements of plasmasphere density structures during geomagnetic storms

    SciTech Connect

    Hoogeveen, G.W.; Jacobson, A.R.

    1997-07-01

    The Los Alamos plasmaspheric drift radio interferometer is a ground-based array that regularly measures periodic disturbances in the plasmasphere. These plasmaspheric density structures have been shown to depend on geomagnetic activity, as indicated by Kp. However, a direct storm time analysis of their behavior has not been done. This paper studies the amplitude, drift velocity, and location of these structures before, during, and after the onset of major geomagnetic storms. Distinct large-amplitude, storm time signatures are found during the first night after onset, continuing through the third night; there were significantly more storm time signatures during nighttime than daytime. The L shells on which the disturbances existed were found to decrease after storm onset, indicating a possible shrinking of the plasmasphere.{copyright} 1997 American Geophysical Union

  11. Ionospheric signatures of a plasmaspheric plume over Europe

    NASA Astrophysics Data System (ADS)

    Yizengaw, Endawoke; Moldwin, Mark B.; Galvan, David A.

    2006-09-01

    Previously, ionospheric signatures of plasmaspheric plumes were reported only at the North American longitude sector. This led to the hypothesis that the geomagnetic field configuration at those longitudes played a vital role in the observation of plasmaspheric plume signatures only over the American continent. Combining ground-based GPS total electron content (TEC), EISCAT incoherent scattering radar (ISR), and DMSP F15 ion drift meter observations we have observed greatly elevated density over the European continent during storm recovery phase on 12 September 2005. The TEC seen over Europe has a tongue of enhanced ionization extending to higher latitudes, which is identical to the plasmaspheric plume signatures that have been often observed over North America. Therefore, our observations clearly demonstrate that ionospheric signatures of plasmaspheric plumes are not limited to the North American sector and suggest that they may be observed at any longitude as long as a dense array of instruments are available to identify these signatures.

  12. The Plasmaspheric Plume and Magnetopause Reconnection

    NASA Technical Reports Server (NTRS)

    Walsh, B. M.; Phan, T. D.; Sibeck, D. G.; Souza, V. M.

    2014-01-01

    We present near-simultaneous measurements from two THEMIS spacecraft at the dayside magnetopause with a 1.5 h separation in local time. One spacecraft observes a high-density plasmaspheric plume while the other does not. Both spacecraft observe signatures of magnetic reconnection, providing a test for the changes to reconnection in local time along the magnetopause as well as the impact of high densities on the reconnection process. When the plume is present and the magnetospheric density exceeds that in the magnetosheath, the reconnection jet velocity decreases, the density within the jet increases, and the location of the faster jet is primarily on field lines with magnetosheath orientation. Slower jet velocities indicate that reconnection is occurring less efficiently. In the localized region where the plume contacts the magnetopause, the high-density plume may impede the solar wind-magnetosphere coupling by mass loading the reconnection site.

  13. Origin and Evolution of Deep Plasmaspheric Notches

    NASA Technical Reports Server (NTRS)

    Gallagher, D. L.; Adrian, M. L.; Liemohn, M. W.

    2005-01-01

    Deep plasmaspheric notches can extend over more than 2 R(sub E) in radial distance and 3 hours MLT in the magnetic equatorial plane, as observed by the extreme ultraviolet (EUV) imager on the IMAGE mission. They are among the largest evacuated features in the exterior plasmaspheric boundary. They can last for days and exhibit a variety of shapes. It appears that weak convection and limited erosion precedes notch formation at the westward, near-Earth edge of the convection plume. Eighteen clear notch events were found and analyzed in 2000. Among these events, notches were found to drift as slowly as 44% of corotation. In only one case was a notch found to drift at the corotation rate within measurement error. On average, these notches drift at about 21.5 h d(sup -1) or 90% of the corotational rate. Notches sometimes exhibit an interior structure that appears as an extended prominence of dense plasma, which forms a W- or M-like feature in IMAGE/EUV images, depending on viewing perspective. Initial modeling suggests that notches and notch prominences may be caused in part by intense small-scale potential structures that result from the localized injection of ring current plasma. Plasma filling rates during recovery are examined in three L shell ranges from L = 2 to L = 3.5 with rates ranging from 5 to 140 cm(sup -3) d(sup -1). Plasma loss during a minor substorm is found to extend to surprisingly low L shell with rates ranging from 100 to 130 cm(sup -3) d(sup -1) across the L shells examined.

  14. The Influence of the Solar Cycle on Plasmasphere Refilling

    NASA Astrophysics Data System (ADS)

    Krall, J.; Huba, J.

    2015-12-01

    During refilling, ionospheric plasma streams into the inner magnetosphere from both the northern and southern hemispheres. Plasmasphere refilling rates depend on both the ionospheric sources and on the thermalization of streaming ions. We use the NRL SAMI3 ionosphere/plasmasphere code[1] coupled to the NRLMSIS empirical atmosphere model and the HWM14 empirical wind model, to simulate H+, He+ and O+ populations in the plasmasphere. The SAMI3 ionosphere code includes 7 ion species (H+, He+, O+, N+, O2+, N2+, NO+), each treated as a separate fluid, with temperature equations being solved for H+, He+, O+ and e. Measurements show that refilling rates decrease with increasing solar activity, an effect reproduced by SAMI3 and its two-dimensional cousin, SAMI2. We find that the refilling rate and the resulting the plasmasphere electron content are sensitive to the thermospheric composition and temperature, as well as photoelectron heating and photoproduction rates. Depending on conditions, simulations suggest that the plasmaspheric contribution to the total electron content can either increase or decrease with solar activity, as represented by the daily and 81-day-average F10.7 indices. [1] Huba, J. and J. Krall, 2013, ``Modeling the plasmasphere with SAMI3'', Geophys. Res. Lett. 40, 6--10, doi:10.1029/2012GL054300 Research supported by NRL base funds and the NASA HSR program.

  15. High Resolution Measurement of Auroral "Hiss" and "Roar"

    NASA Astrophysics Data System (ADS)

    Ye, S.; Labelle, J.; Weatherwax, A.

    2004-05-01

    In December 2002, a Versatile Electromagnetic Wave Receiver (VIEW) together with a new digitization system was deployed at South Pole station. The motivation was to measure three types of auroral radio emissions: Auroral Roar, a relatively narrowband (Δ f/f <0.1) emission near 2 and 3 times the F region ionospheric electron cyclotron frequency (fce); Auroral Hiss, a whistler mode wave emission with frequencies lower than 1MHz ; and Auroral medium frequency (MF) burst, broadband impulsive radio emissions observed at ground level during the breakup phase of auroral substorms. High resolution broad band structure of those three emissions are recorded automatically at South Pole, and are crucial to our understanding the mechanism and relations of auroral radio emissions. This experiment uses a 3x3 meter square magnetic dipole antenna, located 1.7 km away from the South Pole station. A pre-amplifier is buried right below the eastern pylon of the antenna, connected by a 1.7 km long co-axial cable to a LF-HF receiver in the station. The output of the receiver is fed into the Versatile Electromagnetic Wave Receiver (VIEW) and Windows system equipped with a digitization board. Software is written to digitize the selected signals at 1 or 2 MHz. This data acquisition system was designed so that researchers at Dartmouth College can review the data from South Pole weekly and save interesting parts according to instructions sent from Dartmouth. In the year of 2003, the experiment concentrated on the auroral roar frequency band. With 3 hours window per day, it captured more than 30 auroral roar events at South Pole station. The data show detailed structure of Auroral Roar, which is comprised of multiple narrow band features drifting in frequencies in a complicated pattern. ( LaBelle et al., 1995; Shepherd et al., 1998) Starting in 2004, the experiment is concentrating on the auroral hiss frequency band. This mode promises to caputure the first detailed structure of auroral hiss

  16. VLF waves from ground-based transmitters observed by the Van Allen Probes: Statistical model and effects on plasmaspheric electrons

    NASA Astrophysics Data System (ADS)

    Ma, Qianli; Mourenas, Didier; Li, Wen; Artemyev, Anton; Thorne, Richard M.

    2017-07-01

    Whistler mode very low frequency (VLF) waves from powerful ground-based transmitters can resonantly scatter energetic plasmaspheric electrons and precipitate them into the atmosphere. A comprehensive 4 year statistics of Van Allen Probes measurements is carried out to assess their consequences on the dynamics of the inner radiation belt and slot region. Statistical models of the measured wave electric field power and of the inferred full wave magnetic amplitude are provided as a function of L, magnetic local time, season, and Kp over L = 1-3, revealing the localization of VLF wave intensity and its variation with geomagnetic activity over 2012-2016. Since this VLF wave model can be directly used together with existing hiss and lightning-generated wave models in radiation belt simulation codes, we perform numerical calculations of the corresponding quasi-linear pitch angle diffusion rates, allowing us to demonstrate the crucial role played by VLF waves from transmitters in energetic electron loss at L < 2.5.

  17. Control and operation cost optimization of the HISS cryogenic system

    NASA Astrophysics Data System (ADS)

    Porter, J.; Bieser, F.; Anderson, D.

    1983-08-01

    The Heavy Ion Spectrometer System (HISS) relies upon superconducting coils of cryostable design to provide a maximum particle bending field of 3 tesla. A previous paper describes the cryogenic facility including helium refrigeration and gas management. A control strategy which has allowed full time unattended operation, along with significant nitrogen and power cost reductions is discussed. Reduction of liquid nitrogen consumption was accomplished by using the sensible heat available in the cold exhaust gas. Measured nitrogen throughput agrees with calculations for sensible heat utilization of zero to 70%. Calculated consumption saving over this range is 40 liters per hour for conductive losses to the supports only. It is found that the measured throughput differential for the total system is higher.

  18. Global Kinetic Modeling of Banded Electron Structures in the Plasmasphere

    NASA Technical Reports Server (NTRS)

    Liemohn, M. W.; Khazanov, G. V.

    1997-01-01

    Significant fluxes of 10 eV to 30 keV electrons have been detected in the plasmasphere, appearing as banded structures in energy with broad spatial extents and slowly evolving over several days. It is thought that these populations are decaying plasma sheet electrons injected into the corotating region of near-Earth space. This capture can occur when the convective electric field drops rapidly and the Alfven boundary suddenly outward, trapping the inner edge of the plasma sheet along closed drift paths. Our bounce-averaged kinetic model of superthermal electron transport is able to simulate this capture and the subsequent drift, diffusion, and decay of the plasma cloud. Results of this simulation will be shown and discussed, from the initial injection during the elevated convection to the final loss of the particles. It is thought that not only Coulomb collisions but also wave-particle interactions play a significant role in altering the plasma cloud. Quasilinear diffusion is currently being incorporated into the model and the importance of this mechanism will be examined. Also, the high anisotropy of the trapped population could be unstable and generate plasma waves. These and other processes will be investigated to determine the final fate of the cloud and to quantify where, how, and when the energy of the plasma cloud is deposited. Comparisons with CRRES observations of these events are shown to verify the model and explain the data.

  19. Large area flexible plasma-sphere displays for military applications

    NASA Astrophysics Data System (ADS)

    Wedding, C.

    2005-05-01

    Imaging Systems Technology (IST) is engaged in the research and development of large flexible displays using Plasmaspheres as the pixel element. Plasma-spheres are hollow spheres formed of glass containing an ionizable gas. Plasmaspheres are ultra rugged and lightweight. Thus displays made with Plasma-spheres may be made ultra rugged and lightweight. Plasma-sphere displays can be economically mass-produced with low cost roll-to-roll process. They can also be economically produced in low quantities using batch process. Because these displays are lightweight, rugged, and low cost they will find application in rugged military and industrial environments. Additionally, because they can be very large and flexible, they will find future applications in emergent technologies such as large conformable displays for simulators, large command and control centers, or field deployable systems. Currently, IST has successfully demonstrated small flexible monochrome and color Plasmas-sphere displays. In this paper, IST will report on current research progress including the development of a 20" flexible prototype.

  20. Ionospheric signatures of a plasmaspheric plume over Europe

    NASA Astrophysics Data System (ADS)

    Yizengaw, E.; Moldwin, M. B.

    2006-05-01

    Previously, ionospheric signatures of plasmaspheric plumes were reported only at the North American longitude sector. This led to the hypothesis that the geomagnetic field configuration at those longitudes played a vital role in the observation of plasmaspheric plume signatures only over the American continent. The present study indicates that plasmaspheric plumes can be formed at any longitude sector on Earth. Using data from the ground-based global positioning system (GPS) receiver network, we find greatly elevated total electron content (TEC) over European continent during storm recovery phase on 12 September 2005. The TEC seen over Europe has a tongue of enhanced ionization extending to higher latitudes. This could be the signature of plasmaspheric plumes which are routinely observed in IMAGE EUV images (but not in this case due to data availability). The DMSP F15 ion drift meter observations are also used to understand the ion convection pattern during this interval. Therefore, our observations clearly exhibit that the ionospheric signatures of the plasmaspheric plume are not observed only in the North American sector rather it can be observed everywhere as long as a dense array of instruments are available to identify this signature.

  1. A New Global Core Plasma Model of the Plasmasphere

    NASA Astrophysics Data System (ADS)

    Gallagher, D. L.; Comfort, R. H.; Craven, P. D.

    2014-12-01

    The Global Core Plasma Model (GCPM) is the first empirical model for thermal inner magnetospheric plasma designed to integrate previous models and observations into a global, continuous in value and gradient, representation of typical total densities. New information about the plasmasphere, in particular, makes possible significant improvement. The IMAGE Mission Radio Plasma Imager (RPI) has obtained the first observations of total plasma densities along magnetic field lines in the plasmasphere and polar cap. Dynamics Explorer 1 Retarding Ion Mass Spectrometer (RIMS) has provided densities and temperatures in the plasmasphere for five ion species. These and other works enable a new more robust empirical model of thermal in the inner magnetosphere that will be presented.

  2. Plasmaspheric Plumes: Occurrence Frequency and Quantification using Magnetospheric State Vector

    NASA Technical Reports Server (NTRS)

    Adrian, Mark L.; Fung, S. F.; Pinkerton, J. C.; Gallagher, D. L.

    2009-01-01

    Plasmaspheric drainage plumes appear in the aftermath of periods of enhanced convection/erosion and are interpreted as a near-equatorial signature of the redistribution of thermal plasma along streamlines. Analysis of IMAGE/EUV observations reveals that for Kp >3, there is an 84% probability of observing a plasmaspheric plume in EUV data. We present a statistical analysis of the geomagnetic conditions [Kp, Dst, and solar wind-induced electric field] associated with EUV plume observations. Additionally, statistical analysis of the a solar wind-induced convection electric field at Earth [Ey,sm] associated with EUV plume observations are presented. These results are then used to specify a single magnetospheric state vector to define the configuration of magnetosphere associated with the formation of this major plasmaspheric structure.

  3. Plasmasphere-ionosphere coupling. II - Ion composition measurements at plasmaspheric and ionospheric altitudes and comparison with modeling results

    NASA Technical Reports Server (NTRS)

    Horwitz, J. L.; Comfort, R. H.; Richards, P. G.; Chandler, M. O.; Chappell, C. R.; Anderson, P.; Hanson, W. B.; Brace, L. H.

    1990-01-01

    This paper presents Dynamic Explorer data on the plasma coupling between the plasmasphere and ionosphere. DE 1 measurements of ion composition and temperatures at 1.4-3.5 R(F) in the plasmasphere were combined with DE-2 measurements of ion composition and electron and ion temperatures in the upper F region/topside ionosphere, closely spaced in universal and local time for cases in the November 6-11, 1981 period. The observations are compared directly with the field-line interhemispheric plasma (FLIP) model calculations of altitudinal ion density and temperature profiles. It was found that, when the FLIP model permitted fractional trapping of ionospheric photoelectrons and consequent plasmaspheric heating, good agreement with the observations was obtained.

  4. Analysis of the IMAGE RPI electron density data and CHAMP plasmasphere electron density reconstructions with focus on plasmasphere modelling

    NASA Astrophysics Data System (ADS)

    Gerzen, T.; Feltens, J.; Jakowski, N.; Galkin, I.; Reinisch, B.; Zandbergen, R.

    2016-09-01

    The electron density of the topside ionosphere and the plasmasphere contributes essentially to the overall Total Electron Content (TEC) budget affecting Global Navigation Satellite Systems (GNSS) signals. The plasmasphere can cause half or even more of the GNSS range error budget due to ionospheric propagation errors. This paper presents a comparative study of different plasmasphere and topside ionosphere data aiming at establishing an appropriate database for plasmasphere modelling. We analyze electron density profiles along the geomagnetic field lines derived from the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) satellite/Radio Plasma Imager (RPI) records of remote plasma sounding with radio waves. We compare these RPI profiles with 2D reconstructions of the topside ionosphere and plasmasphere electron density derived from GNSS based TEC measurements onboard the Challenging Minisatellite Payload (CHAMP) satellite. Most of the coincidences between IMAGE profiles and CHAMP reconstructions are detected in the region with L-shell between 2 and 5. In general the CHAMP reconstructed electron densities are below the IMAGE profile densities, with median of the CHAMP minus IMAGE residuals around -588 cm-3. Additionally, a comparison is made with electron densities derived from passive radio wave RPI measurements onboard the IMAGE satellite. Over the available 2001-2005 period of IMAGE measurements, the considered combined data from the active and passive RPI operations cover the region within a latitude range of ±60°N, all longitudes, and an L-shell ranging from 1.2 to 15. In the coincidence regions (mainly 2 ⩽ L ⩽ 4), we check the agreement between available active and passive RPI data. The comparison shows that the measurements are well correlated, with a median residual of ∼52 cm-3. The RMS and STD values of the relative residuals are around 22% and 21% respectively. In summary, the results encourage the application of IMAGE RPI data for

  5. Conditions in solar wind and magnetosphere during the nontypical VLF hiss burst on December 8, 2013

    NASA Astrophysics Data System (ADS)

    Kleimenova, N. G.; Manninen, J.; Gromova, L. I.; Turunen, T.; Fedorenko, Yu. V.; Nikitenko, A. S.; Zelinsky, N. R.; Gromov, S. V.

    2015-05-01

    The features of the dynamics of solar wind and IMF parameters were studied during the initial phase of the weak magnetic storm of December 8, 2013, where a nontypical two hour lasting wide-band (˜4-10 kHz) hiss burst was recorded during VLF observations in auroral latitudes near Sodankyla observatory ( L ˜ 5.5), which differed from classical auroral hiss. A similar VLF hiss burst was recorded at Russian Lovozero observatory, which is located ˜400 km to the east. In contrast to a typical auroral hiss, the VLF emissions at both points were left-polarized and arrived at the observation point from the southeast. Although the VLF hiss burst coincided in time with the development of a substorm and the appearance of zenithal bright auroras near the stations traveling north-south, the excitation of the VLF hiss apparently has no relation to the auroras. It is suggested that the VLF emissions were generated due to cyclotron instability far to the east of Scandinavia in the region of plasmapause at L ˜ 3.5, where the equatorial gyrofrequency ( f He) is about 20 kHz. The generated VLF waves could be ducted in the plasmapause at frequencies lower than a half of f He, i.e., below ˜10 kHz, they arrive at the Earth's surface near the projection of their source and propagate in the Earth-ionosphere waveguide to large distances, as left-polarized waves. A sharp increase in the solar wind dynamic pressure was noted during the hiss burst under study, which resulted in a significant contraction of the daytime magnetosphere, a shift of the plasmapause and radiation belt to lower L shells, and the development of a substorm and southward travel of auroral arcs. The VLF hiss may have been generated in the region where energetic particles of the radiation belt crossed the plasmapause. The fact that the hiss under study was generated not in the early morning sector (Scandinavian meridian), but much further to the east, could be indirectly confirmed by quasiperiodic modulation of the

  6. Plasmaspheric Depletion and Refilling after Geomagnetic Storms in the Dynamic Model of the Plasmasphere

    NASA Astrophysics Data System (ADS)

    Moschou, S. P.; Pierrard, V.; Lemaire, J. F.

    2015-12-01

    The three-dimensional physical dynamic kinetic model of the plasmasphere is a physics-based model partially constrained by empirical observations and available for running on the space weather portal. The position of the plasmapause is determined by the interchange instability mechanism. The level of geomagnetic activity driven by the Kp index determines the convection electric field which dominates at large radial distances. During storm and substorm events, the convection rate increases, especially in the postmidnight MLT sector. This leads to an inward motion of the plasmapause in this MLT sector during the storms and a depletion of the outer flux tubes. The combination with the corotation electric field leads later to the formation of a plume in the afternoon sector which then rotates with the Earth. After geomagnetic storms, progressive refilling process takes several days to increase the density in the depleted flux tubes located in regions between the vestigial plasmapause and the new plasmapause situated at larger radial distance. The model is coupled with an empirical model of the ionosphere which determines the boundary conditions at low altitudes. Like in other kinetic models of planetary and stellar atmospheres, the density, flux, velocity and temperatures of the particles are obtained by solving the kinetic evolution equation to determine the velocity distribution function of the particles. Additional new results are related to the consideration of the plasmaspheric wind appearing during low activity periods. Comparisons with IMAGE and CLUSTER observations show good agreement with the results of the model, including during periods when a plume is visible during several successive days.

  7. The dynamics of the plasmasphere boundary layer as determined by ground magnetometers, satellite observations, and modeling

    NASA Astrophysics Data System (ADS)

    Zesta, E.; Boudouridis, A.; Yizengaw, E.; Jorgensen, A. M.; Carranza-fulmer, T. L.; Moldwin, M.; Mann, I. R.; Chi, P. J.

    2013-12-01

    The plasmasphere boundary layer (PBL) separates the cold and dense plasmaspheric plasma from the more tenuous and hot plasma sheet plasma and organizes the spatial distribution of ULF and VLF waves that can contribute to acceleration or loss processes of radiation belt particles through wave-particle interactions. The PBL has been traditionally determined by in situ observations and can be given by empirical models. Recent work has shown that a mid-latitude chain of well-spaced ground magnetometers can also determine the PBL location. Spectral properties, like the cross-phase reversal in the standard field-line resonance (FLR) determination between two stations closely aligned in latitude, have been shown to indicate the presence of a sharp PBL. We merge data from many ground magnetometer pairs from the SAMBA (South American Meridional B-field Array), McMAC (Mid continent Magnetoseismic Chain), and CARISMA (Canadian Array for Realtime Investigations of Magnetic Activity) chains to provide the best available spatial coverage in L values spanning the plasmasphere and PBL, for a range of dynamic states (L=1.6 to greater than 5). The PBL location is identified as the L value of the station pair for which a reverse phase difference is observed in the standard FLR determination. We compare the FLR determined PBL with the trough boundary determined by GPS Total Electron Content (TEC) analysis and with model PBL. Initial results demonstrate that the PBL as identified by the reverse phase differences is in general agreement with TEC identifications and reasonable agreement with models. Reverse Phase Differences are regularly observed at the L range of 2.7 to 3.7 and are highly correlated with Dst and Kp, as determined by daily correlations. We further examine the more detailed time sequence of the PBL dynamics by focusing on key periods around storms preceded by quiet periods, and by using the full L range of the ground magnetometer pairs.

  8. Storm Enhanced Densities simulations using the Ionosphere Plasmasphere Electrodynamics (IPE) Model

    NASA Astrophysics Data System (ADS)

    Maruyama, N.; Richards, P.; Sun, Y. Y.; Fang, T. W.; Fuller-Rowell, T. J.; Richmond, A. D.; Maute, A. I.

    2014-12-01

    Storm time response of the middle latitude ionosphere goes through different phases of positive and negative storms for different events. Storm Enhanced Densities (SEDs) are particularly difficult to self-consistently categorize with physical models. The area of enhanced density is surrounded by steep density gradients and appears to progress rapidly through mid-latitudes and into the polar regions. The goal of this study is to improve our scientific understanding of the plasma height variations associated with SEDs, specifically to determine the relative role of the various drivers including neutral wind, composition, and electric fields. A new Ionosphere-Plasmasphere-Electrodynamics (IPE) model used in this study has been developed by collaboration between CU CIRES, NOAA/SWPC, NOAA/GSD and NCAR/HAO. The main objectives are to improve our specification of ionosphere and plasmasphere in response to external forcing from both above and below, and to couple to whole atmosphere models for understanding the interaction between the terrestrial weather to space weather. The model describes the time dependent, three-dimensional, global density of nine ion species, electron density, temperatures of electron and ions in the ionosphere and plasmasphere. The parallel plasma transport is based on the Field Line Interhemispheric Plasma (FLIP) Model [Richards et al., 1990]. A realistic model of Earth's magnetic field is implemented by using the APEX coordinate system [Richmond, 1995]. Global, seamless plasma transport perpendicular to the magnetic field has been included all the way from the equator to the poles. The electrodynamics solver based on the TIEGCM [Richmond and Maute, 2014] calculates the global electric field self-consistently. This presentation focuses on an impact of IGRF on the variations of plasma gradients associated with SEDs. In particular, difference between IGRF and dipole coordinate system is quantified. Furthermore, the relative roles of the various storm

  9. Self-Consistent Model of Magnetospheric Electric Field, Ring Current, Plasmasphere, and Electromagnetic Ion Cyclotron Waves: Initial Results

    NASA Technical Reports Server (NTRS)

    Gamayunov, K. V.; Khazanov, G. V.; Liemohn, M. W.; Fok, M.-C.; Ridley, A. J.

    2009-01-01

    Further development of our self-consistent model of interacting ring current (RC) ions and electromagnetic ion cyclotron (EMIC) waves is presented. This model incorporates large scale magnetosphere-ionosphere coupling and treats self-consistently not only EMIC waves and RC ions, but also the magnetospheric electric field, RC, and plasmasphere. Initial simulations indicate that the region beyond geostationary orbit should be included in the simulation of the magnetosphere-ionosphere coupling. Additionally, a self-consistent description, based on first principles, of the ionospheric conductance is required. These initial simulations further show that in order to model the EMIC wave distribution and wave spectral properties accurately, the plasmasphere should also be simulated self-consistently, since its fine structure requires as much care as that of the RC. Finally, an effect of the finite time needed to reestablish a new potential pattern throughout the ionosphere and to communicate between the ionosphere and the equatorial magnetosphere cannot be ignored.

  10. Problems with Modeling Plasmasphere Refilling After Geomagnetic Storms

    NASA Astrophysics Data System (ADS)

    Schunk, R. W.

    2015-12-01

    During geomagnetic storms, the plasma in the outer plasmasphere is depleted as the plasma drifts away from the Earth across magnetic field (B) lines due to storm-time electric fields. After the storm, the plasmasphere refills due to an upward flow of plasma from the ionosphere that is initially supersonic (H+). The current numerical models of plasmasphere refilling are typically based on a numerical solution of the ion (H+, O+, He+) and electron continuity, momentum, and energy equations. The equations are solved along closed magnetic field lines that connect conjugate ionospheres, with allowance for cross-B plasma drift during storms. Both diffusion and hydrodynamic approximations have been adopted. The diffusion approximation neglects the nonlinear initial term in the momentum equations, so this approximation is not rigorously valid for early refilling times (~ day). At high altitudes, the plasma becomes collisionless and there are different temperatures parallel and perpendicular to B (not included in current models). Also, single-stream and multi-stream (separate ion streams from the conjugate ionospheres) formulations have been adopted, and the refilling features are different. These and other problems with the current plasmasphere refilling models will be discussed.

  11. A New Global Core Plasma Model of the Plasmasphere

    NASA Technical Reports Server (NTRS)

    Gallagher, D. L.; Comfort, R. H.; Craven, P. D.

    2014-01-01

    The Global Core Plasma Model (GCPM) is the first empirical model for thermal inner magnetospheric plasma designed to integrate previous models and observations into a continuous in value and gradient representation of typical total densities. New information about the plasmasphere, in particular, make possible significant improvement. The IMAGE Mission Radio Plasma Imager (RPI) has obtained the first observations of total plasma densities along magnetic field lines in the plasmasphere and polar cap. Dynamics Explorer 1 Retarding Ion Mass Spectrometer (RIMS) has provided densities in temperatures in the plasmasphere for 5 ion species. These and other works enable a new more detailed empirical model of thermal in the inner magnetosphere that will be presented. Specifically shown here are the inner-plasmasphere RIMS measurements, radial fits to densities and temperatures for H(+), He(+), He(++), O(+), and O(+) and the error associated with these initial simple fits. Also shown are more subtle dependencies on the f10.7 P-value (see Richards et al. [1994]).

  12. Superthermal Electron Energy Interchange in the Ionosphere-Plasmasphere System

    NASA Technical Reports Server (NTRS)

    Khazanov, G. V.; Glocer, A.; Liemohn, M. W.; Himwich, E. W.

    2013-01-01

    A self-consistent approach to superthermal electron (SE) transport along closed field lines in the inner magnetosphere is used to examine the concept of plasmaspheric transparency, magnetospheric trapping, and SE energy deposition to the thermal electrons. The dayside SE population is generated both by photoionization of the thermosphere and by secondary electron production from impact ionization when the photoelectrons collide with upper atmospheric neutral particles. It is shown that a self-consistent approach to this problem produces significant changes, in comparison with other approaches, in the SE energy exchange between the plasmasphere and the two magnetically conjugate ionospheres. In particular, plasmaspheric transparency can vary by a factor of two depending on the thermal plasma content along the field line and the illumination conditions of the two conjugate ionospheres. This variation in plasmaspheric transparency as a function of thermal plasma and ionospheric conditions increases with L-shell, as the field line gets longer and the equatorial pitch angle extent of the fly-through zone gets smaller. The inference drawn from these results is that such a self-consistent approach to SE transport and energy deposition should be included to ensure robustness in ionosphere-magnetosphere modeling networks.

  13. Superthermal electron energy interchange in the ionosphere-plasmasphere system

    NASA Astrophysics Data System (ADS)

    Khazanov, G. V.; Glocer, A.; Liemohn, M. W.; Himwich, E. W.

    2013-02-01

    A self-consistent approach to superthermal electron (SE) transport along closed field lines in the inner magnetosphere is used to examine the concept of plasmaspheric transparency, magnetospheric trapping, and SE energy deposition to the thermal electrons. The dayside SE population is generated both by photoionization of the thermosphere and by secondary electron production from impact ionization when the photoelectrons collide with upper atmospheric neutral particles. It is shown that a self-consistent approach to this problem produces significant changes, in comparison with other approaches, in the SE energy exchange between the plasmasphere and the two magnetically conjugate ionospheres. In particular, plasmaspheric transparency can vary by a factor of two depending on the thermal plasma content along the field line and the illumination conditions of the two conjugate ionospheres. This variation in plasmaspheric transparency as a function of thermal plasma and ionospheric conditions increases with L-shell, as the field line gets longer and the equatorial pitch angle extent of the fly-through zone gets smaller. The inference drawn from these results is that such a self-consistent approach to SE transport and energy deposition should be included to ensure robustness in ionosphere-magnetosphere modeling networks.

  14. Superthermal Electron Energy Interchange in the Ionosphere-Plasmasphere System

    NASA Technical Reports Server (NTRS)

    Khazanov, G. V.; Glocer, A.; Liemohn, M. W.; Himwich, E. W.

    2013-01-01

    A self-consistent approach to superthermal electron (SE) transport along closed field lines in the inner magnetosphere is used to examine the concept of plasmaspheric transparency, magnetospheric trapping, and SE energy deposition to the thermal electrons. The dayside SE population is generated both by photoionization of the thermosphere and by secondary electron production from impact ionization when the photoelectrons collide with upper atmospheric neutral particles. It is shown that a self-consistent approach to this problem produces significant changes, in comparison with other approaches, in the SE energy exchange between the plasmasphere and the two magnetically conjugate ionospheres. In particular, plasmaspheric transparency can vary by a factor of two depending on the thermal plasma content along the field line and the illumination conditions of the two conjugate ionospheres. This variation in plasmaspheric transparency as a function of thermal plasma and ionospheric conditions increases with L-shell, as the field line gets longer and the equatorial pitch angle extent of the fly-through zone gets smaller. The inference drawn from these results is that such a self-consistent approach to SE transport and energy deposition should be included to ensure robustness in ionosphere-magnetosphere modeling networks.

  15. The formation of the light-ion trough and peeling off the plasmasphere

    NASA Astrophysics Data System (ADS)

    Lemaire, J. F.

    2001-07-01

    The plasma density gradients in the outer drift shells of the plasmasphere are generally stable with respect to convective instability during quiet geomagnetic-geoelectric conditions. When the IMF turns southward before the onset of a magnetic substorm, this situation gradually changes: the magnetospheric convection electric field is then enhanced and penetrates deeper in the nightside plasmasphere. The sunward and eastward magnetospheric convection velocity is enhanced in the post-midnight local time sector at /L>4, and occasionally down to /L=2.5. As a result of this enhancement of the azimuthal component of the convection velocity, centrifugal effects are augmented in the distant region of the magnetosphere; the field-aligned potential energy of ions and electrons is reduced along the equatorial portion of magnetic field lines; the field-aligned plasma density distribution, initially in mechanical equilibrium, is accelerated and becomes convectively unstable. As a consequence, a field-aligned polar-wind-like flow of H+-ions (and He+-ions) is driven upward and the mid-latitude ionosphere gets depleted of its light ions. The plasma density at high altitudes diminishes in all flux tubes whose angular speed has been enhanced. It does not change significantly, however, on lower L-shells where the convection velocity has not changed. As a result of the shear in the upward ionization flow, a ``knee'' develops in the cross-L plasma density distribution along the drift shell which is tangent to a surface which has been called the Roche limit surface or zero-parallel-force surface. As a result of Coulomb collisions and wave-particle interaction, the upflowing particles that are able to overcome the reduced potential barrier may become trapped, and will tend to accumulate in the equatorial potential well beyond this zero-parallel-force surface. But, quasi-interchange - a type of ballooning instability driven by gravitational force or centrifugal effects - prevents this

  16. Whistlers Observed Outside the Plasmasphere: Correlation to Plasmaspheric/Plasmapause Features and Implications for the Scattering of Radiation-Belt Electrons

    NASA Technical Reports Server (NTRS)

    Adrian, Mark L.; Gallagher, D. L.

    2007-01-01

    Magnetospherically reflected, lightning-generated whistler waves are an important potential contributor to pitch-angle scattering loss processes of the electron radiation belts. While lightning-generated whistlers are a common feature at, and just inside, the plasmapause, they are infrequently observed outside the plasmasphere. As such, their potential contribution to outer radiation belt loss processes is more tenuous. Recently, Platino et al. [2005] has reported on whistlers observed outside the plasmasphere by Cluster. Here, we present correlative global observations of the plasmasphere, for the reported periods of Cluster-observed whistlers outside the plasmasphere, using IMAGE-EUV data. The intent of this study is to seek the underlying mechanisms that result in whistlers outside the plasmasphere and consequently the anticipated morphology and significance these waves may have on radiation belt dynamics.

  17. Home Sweet Home: How to Build a Madagascar Hissing Cockroach Habitat out of Recycled Materials

    ERIC Educational Resources Information Center

    Wagler, Ron

    2010-01-01

    Madagascar hissing cockroaches (MHC) are amazing insects that can be an integral part of an effective science learning and teaching environment. MHCs have a fascinating social structure. They make excellent pets, teach students how to properly care for animals, and their large size adds to their "wow" factor. These characteristics make them unique…

  18. Home Sweet Home: How to Build a Madagascar Hissing Cockroach Habitat out of Recycled Materials

    ERIC Educational Resources Information Center

    Wagler, Ron

    2010-01-01

    Madagascar hissing cockroaches (MHC) are amazing insects that can be an integral part of an effective science learning and teaching environment. MHCs have a fascinating social structure. They make excellent pets, teach students how to properly care for animals, and their large size adds to their "wow" factor. These characteristics make them unique…

  19. ;Long-hissler; fine structure within auroral hiss: A review and synthesis

    NASA Astrophysics Data System (ADS)

    Kim, Howard F.; LaBelle, James; Spasojević, Maria

    2017-04-01

    One of the most prominent fine-structures of auroral hiss is the ;long-hissler;, defined here as a dispersed feature embedded within broadband auroral hiss emissions in the frequency range 1-40 kHz and lasting longer than 0.3 s. While theory is limited, there is evidence that hisslers can be used in remote sensing of density characteristics at altitudes of thousands of km. By applying an automatic threshold algorithm to VLF data collected at South Pole 2230-0130 UT daily during June-August 2014, 22 h of auroral hiss are identified on 49 of 93 days analyzed, for an occurrence rate of 9.7% during the applicable MLT interval. From manual inspection of these intervals, 414 groups (trains) of long hisslers are identified on 34 of the 49 days on which hiss occurred. Median lower (upper) frequency bounds of these features are 8 (22) kHz, median frequency-time slope is -10 kHz/s, and median hissler repetition time within a train (hissler period) is 1.2 s. Hissler period and frequency-time slope are inversely related. Data from previous studies are reviewed to provide a comprehensive description of the phenomenon. Contrary to some previous studies, subsequent long hissler features are found to commonly overlap in time, and no evidence is found for an inverse relationship between hissler train duration and geomagnetic activity.

  20. Defective hepatic nitric oxide action results in HISS-dependent insulin resistance in spontaneously hypertensive rats.

    PubMed

    Afonso, Ricardo Alexandre; Ribeiro, Rogério Tavares; Macedo, Maria Paula

    2004-01-01

    Peripheral insulin sensitivity is dependent on the action of Hepatic Insulin Sensitizing Substance (HISS), in which hepatic NO (HNO) plays an important role. Insulin resistance has been associated with hypertension. NO action is known to be impaired in Spontaneously Hypertensive Rat (SHR) hypertension models. We tested the hypothesis that the HNO pathway is compromised in SHR, resulting in HISS-dependent insulin resistance. Wistar rats (Wis) were the normotensive controls. Insulin sensitivity was evaluated through the Rapid Insulin Sensitivity Test (RIST), a modified euglycemic clamp. A clamp was performed in basal state (control RIST), followed by ipv administration of the NO synthase (NOS) competitive antagonist L-NMMA (0.73 mg/kg) and a RIST post L-NMMA. HISS-dependent insulin sensitivity was assessed by subtracting the RIST post-L-NMMA from the control RIST and is represented as the resultant insulin sensitivity inhibition. In SHR ipv L-NMMA induced 26+/-5% insulin sensitivity inhibition (187.5+/-15.3 mg glucose/kg, n=6; P<0.05), whereas in Wis, ipv L-NMMA induced 53.8+/-5.9% insulin sensitivity inhibition (138.2+/-14.7 mg glucose/kg, n=6, P<0.05), significantly higher than in SHR (P<0.01). Our results suggest that functional HNO is essential to achieve maximal insulin sensitivity and that HNO action is compromised in hypertension, resulting in HISS-dependent insulin resistance.

  1. Response of plasmaspheric configuration to substorms revealed by Chang’e 3

    NASA Astrophysics Data System (ADS)

    He, Han; Shen, Chao; Wang, Huaning; Zhang, Xiaoxin; Chen, Bo; Yan, Jun; Zou, Yongliao; Jorgensen, Anders M.; He, Fei; Yan, Yan; Zhu, Xiaoshuai; Huang, Ya; Xu, Ronglan

    2016-08-01

    The Moon-based Extreme Ultraviolet Camera (EUVC) of the Chang’e 3 mission provides a global and instantaneous meridian view (side view) of the Earth’s plasmasphere. The plasmasphere is one inner component of the whole magnetosphere, and the configuration of the plasmasphere is sensitive to magnetospheric activity (storms and substorms). However, the response of the plasmaspheric configuration to substorms is only partially understood, and the EUVC observations provide a good opportunity to investigate this issue. By reconstructing the global plasmaspheric configuration based on the EUVC images observed during 20–22 April 2014, we show that in the observing period, the plasmasphere had three bulges which were located at different geomagnetic longitudes. The inferred midnight transit times of the three bulges, using the rotation rate of the Earth, coincide with the expansion phase of three substorms, which implies a causal relationship between the substorms and the formation of the three bulges on the plasmasphere. Instead of leading to plasmaspheric erosion as geomagnetic storms do, substorms initiated on the nightside of the Earth cause local inflation of the plasmasphere in the midnight region.

  2. Response of plasmaspheric configuration to substorms revealed by Chang'e 3.

    PubMed

    He, Han; Shen, Chao; Wang, Huaning; Zhang, Xiaoxin; Chen, Bo; Yan, Jun; Zou, Yongliao; Jorgensen, Anders M; He, Fei; Yan, Yan; Zhu, Xiaoshuai; Huang, Ya; Xu, Ronglan

    2016-08-31

    The Moon-based Extreme Ultraviolet Camera (EUVC) of the Chang'e 3 mission provides a global and instantaneous meridian view (side view) of the Earth's plasmasphere. The plasmasphere is one inner component of the whole magnetosphere, and the configuration of the plasmasphere is sensitive to magnetospheric activity (storms and substorms). However, the response of the plasmaspheric configuration to substorms is only partially understood, and the EUVC observations provide a good opportunity to investigate this issue. By reconstructing the global plasmaspheric configuration based on the EUVC images observed during 20-22 April 2014, we show that in the observing period, the plasmasphere had three bulges which were located at different geomagnetic longitudes. The inferred midnight transit times of the three bulges, using the rotation rate of the Earth, coincide with the expansion phase of three substorms, which implies a causal relationship between the substorms and the formation of the three bulges on the plasmasphere. Instead of leading to plasmaspheric erosion as geomagnetic storms do, substorms initiated on the nightside of the Earth cause local inflation of the plasmasphere in the midnight region.

  3. Response of plasmaspheric configuration to substorms revealed by Chang’e 3

    PubMed Central

    He, Han; Shen, Chao; Wang, Huaning; Zhang, Xiaoxin; Chen, Bo; Yan, Jun; Zou, Yongliao; Jorgensen, Anders M.; He, Fei; Yan, Yan; Zhu, Xiaoshuai; Huang, Ya; Xu, Ronglan

    2016-01-01

    The Moon-based Extreme Ultraviolet Camera (EUVC) of the Chang’e 3 mission provides a global and instantaneous meridian view (side view) of the Earth’s plasmasphere. The plasmasphere is one inner component of the whole magnetosphere, and the configuration of the plasmasphere is sensitive to magnetospheric activity (storms and substorms). However, the response of the plasmaspheric configuration to substorms is only partially understood, and the EUVC observations provide a good opportunity to investigate this issue. By reconstructing the global plasmaspheric configuration based on the EUVC images observed during 20–22 April 2014, we show that in the observing period, the plasmasphere had three bulges which were located at different geomagnetic longitudes. The inferred midnight transit times of the three bulges, using the rotation rate of the Earth, coincide with the expansion phase of three substorms, which implies a causal relationship between the substorms and the formation of the three bulges on the plasmasphere. Instead of leading to plasmaspheric erosion as geomagnetic storms do, substorms initiated on the nightside of the Earth cause local inflation of the plasmasphere in the midnight region. PMID:27576944

  4. Plasmasphere Refilling After Geomagnetic Storms Observed by EMMA Magnetometer Network

    NASA Astrophysics Data System (ADS)

    Del Corpo, A.; Vellante, M.; Heilig, B.; Lichtenberger, J.; Reda, J.; Pietropaolo, E.; Chi, P. J.

    2015-12-01

    We present the results of a study of plasmasphere dynamics during a few geomagnetic storms through examination of radial profiles of the equatorial plasma mass density. The plasma mass density is derived from field line resonance (FLR) frequencies observations across EMMA, a meridional network of 25 magnetometer stations extending from Central Italy to North Finland (1.5 < L < 6.5). The study focuses on plasmaspheric refilling following depletion due to geomagnetic activity. From the time variation of the equatorial plasma mass density we derived daytime refilling rates and the corresponding upward plasma fluxes from the ionosphere for different L-values. Daily averaged refilling rates occurring during the recovery phase have been also investigated.

  5. SAMI3_ICON: Model of the Ionosphere/Plasmasphere System

    NASA Astrophysics Data System (ADS)

    Huba, J. D.; Maute, A.; Crowley, G.

    2017-10-01

    The NRL ionosphere/plasmasphere model SAMI3 has been modified to support the NASA ICON mission. Specifically, SAMI3_ICON has been modified to import the thermospheric composition, temperature, and winds from TIEGCM-ICON and the high-latitude potential from AMIE data. The codes will be run on a daily basis during the ICON mission to provide ionosphere and thermosphere properties to the science community. SAMI3_ICON will provide ionospheric and plasmaspheric parameters such as the electron and ion densities, temperatures, and velocities, as well as the total electron content (TEC), peak ionospheric electron density (NmF2) and height of the F layer at NmF2 (hmF2).

  6. Self-consistent superthermal electron effects on plasmaspheric refilling

    NASA Astrophysics Data System (ADS)

    Liemohn, M. W.; Khazanov, G. V.; Moore, T. E.; Guiter, S. M.

    1997-04-01

    The effects of self-consistently including superthermal electrons in the definition of the ambipolar electric field are investigated for the case of plasmaspheric refilling after a geomagnetic storm. By using the total electron population in the hydrodynamic equations, a method for incorporating superthermal electron parameters in the electric field and electron temperature calculation is developed. Also, the ambipolar electric field is included in the kinetic equation for the superthermal electrons through a change of variables using the total energy and the first adiabatic invariant. Calculations based on these changes are performed by coupling time-dependent models of the thermal plasma and superthermal electrons. Results from this treatment of the electric field and the self-consistent development of the solution are discussed in detail. Specifically, there is a decreased thermal electron density in the plasmasphere during the first few minutes of refilling, a slightly accelerated proton shock front, and a decreased superthermal electron flux due to the deceleration by the electric field. The timescales of plasmaspheric refilling are discussed and determined to be somewhat shorter than previously calculated for the thermal plasma and superthermal electron population due to the effects of the field-aligned potential.

  7. The Origin and Evolution of Deep Plasmaspheric Notches

    NASA Technical Reports Server (NTRS)

    Gallagher, D. L.; Adrian, M. L.; Liemohn, M.

    2004-01-01

    Deep plasmaspheric notches can extend over more than 2 RE in radial distance and 3 hours MLT in the magnetic equatorial plane. They appear to be among the largest evacuated features in the exterior plasmaspheric boundary. They can last for days and exhibit varying structure. It appears that low-density channels resulting from the entrainment of the plasmaspheric convection plume during storm-time recovery share the same origin as notches. Notches rather than channels result from differences in storm- time conditions. Strong convection tends to result in low-density channels, while weaker convection and limited erosion results in notches. Eighteen events in 2000 have been analyzed. Among these events, notches were found to drift as slowly as 72% of corotation. In only one case was a notch found to drift at the corotation rate within measurement error. On average, notches drift at about 2 1.5 hours per day or 90% of the co-rotational rate. Notches also sometimes exhibit an interior structure that appears as an extended prominence of dense plasma, which forms a W-like feature in IMAGEEUV images when viewed from Earth-center. Modeling suggests such features may be caused by small-scale potential structures that result from the localized injection of ring current plasma. Plasma filling rates during recovery and drainage during a minor storm are reported.

  8. 2-D Drift Velocities from the IMAGE EUV Plasmaspheric Imager

    NASA Technical Reports Server (NTRS)

    Gallagher, D.; Adrian, M.

    2007-01-01

    The IMAGE Mission extreme ultraviolet imager (EUY) observes He+ plasmaspheric ions throughout the inner magnetosphere. Limited by ionizing radiation and viewing close to the Sun, images of the He+ distribution are available every 10 minutes for many hours as the spacecraft passes through apogee in its highly elliptical orbit. As a consistent constituent at about 15%, He+ is an excellent surrogate for monitoring all of the processes that control the dynamics of plasmaspheric plasma. In particular, the motion ofHe+ transverse to the ambient magnetic field is a direct indication of convective electric fields. The analysis of boundary motions has already achieved new insights into the electrodynamic coupling processes taking place between energetic magnetospheric plasmas and the ionosphere. Yet to be fulfilled, however, is the original promise that global EUY images of the plasmasphere might yield two-dimensional pictures of meso-scale to macro-scale electric fields in the inner magnetosphere. This work details the technique and initial application of an IMAGE EUY analysis that appears capable of following thermal plasma motion on a global basis.

  9. Can the Plasmaspheric Plume Significantly Contribute to Magnetosheath Densities?

    NASA Technical Reports Server (NTRS)

    Gallagher, Dennis; Goldstein, Jerry; Sibeck, David

    2010-01-01

    Intervals of strong magnetospheric convection electric fields can result in the removal of large portions of the outer plasmasphere and its transport to the vicinity of the magnetopause. Of growing interest is the disposition of that plasma and its possible influence on the processes operating in the regions contributed to by this dense thermal plasma of ionospheric origin. Plasmaspheric plasma may recirculate within the outer magnetosphere through the flanks to become part of the plasmasheet, be entrained on reconnected magnetic field lines drawn anti-sunward over the polar cap, or be lost into the magnetosheath flow and into the solar wind. Of interest here is whether it is reasonable to anticipate that the plume material is sufficient to contribute substantially to magnetosheath densities at the magnetopause where it could influence reconnection between the interplanetary and terrestrial magnetic fields. We present the results of model simulations of plasmaspheric plume and magnetosheath plasmas in the context of several storm-time event periods. Plume and magnetosheath densities are compared as a function of location and storm phase. The short answer is, "yes", but not always and not at all locations. The full answer will be presented.

  10. Temperature anisotropies in the terrestrial ionosphere and plasmasphere

    SciTech Connect

    Demars, H.G.; Schunk, R.W.

    1987-11-01

    The available theoretical and experimental evidence for ion and electron temperature anisotropies in the terrestrial ionosphere-plasmasphere system is reviewed. The review is concerned only with temperature anisotropies in the thermal (less than 1 eV) populations and does not cover energized auroral populations, such as ion beams, conics, and bowl distributions. Currently, the bulk of the work dealing with temperature anisotropies has been theoretical. Various models have been used to predict ion and electron temperature anisotropies, including kinetic, semikinetic, hydromagnetic and generalized transport models. Temperature anisotropies have been predicted in the polar wind, along plasmapause field lines, during the refilling of the outer plasmasphere after depletion by a magnetic storm, and at F region altitudes in regions of rapid plasma convection. The experimental evidence for temperature anisotropies, on the other hand, is limited. Some of the observations support the theoretical predictions, while other observations indicate the presence of temperature anisotropies in regions where the models predict isotropic temperature distributions. More extensive observations are needed in order to elucidate the underlying processes controlling the thermal structure in the ionosphere-plasmasphere system.

  11. Self-Consistent Superthermal Electron Effects on Plasmaspheric Refilling

    NASA Technical Reports Server (NTRS)

    Liemohn, M. W.; Khazanov, G. V.; Moore, T. E.; Guiter, S. M.

    1997-01-01

    The effects of self-consistently including superthermal electrons in the definition of the ambipolar electric field are investigated for the case of plasmaspheric refilling after a geomagnetic storm. By using the total electron population in the hydrodynamic equations, a method for incorporating superthermal electron parameters in the electric field and electron temperature calculation is developed. Also, the ambipolar electric field is included in the kinetic equation for the superthermal electrons through a change of variables using the total energy and the first adiabatic invariant. Calculations based on these changes are performed by coupling time-dependent models of the thermal plasma and superthermal electrons. Results from this treatment of the electric field and the self-consistent development of the solution are discussed in detail. Specifically, there is a decreased thermal electron density in the plasmasphere during the first few minutes of refilling, a slightly accelerated proton shock front, and a decreased superthermal electron flux due to the deceleration by the electric field. The timescales of plasmaspheric refilling are discussed and determined to be somewhat shorter than previously calculated for the thermal plasma and superthermal electron population due to the effects of the field-aligned potential.

  12. Narrowband VLF observations as validation of Plasmaspheric model

    NASA Astrophysics Data System (ADS)

    Collier, Andrew; Clilverd, Mark; Rodger, C. J.; Delport, Brett; Lichtenberger, János

    2012-07-01

    PLASMON is a European Union FP7 project which will use observations of whistlers and field line resonances to construct a data assimilative model of the plasmasphere. This model will be validated by comparison with electron precipitation data derived from narrowband VLF observations of subionospheric propagation from the AARDDVARK network. A VLF receiver on Marion Island, located at 46.9° S 37.1° E (L = 2.60), is able to observe the powerful NWC transmitter in Australia over a 1.4 < L < 3.0 path which passes exclusively over the ocean. The signal is thus very strong and exhibits an excellent signal-to-noise ratio. Data from the UltraMSK narrowband VLF receiver on Marion Island are used to examine evidence of particle precipitation along this path, thereby inferring the rate at which electrons are scattered into the bounce loss cone. This path covers a small range of L-values so that there is little ambiguity in the source of any peturbations. Perturbations detected on the path during geomagnetic storms should predominantly be responses to energetic electron precipitation processes occurring inside the plasmasphere. Comparisons will be made to preliminary plasmaspheric results from the PLASMON project.

  13. Modeling of Field-Aligned Guided Echoes in the Plasmasphere

    NASA Technical Reports Server (NTRS)

    Fung, Shing F.; Green, James L.

    2004-01-01

    The conditions under which high frequency (f>>f(sub uh)) long-range extraordinary-mode discrete field-aligned echoes observed by the Radio Plasma Imager (RPI) on board the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) satellite in the plasmasphere are investigated by ray tracing modeling. Field-aligned discrete echoes are most commonly observed by RPI in the plasmasphere although they are also observed over the polar cap region. The plasmasphere field-aligned echoes appearing as multiple echo traces at different virtual ranges are attributed to signals reflected successively between conjugate hemispheres that propagate along or nearly along closed geomagnetic field lines. The ray tracing simulations show that field-aligned ducts with as little as 1% density perturbations (depletions) and less than 10 wavelengths wide can guide nearly field-aligned propagating high frequency X mode waves. Effective guidance of wave at a given frequency and wave normal angle (Psi) depends on the cross-field density scale of the duct, such that ducts with stronger density depletions need to be wider in order to maintain the same gradient of refractive index across the magnetic field. While signal guidance by field aligned density gradient without ducting is possible only over the polar region, conjugate field-aligned echoes that have traversed through the equatorial region are most likely guided by ducting.

  14. Temperature of the plasmasphere from Van Allen Probes HOPE

    NASA Astrophysics Data System (ADS)

    Genestreti, K. J.; Goldstein, J.; Corley, G. D.; Farner, W.; Kistler, L. M.; Larsen, B. A.; Mouikis, C. G.; Ramnarace, C.; Skoug, R. M.; Turner, N. E.

    2017-01-01

    We introduce two novel techniques for estimating temperatures of very low energy space plasmas using, primarily, in situ data from an electrostatic analyzer mounted on a charged and moving spacecraft. The techniques are used to estimate proton temperatures during intervals where the bulk of the ion plasma is well below the energy bandpass of the analyzer. Both techniques assume that the plasma may be described by a one-dimensional E→×B→ drifting Maxwellian and that the potential field and motion of the spacecraft may be accounted for in the simplest possible manner, i.e., by a linear shift of coordinates. The first technique involves the application of a constrained theoretical fit to a measured distribution function. The second technique involves the comparison of total and partial-energy number densities. Both techniques are applied to Van Allen Probes Helium, Oxygen, Proton, and Electron (HOPE) observations of the proton component of the plasmasphere during two orbits on 15 January 2013. We find that the temperatures calculated from these two order-of-magnitude-type techniques are in good agreement with typical ranges of the plasmaspheric temperature calculated using retarding potential analyzer-based measurements - generally between 0.2 and 2 eV (2000-20,000 K). We also find that the temperature is correlated with L shell and hot plasma density and is negatively correlated with the cold plasma density. We posit that the latter of these three relationships may be indicative of collisional or wave-driven heating of the plasmasphere in the ring current overlap region. We note that these techniques may be easily applied to similar data sets or used for a variety of purposes.

  15. Plasmaspheric Electron Densities and Plasmashere-Ionosphere Coupling Fluxes

    NASA Astrophysics Data System (ADS)

    Lichtenberger, Janos; Cherneva, Nina; Shevtsov, Boris; Sannikov, Dmitry; Ferencz, Csaba; Koronczay, David

    The Automatic Whistler Detector and Analyzer Network (AWDANet) is able to detect and analyze whistlers in quasi-realtime and can provide equatorial electron density data. The plasmaspheric electron densities and ionosphere-plasmasphere coupling fluxes are key parameters for plasmasphere models in Space Weather related investigations, particularly in modeling charged particle accelerations and losses in Radiation Belts. The global AWDANet [1] detects millions of whistlers in a year. The system has been recently completed with automatic analyzer capability in PLASMON (http://plasmon.elte.hu) project. It is based on a recently developed whistler inversion model [2], that opened the way for an automated process of whistler analysis, not only for single whistler events but for complex analysis of multiple-path propagation whistler groups [3]. In this paper we present the results of quasi-real-time runs processing whistlers from quiet and disturb periods from Karymshina station (Kamchatka, Russia). Refilling rates, that are not yet known in details are also presented for the various periods. 1.Lichtenberger, J., C. Ferencz, L. Bodnár, D. Hamar, and P. Steinbach (2008), Automatic whistler detector and analyzer system: Automatic whistler detector, J. Geophys. Res., 113, A12201, doi:10.1029/2008JA013467. 2. Lichtenberger, J. (2009), A new whistler inversion method, J. Geophys. Res., 114, A07222, doi:10.1029/2008JA013799. 3. Lichtenberger, J., C. Ferencz, D. Hamar, P. Steinbach, C. J. Rodger, M. A. Clilverd, and A. B. Collier (2010), Automatic Whistler Detector and Analyzer system: Implementation of the analyzer algorithm, J. Geophys. Res., 115, A12214, doi:10.1029/2010JA015931.

  16. Modeling the plasmasphere to topside ionosphere scale height ratio

    NASA Astrophysics Data System (ADS)

    Marinov, Pencho; Kutiev, Ivan; Belehaki, Anna; Tsagouri, Ioanna

    2015-08-01

    A new model of plasmasphere to topside ionosphere scale heights ratio is developed, based on topside electron density (Ne) profiles deduced from the International Satellites for Ionospheric Studies (ISIS)-1 satellite measurements. The model is able to improve operational algorithms for space weather predictions. The topside ionospheric and plasmaspheric scale heights are determined by the lowest and largest gradients of measured profiles, respectively, converted in dh/dlnNe units. The new model depends on four parameters: the month of the year (M), the local time (LT), the geomagnetic latitude (glat), and the ln(O+) density (zO) at the O+-H+ ion transition height. It is designed to replace the old one-dimensional model of the ratio in the TaD (TSM-assisted Digisonde) profiler. The parameters M, LT, and glat are approximated by trigonometric basis functions, while zO is described by a polynomial. A series of models were produced with different number of coefficients (number of terms) of the basis functions. Comparison between models revealed that those with larger number of coefficients can produce unrealistic extremes of the model curves due to the non-uniform sampling of data along the axes. Further considered is the simplest model approximating M, LT, and glat by simple 24 sinusoidal functions and linearly depending on zO. The model description and its 54 coefficients are given in Appendix 1 and can be used by other users for reconstruction of plasmasphere density profiles. The main variation of the ratio along geomagnetic latitude at fixed values of the other model parameters is illustrated in a series of plots.

  17. Potential of Computer-aided Diagnosis of High Spectral and Spatial (HiSS) MRI in the Classification of Breast Lesions

    PubMed Central

    Bhooshan, Neha; Giger, Maryellen; Medved, Milica; Li, Hui; Wood, Abbie; Yuan, Yading; Lan, Li; Marquez, Angelica; Karczmar, Greg; Newstead, Gillian

    2014-01-01

    Purpose: To compare the performance of CADx analysis of pre-contrast HiSS MRI to that of clinical DCE-MRI in the diagnostic classification of breast lesions. Materials and Methods: Thirty-four malignant and seven benign lesions were scanned using 2D HiSS and clinical 4D DCE-MRI protocols. Lesions were automatically segmented. Morphological features were calculated for HiSS whereas both morphological and kinetic features were calculated for DCE-MRI. After stepwise feature selection, Bayesian artificial neural networks merged selected features, and ROC analysis evaluated the performance with leave-one-lesion-out validation. Results: AUC values of 0.92 ± 0.06 and 0.90 ± 0.05 were obtained using CADx on HiSS and DCE-MRI, respectively, in the task of classifying benign and malignant lesions. While we failed to show that the higher HiSS performance was significantly better than DCE-MRI, non-inferiority testing confirmed that HiSS was not worse than DCE-MRI. Conclusion: CADx of HiSS (without contrast) performed similarly to CADx on clinical DCE-MRI; thus, computerized analysis of HiSS may provide sufficient information for diagnostic classification. The results are clinically important for patients in whom contrast agent is contra-indicated. Even in the limited acquisition mode of 2D single slice HiSS, by using quantitative image analysis to extract characteristics from the HiSS images, similar performance levels were obtained as compared to those from current clinical 4D DCE-MRI. As HiSS acquisitions become possible in 3D, CADx methods can also be applied. Since HiSS and DCE-MRI are based on different contrast mechanisms, the use of the two protocols in combination may increase diagnostic accuracy. PMID:24023011

  18. Roles of whistler mode waves and magnetosonic waves in changing the outer radiation belt and the slot region

    NASA Astrophysics Data System (ADS)

    Li, L. Y.; Yu, J.; Cao, J. B.; Yang, J. Y.; Li, X.; Baker, D. N.; Reeves, G. D.; Spence, H.

    2017-05-01

    Using the Van Allen Probe long-term (2013-2015) observations and quasi-linear simulations of wave-particle interactions, we examine the combined or competing effects of whistler mode waves (chorus or hiss) and magnetosonic (MS) waves on energetic (<0.5 MeV) and relativistic (>0.5 MeV) electrons inside and outside the plasmasphere. Although whistler mode chorus waves and MS waves can singly or jointly accelerate electrons from the hundreds of keV energy to the MeV energy in the low-density trough, most of the relativistic electron enhancement events are best correlated with the chorus wave emissions outside the plasmapause. Inside the plasmasphere, intense plasmaspheric hiss can cause the net loss of relativistic electrons via persistent pitch angle scattering, regardless of whether MS waves were present or not. The intense hiss waves not only create the energy-dependent electron slot region but also remove a lot of the outer radiation belt electrons when the expanding dayside plasmasphere frequently covers the outer zone. Since whistler mode waves (chorus or hiss) can resonate with more electrons than MS waves, they play dominant roles in changing the outer radiation belt and the slot region. However, MS waves can accelerate the energetic electrons below 400 keV and weaken their loss inside the plasmapause. Thus, MS waves and plasmaspheric hiss generate different competing effects on energetic and relativistic electrons in the high-density plasmasphere.

  19. Occurrence of EMIC waves and plasmaspheric plasmas derived from THEMIS observations in the outer magnetosphere: Revisit

    NASA Astrophysics Data System (ADS)

    Kim, K. H.; Kim, G. J.; Lee, D. H.; Kwon, H. J.

    2016-12-01

    We have statistically studied the relationship between electromagnetic ion cyclotron (EMIC) waves and cold plasmaspheric plasma (Nsp) in the L range of 6-12 using the Time History of Events and Macroscale Interactions during Substorms (THEMIS) data for 2008-2011. The important observational results are as follows: (1) Under quiet geomagnetic conditions (Kp = 0-1), the maximum occurrence rate of the hydrogen (H) band EMIC waves appears in the early morning sector (0600-0900 MLT) at the outermost region (L = 10-12). (2) Under moderate and disturbed conditions (Kp > 2), the H-band occurrence rate is higher in the morning-to-early afternoon sector for L > 10. (3) The high occurrence region of helium (He) band waves for Kp = 0-1 varies from L = 7 to 12 in radial distances along the local time (i.e., at L 7 near noon and at L = 8-12 near late afternoon). (4) The He-band waves for Kp > 2 are mainly localized between 1200 and 1800 MLT with a peak around 1500-1600 MLT at L = 8-10. (5) Nsp is much higher for the He-band intervals than for the H-band intervals by a factor of 10 or more. The He-band high occurrence appears at a steep Nsp gradient region. (6) The morning-afternoon asymmetry of the normalized frequency seen both in H and He bands is similar to the asymmetric distribution of Nsp along the local time. These observations indicate that the cold plasma density plays a significant role in determining the spectral properties of EMIC waves. We discuss whether a morning-afternoon asymmetry of the EMIC wave properties can be explained by the spatial distribution of cold plasmaspheric plasma.

  20. Occurrence of EMIC waves and plasmaspheric plasmas derived from THEMIS observations in the outer magnetosphere: Revisit

    NASA Astrophysics Data System (ADS)

    Kim, Gi-Jeong; Kim, Khan-Hyuk; Lee, Dong-Hun; Kwon, Hyuck-Jin; Park, Jong-Sun

    2016-10-01

    We have statistically studied the relationship between electromagnetic ion cyclotron (EMIC) waves and cold plasmaspheric plasma (Nsp) in the L range of 6-12 using the Time History of Events and Macroscale Interactions during Substorms (THEMIS) data for 2008-2011. The important observational results are as follows: (1) Under quiet geomagnetic conditions (Kp ≤ 1), the maximum occurrence rate of the hydrogen (H) band EMIC waves appears in the early morning sector (0600-0900 MLT) at the outermost region (L= 10-12). (2) Under moderate and disturbed conditions (Kp ≥ 2), the H-band occurrence rate is higher in the morning-to-early-afternoon sector for L > 10. (3) The high-occurrence region of helium (He) band waves for Kp ≤ 1 varies from L = 7 to 12 in radial distances along the local time (i.e., at L ˜ 7 near noon and at L= 8-12 near late afternoon). (4) The He-band waves for Kp ≥ 2 are mainly localized between 1200 and 1800 MLT with a peak around 1500-1600 MLT at L= 8-10. (5) Nsp is much higher for the He-band intervals than for the H-band intervals by a factor of 10 or more. The He-band high occurrence appears at a steep Nsp gradient region. (6) The morning-afternoon asymmetry of the normalized frequency seen both in H-band and He-band is similar to the asymmetric distribution of Nsp along the local time. These observations indicate that the cold plasma density plays a significant role in determining the spectral properties of EMIC waves. We discuss whether a morning-afternoon asymmetry of the EMIC wave properties can be explained by the spatial distribution of cold plasmaspheric plasma.

  1. SAR arc observation as the mapping of plasmasphere dusk-bulge during a magnetic storm

    NASA Astrophysics Data System (ADS)

    Ievenko, Igor; Parnikov, Stanislav

    2016-07-01

    The stable auroral red (SAR) arcs are the consequence of interaction of the outer plasmasphere (plasmapause) with energetic ions of the ring current. In this work we analyze the observation of aurorae and SAR arc with the all-sky imager (ASI) at the Yakutsk meridian (130ºE; 200ºE, geom.) during the magnetic storm main phase on March 17, 2015. ASI registers the SAR arc with a maximum of its intensity and the latitude on the westward horizon of station from the start of observations at ~1116 UT during the decrease of magnetic activity after the main phase onset of magnetic storm at ~0630 UT. The measurements of the thermal ion fluxes with ECT HOPE Instrument aboard the Van Allen Probes B satellite at ~1230 UT testify to a plasmapause location on L ~ 3.5 at the meridian ~1825 MLT. The inner boundary of the energetic H+ and O+ ions flux has been registered by the satellite on L ~ 2.8-3.3 at the meridian ~ 1800 MLT at 1210-1220 UT. At this time ASI observes SAR arc up to a meridian 1840 MLT on the westward horizon of station. Further the dynamics of aurorae in the 557.7, 630.0, 470.9 and 486.1 (Hβ) nm emissions owing to sharp changes in the solar wind and during three substorms is observed. We consider differences in the precipitation dynamics of energetic protons and electrons during substorms. It is shown that the SAR arc registered with ASI maps the ring current overlap with the region of plasmasphere dusk-bulge or plume. The research is supported by RFBR grant No 15-05-02372 a.

  2. Harmonic H(+) gyrofrequency structures in auroral hiss observed by high-altitude auroral sounding rockets

    NASA Technical Reports Server (NTRS)

    Kintner, P. M.; Vago, J.; Scales, W.; Yau, A.; Whalen, B.; Arnoldy, R.; Moore, T.

    1991-01-01

    Two recent sounding rocket experiments have yielded VLF wave data with spectral structures ordered by the hydrogen gyrofrequency. The spectral structures occur near and above the lower hybrid frequency in association with auroral hiss. These structures are observed within and near regions of auroral electron precipitation and transverse ion acceleration. They are accompanied by auroral hiss but are anticorrelated with spectral peaks at the lower hybrid frequency. They are typically found above 500 km altitude, have no measurable magnetic component, and are at least occasionally short wavelength. Because the spectral structures appear to be electrostatic, are ordered by the hydrogen gyrofrequency, and are short wavelength, the structures are interpreted as modes which connect the lower hybrid mode with the hydrogen Bernstein modes. A study of the plasma wave mode structure in the vicinity of the lower hybrid frequency is presented to substantiate this interpretation. These results imply that these waves are a common feature of the auroral zone ionsphere above 500 km altitude and exist any time that auroral hiss exists. The absence of previous satellite observations of this phenomenon can be explained by Doppler broadening.

  3. Pion correlations in relativistic heavy ion collisions at Heavy Ion Spectrometer Systems (HISS)

    SciTech Connect

    Christie, W.B. Jr.

    1990-05-01

    This thesis contains the setup, analysis and results of experiment E684H Multi-Pion Correlations in Relativistic Heavy Ion Collisions''. The goals of the original proposal were: (1) To initiate the use of the HISS facility in the study of central Relativistic Heavy Ion Collisions (RHIC). (2) To perform a second generation experiment for the detailed study of the pion source in RHIC. The first generation experiments, implied by the second goal above, refer to pion correlation studies which the Riverside group had performed at the LBL streamer chamber. The major advantage offered by moving the pion correlation studies to HISS is that, being an electronic detector system, as opposed to the Streamer Chamber which is a visual detector, one can greatly increase the statistics for a study of this sort. An additional advantage is that once one has written the necessary detector and physics analysis code to do a particular type of study, the study may be extended to investigate the systematics, with much less effort and in a relatively short time. This paper discusses the Physics motivation for this experiment, the experimental setup and detectors used, the pion correlation analysis, the results, and the conclusions possible future directions for pion studies at HISS. If one is not interested in all the details of the experiment, I believe that by reading the sections on intensity interferometry, the section the fitting of the correlation function and the systematic corrections applied, and the results section, one will get a fairly complete synopsis of the experiment.

  4. Harmonic H sup + gyrofrequency structures in auroral hiss observed by high-altitude auroral sounding rockets

    SciTech Connect

    Kintner, P.M.; Vago, J. ); Scales, W. ); Yau, A.; Whalen, B. ); Arnoldy, R. ); Moore, T. )

    1991-06-01

    Two recent sounding rocket experiments have yielded VLF wave data with spectral structures ordered by the hydrogen gyrofrequency. The spectral structures occur near and above the lower hybrid frequency in association with auroral hiss. These structures are observed within and near regions of auroral electron precipitation and transverse ion acceleration. They are accompanied by auroral hiss but are anticorrelated with spectral peaks at the lower hybrid frequency. They are typically found above 500 km altitude, have no measureable magnetic component, and are at least occasionally short wavelength (k{rho}{sub i}{ge}1). Because the spectral structures appear to be electrostatic, are ordered by the hydrogen gyrofrequency, and are short wavelength, the authors interpret the structures as modes which connect the lower hybrid mode with the hydrogen Bernstein modes. A study of the plasma wave mode structure in the vicinity of the lower hybrid frequency is presented to substantiate this interpretation. The results imply that these waves are a common feature of the auroral zone ionosphere above 500 km altitude and exist any time that auroral hiss exists. The absence of previous satellite abservations of this phenomenon can be explained by Doppler broadening.

  5. Plasmaspheric Shoulders Seen in the Global Euv Images and Its Relation to the Overshielding Electric Field Identified By Ground-Based Magnetometers

    NASA Astrophysics Data System (ADS)

    Yoshikawa, I.; Hamaguchi, T.

    2014-12-01

    We have investigated plasmaspheric EUV images and ground-based magnetic field measurements to understand the formation of the plasmaspheric shoulder. By surveying the all the EUV image of plasmasphere, we have identified the 13 plasmaspheric shoulders. 12 of them were coincident with overshielding identified by magnetic field measurement and emerged in the dawnside. It is most likely that overshielding builds up the plasmaspheric shoulders, as predicted by Goldstein et al. [2002, 2003].

  6. Ground and satellite observations of the SAR arc in the dusk-bulge region of the plasmasphere

    NASA Astrophysics Data System (ADS)

    Ievenko, Igor; Parnikov, Stanislav; Alexeyev, Valeriy

    It is known that stable auroral red (SAR) arcs are the consequence of interaction of the outer plasmasphere (plasmapause) with energetic ions of the ring current. An arisen downward flux of superthermal electrons along the magnetic field lines increases the ambient electron temperature at the altitudes of ionosphere F2 region in the form of Te-peak. As a result, an enhancement of the atomic oxygen red line intensity in the SAR arc mapping the plasmapause (cold plasma density radial gradient) takes place. A boundary location of plasmasphere (plasmapause) in the dusk-bulge region strongly depends on LT and shifts towards the lower latitudes during evening hours. The ground observer can register a relative motion of this boundary projection at the height of the ionosphere F2 region if it is mapped by the red arc at this time. In this work the results of observations of the SAR arc equatorward movement by the meridian scanning photometer at 19-20 LT at the Yakutsk meridian (199ºE geomagnetic longitude) during a recovery phase of the weak magnetic storm on February 7, 2000 are presented. The data of simultaneous registration of Te-peaks aboard DMSP F14 and F15 satellites at the meridian of optical observations and eastward of it shows that the SAR arc in this event maps the cold plasma density radial gradient in the dusk-bulge region. A wide band of the westward ionospheric drift (SAPS) observed by F14 and F15 is probably a specific signature of this plasmasphere region.

  7. Plasmaspheric H+, He+, O+, He++, and O++ Densities and Temperatures

    NASA Astrophysics Data System (ADS)

    Gallagher, D. L.; Craven, P. D.; Comfort, R. H.

    2013-12-01

    Thermal plasmaspheric densities and temperatures for five ion species have recently become available, even though these quantities were derived some time ago from the Retarding Ion Mass Spectrometer onboard the Dynamics Explorer 1 satellite over the years 1981-1984. The quantitative properties will be presented. Densities are found to have one behavior with lessor statistical variation below about L=2 and another with much greater variability above that L-shell. Temperatures also have a behavior difference between low and higher L-values. The density ratio He++/H+ is the best behaved with values of about 0.2% that slightly increase with increasing L. Unlike the He+/H+ density ratio that on average decreases with increasing L-value, the O+/H+ and O++/H+ density ratios have decreasing values below about L=2 and increasing average ratios at higher L-values. Hydrogen ion temperatures range from about 0.2 eV to several 10s of eV for a few measurements, although the bulk of the observations are of temperatures below 3 eV, again increasing with L-value. The temperature ratios of He+/H+ are tightly ordered around 1.0 except for the middle plasmasphere between L=3.5 and 4.5 where He+ temperatures can be significantly higher. The temperatures of He++, O+, and O++ are consistently higher than H+.

  8. Studies on Equatorial Shock Formation During Plasmaspheric Refilling

    NASA Technical Reports Server (NTRS)

    Singh, Nagendra

    1995-01-01

    During the grant period from August 1, 1994 to October 31, 1995 we have continued to investigate the effects of plasma wave instabilities on the early stage plasmaspheric refilling. Since ion beams are the primary feature of the interhemispheric plasma flows during the early stage refilling, ion-beam driven instabilities and associated waves are of primary interest. The major findings of this research are briefly summarized here. After a systematic examination of the relevant plasma instabilities, we realized that when the interhemispheric plasma flows begin to interpenetrate at the equator, the most relevant plasma instability is the electrostatic ion cyclotron wave instability. Only at later stages the ion-acoustic instability may be affecting the plasma flow. An interesting property of the electrostatic ion cyclotron wave is that it heats ions perpendicular to the magnetic field. When the ions in the field-aligned flows are transversely heated, they are trapped in the magnetic flux tube, thus affecting the refilling process. The eic wave instability is a microprocess with scale length of the order of ion Larmor radius and the corresponding time scale is the ion cyclotron period. We have attempted to tackle the problem for the plasmaspheric refilling by incorporating the effects of eic wave instability on the mesoscale plasma flow when the properties of the latter exceeds the critical conditions for the former. We have compared the results on refilling from the model with and without the eic instability effects.

  9. VLF wave intensity in the plasmasphere due to tropospheric lightning

    NASA Astrophysics Data System (ADS)

    Colman, J. J.; Starks, M. J.

    2013-07-01

    climatology of VLF (very low frequency) wave intensity from lightning in the plasmasphere is constructed. Starting from Optical Transient Detector/Lightning Imaging Sensor (OTD/LIS) lightning data representing 1995-2005, a climatology of strikes is assembled with 1° × 1° latitude-longitude spatial resolution, averaged into 2 h bins for each month of the year. Assuming a linear relationship between optical flash rate and VLF power flux, and that the VLF amplitude drops off as one over distance, a proxy for VLF power is developed. A typical lightning spectrum is applied and the values are scaled by appropriate transionospheric absorptions for each time and place. These values are mapped along geomagnetic field lines in order to compare them to E-field spectral densities measured by the DEMETER satellite between 2005 and 2009. An overview of the DEMETER survey mode data is presented which leads to the best scaling of the lightning VLF climatology in LEO (low earth orbit). The resulting data set represents a monthly, 2-hour, solar minimum climatology of VLF wave intensity from lightning in LEO. Finally, the E-field spectral densities are converted to Poynting flux, mapped to the plasmasphere, and converted to B-field spectral densities. Good overall agreement is found with previous observations and estimates. This new climatology is expected to have a significant impact on calculations of pitch-angle diffusion for relativistic electrons in the inner radiation belt.

  10. A novel data assimilation technique for the plasmasphere

    NASA Astrophysics Data System (ADS)

    Nikoukar, Romina; Bust, Gary; Murr, David

    2015-10-01

    We present a novel technique for imaging and data assimilation of the topside ionosphere and plasmasphere. The methodology is based upon the three-dimensional variational technique (3DVAR), where an empirical background model is utilized. However, to prevent nonphysical vertical variation in density estimates, we devise statistical methods to enforce a roughness penalty in the traditional 3DVAR optimization. The upward looking total electron content (TEC) observations from the Global Positioning System (GPS) receiver on board Constellation Observing System for Meteorology, Ionosphere and Climate satellites are utilized in the assimilation algorithm. The estimation results show reasonable agreement with in situ density measurements of Defense Meteorological Satellite Program satellites and Van Allen Probes derived densities during geomagnetically quiet and severe storm time conditions, respectively. These preliminary results demonstrate great potential for the use of GPS TEC measurements from low-Earth orbit satellites in monitoring and studying the morphology and dynamics of large-scale structures of the electron density in the topside ionosphere and plasmasphere.

  11. Plasmaspheric H+, He+, He++, O+, and O++ Densities and Temperatures

    NASA Technical Reports Server (NTRS)

    Gallagher, G. L.; Craven, P. D.; Comfort, R. H.

    2013-01-01

    Thermal plasmaspheric densities and temperatures for five ion species have recently become available, even though these quantities were derived some time ago from the Retarding Ion Mass Spectrometer onboard the Dynamics Explorer 1 satellite over the years 1981-1984. The quantitative properties will be presented. Densities are found to have one behavior with lessor statistical variation below about L=2 and another with much greater variability above that Lshell. Temperatures also have a behavior difference between low and higher L-values. The density ratio He++/H+ is the best behaved with values of about 0.2% that slightly increase with increasing L. Unlike the He+/H+ density ratio that on average decreases with increasing Lvalue, the O+/H+ and O++/H+ density ratios have decreasing values below about L=2 and increasing average ratios at higher L-values. Hydrogen ion temperatures range from about 0.2 eV to several 10s of eV for a few measurements, although the bulk of the observations are of temperatures below 3 eV, again increasing with L-value. The temperature ratios of He+/H+ are tightly ordered around 1.0 except for the middle plasmasphere between L=3.5 and 4.5 where He+ temperatures can be significantly higher. The temperatures of He++, O+, and O++ are consistently higher than H+.

  12. Plasmaspheric H+, He+, O+, He++, and O++ Densities and Temperatures

    NASA Technical Reports Server (NTRS)

    Gallagher, D. L.; Craven, P. D.; Comfort H.

    2013-01-01

    Thermal plasmaspheric densities and temperatures for five ion species have recently become available, even though these quantities were derived some time ago from the Retarding Ion Mass Spectrometer onboard the Dynamics Explorer 1 satellite over the years 1981-1984. The quantitative properties will be presented. Densities are found to have one behavior with lessor statistical variation below about L=2 and another with much greater variability above that Lshell. Temperatures also have a behavior difference between low and higher L-values. The density ratio He++/H+ is the best behaved with values of about 0.2% that slightly increase with increasing L. Unlike the He+/H+ density ratio that on average decreases with increasing Lvalue, the O+/H+ and O++/H+ density ratios have decreasing values below about L=2 and increasing average ratios at higher L-values. Hydrogen ion temperatures range from about 0.2 eV to several 10s of eV for a few measurements, although the bulk of the observations are of temperatures below 3 eV, again increasing with L-value. The temperature ratios of He+/H+ are tightly ordered around 1.0 except for the middle plasmasphere between L=3.5 and 4.5 where He+ temperatures can be significantly higher. The temperatures of He++, O+, and O++ are consistently higher than H+.

  13. Sources of variability in equatorial topside ionospheric and plasmaspheric temperatures

    NASA Astrophysics Data System (ADS)

    Varney, Roger H.; Hysell, David L.; Huba, J. D.

    2013-10-01

    Jicamarca measurements of electron temperatures at high altitudes (500-1500km) from the last solar minimum routinely show variations of hundreds of Kelvin from day-to-day. Possible sources of these variations are explored using the SAMI2-PE is another model of the ionosphere including photoelectron transport (SAMI2-PE) model, which includes a multistream photoelectron transport model. Changes to the electric fields, meridional winds, and thermospheric densities can all change the electron densities and temperatures at high altitudes. The high altitude electron temperatures are primarily determined by a balance between heating from photoelectrons which travel up the field lines and thermal diffusion which carries heat back down the field lines. The winds and electric fields will change the altitude and densities of the off-equatorial F-region peaks, especially on the field lines connected to the equatorial arcs. The densities and temperatures in the plasmasphere will self consistently adjust themselves to achieve diffusive equilibrium with the off-equatorial F-regions. Furthermore, decreases in the density and/or altitude of the F-region makes it easier for photoelectrons to escape to high altitudes. These connections between the equatorial plasmasphere, the off-equatorial F-regions, and the neutral thermosphere suggest that high altitude measurements at Jicamarca could be used to study thermospheric variability.

  14. Premidnight plasmaspheric {open_quotes}plumes{close_quotes}

    SciTech Connect

    Ober, D.M.; Horwitz, J.L.; Thomsen, M.F.; Elphic, R.C.; McComas, D.J.; Belian, R.D.; Moldwin, M.B.

    1997-06-01

    To explain observations of brief intervals of cold, dense plasma by geosynchronous satellites in the midnight sector prior to or during substorm onset, it has recently been proposed that dense plasmaspheric plasma is drawn out to geosynchronous orbit in the premidnight region by inductive electric fields during the growth phase of a geomagnetic substorm. We present here the results of a statistical study of such intervals observed with the Los Alamos magnetospheric plasma analyzer (MPA) on geosynchronous satellite 1989-046 between March and December 1993. We find that these premidnight cold plasma intervals occur only after extended periods of low magnetospheric activity identified by Kp and the midnight boundary index (MBI). We also find that the satellite typically enters the cold plasma region from the trough region and exits it into the plasma sheet. Finally, while measurements of the flow velocity of the cold plasma are rendered uncertain by the asymmetric spacecraft charge or photoelectron sheath, such measurements show no evidence of the outward flow that would be expected from the extrusion hypothesis. Rather, there are some indications that these cold plasma regions flow sunward in the (corotation) satellite frame. These results suggest an alternative explanation for the premidnight cold plasma: corotation-dominated transport of dayside plasmaspheric structures into the premidnight sector. The implications of our observations for the extrusion hypothesis and for the alternative explanation are discussed.{copyright} 1997 American Geophysical Union

  15. Plasmaspheric ion temperature dynamics related to ionospheric and ring current parameter variations: Multipoint observations

    NASA Astrophysics Data System (ADS)

    Kotova, Galina; Bezrukikh, Vladilen; Verigin, Mikhael

    Thermal plasma measurements on INTERBALL 2 (1996) and its subsatellite MAGION 5 (1999 - 2001) are used to deduce proton temperature and density distributions in the Earth's plasmasphere. A study of the temperature behavior during moderate magnetic storms development revealed that in the inner plasmasphere (L ¡ 2.8) night time ion temperature was depressed in the storm main phase, but exceeded quiet time values in the storm recovery phase. Multipoint observations in the plasmasphere, ionosphere (DMSP) and magnetosphere (IMAGE, POLAR) are used for examining possible reasons of such temperature behavior. This work was partially supported by Programs P16/2 and OFN 16 of Russian Academy of Sciences.

  16. Statistical study of ion flows in the dayside and nightside plasmasphere

    NASA Astrophysics Data System (ADS)

    Menietti, J. D.; Burch, J. L.; Gallagher, D. L.

    1988-07-01

    A statistical survey of ion flows has been performed with the DE-1 high-altitude plasma instrument during a period of solar maximum conditions. The results indicate that a significant dayside to nightside interhemispheric flow occurs in the outer plasmasphere during periods of increased magnetic activity along convecting magnetic field lines. The ion temperature is found to decrease steadily equatorward into the outer plasmasphere. Although ion abundance ratios obtained using the retarding ion mass spectrometer show that the predominant ion species was H(+), relatively large densities of O(+) were observed in the plasmasphere on several passes.

  17. Plasmasphere refilling: New numerical and observational tools

    SciTech Connect

    Winske, D.; Gary, S.P.; Thomsen, M.F.; Miller, R.H.

    1997-08-01

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The outflow of plasma from the ionosphere and its interactions in the outer magnetosphere remain important problems in space physics. While outflow is a continuous process, it becomes even more important after geomagnetic substorms when magnetic field lines that have been vented of plasma are reconnected. The purpose of this project was to develop new computational, theoretical, and observational tools to study plasma dynamics and heating associated with the outflow and refilling processes. In particular, we have developed new numerical methods to model the transition from collisional plasma flow at low altitudes to collisionless behavior at high altitudes and incorporated them in a multi-species kinetic simulation model to model the outflow process. We have also investigated electromagnetic instabilities in the outer magnetosphere to understand their contribution to the heating of upflowing protons and minority ions. In addition, new observational techniques have been used to analyze geosynchronous plasma data and to assess the effect of the spacecraft potential on the observations.

  18. Determination of solar cycle variations of midlatitude ELF/VLF chorus and hiss via automated signal detection

    NASA Astrophysics Data System (ADS)

    Golden, D. I.; Spasojevic, M.; Inan, U. S.

    2011-03-01

    An automated algorithm for detecting chorus and hiss emissions in ground-based extremely low frequency/very low frequency (ELF/VLF) wave receiver data is developed and applied to 10 years of data collected at Palmer Station, Antarctica (L = 2.4, 50°S invariant latitude). The algorithm consists of three major processing steps. First, sferics and power line hum are removed from the broadband data. Second, individual events are detected and a set of 19 scalar event parameters are determined. Finally, on the basis of the parameters, detected events are categorized by a sequential pair of neural networks as either chorus, hiss, or noise. The detector runs on a modern 8-core computer at a speed of 350x real time. Results of training indicate that the neural networks are capable of differentiating between noise and emissions with a 92% success rate and between chorus and hiss with an 84% success rate. Data collected at Palmer from May 2000 to May 2010 were processed, and yearly and seasonal trends of chorus and hiss are analyzed. Yearly occurrence rates of chorus and hiss are strongly dependent on the geomagnetic disturbance level, as measured by Kp and AE, whereas seasonal occurrence rates are more strongly dependent on variations of the day/night terminator and associated variations in ionospheric absorption.

  19. Retrieval of plasmaspheric He+ density distributions from EUV imaging data

    NASA Astrophysics Data System (ADS)

    Keika, K.; Brandt, P. C.; Toigo, A. D.; Demajistre, R.

    2013-12-01

    We retrieve the He+ density distribution in the plasmasphere from EUV imaging data, by using a forward modeling technique. We use a parametric model for the density distribution to simulate line-of-sight integrated He+ densities (i.e., EUV images), and then find parameters that give the best fit to real EUV images. The He+ density (nHe+) distribution is described as a function of radial distance (r) and L: nHe+ = n0 (L0/L)^α_L * (r0L/rL0)^α_f, where n0 and L0 are He+ density and L value at the inner boundary of this model (i.e., the topside ionosphere), and α_L and α_f are parameters that represent L and field-aligned dependence of He+ density, respectively. We evaluated how well our forward model can retrieve the He+ density distribution, by performing the following analysis. (1) EUV emission intensities were simulated through the EUV camera response function, given a vantage point of the IMAGE satellite. (2) EUV images were simulated for a large number of (α_L, α_f) pairs: α_L was chosen from 4.0 to 6.0 with 0.1 increment, and α_f was from 0.0 to 2.0 with 0.1 increment. (3) The EUV image corresponding to the (α_L, α_f)=(5.0, 1.0) pair was chosen as our synthetic EUV image. After noise was added to the synthetic image, the forward modeling was applied to all simulated images made in (2). The reduced chi2 (rchi2) was used to determine how well simulated image data fit to the synthetic image. The results of this analysis confirm that the He+ density distributions can be retrieved with good certainty within |40 deg.| MLAT. However, beyond this magnetic latitude it is difficult to determine the L dependence or field-aligned dependence of plasmaspheric He+ density. For further evaluation and better accuracy, we use density distributions provided by physics-based ionosphere/plasmasphere models as our synthetic data. We also apply our forward simulation model to real EUV image data from the EUV imager onboard IMAGE.

  20. The trapping of equatorial magnetosonic waves in the Earth's outer plasmasphere

    NASA Astrophysics Data System (ADS)

    Ma, Q.; Li, W.; Chen, L.; Thorne, R. M.; Kletzing, C. A.; Kurth, W. S.; Hospodarsky, G. B.; Reeves, G. D.; Henderson, M. G.; Spence, H. E.

    2014-09-01

    We investigate the excitation and propagation of equatorial magnetosonic waves observed by the Van Allen Probes and describe evidence for a trapping mechanism for magnetosonic waves in the Earth's plasmasphere. Intense equatorial magnetosonic waves were observed inside the plasmasphere in association with a pronounced proton ring distribution, which provides free energy for wave excitation. Instability analysis along the inbound orbit demonstrates that broadband magnetosonic waves can be excited over a localized spatial region near the plasmapause. The waves can subsequently propagate into the inner plasmasphere and remain trapped over a limited radial extent, consistent with the predictions of near-perpendicular propagation. By performing a similar analysis on another observed magnetosonic wave event, we demonstrate that magnetosonic waves can also be trapped within local density structures. We suggest that perpendicular wave propagation is important for explaining the presence of magnetosonic waves in the Earth's plasmasphere at locations away from the generation region.

  1. Evaluating the Accuracy of Plasmasphere Data Assimilation from Ground-Based Observations

    NASA Astrophysics Data System (ADS)

    Jorgensen, A. M.; Lichtenberger, J.; Friedel, R. H.; Clilverd, M.; Heilig, B.; Vellante, M.; Raita, T.; Rodger, C. J.; Reda, J.; Collier, A.; Holzworth, R. H.; Ober, D. M.; Boudouridis, A.; Zesta, E.; Chi, P. J.

    2013-05-01

    VLF and magnetometer observations can be used to remotely sense the plasmasphere. VLF whistler waves can be used to measure the electron density and magnetic Field Line Resonance (FLR) measurements can be used to measure the mass density. In principle it is then possible to remotely map the plasmasphere with a network of ground-based stations which are also less expensive and more permanent than satellites. The PLASMON project, funded by the EU FP-7 program, is in the process of doing just this. A large number of ground-based observations will be input into a data assimilative framework which models the plasmasphere structure and dynamics. The data assimilation framework combines the Ensemble Kalman Filter with the Dynamic Global Core Plasma Model. Here we simulate the observations from these networks, with appropriate uncertainties, and use them to drive the data assimilation framework to recover the plasmaspheric configuration. We will discuss the level of accuracy that can be achieved.

  2. Evaluating the Accuracy of Plasmasphere Data Assimilation from Ground-Based Observations

    NASA Astrophysics Data System (ADS)

    Jorgensen, A. M.; Lichtenberger, J.; Duffy, J.; Friedel, R. H.; Clilverd, M.; Heilig, B.; Vallante, M.; Manninen, J. K.; Rodger, C. J.; Collier, A.; Reda, J.; Holzworth, R. H.; Ober, D. M.; Boudouridis, A.; Zesta, E.; Chi, P. J.

    2012-12-01

    VLF and magnetometer observations can be used to remotely sense the plasmasphere. VLF whistler waves can be used to measure the electron density and magnetic Field Line Resonance (FLR) measurements can be used to measure the mass density. In principle it is then possible to remotely map the plasmasphere with a network of ground-based stations which are also less expensive and more permanent than satellites. The PLASMON project, funded by the EU FP-7 program, is in the process of doing just this. A large number of ground-based observations will be input into a data assimilative framework which models the plasmasphere structure and dynamics. The data assimilation framework combines the Ensemble Kalman Filter with the Dynamic Global Core Plasma Model. Here we simulate the observations from these networks, with appropriate uncertainties, and use them to drive the data assimilation framework to recover the plasmaspheric configuration. We will discuss the level of accuracy that can be achieved.

  3. Direct Measurements of Reconnection Rate Attenuation by Plasmasphere Plumes

    NASA Astrophysics Data System (ADS)

    Sanchez, E. R.; Takahashi, K.

    2013-12-01

    It is widely hypothesized that mass loading of the magnetosphere (the process whereby the average mass density of the magnetosphere increases from its nominal value) significantly impacts solar wind-magnetosphere coupling and circulation within the magnetosphere. One important way in which mass loading can affect the magnetosphere occurs when enhanced convection after a lull in geomagnetic activity brings super-dense plasma from the plasmasphere (the so-called plasmsphere plume) into the dayside reconnection site. We measured the magnetic flux across the dayside polar cap boundary (a proxy of the dayside magnetic field reconnection rate) and tracked the sunward migration of the plasma plume for three storms that occurred after long intervals of quiet conditions. Significant intermittent reduction in the dayside reconnection potential (approximately 66% in the most pronounced case) was observed in the hours following the onset of negative IMF Bz condition, in agreement with the hypothesis that super-dense magnetospheric plasma convected into the dayside magnetopause inhibits reconnection.

  4. Temporal features of the refilling of a plasmaspheric flux tube

    NASA Technical Reports Server (NTRS)

    Singh, Nagendra; Schunk, R. W.; Thiemann, H.

    1986-01-01

    The refilling of plasmaspheric flux tubes was studied by assuming that the protonosphere provides an ionospheric boundary where the H(+) density can be assumed; the supersonic flow in the flux tube is driven by the depletion of the plasma from the flux tube, while the base density and pressure in the protonosphere remain constant. The time-dependent continuity and momentum equations for the H(+) ions were solved. The electron gas was assumed to obey the Boltzmann law, and the proton gas was assumed to be isothermal. In agreement with the postulate of Banks et al. (1971), it was found that an important feature of the refilling is the formation of a shock pair at the equator; as the shocks propagate toward the ionosphere, the refilling occurs. Depending on the density at the ionospheric boundaries, a fair agreement was found between the refilling rates obtained for L = 6.6 and those from the GEOS 2 observations.

  5. Analysis of plasmaspheric plumes: CLUSTER and IMAGE observations and numerical simulations

    NASA Technical Reports Server (NTRS)

    Darouzet, Fabien; DeKeyser, Johan; Decreau, Pierrette; Gallagher, Dennis; Pierrard, Viviane; Lemaire, Joseph; Dandouras, Iannis; Matsui, Hiroshi; Dunlop, Malcolm; Andre, Mats

    2005-01-01

    Plasmaspheric plumes have been routinely observed by CLUSTER and IMAGE. The CLUSTER mission provides high time resolution four-point measurements of the plasmasphere near perigee. Total electron density profiles can be derived from the plasma frequency and/or from the spacecraft potential (note that the electron spectrometer is usually not operating inside the plasmasphere); ion velocity is also measured onboard these satellites (but ion density is not reliable because of instrumental limitations). The EUV imager onboard the IMAGE spacecraft provides global images of the plasmasphere with a spatial resolution of 0.1 RE every 10 minutes; such images acquired near apogee from high above the pole show the geometry of plasmaspheric plumes, their evolution and motion. We present coordinated observations for 3 plume events and compare CLUSTER in-situ data (panel A) with global images of the plasmasphere obtained from IMAGE (panel B), and with numerical simulations for the formation of plumes based on a model that includes the interchange instability mechanism (panel C). In particular, we study the geometry and the orientation of plasmaspheric plumes by using a four-point analysis method, the spatial gradient. We also compare several aspects of their motion as determined by different methods: (i) inner and outer plume boundary velocity calculated from time delays of this boundary observed by the wave experiment WHISPER on the four spacecraft, (ii) ion velocity derived from the ion spectrometer CIS onboard CLUSTER, (iii) drift velocity measured by the electron drift instrument ED1 onboard CLUSTER and (iv) global velocity determined from successive EUV images. These different techniques consistently indicate that plasmaspheric plumes rotate around the Earth, with their foot fully co-rotating, but with their tip rotating slower and moving farther out.

  6. Analysis of plasmaspheric plumes: CLUSTER and IMAGE observations and numerical simulations

    NASA Technical Reports Server (NTRS)

    Darouzet, Fabien; DeKeyser, Johan; Decreau, Pierrette; Gallagher, Dennis; Pierrard, Viviane; Lemaire, Joseph; Dandouras, Iannis; Matsui, Hiroshi; Dunlop, Malcolm; Andre, Mats

    2005-01-01

    Plasmaspheric plumes have been routinely observed by CLUSTER and IMAGE. The CLUSTER mission provides high time resolution four-point measurements of the plasmasphere near perigee. Total electron density profiles can be derived from the plasma frequency and/or from the spacecraft potential (note that the electron spectrometer is usually not operating inside the plasmasphere); ion velocity is also measured onboard these satellites (but ion density is not reliable because of instrumental limitations). The EUV imager onboard the IMAGE spacecraft provides global images of the plasmasphere with a spatial resolution of 0.1 RE every 10 minutes; such images acquired near apogee from high above the pole show the geometry of plasmaspheric plumes, their evolution and motion. We present coordinated observations for 3 plume events and compare CLUSTER in-situ data (panel A) with global images of the plasmasphere obtained from IMAGE (panel B), and with numerical simulations for the formation of plumes based on a model that includes the interchange instability mechanism (panel C). In particular, we study the geometry and the orientation of plasmaspheric plumes by using a four-point analysis method, the spatial gradient. We also compare several aspects of their motion as determined by different methods: (i) inner and outer plume boundary velocity calculated from time delays of this boundary observed by the wave experiment WHISPER on the four spacecraft, (ii) ion velocity derived from the ion spectrometer CIS onboard CLUSTER, (iii) drift velocity measured by the electron drift instrument ED1 onboard CLUSTER and (iv) global velocity determined from successive EUV images. These different techniques consistently indicate that plasmaspheric plumes rotate around the Earth, with their foot fully co-rotating, but with their tip rotating slower and moving farther out.

  7. Analytic description of the electron temperature behavior in the upper ionosphere and plasmasphere

    NASA Technical Reports Server (NTRS)

    Khazanov, G. V.; Nagy, A. F.; Gombosi, T. I.; Koen, M. A.; Cariglia, S. J.

    1992-01-01

    Approximate analytic solutions to the well-known and commonly used time-dependent electron energy balance equation for the upper ionosphere and plasmasphere have been obtained and are discussed. The various potential heating sources for the terrestrial plasmasphere are summarized and the corresponding electron temperatures and related characteristic heating and cooling times are calculated. A comparison between the analytic expressions for the temperature variations and relevant measurements shows excellent agreement.

  8. Global Observing System Simulation Experiments of the Ionosphere, Thermosphere and Plasmasphere

    DTIC Science & Technology

    2013-10-30

    variability. As many of these structures as desired can be added to the background density field. 2. Traveling Ionospheric Disturbances (TIDS): IDL...GLOBAL OBSERVING SYSTEM SIMULATION EXPERIMENTS OF THE IONOSPHERE , THERMOSPHERE AND PLASMASPHERE LARS DYRUD JOHNS HOPKINS UNIVERSITY, THE 10/30/2013...21-10-2013 Final Report July 2012 - July 2013 Global OSSE of the Ionosphere , Thermosphere and Plasmasphere FA9550-12-1-0309 Gary Bust Lars Dyrud The

  9. Where does the plasmasphere begin? Revisit to topside ionospheric profiles in comparison with plasmaspheric TEC from Jason-1

    NASA Astrophysics Data System (ADS)

    Lee, Han-Byul; Kim, Yong Ha; Kim, Eunsol; Hong, Junseok; Kwak, Young-Sil

    2016-10-01

    Topside ionospheric profiles have been measured by Alouette 1 and ISIS 1/2 in the periods of 1962-1972 and 1972-1979, respectively. The profiles cover from the orbital altitude of 1000 km to the F2 peak and show large variations over local time, latitude, and seasons. We here analyze these variations in comparison with plasmaspheric total electron contents (pTECs) that were measured by Jason-1 satellite from the altitude of 1336 km to 20,200 km (GPS orbit). The scale heights of the profiles are generally smaller in the daytime than nighttime but show large day-to-day variations, implying that the ionospheric profiles at 1000 km are changing dynamically, rather than being in diffusive equilibrium. We also derived transition heights between O+ and H+, which show a clear minimum at dawn for low-latitude profiles due to decreasing O+ density at night. To compare with pTEC, we compute topside ionospheric total electron content (tiTEC) by integrating over 800-1336 km using the slope of the profiles. The tiTEC varies in a clear diurnal pattern from 0.3 to 1 and 3 total electron content unit (TECU, 1 TECU = 1016 el m-2) for low and high solar activity, respectively, whereas Jason-1 pTEC values are distributed over 2-6 TECU and 4-8 TECU for low and high solar activity, respectively, with no apparent diurnal modulation. Latitudinal variations of tiTEC show distinctive hemispheric asymmetry while that of Jason-1 pTEC is closely symmetric about the magnetic equator. The local time and latitudinal variations of tiTEC basically resemble those of the ionosphere but are characteristically different from those of Jason-1 pTEC. Based on the difference between tiTEC and pTEC variations, we propose that the region above 1300 km should be considered as the plasmasphere. Lower altitudes for the base of "plasmaspheric TEC," as used in some studies, would cause contamination of ionospheric influence.

  10. Non-Parametric Approarch for Global Plasmaspheric Electron Density Tomography using the Characteristics of Whistler Waves

    NASA Astrophysics Data System (ADS)

    Goto, Y.; Kasahara, Y.; Sato, T.

    2005-12-01

    The Earth's plasmasphere is investigated not only for scientific interests but also for engineering applications since the plasmaspheric plasma cannot be ignored for high-precision navigation and positioning from artificial satellites. The electron density in the plasmasphere is generally observed from spacecraft because the ionosphere disturbs us from direct observations from the ground. In the present study, we introduce an estimation method of the plasmaspheric electron density profile using whistler waves which are one of the most familiar VLF waves observed from satellites in the plasmasphere. While the propagation characteristics of ducted whistlers were used to acquire the signature of the plasmasphere, those of non-ducted ones were rarely used because of their complexity. The propagation characteristics of non-ducted whistlers cannot be calculated analytically but numerically. Recent advancement of computer technology made it possible to trace a few million of ray paths in a short time, and the initial ray parameters at wave sources are easily translated into those at observation points, which are a simple mapping. The estimation method is based on a model fitting in which an non-parametric model is used to represent the electron density profile like computer tomography in order not to deform the information of observed wave data. The wave normal directions and the spectrums of whistlers can be theoretically calculated for a given electron density profile by ray tracing. Comparing these theoretical values with observed ones, an electron density profile which is consistent to a given wave parameter set is obtained.

  11. The possible modifications of the HISSE model for pure LANDSAT agricultural data

    NASA Technical Reports Server (NTRS)

    Peters, C.

    1981-01-01

    A method for relaxing the assumption of class conditional independence of LANDSAT spectral measurements within the same patch (field) is discussed. Theoretical arguments are given which show that any significant refinement of the model beyond this proposal will not allow the reduction, essential to HISSE, of the pure data to patch summary statistics. A slight alteration of the new model is shown to be a reasonable approximation to the model which describes pure data elements from the same patch as jointly Gaussian with a covariance function which exhibits exponential decay with respect to spatial separation.

  12. Developmental environment affects risk-acceptance in the hissing cockroach, Gromphadorhina portentosa.

    PubMed

    Mishra, Sandeep; Logue, David M; Abiola, Ife O; Cade, William H

    2011-02-01

    Consistent individual differences in the tendency to accept risk have been demonstrated in invertebrates, fish, birds, and mammals, including humans. These individual differences have been associated with size, growth rate, survival, and reproductive success. Little research, however, has investigated the effect of developmental environment on individual differences in risk-acceptance. Competing hypotheses offer different explanations of how variation in the quality of the developmental environment affects risk-acceptance in adults. The first hypothesis states that individuals developing in poor quality environments take risks because such behavior is their only means of obtaining adequate fitness returns. The second hypothesis states that individuals developing in poor environments avoid risk because their poor physical condition makes them especially vulnerable to injury or death. We measured several forms of risk-accepting behavior (exploration, foraging, and recovery after disturbance) in male hissing cockroaches (Gromphadorhina portentosa) that had developed in nutritional and social environments of varying quality. Individuals raised on poor nutrition diets exhibited lower levels of risk-acceptance than those raised on high nutrition diets. Risk-acceptance among individuals that developed on poor nutrition diets was negatively correlated with body size. We conclude that quality of developmental environment affects risk-acceptance across behavioral contexts in male hissing cockroaches. Our findings are consistent with the hypothesis that condition-dependent vulnerability mediates the relationship between developmental environment and risk-acceptance.

  13. Comparison of Two IRI Plasmasphere Extensions with GPS-TEC Observations

    NASA Technical Reports Server (NTRS)

    Gulyacva, Tamara; Gallagher, Dennis

    2005-01-01

    Two plasmasphere extensions of the International Reference Ionosphere are made available for the users. It is aimed to estimate the effect of charged particles on technical devices in the Earth's environment and to define the ionosphere-plasmasphere operational conditions compatible with existing and future systems of radio communication, radio navigation and other relevant radio technologies in the ranges of medium and higher frequencies. The Global Core Plasma Model (GCPM-2000) of Gallagher et al. (2000) is an empirical description of thermal plasma densities in the plasmasphere, plasmapause, magnetospheric trough, and polar cap. GCPM-2000 uses the Kp index and is coupled to IRI in the transition region 500-600 km. The IZMIRAN plasmasphere model (Chasovitin et al., 1998; Gulyaeva et al., 2002) is an empirical model based on whistler and satellite observations. It presents global vertical analytical profiles of electron density smoothly fitted to IRI electron density profile at 1000 km altitude and extended towards the plasmapause (up to 36,000 km). For the smooth fitting of the two models, the shape of the IRI topside electron density profile is improved using ISIS 1, ISIS 2, and IK19 satellite inputs (Gulyaeva, 2003). The plasmasphere model depends on solar activity and magnetic activity (kp-index). The two IRI plasmasphere extensions are compared in the present study with the total electron content derived from records of Global Positioning Satellites (GPS-TEC) observations for different latitudinal, solar activity, magnetic activity, diurnal and seasonal conditions. The differences of model TEC with observed TEC in the topside ionosphere and plasmasphere are discussed.

  14. Comparison of Two IRI Plasmasphere Extensions with GPS-TEC Observations

    NASA Technical Reports Server (NTRS)

    Gulyacva, Tamara; Gallagher, Dennis

    2005-01-01

    Two plasmasphere extensions of the International Reference Ionosphere are made available for the users. It is aimed to estimate the effect of charged particles on technical devices in the Earth's environment and to define the ionosphere-plasmasphere operational conditions compatible with existing and future systems of radio communication, radio navigation and other relevant radio technologies in the ranges of medium and higher frequencies. The Global Core Plasma Model (GCPM-2000) of Gallagher et al. (2000) is an empirical description of thermal plasma densities in the plasmasphere, plasmapause, magnetospheric trough, and polar cap. GCPM-2000 uses the Kp index and is coupled to IRI in the transition region 500-600 km. The IZMIRAN plasmasphere model (Chasovitin et al., 1998; Gulyaeva et al., 2002) is an empirical model based on whistler and satellite observations. It presents global vertical analytical profiles of electron density smoothly fitted to IRI electron density profile at 1000 km altitude and extended towards the plasmapause (up to 36,000 km). For the smooth fitting of the two models, the shape of the IRI topside electron density profile is improved using ISIS 1, ISIS 2, and IK19 satellite inputs (Gulyaeva, 2003). The plasmasphere model depends on solar activity and magnetic activity (kp-index). The two IRI plasmasphere extensions are compared in the present study with the total electron content derived from records of Global Positioning Satellites (GPS-TEC) observations for different latitudinal, solar activity, magnetic activity, diurnal and seasonal conditions. The differences of model TEC with observed TEC in the topside ionosphere and plasmasphere are discussed.

  15. Relativistic heavy ion fragmentation at HISS (Heavy Ion Spectrometer System)

    SciTech Connect

    Tull, C.E.

    1990-10-01

    An experiment was conducted at the Lawrence Berkeley Laboratory to measure projectile fragmentation of relativistic heavy ions. Charge identification was obtained by the use of a Cerenkov Hodoscope operating above the threshold for total internal reflection, while velocity measurement was performed by use of a second set of Cerenkov radiators operating at the threshold for total internal reflection. Charge and mass resolution for the system was {sigma}{sub Z} = 0.2 e and {sigma}{sub A} = 0.2 u. Measurements of the elemental and isotopic production cross sections for the fragmentation of {sup 40}Ar at 1.65{center dot}A GeV have been compared with an Abrasion-Ablation Model based on the evaporation computer code GEMINI. The model proves to be an accurate predictor of the cross sections for fragments between Chlorine and Boron. The measured cross section were reproduced using simple geometry with charge dispersions induced by zero-point vibrations of the giant dipole resonance for the prompt abrasion stage, and injecting an excitation energy spectrum based on a final state interaction with scaling factor E{sub fsi} = 38.8 MeV/c. Measurement of the longitudinal momentum distribution widths for projectile fragments are consistent with previous experiment and can be interpreted as reflecting the Fermi momentum distribution in the initial projectile nucleus. Measurement of the transverse momentum indicate an additional, unexplained dependence of the reduced momentum widths on fragment mass. This dependence has the same sign and similar slope to previously measured fragments of {sup 139}La, and to predictions based on phase-space constraints on the final state of the system.

  16. Sounding of the Plasmasphere by McMAC Magnetometers

    NASA Astrophysics Data System (ADS)

    Chi, P. J.; McMAC Team

    2012-04-01

    Properly positioned ground magnetometers can be used to detect resonance of magnetospheric field lines as a way to make unique observations of the plasma mass density of the magnetosphere. In this paper we describe the field line resonance (FLR) frequencies systematically observed by the Mid-continent MAgnetoseismic Chain (McMAC), which consists of 10 stations in the United States and Mexico along 300° magnetic longitude. With an average separation by 272 km between adjacent stations McMAC is well suited to remotely sensing the plasma density at L-values between 1.6 and 3.3 through the gradient method of FLR measurements. We analyzed a full year of McMAC observations spanning between July 2006 and June 2007, and FLR frequencies were automatically identified in cross-phase and cross-power spectrograms by a computer routine. In all of the FLR observations by pairs of McMAC stations, the occurrence rate of FLR can reach as high as 55% around local noon at L = 2.7. The occurrence rate drops at lower latitudes due to weaker FLR signals. At L = 3.3 the FLR occurrence is clearly reduced in afternoon hours, possibly because of occasional presence of the plasmapause that can obstruct FLR generation and/or detection. By examining the results from all possible pairs of McMAC stations, we find that, at L ≤ 2.5, FLR signatures can still be found even when the separation between two stations exceeds 1000 km. The fundamental mode FLR frequencies, in addition to the inferred equatorial plasma mass densities of the magnetosphere, are tabulated with respect to L-value and time. The most probable fundamental mode frequency is found to be approximately 75 mHz at L = 1.6 and decreases with increasing L-value. The distribution of the fundamental mode frequency at L = 3.3, however, exhibits two distinct groups: The lower frequencies centered at 10 mHz representing the measurements inside the plasmasphere whereas the higher frequencies centered at 39 mHz indicating the faster field

  17. Plasmasphere dynamics in the duskside bulge region: A new look at old topic

    NASA Technical Reports Server (NTRS)

    Carpenter, D. L.; Giles, B. L.; Chappell, C. R.; Decreau, P. M. E.; Anderson, R. R.; Persoon, A. M.; Smith, A. J.; Corcuff, Y.; Canu, P.

    1993-01-01

    Data acquired during several multiday periods in 1982 at ground stations Siple, Halley, and Kerguelen and on satellites Dynamics Explorer 1, International Sun Earth Explorer 1, and GEOS 2 have been used to investigate thermal plasma structure and dynamics in the duskside plasmasphere bulge region of the Earth. The distribution of thermal plasma in the dusk bulge sector is difficult to describe realistically, in part because of the time integral manner in which the thermal plasma distribution depends upon on the effects of bulk cross-B flow and interchange plasma flows along B. While relatively simple MHD models can be useful for qualitatively predicting certain effects of enhanced convection on a quiet plasmasphere, such as an initial sunward entrainment of the outer regions, they are of limited value in predicting the duskside thermal plasma structures that are observed. Furthermore, use of such models can be misleading if one fails to realize that they do not address the question of the formation of the steep plasmapause profile or provide for a possible role of instabilities or other irreversible processes in plasmapause formation. Our specific findings, which are based both upon the present case studies and upon earlier work, include the following: (1) during active periods the plasmasphere appears to become divided into two entities, a main plasmasphere and a duskside bulge region. (2) in the aftermath of an increase in convection activity, the main plasmasphere tends (from a statistical point of view) to become roughly circular in equatorial cross section, with only a slight bulge at dusk; (3) the abrupt westward edge of the duskside bulge observed from whistlers represents a state in the evolution of sunward extending streamers; (4) in the aftermath of a weak magnetic storm, 10 to 30% of the plasma 'removed' from the outer plasmasphere appears to remain in the afternoon-dusk sector beyond the main plasmasphere. (5) outlying dense plasma structures may

  18. Effects of Convection Electric Fields on Modeled Plasmaspheric Densities and ccc Temperatures

    NASA Technical Reports Server (NTRS)

    Comfort, Richard H.; Richards, Phil G.; Liao, Jin-Hua; Craven, Paul D.

    1998-01-01

    This paper examines the effects of convection electric fields on plasmaspheric H+, O+, He+, and N+ densities and electron and ion temperatures. These effects are studied with the aid of the Field Line Interhemispheric Plasma (FLIP) model, which has recently been extended to include the effects of ExB drifts. The FLIP model solves the continuity and momentum equations for the major ion species as well as the energy equations for ions and electrons along entire drifting flux tubes from 100 km altitude in the northern hemisphere to 100 km altitude in the southern hemisphere. Electron heating in the ionosphere and plasmasphere is provided by the solution of two-stream equations for photoelectrons. The dawn-dusk electric field imposed by the solar wind causes changes in plasmaspheric density and temperature as the plasma drifts onto flux tubes having different volumes. In an idealized convection model, outward drifts in the afternoon cause decreases in the plasmasphere density and temperature while inward drifts in the evening cause increases in plasmasphere density and temperature. In this paper we examine the effects of convection electric fields on the rate of refilling of flux tubes and investigate the hypothesis that convection electric fields are responsible for the unusually high evening electron temperatures and the post-midnight density maxima often observed in the winter ionosphere above Millstone Hill.

  19. Plasmaspheric filament: an isolated magnetic flux tube filled with dense plasmas

    NASA Astrophysics Data System (ADS)

    Murakami, Go; Yoshikawa, Ichiro; Yoshioka, Kazuo; Yamazaki, Atsushi; Kagitani, Masato; Taguchi, Makoto; Kikuchi, Masayuki; Kameda, Shingo; Nakamura, Masato

    2013-01-01

    Abstract<p label="1">The Telescope of Extreme Ultraviolet (TEX) onboard Japan's lunar orbiter KAGUYA provided the first sequential images of the Earth's <span class="hlt">plasmasphere</span> from the "side" (meridian) view. The TEX instrument obtained the global distribution of the terrestrial helium ions (He+) by detecting resonantly scattered emission at 30.4 nm. One of the most striking features of the <span class="hlt">plasmasphere</span> found by TEX is an arc-shaped structure of enhanced brightness, which we call a "<span class="hlt">plasmaspheric</span> filament". In the TEX image on 2 June 2008, the filament structure was clearly aligned to the dipole magnetic field line of L = 3.7 at 7.3 magnetic local time. Our analysis suggests that the filament represents an isolated flux tube filled with four times higher He+ density than its neighbors. We found four events of <span class="hlt">plasmaspheric</span> filament in the images obtained between March and June 2008, and in all four events, the geomagnetic activity was quite low. The <span class="hlt">plasmaspheric</span> filament in the TEX image is the first evidence that a "finger" structure seen in the IMAGE-EUV image is the projection of an isolated flux tube.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRA..120.5983G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRA..120.5983G"><span>Ionospheric and <span class="hlt">plasmaspheric</span> electron contents inferred from radio occultations and global ionospheric maps</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>González-Casado, G.; Juan, J. M.; Sanz, J.; Rovira-Garcia, A.; Aragon-Angel, A.</p> <p>2015-07-01</p> <p>We introduce a methodology to extract the separate contributions of the ionosphere and the <span class="hlt">plasmasphere</span> to the vertical total electron content, without relying on a fixed altitude to perform that separation. The method combines two previously developed and tested techniques, namely, the retrieval of electron density profiles from radio occultations using an improved Abel inversion technique and a two-component model for the topside ionosphere plus protonosphere. Taking measurements of the total electron content from global ionospheric maps and radio occultations from the Constellation Observing System for Meteorology, Ionosphere, and Climate/FORMOSAT-3 constellation, the ionospheric and <span class="hlt">plasmaspheric</span> electron contents are calculated for a sample of observations covering 2007, a period of low solar and geomagnetic activity. The results obtained are shown to be consistent with previous studies for the last solar minimum period and with model calculations, confirming the reversal of the winter anomaly, the hemispheric asymmetry of the semiannual anomaly, and the existence in the <span class="hlt">plasmasphere</span> of an annual anomaly in the South American sector of longitudes. The analysis of the respective fractional contributions from the ionosphere and the <span class="hlt">plasmasphere</span> to the total electron content shows quantitatively that during the night the <span class="hlt">plasmasphere</span> makes the largest contribution, peaking just before sunrise and during winter. On the other hand, the fractional contribution from the ionosphere reaches a maximum value around noon, which is nearly independent of season and geomagnetic latitude.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5072910','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5072910"><span>Some characteristics of midlatitude F layer storms generated by thermosphere-<span class="hlt">plasmasphere</span> coupling processes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Miller, N.J.</p> <p>1983-01-01</p> <p>In this dissertation, calculations are interpreted that have been made to describe stormtime variations in equinoctial dayside plasma parameters when the variations are primarily caused by processes dependent upon collisional coupling between the thermosphere and the <span class="hlt">plasmasphere</span>. The calculations are made with a computer model formed by linking two theoretical models: a pre-existing thermospheric model that describes dayside variations in thermospheric parameters during stormtime heating of the thermosphere; a <span class="hlt">plasmaspheric</span> model which was developed to describe dayside <span class="hlt">plasmaspheric</span> variations caused by the thermospheric variations described by the thermospheric model and by variations in a magnetospheric electric field. Both portions of the computerized storm model solve partial differential equations describing conservation of species, momentum, and energy by replacing dependent variables with expansions in time series. The thermospheric portion of the storm model solves for variations in gas temperature, horizontal wind velocity, and densities of atomic oxygen and molecular nitrogen while the <span class="hlt">plasmaspheric</span> portion of the storm model solves for variations in ion densities of oxygen and hydrogen, ion fluxes and electrons, and heat fluxes through ions and electrons. Other calculations that have been used to describe variations in thermospheric and <span class="hlt">plasmaspheric</span> parameters are summarized and the advantages and limitations of the model calculations used to obtain results presented in this dissertation are noted.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010cosp...38.2199D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010cosp...38.2199D"><span>Formation of <span class="hlt">plasmasphere</span> in the non-ideal corotation field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dumin, Yurii</p> <p></p> <p>It is well-known that the standard model of <span class="hlt">plasmasphere</span> formation by the combined action of convection and the ideal corotation fields is too simplified and does not describe some important features. One of attempts to improve it was undertaken a few years ago in our paper [1], where we considered generation of the corotation field in the strongly-anisotropic magnetospheric plasma and took into account distortion of this field in high latitudes due to escape of the polarization charges along the open magnetic field lines. In the present report, we further develop the idea of refinement of the corotation field, particularly, by the consideration of the magnetic dipole inclined with respect to the rotation axis. It will be shown that all the above-mentioned improvements result in the more adequate description of the position of plasmapause both in the quiet and disturbed conditions. References: 1. Yu.V. Dumin. The Corotation Field in Collisionless Magnetospheric Plasma and Its Influence on Average Electric Field in the Lower Atmosphere. Advances in Space Research, v.30, p.2209 (2002).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24604196','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24604196"><span>Simultaneous ground- and space-based observations of the <span class="hlt">plasmaspheric</span> plume and reconnection.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Walsh, B M; Foster, J C; Erickson, P J; Sibeck, D G</p> <p>2014-03-07</p> <p>Magnetic reconnection is the primary process through which energy couples from the solar wind into Earth's magnetosphere and ionosphere. Conditions both in the incident solar wind and in the magnetosphere are important in determining the efficiency of this energy transfer. In particular, the cold, dense <span class="hlt">plasmaspheric</span> plume can substantially impact the coupling in the dayside reconnection region. Using ground-based total electron content (TEC) maps and measurements from the THEMIS spacecraft, we investigated simultaneous ionosphere and magnetosphere observations of the <span class="hlt">plasmaspheric</span> plume and its involvement in an unsteady magnetic reconnection process. The observations show the full circulation pattern of the <span class="hlt">plasmaspheric</span> plume and validate the connection between signatures of variability in the dense plume and reconnection at the magnetopause as measured in situ and through TEC measurements in the ionosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GeoRL..42.3707L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GeoRL..42.3707L"><span>Real-time imaging of density ducts between the <span class="hlt">plasmasphere</span> and ionosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Loi, Shyeh Tjing; Murphy, Tara; Cairns, Iver H.; Menk, Frederick W.; Waters, Colin L.; Erickson, Philip J.; Trott, Cathryn M.; Hurley-Walker, Natasha; Morgan, John; Lenc, Emil; Offringa, André R.; Bell, Martin E.; Ekers, Ronald D.; Gaensler, B. M.; Lonsdale, Colin J.; Feng, Lu; Hancock, Paul J.; Kaplan, David L.; Bernardi, G.; Bowman, J. D.; Briggs, F.; Cappallo, R. J.; Deshpande, A. A.; Greenhill, L. J.; Hazelton, B. J.; Johnston-Hollitt, M.; McWhirter, S. R.; Mitchell, D. A.; Morales, M. F.; Morgan, E.; Oberoi, D.; Ord, S. M.; Prabu, T.; Shankar, N. Udaya; Srivani, K. S.; Subrahmanyan, R.; Tingay, S. J.; Wayth, R. B.; Webster, R. L.; Williams, A.; Williams, C. L.</p> <p>2015-05-01</p> <p>Ionization of the Earth's atmosphere by sunlight forms a complex, multilayered plasma environment within the Earth's magnetosphere, the innermost layers being the ionosphere and <span class="hlt">plasmasphere</span>. The <span class="hlt">plasmasphere</span> is believed to be embedded with cylindrical density structures (ducts) aligned along the Earth's magnetic field, but direct evidence for these remains scarce. Here we report the first direct wide-angle observation of an extensive array of field-aligned ducts bridging the upper ionosphere and inner <span class="hlt">plasmasphere</span>, using a novel ground-based imaging technique. We establish their heights and motions by feature tracking and parallax analysis. The structures are strikingly organized, appearing as regularly spaced, alternating tubes of overdensities and underdensities strongly aligned with the Earth's magnetic field. These findings represent the first direct visual evidence for the existence of such structures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150007962','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150007962"><span>Simultaneous Ground- and Space-Based Observations of the <span class="hlt">Plasmaspheric</span> Plume and Reconnection</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Walsh, B. M.; Foster, J. C.; Erickson, P. J.; Sibeck, D. G.</p> <p>2014-01-01</p> <p>Magnetic reconnection is the primary process through which energy couples from the solar wind into Earth's magnetosphere and ionosphere. Conditions both in the incident solar wind and in the magnetosphere are important in determining the efficiency of this energy transfer. In particular, the cold, dense <span class="hlt">plasmaspheric</span> plume can substantially impact the coupling in the dayside reconnection region. Using ground-based total electron content (TEC) maps and measurements from the THEMIS spacecraft, we investigated simultaneous ionosphere and magnetosphere observations of the <span class="hlt">plasmaspheric</span> plume and its involvement in an unsteady magnetic reconnection process. The observations show the full circulation pattern of the <span class="hlt">plasmaspheric</span> plume and validate the connection between signatures of variability in the dense plume and reconnection at the magnetopause as measured in situ and through TEC measurements in the ionosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSM23B4191S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSM23B4191S"><span>The Disappearance of the Post-Midnight High Energy Ion <span class="hlt">Plasmasphere</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sarno-Smith, L. K.; Liemohn, M. W.; Katus, R. M.; Wygant, J. R.; Skoug, R. M.; Larsen, B.; Thomsen, M. F.; Moldwin, M.</p> <p>2014-12-01</p> <p>The Van Allen Probes Helium Oxygen Proton Electron (HOPE) instrument measures a high energy tail of the thermal <span class="hlt">plasmasphere</span> that has strong MLT dependence in the near Earth space. In our study, we statistically analyze a 16 month period of HOPE data, looking at quiet times with a Kp index of less than 3. The high energy <span class="hlt">plasmasphere</span> tail is the upper 5% of <span class="hlt">plasmasphere</span> energies, consisting of ions between 1 - 10 eV. We calculated plasma densities over this energy range and see that there is strong depletion in O+ and H+ from 1-4 MLT and a similar but less dramatic density decline in He+. Our results are compared with the Van Allen Probes Electric Fields and Waves (EFW) instrument space craft potential to rule out spacecraft charging. We conclude that the post-midnight ion disappearance is due to diurnal ionospheric temperature variation and charge exchange processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRA..121..227C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRA..121..227C"><span>Global MHD modeling of resonant ULF waves: Simulations with and without a <span class="hlt">plasmasphere</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Claudepierre, S. G.; Toffoletto, F. R.; Wiltberger, M.</p> <p>2016-01-01</p> <p>We investigate the <span class="hlt">plasmaspheric</span> influence on the resonant mode coupling of magnetospheric ultralow frequency (ULF) waves using the Lyon-Fedder-Mobarry (LFM) global magnetohydrodynamic (MHD) model. We present results from two different versions of the model, both driven by the same solar wind conditions: one version that contains a <span class="hlt">plasmasphere</span> (the LFM coupled to the Rice Convection Model, where the Gallagher <span class="hlt">plasmasphere</span> model is also included) and another that does not (the stand-alone LFM). We find that the inclusion of a cold, dense <span class="hlt">plasmasphere</span> has a significant impact on the nature of the simulated ULF waves. For example, the inclusion of a <span class="hlt">plasmasphere</span> leads to a deeper (more earthward) penetration of the compressional (azimuthal) electric field fluctuations, due to a shift in the location of the wave turning points. Consequently, the locations where the compressional electric field oscillations resonantly couple their energy into local toroidal mode field line resonances also shift earthward. We also find, in both simulations, that higher-frequency compressional (azimuthal) electric field oscillations penetrate deeper than lower frequency oscillations. In addition, the compressional wave mode structure in the simulations is consistent with a radial standing wave oscillation pattern, characteristic of a resonant waveguide. The incorporation of a <span class="hlt">plasmasphere</span> into the LFM global MHD model represents an advance in the state of the art in regard to ULF wave modeling with such simulations. We offer a brief discussion of the implications for radiation belt modeling techniques that use the electric and magnetic field outputs from global MHD simulations to drive particle dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27668142','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27668142"><span>Global MHD modeling of resonant ULF waves: Simulations with and without a <span class="hlt">plasmasphere</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Claudepierre, S G; Toffoletto, F R; Wiltberger, M</p> <p>2016-01-01</p> <p>We investigate the <span class="hlt">plasmaspheric</span> influence on the resonant mode coupling of magnetospheric ultralow frequency (ULF) waves using the Lyon-Fedder-Mobarry (LFM) global magnetohydrodynamic (MHD) model. We present results from two different versions of the model, both driven by the same solar wind conditions: one version that contains a <span class="hlt">plasmasphere</span> (the LFM coupled to the Rice Convection Model, where the Gallagher <span class="hlt">plasmasphere</span> model is also included) and another that does not (the stand-alone LFM). We find that the inclusion of a cold, dense <span class="hlt">plasmasphere</span> has a significant impact on the nature of the simulated ULF waves. For example, the inclusion of a <span class="hlt">plasmasphere</span> leads to a deeper (more earthward) penetration of the compressional (azimuthal) electric field fluctuations, due to a shift in the location of the wave turning points. Consequently, the locations where the compressional electric field oscillations resonantly couple their energy into local toroidal mode field line resonances also shift earthward. We also find, in both simulations, that higher-frequency compressional (azimuthal) electric field oscillations penetrate deeper than lower frequency oscillations. In addition, the compressional wave mode structure in the simulations is consistent with a radial standing wave oscillation pattern, characteristic of a resonant waveguide. The incorporation of a <span class="hlt">plasmasphere</span> into the LFM global MHD model represents an advance in the state of the art in regard to ULF wave modeling with such simulations. We offer a brief discussion of the implications for radiation belt modeling techniques that use the electric and magnetic field outputs from global MHD simulations to drive particle dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRA..120.4567G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRA..120.4567G"><span>Simultaneous Pi2 observations by the Van Allen Probes inside and outside the <span class="hlt">plasmasphere</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ghamry, E.; Kim, K.-H.; Kwon, H.-J.; Lee, D.-H.; Park, J.-S.; Choi, J.; Hyun, K.; Kurth, W. S.; Kletzing, C.; Wygant, J. R.; Huang, J.</p> <p>2015-06-01</p> <p><span class="hlt">Plasmaspheric</span> virtual resonance (PVR) model has been proposed as one of source mechanisms for low-latitude Pi2 pulsations. Since PVR-associated Pi2 pulsations are not localized inside the <span class="hlt">plasmasphere</span>, simultaneous multipoint observations inside and outside the <span class="hlt">plasmasphere</span> require to test the PVR model. Until now, however, there are few studies using simultaneous multisatellite observations inside and outside the <span class="hlt">plasmasphere</span> for understanding the radial structure of Pi2 pulsation. In this study, we focus on the Pi2 event observed at low-latitude Bohyun (BOH, L = 1.35) ground station in South Korea in the postmidnight sector (magnetic local time (MLT) = 3.0) for the interval from 1730 to 1900 UT on 12 March 2013. By using electron density derived from the frequency of the upper hybrid waves detected at Van Allen Probe-A (VAP-A) and Van Allen Probe-B (VAP-B), the plasmapause is identified. At the time of the Pi2 event, VAP-A was outside the <span class="hlt">plasmasphere</span> near midnight (00:55 MLT and L =˜ 6), while VAP-B was inside the <span class="hlt">plasmasphere</span> in the postmidnight sector (02:15 MLT and L =˜ 5). VAP-B observed oscillations in the compressional magnetic field component (Bz) and the dawn-to-dusk electric field component (Ey), having high coherence with the BOH Pi2 pulsation in the H component. The H-Bz and H-Ey cross phases at VAP-B inside the <span class="hlt">plasmasphere</span> were near -180° and -90°, respectively. These phase relationships among Bz, Ey, and H are consistent with a radially standing oscillation of the fundamental mode reported in previous studies. At VAP-A outside the <span class="hlt">plasmasphere</span>, Bz oscillations were highly correlated with BOH Pi2 pulsations with ˜-180° phase delay, and the H-Ey cross phase is near -90°. From these two-satellite observations, we suggest that the fundamental PVR mode is directly detected by VAP-A and VAP-B.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMSA33C..03G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMSA33C..03G"><span>Causes of variability in <span class="hlt">plasmasphere</span> rotation rate: IMAGE EUV observations (Invited)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Galvan, D. A.; Moldwin, M.; Sandel, B. R.; Crowley, G.</p> <p>2010-12-01</p> <p>IMAGE EUV observations demonstrate that the <span class="hlt">plasmasphere</span> usually does not corotate as assumed in simple convection models, even at low L shells. The prevailing hypothesis states that <span class="hlt">plasmaspheric</span> subcorotation is due to enhanced auroral zone Joule heating which drives equatorward thermospheric winds. As the neutral thermospheric material moves to lower latitudes, it grows farther from the Earth’s spin axis and turns westward to conserve angular momentum. This induces a westward motion in the ionosphere (a subcorotation), which produces a change in the corotation electric field that maps out to the <span class="hlt">plasmasphere</span>, causing a subcorotation there as well. We test this hypothesis by searching for a correlation between <span class="hlt">plasmaspheric</span> rotation rates and several geomagnetic indices (used as proxies for enhanced Joule heating in the auroral zone). We carry out a statistical survey of <span class="hlt">plasmaspheric</span> rotation rates over several months of IMAGE EUV data in 2001, using two different measurement techniques. Azimuthal features such as “notches” are tracked in local time over a single pass of the IMAGE satellite, both visually and using an automated cross-correlation routine. Each technique provides an estimate of the plasmasphere’s rotation rate. We find a weak correlation between rotation rate and Dst, Kp, AE, the midnight boundary index (MBI), and Joule heating estimates from assimilative mapping of ionospheric electrodynamics (AMIE) at L = 2.5, but not at L = 3.5. In general, lower rotation rates correspond to higher auroral and geomagnetic activity. We also make the first direct observation of <span class="hlt">plasmaspheric</span> superrotation. The rotation rate is found to be highly variable on multi-day timescales, but the typical state of the <span class="hlt">plasmasphere</span> is subcorotation, with inferred mean values ranging from 88% to 95% of corotation, depending on L shell. In addition, a statistical analysis shows that rotation rates near dusk are generally lower than those at dawn, suggesting that local</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040000698&hterms=3d+reconstruction&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3D3d%2Breconstruction','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040000698&hterms=3d+reconstruction&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3D3d%2Breconstruction"><span>Limited Angle Reconstruction Method for Reconstructing Terrestrial <span class="hlt">Plasmaspheric</span> Densities from EUV Images</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Newman, Timothy; Santhanam, Naveen; Zhang, Huijuan; Gallagher, Dennis</p> <p>2003-01-01</p> <p>A new method for reconstructing the global 3D distribution of plasma densities in the <span class="hlt">plasmasphere</span> from a limited number of 2D views is presented. The method is aimed at using data from the Extreme Ultra Violet (EUV) sensor on NASA s Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) satellite. Physical properties of the <span class="hlt">plasmasphere</span> are exploited by the method to reduce the level of inaccuracy imposed by the limited number of views. The utility of the method is demonstrated on synthetic data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006P%26SS...54.1197S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006P%26SS...54.1197S"><span>Cassini observations of Saturn's inner <span class="hlt">plasmasphere</span>: Saturn orbit insertion results</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sittler, E. C.; Thomsen, M.; Johnson, R. E.; Hartle, R. E.; Burger, M.; Chornay, D.; Shappirio, M. D.; Simpson, D.; Smith, H. T.; Coates, A. J.; Rymer, A. M.; McComas, D. J.; Young, D. T.; Reisenfeld, D.; Dougherty, M.; Andre, N.</p> <p>2006-10-01</p> <p>We present new and definitive results of Cassini plasma spectrometer (CAPS) data acquired during passage through Saturn's inner <span class="hlt">plasmasphere</span> by the Cassini spacecraft during the approach phase of the Saturn orbit insertion period. This analysis extends the original analysis of Sittler et al. [2005. Preliminary results on Saturn's inner <span class="hlt">plasmasphere</span> as observed by Cassini: comparison with Voyager. Geophys. Res. Lett. 32, L14S07, doi:10.1029/2005GL022653] to L˜10 along with also providing a more comprehensive study of the interrelationship of the various fluid parameters. Coincidence data are sub-divided into protons and water group ions. Our revised analysis uses an improved convergence algorithm which provides a more definitive and independent estimate of the spacecraft potential ΦSC for which we enforce the protons and water group ions to co-move with each other. This has allowed us to include spacecraft charging corrections to our fluid parameter estimations and allow accurate estimations of fluctuations in the fluid parameters for future correlative studies. In the appendix we describe the ion moments algorithm, and minor corrections introduced by not weighting the moments with sin θ term in Sittler et al. [2005] (Correction offset by revisions to instruments geometric factor). Estimates of the spacecraft potential and revised proton densities are presented. Our total ion densities are in close agreement with the electron densities reported by Moncuquet et al. [2005. Quasi-thermal noise spectroscopy in the inner magnetosphere of Saturn with Cassini/RPWS: electron temperatures and density. Geophys. Res. Lett. 32, L20S02, doi:10.1029/2005GL022508] who used upper hybrid resonance (UHR) emission lines observed by the radio and plasma wave science (RPWS) instrument. We show a positive correlation between proton temperature and water group ion temperature. The proton and thermal electron temperatures track each with both having a positive radial gradient. These</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19720035483&hterms=uses+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Duses%2Benergy','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19720035483&hterms=uses+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Duses%2Benergy"><span>Comparison of very-low-frequency auroral <span class="hlt">hiss</span> with precipitating low-energy electrons by the use of simultaneous data from two Ogo 4 experiments.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hoffman, R. A.; Laaspere, T.</p> <p>1972-01-01</p> <p>Determination of the origin of auroral <span class="hlt">hiss</span> by comparing the records of a vlf experiment (0.3 to 18 kHz) with simultaneous data obtained by an auroral-particle experiment having detectors for precipitating electrons at 0.7, 2.3, and 7.3 keV. It is found that, on the dayside of the earth, the occurrence of vlf <span class="hlt">hiss</span> correlates well with precipitation events at 0.7 keV, but in general very poorly with activity in the higher-energy channels. Exact correlation between variations in vlf <span class="hlt">hiss</span> intensity and in electron fluxes is rare even at 0.7 keV. In addition, vlf <span class="hlt">hiss</span> tends to be observed over a somewhat larger spatial region than precipitating 0.7-keV electrons. It is concluded that, on the dayside, auroral <span class="hlt">hiss</span> is generated by soft (E less than 1 keV) 'cusp region' electrons and that the lack of detailed correlation between the two phenomena is caused by propagation effects as the <span class="hlt">hiss</span> travels downward and spreads from the generation region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25746766','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25746766"><span>Evaluation methods used on health information systems (<span class="hlt">HISs</span>) in Iran and the effects of <span class="hlt">HISs</span> on Iranian healthcare: a systematic review.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ahmadian, Leila; Nejad, Simin Salehi; Khajouei, Reza</p> <p>2015-06-01</p> <p>The most important goal of a health information system (HIS) is improvement of quality, effectiveness and efficiency of health services. To achieve this goal, health care systems should be evaluated continuously. The aim of this paper was to study the impacts of <span class="hlt">HISs</span> in Iran and the methods used for their evaluation. We systematically searched all English and Persian papers evaluating health information systems in Iran that were indexed in SID, Magiran, Iran medex, PubMed and Embase databases until June 2013. A data collection form was designed to extract required data such as types of systems evaluated, evaluation methods and tools. In this study, 53 out of 1103 retrieved articles were selected as relevant and reviewed by the authors. This study indicated that 28 studies used questionnaires to evaluate the system and in 27 studies the study instruments were distributed within a research population. In 26 papers the researchers collected the information by means of interviews, observations, heuristic evaluation and the review of documents and records. The main effects of the evaluated systems in health care settings were improving quality of services, reducing time, increasing accessibility to information, reducing costs and decreasing medical errors. Evaluation of health information systems is central to their development and enhancement, and to understanding their effect on health and health services. Despite numerous evaluation methods available, the reviewed studies used a limited number of methods to evaluate HIS. Additionally, the studies mainly discussed the positive effects of HIS on health care services. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22892068','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22892068"><span>The Madagascar <span class="hlt">hissing</span> cockroach as a novel surrogate host for Burkholderia pseudomallei, B. mallei and B. thailandensis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fisher, Nathan A; Ribot, Wilson J; Applefeld, Willard; DeShazer, David</p> <p>2012-06-22</p> <p>Burkholderia pseudomallei and Burkholderia mallei are gram-negative pathogens responsible for the diseases melioidosis and glanders, respectively. Both species cause disease in humans and animals and have been designated as category B select agents by the Centers for Disease Control and Prevention (CDC). Burkholderia thailandensis is a closely related bacterium that is generally considered avirulent for humans. While it can cause disease in rodents, the B. thailandensis 50% lethal dose (LD50) is typically ≥ 104-fold higher than the B. pseudomallei and B. mallei LD50 in mammalian models of infection. Here we describe an alternative to mammalian hosts in the study of virulence and host-pathogen <span class="hlt">interactions</span> of these Burkholderia species. Madagascar <span class="hlt">hissing</span> cockroaches (MH cockroaches) possess a number of qualities that make them desirable for use as a surrogate host, including ease of breeding, ease of handling, a competent innate immune system, and the ability to survive at 37°C. MH cockroaches were highly susceptible to infection with B. pseudomallei, B. mallei and B. thailandensis and the LD50 was <10 colony-forming units (cfu) for all three species. In comparison, the LD50 for Escherichia coli in MH cockroaches was >105 cfu. B. pseudomallei, B. mallei, and B. thailandensis cluster 1 type VI secretion system (T6SS-1) mutants were all attenuated in MH cockroaches, which is consistent with previous virulence studies conducted in rodents. B. pseudomallei mutants deficient in the other five T6SS gene clusters, T6SS-2 through T6SS-6, were virulent in both MH cockroaches and hamsters. Hemocytes obtained from MH cockroaches infected with B. pseudomallei harbored numerous intracellular bacteria, suggesting that this facultative intracellular pathogen can survive and replicate inside of MH cockroach phagocytic cells. The hemolymph extracted from these MH cockroaches also contained multinuclear giant cells (MNGCs) with intracellular B. pseudomallei, which indicates</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3431275','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3431275"><span>The Madagascar <span class="hlt">hissing</span> cockroach as a novel surrogate host for Burkholderia pseudomallei, B. mallei and B. thailandensis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2012-01-01</p> <p>Background Burkholderia pseudomallei and Burkholderia mallei are gram-negative pathogens responsible for the diseases melioidosis and glanders, respectively. Both species cause disease in humans and animals and have been designated as category B select agents by the Centers for Disease Control and Prevention (CDC). Burkholderia thailandensis is a closely related bacterium that is generally considered avirulent for humans. While it can cause disease in rodents, the B. thailandensis 50% lethal dose (LD50) is typically ≥ 104-fold higher than the B. pseudomallei and B. mallei LD50 in mammalian models of infection. Here we describe an alternative to mammalian hosts in the study of virulence and host-pathogen <span class="hlt">interactions</span> of these Burkholderia species. Results Madagascar <span class="hlt">hissing</span> cockroaches (MH cockroaches) possess a number of qualities that make them desirable for use as a surrogate host, including ease of breeding, ease of handling, a competent innate immune system, and the ability to survive at 37°C. MH cockroaches were highly susceptible to infection with B. pseudomallei, B. mallei and B. thailandensis and the LD50 was <10 colony-forming units (cfu) for all three species. In comparison, the LD50 for Escherichia coli in MH cockroaches was >105 cfu. B. pseudomallei, B. mallei, and B. thailandensis cluster 1 type VI secretion system (T6SS-1) mutants were all attenuated in MH cockroaches, which is consistent with previous virulence studies conducted in rodents. B. pseudomallei mutants deficient in the other five T6SS gene clusters, T6SS-2 through T6SS-6, were virulent in both MH cockroaches and hamsters. Hemocytes obtained from MH cockroaches infected with B. pseudomallei harbored numerous intracellular bacteria, suggesting that this facultative intracellular pathogen can survive and replicate inside of MH cockroach phagocytic cells. The hemolymph extracted from these MH cockroaches also contained multinuclear giant cells (MNGCs) with intracellular B</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1986AdSpR...6...31C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1986AdSpR...6...31C"><span><span class="hlt">Plasmasphere</span> thermal structure as measured by ISEE-1 and DE-1</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Comfort, R. H.</p> <p></p> <p>Characteristics of <span class="hlt">plasmaspheric</span> ion thermal structure are presented from a statistical survey of low-energy of ion measurements made by the retarding ion mass spectrometer (RIMS) on the DE-1 satellite. Morning and evening results are compared to illustrate diurnal trends. Typical day side temperature range from about 4000 K in the inner <span class="hlt">plasmasphere</span> to over 10,000 K in the outer <span class="hlt">plasmasphere</span>, while corresponding evening side temperatures range from near 2000 K to over 10,000 K. Magnetic activity is found to affect the morning and evening sides somewhat differently. Temperatures are found to remain constant or increase with altitude along magnetic field lines, depending on local time and L shell. Thermal equilibrium between H(+) and He(+) prevails to a high degree throughout the <span class="hlt">plasmasphere</span>. Ion temperatures from the Plasma Composition Experiment (PCE) on ISEE-1 are generally consistent with those from DE-1/RIMS, but are lower and tend to indicate more large scale structure on the day side.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSA41C..04M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSA41C..04M"><span>Ionosphere-<span class="hlt">Plasmasphere</span>-Electrodynamics (IPE) model and its coupling to terrestrial weather toward transitioning to operation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Maruyama, N.; Richards, P. G.; Fedrizzi, M.; Fang, T. W.; Fuller-Rowell, T. J.; Codrescu, M.; Li, P.; Theurich, G.; Oehmke, R.; DeLuca, C.; Akmaev, R. A.; Wang, H.; Maute, A. I.; Pedatella, N. M.; Richmond, A. D.</p> <p>2015-12-01</p> <p>The Ionosphere-<span class="hlt">Plasmasphere</span>-Electrodynamics (IPE) model is a new, time dependent, three-dimensional model of ionosphere and <span class="hlt">plasmasphere</span> recently developed through collaboration between University of Colorado, George Mason University, NOAA Space Weather Prediction Center (SWPC), NOAA Global Systems Division (GSD), NCAR HAO and NESII. It provides time dependent, global, three-dimensional plasma densities for nine ion species, electron and ion temperatures, and both parallel and perpendicular velocities of the ionosphere and <span class="hlt">plasmasphere</span>. IPE reproduces not only the climatology of global TEC observations, but the model has also been applied to Space Weather events, such as Sudden Stratospheric Warmings (SSW) and geomagnetic storms. The model follows the storm time redistribution of the plasma density in the ionosphere and <span class="hlt">plasmasphere</span>, including the development of the Storm Enhanced Density (SED). While the standalone IPE continues to be improved, IPE has been coupled to Whole Atmosphere Model (WAM), a special configuration of the GFS (Global Forecast System), in order to respond to terrestrial weather. IPE has been included as a component of the NOAA Environmental Modeling System (NEMS) coupled system using the Earth System Modeling Framework (ESMF) and National Unified Operational Prediction Capability (NUOPC) layer. In this presentation, an overview of the IPE model development and current status is presented. Furthermore, the preliminary results from the coupled WAM-IPE model is shown to demonstrate the impact of meteorological perturbations on the ionosphere. The presentation is summarized by the discussions on the challenges in the coupling effort toward the ultimate goal of transitioning to operations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20060048236&hterms=comparison+total&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dcomparison%2Btotal','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20060048236&hterms=comparison+total&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dcomparison%2Btotal"><span>Comparison of Two IRI <span class="hlt">plasmasphere</span> Extensions with GPS-TEC Observations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gulyaeva, T. L.; Gallagher, Dennis L.</p> <p>2006-01-01</p> <p>Comparisons of two model results with Global Positioning System GPS-TEC measurements have been carried out for different latitudinal, solar activity, magnetic activity, diurnal and seasonal conditions. The models evaluated are the Global Core Plasma Model (GCPM-2000) and the IRI extension with Russian <span class="hlt">plasmasphere</span> model (IRI*).Data of 23 observatories providing GPS-TEC and ionosonde data have been used. It is shown that IRI* <span class="hlt">plasmasphere</span> electron density is greater than GCPM results by an order of magnitude at 6370 km altitude (one Earth's radius) with this excess growing to 2-3 orders of magnitude towards the GPS satellite altitude of 20000 km. Another source of model and GPS-TEC differences is a way of selection of the F2 layer peak parameters driving the models either with ITU-R (former CCIR) maps or ionosonde observations. <span class="hlt">Plasmasphere</span> amendment to IRI improves accuracy of TEC model predictions because the <span class="hlt">plasmasphere</span> contribution to the total TEC varies from 10% by daytime under quiet magnetic conditions to more than 50% by night under stormy conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSM54B..04F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSM54B..04F"><span>Chang'e-3 Extreme Ultraviolet Camera Observations of the Dynamics of the Earth's <span class="hlt">Plasmasphere</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fok, M. C. H.; Zhang, X.; He, F.; Chen, B.; Wang, H. N.; Shen, C.; Ping, J.; Nakano, S.</p> <p>2015-12-01</p> <p>The Moon-based Extreme Ultraviolet Camera (EUVC) aboard China's Chang'e-3 (CE-3) lunar lander has successfully imaged the global <span class="hlt">plasmasphere</span> on the Moon for the first time through detecting the resonantly scattered sunlight by <span class="hlt">plasmaspheric</span> He+ at 30.4 nm with a spatial resolution of 0.1 RE and a time resolution of 10 min. The characteristics and the analyzing methods of the EUVC images are introduced in detail in this report. The plasmapause locations on the magnetic equator are reconstructed with the Minimum L Algorithm and are quantitatively compared with those extracted from in-situ observations by DMSP, THEMIS, and RBSP satellites. Then the plasmapause evolutions during substorms on February 21 2014 and April 21 2014 are investigated. It is found that the evolutions of plasmapause correlate well in both universal time and magnetic local time with the equatorial boundaries of auroral oval during substorms. During these two cases, the solar-wind-driven convection and the geomagnetic activity are relatively weak and steady, and the plasmapause motions can reliably be attributed to the substorms. It is proposed that correlations between the auroral signatures and the plasmapause motions may be due to the generation and Earthward-propagation of dipolarization front and resultant pitch angle scattering. In future work, we will search more in-situ and remote sensing data in both the <span class="hlt">plasmasphere</span> and the magnetotail regions to investigate the correlations between the <span class="hlt">plasmaspheric</span> erosions, the dipolarization fronts, and the energetic ions injections.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AdSpR..39..744G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AdSpR..39..744G"><span>Comparison of two IRI electron-density <span class="hlt">plasmasphere</span> extensions with GPS-TEC observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gulyaeva, T. L.; Gallagher, D. L.</p> <p></p> <p>Comparisons of two model results with Global Positioning System, GPS-TEC, measurements have been carried out for different latitudinal, solar activity, magnetic activity, diurnal, and seasonal conditions. The models evaluated are the Global Core Plasma Model (GCPM-2000) and the IRI extension (IRI ∗) with the Russian <span class="hlt">plasmasphere</span> model. Data from 23 observatories providing GPS-TEC and ionosonde data have been used. It is shown that the IRI ∗ <span class="hlt">plasmasphere</span> electron densities are greater than the GCPM results by an order of magnitude at 6370 km altitude (one Earth radius), becoming two to three orders of magnitude larger at the GPS satellite orbital altitude of 20,200 km. Another source of model and GPS-TEC differences is the selection of the ionospheric F2 layer peak parameters driving the models, either with ITU-R (former CCIR) maps or ionosonde observations. The <span class="hlt">plasmasphere</span> model extension of IRI improves the accuracy of the TEC model predictions taking into account the <span class="hlt">plasmasphere</span> contribution to the total electron content which could vary from 10% during daytime under quiet magnetic conditions to more than 50% during the night under storm-time conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040171673','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040171673"><span>A <span class="hlt">Plasmaspheric</span> Mass Density Model and Constraints on its Heavy Ion Concentration</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Berube, D.; Moldwin, M. B.; Green, J. L.</p> <p>2004-01-01</p> <p>The first empirical model of the equatorial mass density of the <span class="hlt">plasmasphere</span> is constructed using ground-based ULF wave diagnostics. <span class="hlt">Plasmaspheric</span> mass density between L=l.7 and L=3.2 has been determined using over 5200 hours of data from pairs of stations in the MEASURE array of ground magnetometers. The least-squares fit to the data as a function of L shows that mass density falls logarithmically with L. Average ion mass as a function of L is also estimated by combining the mass density model with <span class="hlt">plasmaspheric</span> electron density profiles determined from the IMAGE Radio Plasma Imager (RPI). Additionally, we use the RPI electron density database to examine how the average ion mass changes under different levels of geomagnetic activity. We find that average ion mass is greatest under the most disturbed conditions. This result indicates that heavy ion concentrations are enhanced during large geomagnetic disturbances, and therefore play an important role in storm-time <span class="hlt">plasmaspheric</span> dynamics. The average ion mass is also used to constrain the concentrations of He(+) and O(+). Estimates of the He(+) concentration determined this way can be useful for interpreting IMAGE Extreme Ultraviolet Imager (EUV) images.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSA31E2375F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSA31E2375F"><span>Simulating Storm Enhanced Densities (SEDs) Using Ionosphere-<span class="hlt">Plasmasphere</span>-Electrodynamics (IPE) Model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fedrizzi, M.; Maruyama, N.; Fuller-Rowell, T. J.; Richards, P. G.; Fang, T. W.; Codrescu, M.</p> <p>2015-12-01</p> <p>Storm-enhanced densities (SEDs) are increased ion concentrations seen in longitudinally narrow regions extending from middle latitudes to the polar cusp region. Signatures of SEDs have been observed in total electron content measurements obtained from networks of GPS receivers. They have also been observed as <span class="hlt">plasmaspheric</span> plumes by the extreme ultraviolet imager onboard IMAGE spacecraft, and more recently by the Van Allen Probes. Various mechanisms have been suggested to explain these density enhancements. In order to assess these theories and advance the understanding of the processes causing the dynamical evolution of SEDs in the ionosphere, a global ionosphere-<span class="hlt">plasmasphere</span> model with a realistic specification of storm time dependent electric field and neutral atmosphere is required. In this study, the recently developed Ionosphere-<span class="hlt">Plasmasphere</span>-Electrodynamics (IPE) model is used to simulate the SED observed during the March 17th, 2013 geomagnetic storm event. The IPE model provides time dependent, global, three dimensional plasma densities for nine ion species, electron and ion temperatures, parallel and perpendicular velocities of ionosphere and <span class="hlt">plasmasphere</span>. The geomagnetic storm high latitude drivers rely on the empirical models of the time-dependent Weimer magnetospheric convection and TIROS/NOAA auroral precipitation patterns. The neutral atmosphere composition and winds come from either empirical the MSIS and HWM models, or the Coupled model of the Thermosphere, Ionosphere, <span class="hlt">Plasmasphere</span> and electrodynamics (CTIPe). The simulations are used to evaluate the relative importance between electric field, neutral wind and neutral composition in reproducing the SEDs. Furthermore, observations from ground and space are used to validate the model results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSM43B2309H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSM43B2309H"><span>Solar-cycle variation of the <span class="hlt">plasmasphere</span> observed from the Akebono PWS data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hasegawa, S.; Miyoshi, Y.; Kitamura, N.; Keika, K.; Kumamoto, A.; Machida, S.</p> <p>2013-12-01</p> <p><span class="hlt">Plasmaspheric</span> density structures have been studied for a long time. Although it has been clarified that the density is roughly constant along field lines in the outer <span class="hlt">plasmasphere</span> [Goldstein et al., 2001; Denton et al., 2002, 2004], field-aligned density distributions of the inner <span class="hlt">plasmasphere</span> has not been studied intensively. Moreover, continuous observation results longer than one-solar cycle have not been reported. Consequently, long-term variations of the <span class="hlt">plasmaspheric</span> density over a solar cycle remains unknown. In this study, using electron density data based on plasma wave observations from the PWS experiments on board the Akebono satellite from 1989 to 2008, we conduct statistical analyses on variations of structures of the <span class="hlt">plasmasphere</span> and plasmatrough. First, we select PWS data during geomagnetically quiet periods ( Kp less than or equal to 3 and Dst greater than or equal to -50 nT ), and derive spatial distributions as a function of L-magnetic local time and altitude-magnetic latitude. Second, assuming that densities along field lines are a function of geocentric distance R at an altitude of higher than 4000 km, we estimate the equatorial density and field-aligned density distributions. The equatorial plasma density and field-aligned density distributions depend on the L shell and the solar cycle. At small L shells ( L less than 3.7 ), field-aligned distributions do not clearly depend on solar cycle, and the estimated equatorial density tends to be small during the solar minimum. At large L shells ( L larger than or equal to 3.7 ) including the plasma trough and outside the plasmapause, on the other hand, field-aligned distributions vary with the solar cycle and the density tends to be low during the solar minimum. The equatorial density at the solar minimum is higher than that at the solar maximum.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSM23B4233J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSM23B4233J"><span>Constraining the <span class="hlt">plasmasphere</span> dynamics with multiple data sets and data assimilation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jorgensen, A. M.; Lichtenberger, J.; Heilig, B.; Vellante, M.; Reda, J.; Friedel, R. H. W.; Henderson, M. G.; Ober, D. M.; Boudouridis, A.; Zesta, E.; Chi, P. J.; Cho, J.; Katus, R. M.</p> <p>2014-12-01</p> <p>The Earth's <span class="hlt">plasmasphere</span> is a region of dense plasma, originating inthe ionosphere, extending nearly to geostationary orbit. The preciseextent of the <span class="hlt">plasmasphere</span> is dynamic, particularly duringgeomagnetic active conditions. Knowing the exact distribution ofplasma in the <span class="hlt">plasmasphere</span> is important as an input to coupledmagnetospheric models. In particular, density gradients inside theplasmasphere and at the plasmapause, are important in controllingwaves which are responsible for the growth and decay of the radiationbelts. At the most basic level the <span class="hlt">plasmasphere</span> can be described interms of plasma exchange with the ionosphere and convection due to animposed electric field. At that level <span class="hlt">plasmasphere</span> modeling isrelatively simple. However there is currently insufficient knowledgeof the drivers, particularly the electric field, to model theplasmasphere boundaries at the most accurate level to providesufficient quality inputs to wave and radiation belt models. One solution to this problem is to use a data assimilationapproach. Data assimilation wraps a feedback loop around theplasmasphere model in which free, ideally unknown, model parametersare adjusted to maximize the agreement between the model andobservations. There are many possible implementations of this feedbackloop. We use the Ensemble Kalman Filter in which a statisticalensemble of models tracks the observations through lineartransformations. In previous work we have used either ground-basedobservations from the PLASMON project (funded by the European SeventhFramework Program), or a small number of space-based observations. Thenext step is to use a larger number of data sources, including avariety of ground-based and space-based observations as well as otherknowledge contains in empirical models. We will discuss our approachto incorporating disparate data sets and demonstrate some assimilationresults which combine different data sources.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRA..121..817P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRA..121..817P"><span>Imaging the topside ionosphere and <span class="hlt">plasmasphere</span> with ionospheric tomography using COSMIC GPS TEC</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pinto Jayawardena, Talini S.; Chartier, Alex T.; Spencer, Paul; Mitchell, Cathryn N.</p> <p>2016-01-01</p> <p>GPS-based ionospheric tomography is a well-known technique for imaging the total electron content (TEC) between GPS satellites and receivers. However, as an integral measurement of electron concentration, TEC typically encompasses both the ionosphere and <span class="hlt">plasmasphere</span>, masking signatures from the topside ionosphere-<span class="hlt">plasmasphere</span> due to the dominant ionosphere. Imaging these regions requires a technique that isolates TEC in the topside ionosphere-<span class="hlt">plasmasphere</span>. Multi-Instrument Data Analysis System (MIDAS) employs tomography to image the electron distribution in the ionosphere. Its implementation for regions beyond is yet to be seen due to the different dynamics present above the ionosphere. This paper discusses the extension of MIDAS to image these altitudes using GPS phase-based TEC measurements and follows the work by Spencer and Mitchell (2011). Plasma is constrained to dipole field lines described by Euler potentials, resulting in a distribution symmetrical about the geomagnetic equator. A simulation of an empirical <span class="hlt">plasmaspheric</span> model by Gallagher et al. (1988) is used to verify the technique by comparing reconstructions of the simulation with the empirical model. The Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) is used as GPS receiver locations. The verification is followed by a validation of the modified MIDAS algorithm, where the regions' TEC is reconstructed from COSMIC GPS phase measurements and qualitatively compared with previous studies using Jason-1 and COSMIC data. Results show that MIDAS can successfully image features/trends of the topside ionosphere-<span class="hlt">plasmasphere</span> observed in other studies, with deviations in absolute TEC attributed to differences in data set properties and the resolution of the images.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1985JGR....90.1647M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1985JGR....90.1647M"><span>Enhanced ion outflows measured by the DE 1 high altitude plasma instrument in the dayside <span class="hlt">plasmasphere</span> during the recovery phase</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Menietti, J. D.; Winningham, J. D.; Burch, J. L.; Peterson, W. K.; Waite, J. H., Jr.; Weimer, D. R.</p> <p>1985-02-01</p> <p>Ion flow velocities both parallel and perpendicular to the magnetic field, and including the effects of spacecraft charging and spacecraft velocity, have been measured during the recovery phase of two large magnetic storms on October 14 and 21 of 1981. These measurements were made both inside and outside the <span class="hlt">plasmasphere</span> and indicate unreported yet substantial outflows of ions within the dayside <span class="hlt">plasmasphere</span> (October 14). Combined data from instruments on board the Dynamics Explorer satellite, including the high altitude plasma instrument, the energetic ion composition spectrometer, the retarding ion mass spectrometer, and the plasma wave instrument, indicate that these ions are most likely dominantly O(+) at energies at least as low as 5 eV. The nightside pass (October 21), which occurred during the recovery phase of a similar storm, showed no <span class="hlt">plasmaspheric</span> outflows. The results indicate that a large contribution to the outflux into the dayside <span class="hlt">plasmasphere</span> during the recovery period is due to E greater than 5 eV ions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19850041218&hterms=High+Altitude+Plasma+Instrument&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DHigh%2BAltitude%2BPlasma%2BInstrument','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19850041218&hterms=High+Altitude+Plasma+Instrument&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DHigh%2BAltitude%2BPlasma%2BInstrument"><span>Enhanced ion outflows measured by the DE 1 high altitude plasma instrument in the dayside <span class="hlt">plasmasphere</span> during the recovery phase</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Menietti, J. D.; Winningham, J. D.; Burch, J. L.; Peterson, W. K.; Waite, J. H., Jr.; Weimer, D. R.</p> <p>1985-01-01</p> <p>Ion flow velocities both parallel and perpendicular to the magnetic field, and including the effects of spacecraft charging and spacecraft velocity, have been measured during the recovery phase of two large magnetic storms on October 14 and 21 of 1981. These measurements were made both inside and outside the <span class="hlt">plasmasphere</span> and indicate unreported yet substantial outflows of ions within the dayside <span class="hlt">plasmasphere</span> (October 14). Combined data from instruments on board the Dynamics Explorer satellite, including the high altitude plasma instrument, the energetic ion composition spectrometer, the retarding ion mass spectrometer, and the plasma wave instrument, indicate that these ions are most likely dominantly O(+) at energies at least as low as 5 eV. The nightside pass (October 21), which occurred during the recovery phase of a similar storm, showed no <span class="hlt">plasmaspheric</span> outflows. The results indicate that a large contribution to the outflux into the dayside <span class="hlt">plasmasphere</span> during the recovery period is due to E greater than 5 eV ions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3014739','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3014739"><span>Foot Morphology and Substrate Adhesion in the Madagascan <span class="hlt">Hissing</span> Cockroach, Gromphadorhina portentosa</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>van Casteren, Adam; Codd, Jonathan R.</p> <p>2010-01-01</p> <p>Insects are successful terrestrial organisms able to locomote over a wide range of obstacles and substrates. This study investigated how foot morphology (tarsal structure) correlates with substrate adhesion and ecological niche in the Madagascan <span class="hlt">hissing</span> cockroach, Gromphadorhina portentosa Schaum (Blattaria: Blaberidae). Using light and scanning electron microscopy, the morphology of the different structures of the tarsus of G. portentosa was analysed. Using an Instron® universal testing machine, a series of peak force experiments were then conducted to record the force required to lift the cockroaches off different substrates. G. portentosa was pulled off 10 different substrates, which consisted of smooth Perspex; Perspex scored at 1cm intervals; Perspex hatched at 1 cm, 0.5 cm, and 1 mm intervals; Perspex abraded with fine grade sandpaper; Perspex abraded with coarse grade sandpaper; wood; glass; and Teflon. A clear relationship was seen where an increase in scoring on the Perspex caused a decrease in adhesive ability of G. portentosa. This may be due to there being adequate contact area for the attachment of the pads and to allow the claws to engage. The results obtained suggest that to achieve the greatest adhesion to substrates, G. portentosa uses a combined effect of both adhesive pads and pretarsal claws. Adhesion to a wide range of substrates appears to be an adaptation to life as a wingless forest floor dweller. PMID:20575737</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20575737','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20575737"><span>Foot morphology and substrate adhesion in the Madagascan <span class="hlt">hissing</span> cockroach, Gromphadorhina portentosa.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>van Casteren, Adam; Codd, Jonathan R</p> <p>2010-01-01</p> <p>Insects are successful terrestrial organisms able to locomote over a wide range of obstacles and substrates. This study investigated how foot morphology (tarsal structure) correlates with substrate adhesion and ecological niche in the Madagascan <span class="hlt">hissing</span> cockroach, Gromphadorhina portentosa Schaum (Blattaria: Blaberidae). Using light and scanning electron microscopy, the morphology of the different structures of the tarsus of G. portentosa was analysed. Using an Instron universal testing machine, a series of peak force experiments were then conducted to record the force required to lift the cockroaches off different substrates. G. portentosa was pulled off 10 different substrates, which consisted of smooth Perspex; Perspex scored at 1cm intervals; Perspex hatched at 1 cm, 0.5 cm, and 1 mm intervals; Perspex abraded with fine grade sandpaper; Perspex abraded with coarse grade sandpaper; wood; glass; and Teflon. A clear relationship was seen where an increase in scoring on the Perspex caused a decrease in adhesive ability of G. portentosa. This may be due to there being adequate contact area for the attachment of the pads and to allow the claws to engage. The results obtained suggest that to achieve the greatest adhesion to substrates, G. portentosa uses a combined effect of both adhesive pads and pretarsal claws. Adhesion to a wide range of substrates appears to be an adaptation to life as a wingless forest floor dweller.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1984JGR....89..925L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1984JGR....89..925L"><span>Correlation of auroral <span class="hlt">hiss</span> and upward electron beams near the polar cusp</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lin, C. S.; Burch, J. L.; Shawhan, S. D.; Gurnett, D. A.</p> <p>1984-02-01</p> <p>Data were obtained from the DE-1 high-altitude plasma instrument (HAPI) and plasma wave instrument (PWI) during outbound passes through the polar cusp near local noon. The observed distribution functions of electron beams are fitted by drifting Maxwellian functions and the observed distribution functions of hot background electrons by isotropic Maxwellian functions. In addition, the cold plasma density is inferred from knowledge of the electron plasma frequency and the measured density of the warm plasma, including the electron beam distribution. The empirically fitted plasma parameters, including density, temperature and drifting energy, are used to solve the linear dispersion equation for the resulting whistler mode emissions. Because the whistler mode becomes quasi-electrostatic for wave-normal angles near the resonance cone, the electrostatic approximation is used for the whistler mode dispersion relation. The results of wave instability analyses are then compared with the wave observations. A ray tracing of cusp <span class="hlt">hiss</span> emission is conducted to locate the wave source region (at about one earth-radius).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4550421','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4550421"><span>Effective Stimulus Parameters for Directed Locomotion in Madagascar <span class="hlt">Hissing</span> Cockroach Biobot</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Erickson, Jonathan C.; Shingiro, Aristide; Bowen, Thomas</p> <p>2015-01-01</p> <p>Swarms of insects instrumented with wireless electronic backpacks have previously been proposed for potential use in search and rescue operations. Before deploying such biobot swarms, an effective long-term neural-electric stimulus interface must be established, and the locomotion response to various stimuli quantified. To this end, we studied a variety of pulse types (mono- vs. bipolar; voltage- vs. current-controlled) and shapes (amplitude, frequency, duration) to parameters that are most effective for evoking locomotion along a desired path in the Madagascar <span class="hlt">hissing</span> cockroach (G. portentosa) in response to antennal and cercal stimulation. We identified bipolar, 2 V, 50 Hz, 0.5 s voltage controlled pulses as being optimal for evoking forward motion and turns in the expected contraversive direction without habituation in ≈50% of test subjects, a substantial increase over ≈10% success rates previously reported. Larger amplitudes for voltage (1–4 V) and current (50–150 μA) pulses generally evoked larger forward walking (15.6–25.6 cm; 3.9–5.6 cm/s) but smaller concomitant turning responses (149 to 80.0 deg; 62.8 to 41.2 deg/s). Thus, the radius of curvature of the initial turn-then-run locomotor response (≈10–25 cm) could be controlled in a graded manner by varying the stimulus amplitude. These findings could be used to help optimize stimulus protocols for swarms of cockroach biobots navigating unknown terrain. PMID:26308337</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26308337','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26308337"><span>Effective Stimulus Parameters for Directed Locomotion in Madagascar <span class="hlt">Hissing</span> Cockroach Biobot.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Erickson, Jonathan C; Herrera, María; Bustamante, Mauricio; Shingiro, Aristide; Bowen, Thomas</p> <p>2015-01-01</p> <p>Swarms of insects instrumented with wireless electronic backpacks have previously been proposed for potential use in search and rescue operations. Before deploying such biobot swarms, an effective long-term neural-electric stimulus interface must be established, and the locomotion response to various stimuli quantified. To this end, we studied a variety of pulse types (mono- vs. bipolar; voltage- vs. current-controlled) and shapes (amplitude, frequency, duration) to parameters that are most effective for evoking locomotion along a desired path in the Madagascar <span class="hlt">hissing</span> cockroach (G. portentosa) in response to antennal and cercal stimulation. We identified bipolar, 2 V, 50 Hz, 0.5 s voltage controlled pulses as being optimal for evoking forward motion and turns in the expected contraversive direction without habituation in ≈50% of test subjects, a substantial increase over ≈10% success rates previously reported. Larger amplitudes for voltage (1-4 V) and current (50-150 μA) pulses generally evoked larger forward walking (15.6-25.6 cm; 3.9-5.6 cm/s) but smaller concomitant turning responses (149 to 80.0 deg; 62.8 to 41.2 deg/s). Thus, the radius of curvature of the initial turn-then-run locomotor response (≈10-25 cm) could be controlled in a graded manner by varying the stimulus amplitude. These findings could be used to help optimize stimulus protocols for swarms of cockroach biobots navigating unknown terrain.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AnGeo..35..599M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AnGeo..35..599M"><span>Determinations of ionosphere and <span class="hlt">plasmasphere</span> electron content for an African chain of GPS stations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mazzella, Andrew J., Jr.; Bosco Habarulema, John; Yizengaw, Endawoke</p> <p>2017-05-01</p> <p>The confluence of recent instrumentation deployments in Africa with developments for the determination of <span class="hlt">plasmasphere</span> electron content using Global Positioning System (GPS) receivers has provided new opportunities for investigations in that region. This investigation, using a selected chain of GPS stations, extends the method (SCORPION) previously applied to a chain of GPS stations in North America in order to separate the ionosphere and <span class="hlt">plasmasphere</span> contributions to the total electron content (TEC) during a day (24 July) in 2011. The results span latitudes from the southern tip of Africa, across the Equator, to the southern Arabian Peninsula, providing a continuous latitudinal profile for both the ionosphere and <span class="hlt">plasmasphere</span> during this day.The peak diurnal vertical ionosphere electron content (IEC) increases from about 14 TEC units (1 TEC unit = 1016 electrons m-2) at the southernmost station to about 32 TEC units near the geographic equator, then decreases to about 28 TEC units at the Arabian Peninsula. The peak diurnal slant <span class="hlt">plasmasphere</span> electron content (PEC) varies between about 4 and 7 TEC units among the stations, with a local latitudinal profile that is significantly influenced by the viewing geometry at the station location, relative to the magnetic field configuration. In contrast, the peak vertical PEC varies between about 1 and 6 TEC units among the stations, with a more uniform latitudinal variation.Comparisons to other GPS data analyses are also presented for TEC, indicating the influence of the PEC on the determination of latitudinal TEC variations and also on the absolute TEC levels, by inducing an overestimate of the receiver bias. The derived TEC latitudinal profiles, in comparison to global map profiles, tend to differ from the map results only about as much as the map results differ among themselves. A combination of ionosonde IEC and alternative GPS TEC measurements, which in principle permits a PEC determination through their difference, was</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUFMSA13B..03L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUFMSA13B..03L"><span>First Satellite Observation Results of Equatorial Convective Velocity in the Inner Magnetosphere in Association with <span class="hlt">Plasmaspheric</span> Plume</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lin, C. S.; Yeh, H.; Sandel, B. R.; Goldstein, J.; Rich, F. J.; Burke, W. J.</p> <p>2005-12-01</p> <p>Equatorial ion convective velocity in the inner magnetosphere has been deduced from ROCSAT-1 and DMSP measurements of ion drift velocity in the ionosphere. Convective velocities are mapped from the ionosphere to the equatorial plane based on the equipotential assumption along magnetic field lines. We report here for the first time signatures of equatorial convective velocity in association with the <span class="hlt">plasmaspheric</span> drainage plume, which was observed by IMAGE EUV instrument during the recovery phase of the 2000 Bastille Day magnetic storm. The azimuthal profile of the zonal convective velocity deduced from the ROCSAT-1 data indicates a sharp azimuthal gradient at the sunward edge of the <span class="hlt">plasmaspheric</span> plume as the zonal velocity changes from sunward to anti-sunward direction. Thus the <span class="hlt">plasmaspheric</span> plasma in the inertial frame was sub-corotational before reaching the longitude of the <span class="hlt">plasmaspheric</span> plume and became supra-corotational after passing the longitude of the <span class="hlt">plasmaspheric</span> plume. The radial profile of the zonal convective velocity near the plume deduced from the DMSP data indicates an increase of strong sunward zonal velocity with radial distance. These results imply complicated electric field structures for producing <span class="hlt">plasmaspheric</span> plumes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20010021215&hterms=Archimedes&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DArchimedes','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20010021215&hterms=Archimedes&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DArchimedes"><span>IMAGE EUV Observations and Modeling of the <span class="hlt">Plasmaspheric</span> Density Trough Associated with the 24 May 2000 Geomagnetic Storm</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Adrian, M.L.; Gallagher, D. L.; Green, J. L.; Sandel, B. R.; Rose, M. Franklin (Technical Monitor)</p> <p>2000-01-01</p> <p>The IMAGE EUV imager observed a <span class="hlt">plasmaspheric</span> density trough in association with a geomagnetically active period on 24 May 2000. At EUV wavelengths, this density trough appeared as an Archimedes spiral extending from Earth's shadow to approximately 1800 MLT. We present an analysis of this density trough using simulated EUV images. Observational EUV images are subjected to edge analysis to establish the plasmapause L-shell and the location of the density trough in terms of L-shell, MLT extent, and radial width. The <span class="hlt">plasmaspheric</span> density distribution is modeled using both static and dynamic models for the <span class="hlt">plasmasphere</span>. The background <span class="hlt">plasmasphere</span> is then numerically simulated using the 4-parameter <span class="hlt">plasmaspheric</span> density model contained within the Global Core Plasma Model (GCPM) [Gallagher et al., 20001 and the Dynamic Global Core Plasma Model (DGCPM). Simulated EUV images of the model <span class="hlt">plasmasphere</span> are produced once an artificial density depletion, matching the observed MLT extent and width, has been removed. Once the azimuthal extent and width of the trough have been simulated, the depth of the artificial density depletion is iteratively adjusted to produce simulated EUV images that approximate observation. The results of this analysis and discussion of possible origins for this density trough will be presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20010021215&hterms=archimedes&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Darchimedes','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20010021215&hterms=archimedes&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Darchimedes"><span>IMAGE EUV Observations and Modeling of the <span class="hlt">Plasmaspheric</span> Density Trough Associated with the 24 May 2000 Geomagnetic Storm</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Adrian, M.L.; Gallagher, D. L.; Green, J. L.; Sandel, B. R.; Rose, M. Franklin (Technical Monitor)</p> <p>2000-01-01</p> <p>The IMAGE EUV imager observed a <span class="hlt">plasmaspheric</span> density trough in association with a geomagnetically active period on 24 May 2000. At EUV wavelengths, this density trough appeared as an Archimedes spiral extending from Earth's shadow to approximately 1800 MLT. We present an analysis of this density trough using simulated EUV images. Observational EUV images are subjected to edge analysis to establish the plasmapause L-shell and the location of the density trough in terms of L-shell, MLT extent, and radial width. The <span class="hlt">plasmaspheric</span> density distribution is modeled using both static and dynamic models for the <span class="hlt">plasmasphere</span>. The background <span class="hlt">plasmasphere</span> is then numerically simulated using the 4-parameter <span class="hlt">plasmaspheric</span> density model contained within the Global Core Plasma Model (GCPM) [Gallagher et al., 20001 and the Dynamic Global Core Plasma Model (DGCPM). Simulated EUV images of the model <span class="hlt">plasmasphere</span> are produced once an artificial density depletion, matching the observed MLT extent and width, has been removed. Once the azimuthal extent and width of the trough have been simulated, the depth of the artificial density depletion is iteratively adjusted to produce simulated EUV images that approximate observation. The results of this analysis and discussion of possible origins for this density trough will be presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009SSRv..145..107M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009SSRv..145..107M"><span>Electric Fields and Magnetic Fields in the <span class="hlt">Plasmasphere</span>: A Perspective From CLUSTER and IMAGE</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Matsui, Hiroshi; Foster, John C.; Carpenter, Donald L.; Dandouras, Iannis; Darrouzet, Fabien; de Keyser, Johan; Gallagher, Dennis L.; Goldstein, Jerry; Puhl-Quinn, Pamela A.; Vallat, Claire</p> <p>2009-05-01</p> <p>The electric field and magnetic field are basic quantities in the <span class="hlt">plasmasphere</span> measured since the 1960s. In this review, we first recall conventional wisdom and remaining problems from ground-based whistler measurements. Then we show scientific results from Cluster and Image, which are specifically made possible by newly introduced features on these spacecraft, as follows. 1. In situ electric field measurements using artificial electron beams are successfully used to identify electric fields originating from various sources. 2. Global electric fields are derived from sequences of <span class="hlt">plasmaspheric</span> images, revealing how the inner magnetospheric electric field responds to the southward interplanetary magnetic fields and storms/substorms. 3. Understanding of sub-auroral polarization stream (SAPS) or sub-auroral ion drifts (SAID) are advanced through analysis of a combination of magnetospheric and ionospheric measurements from Cluster, Image, and DMSP. 4. Data from multiple spacecraft have been used to estimate magnetic gradients for the first time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19860057105&hterms=phase+equilibria&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dphase%2Bequilibria','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19860057105&hterms=phase+equilibria&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dphase%2Bequilibria"><span>Latitudinal plasma distribution in the dusk <span class="hlt">plasmaspheric</span> bulge - Refilling phase and quasi-equilibrium state</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Decreau, P. M. E.; Carpenter, D.; Chappell, C. R.; Green, J.; Waite, J. H., Jr.</p> <p>1986-01-01</p> <p>Very low-energy trapped ions, mostly protons, have been observed in a region of moderate density characteristic of the plasmapause boundary and of the <span class="hlt">plasmaspheric</span> bulge. The present paper is concerned with an examination of the latitudinal structure of the bulge under quasi-steady conditions and the conditions of the recovery phase. Details regarding the data base are considered along with observations of the morphology and dynamics of the bulge, the latitudinal density distribution in the expanded bulge, the convection scenario during the replenishment phase, and latitudinal effects on plasma characteristics during <span class="hlt">plasmasphere</span> refilling. The data utilized have been mainly provided by the DE 1 and GEOS 2 spacecraft traveling in two perpendicular planes. It is found that the bulge is a dynamic region, where no reasonable interpretation of the observed density distribution can be achieved without taking into account the mechanism of magnetospheric convection.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JSWSC...3A..23L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JSWSC...3A..23L"><span>The <span class="hlt">plasmasphere</span> during a space weather event: first results from the PLASMON project</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lichtenberger, János; Clilverd, Mark A.; Heilig, Balázs; Vellante, Massimo; Manninen, Jyrki; Rodger, Craig J.; Collier, Andrew B.; Jørgensen, Anders M.; Reda, Jan; Holzworth, Robert H.; Friedel, Reinhard; Simon-Wedlund, Mea</p> <p>2013-06-01</p> <p>The results of the first 18 months of the PLASMON project are presented. We have extended our three, existing ground-based measuring networks, AWDANet (VLF/whistlers), EMMA/SANSA (ULF/FLRs), and AARDDVARK (VLF/perturbations on transmitters’ signal), by three, eight, and four new stations, respectively. The extended networks will allow us to achieve the four major scientific goals, the automatic retrieval of equatorial electron densities and density profiles of the <span class="hlt">plasmasphere</span> by whistler inversion, the retrieval of equatorial plasma mass densities by EMMA and SANSA from FLRs, developing a new, data assimilative model of <span class="hlt">plasmasphere</span> and validating the model predictions through comparison of modeled REP losses with measured data by AARDDVARK network. The first results on each of the four objectives are presented through a case study on a space weather event, a dual storm sudden commencement which occurred on August 3 and 4, 2010.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRA..121.8537F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRA..121.8537F"><span><span class="hlt">Interactions</span> between magnetosonic waves and ring current protons: Gyroaveraged test particle simulations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fu, Song; Ni, Binbin; Li, Jinxing; Zhou, Chen; Gu, Xudong; Huang, Shiyong; Zhang, Hui; Ge, Yasong; Cao, Xing</p> <p>2016-09-01</p> <p>Gyroaveraged test particle simulations are implemented to quantitatively investigate <span class="hlt">interactions</span> between linearly polarized magnetosonic waves (i.e., equatorial noises) and ring current protons inside and outside the <span class="hlt">plasmasphere</span> at L = 4.5. For magnetosonic waves at the frequency of 33.3 Hz (fw/fcp = 6.4 at the magnetic equator, for L = 4.5), it is found that wave-particle <span class="hlt">interactions</span> at the resonance order corresponding to the lowest resonant proton energy (i.e., N = 6) are dominant. The <span class="hlt">interactions</span> at other resonance orders make much less contribution. Near the equatorial loss cone at L = 4.5, magnetosonic waves produce strongest proton pitch angle diffusion at 20 keV inside the <span class="hlt">plasmasphere</span> and at 100 keV outside the <span class="hlt">plasmasphere</span>, respectively, reaching a rate above 10-6 s-1. The corresponding energy diffusion dominates over pitch angle diffusion at high pitch angles; therefore, magnetosonic waves are likely to accelerate protons at a few keV inside the <span class="hlt">plasmasphere</span> and at 10 keV outside the <span class="hlt">plasmasphere</span>. Due to the emission equatorial confinement, the effect of transit time scattering also occurs for <span class="hlt">interactions</span> of magnetosonic waves with ring current protons and tends to be increasingly important outside the <span class="hlt">plasmasphere</span>, which is consistent with previous studies on <span class="hlt">interactions</span> of magnetosonic waves with radiation belt electrons.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950047203&hterms=Tamas&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAuthor-Name%26N%3D0%26No%3D40%26Ntt%3DTamas','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950047203&hterms=Tamas&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAuthor-Name%26N%3D0%26No%3D40%26Ntt%3DTamas"><span>Non-steady-state transport of superthermal electrons in the <span class="hlt">plasmasphere</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Khazanov, George V.; Liemohn, Michael W.; Gombosi, Tamas I.; Nagy, Andrew F.</p> <p>1993-01-01</p> <p>Numerical solutions to the time-dependent kinetic equation, which describes the transport of superthermal electrons in the splasmasphere between the two conjugate ionospheres, are presented. The model calculates the distribution function as a function of time, field-aligned distance, energy, and pitch-angle. The processes of refilling, depleting, and establishing steady-state conditions of superthermal electrons in the <span class="hlt">plasmasphere</span> are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.8650L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.8650L"><span><span class="hlt">Plasmaspheric</span> electron densities: the importance in modelling radiation belts and in SSA operation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lichtenberger, János; Jorgensen, Anders; Koronczay, Dávid; Ferencz, Csaba; Hamar, Dániel; Steinbach, Péter; Clilverd, Mark; Rodger, Craig; Juhász, Lilla; Sannikov, Dmitry; Cherneva, Nina</p> <p>2016-04-01</p> <p>The Automatic Whistler Detector and Analyzer Network (AWDANet, Lichtenberger et al., J. Geophys. Res., 113, 2008, A12201, doi:10.1029/2008JA013467) is able to detect and analyze whistlers in quasi-realtime and can provide equatorial electron density data. The <span class="hlt">plasmaspheric</span> electron densities are key parameters for <span class="hlt">plasmasphere</span> models in Space Weather related investigations, particularly in modeling charged particle accelerations and losses in Radiation Belts. The global AWDANet detects millions of whistlers in a year. The network operates since early 2002 with automatic whistler detector capability and it has been recently completed with automatic analyzer capability in PLASMON (http://plasmon.elte.hu, Lichtenberger et al., Space Weather Space Clim. 3 2013, A23 DOI: 10.1051/swsc/2013045.) Eu FP7-Space project. It is based on a recently developed whistler inversion model (Lichtenberger, J. J. Geophys. Res., 114, 2009, A07222, doi:10.1029/2008JA013799), that opened the way for an automated process of whistler analysis, not only for single whistler events but for complex analysis of multiple-path propagation whistler groups. The network operates in quasi real-time mode since mid-2014, fifteen stations provide equatorial electron densities that are used as inputs for a data assimilative <span class="hlt">plasmasphere</span> model but they can also be used directly in space weather research and models. We have started to process the archive data collected by AWDANet stations since 2002 and in this paper we present the results of quasi-real-time and off-line runs processing whistlers from quiet and disturb periods. The equatorial electron densities obtained by whistler inversion are fed into the assimilative model of the <span class="hlt">plasmasphere</span> providing a global view of the region for processed the periods</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA538259','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA538259"><span>Sensitivity Analysis of Empirical Parameters in the Ionosphere-<span class="hlt">Plasmasphere</span> Model</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2011-03-01</p> <p>like pattern of TEC enhancements and deple- tions at equatorial and low latitudes. Scherliess et al. (2008) studied the longitudinal variability of...parameters used in physics-based models was completed in this study to determine their effect on electron densities and total electron content (TEC...in the ionosphere. The model used was the Ionosphere- <span class="hlt">Plasmasphere</span> Model (IPM) developed by Utah State University. The empirical pa- rameters studied</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA087948','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA087948"><span>Quantitative Simulation of a Magnetospheric Substorm. 3. <span class="hlt">Plasmaspheric</span> Electric Fields and Evolution of the Plasmapause.</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1980-01-25</p> <p><span class="hlt">plasmaspheric</span> electric fields during magnetically disturbed periods are based on incoherent scatter radar results fromn St. Santin [ Testud et al., 1975...Millstone Hill radar results showing westward F-region ion drifts of almost 200 m/sec in the afternoon sector on 14 May, 1969. Testud et al. [1975...electrojet (AE) index. Testud et al. [1975] and Blanc et al. £1977] have both presented St. Santin backscatter measurements that show westward and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996AdSpR..17..213S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996AdSpR..17..213S"><span>Aspects of wave-particle <span class="hlt">interactions</span> at mid-latitudes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Smith, A. J.</p> <p></p> <p>Arguably the most significant source of particle precipitation into the ionosphere at mid-latitudes (L ~ 2-3), at least for electrons in the tens to hundreds of keV energy range, is that which arises from the <span class="hlt">interaction</span> between trapped particles and whistler-mode waves in the magnetosphere. Quasi-steady <span class="hlt">plasmaspheric</span> <span class="hlt">hiss</span> has long been postulated as a major class of waves contributing to the loss of radiation belt particles but recent studies have suggested that under some conditions, impulsive precipitation caused by <span class="hlt">interactions</span> with lightning-generated whistlers may be equally important as a loss process. Such lightning-induced electron precipitation (LEP) and its ionospheric signature is the subject of this paper. Although LEP may be detected and studied by a variety of ground-based, balloon-borne and satellite-borne sensors, through optical emissions, X-ray production, enhanced conductivity, or the direct measurement of the precipitating particles themselves, a technique using ground-based narrow-band VLF receivers to measure the Trimpi effect (the transient perturbations in amplitude and/or phase of received narrow-band VLF transmissions) caused by LEP-associated ionisation enhancements has become increasingly popular due to its simple instrumentation and wide field of view. Most work has concentrated on the 2 < L < 3 region where typical whistler spectra, trapped electron energy distributions and magnetospheric plasma densities and magnetic field strengths are most favourable for the Trimpi effect. In order to use the technique to study in detail the characteristics and distribution of LEP (and its importance as a trapped-particle loss mechanism), using a network of intersecting transmitter-receiver great-circle paths (TRGCPs), a consensus on how to interpret the observational data is crucial, though this has recently been the subject of controversy. Whilst most studies suggest that only LEP within ~200 km of the TRGCP gives rise to an observable Trimpi</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28801771','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28801771"><span>Morphology and ultrastructure of the tarsal adhesive organs of the Madagascar <span class="hlt">hissing</span> cockroach Gromphadorhina portentosa.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schmitt, Christian; Betz, Oliver</p> <p>2017-08-12</p> <p>The present transmission and scanning electron microscopic study of the ultramorphology of the pliable attachment pads (arolium, euplantulae) of the Madagascar <span class="hlt">hissing</span> cockroach Gromphadorhina portentosa reveals structural evidence for their function in producing, storing, and secreting an adhesion-mediating secretion and releasing it to the exterior. The exocrine epidermal tissue of both the arolium and the euplantula is significantly enlarged by numerous invaginations stretching into the hemolymph cavity. Its cells show large nuclei, numerous mitochondria, Golgi complexes, and a prominent rough-surfaced endoplasmic reticulum integrated within an electron-dense cytoplasm that contains numerous vesicles of diverse electron density and size. Invaginations of the cell membrane provide evidence for strong membrane turnover. The glandular epithelium of both the arolium and the euplantula releases the adhesion-mediating secretion into a subcuticular void from which it has to permeate the thick cuticle of the adhesive pads. The subcuticular void is compartmentalized by cuticle bands through which the adhesion-mediating secretion permeates via small canals. The secretion subsequently enters a larger storage reservoir before being received by a prominent sponge-like cuticle. The structural differences between the arolium and the euplantula consist of the number and length of the interdigitations spanning the hemolymph cavity, of the subdivision of the subcuticular reservoir by cuticle bands, and of the thickness of the sponge-like cuticle. The structural results are discussed with respect to the production of a chemically complex (emulsion-like) adhesive, its controlled release to the exterior, and the micromechanical properties of the cuticle of the pliable pad.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3210583','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3210583"><span>Non-contrast enhanced MRI for evaluation of breast lesions: comparison of non-contrast enhanced high spectral and spatial resolution (<span class="hlt">HiSS</span>) images vs. contrast enhanced fat-suppressed images</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Medved, Milica; Fan, Xiaobing; Abe, Hiroyuki; Newstead, Gillian M.; Wood, Abbie M.; Shimauchi, Akiko; Kulkarni, Kirti; Ivancevic, Marko K.; Pesce, Lorenzo L.; Olopade, Olufunmilayo I.; Karczmar, Gregory S.</p> <p>2011-01-01</p> <p>RATIONALE AND OBJECTIVES To evaluate high spectral and spatial resolution (<span class="hlt">HiSS</span>) MRI for diagnosis of breast cancer without injection of contrast media: to compare the performance of pre-contrast <span class="hlt">HiSS</span> images to conventional contrast-enhanced fat-suppressed T1-weighted images, based on image quality and in the task of classifying benign and malignant breast lesions. MATERIALS AND METHODS Ten benign and 44 malignant lesions were imaged at 1.5T with <span class="hlt">HiSS</span> (pre-contrast administration) and conventional fat-suppressed imaging (3–10 min post-contrast). This set of 108 images, after randomization, was evaluated by three experienced radiologists blinded to the imaging technique. BIRADS morphologic criteria (lesion shape; lesion margin; internal signal intensity pattern) and final assessment were used to measure reader performance. Image quality was evaluated based on boundary delineation and quality of fat suppression. An overall probability of malignancy was assigned to each lesion for <span class="hlt">HiSS</span> and conventional images separately. RESULTS On boundary delineation and quality of fat-suppression, pre-contrast <span class="hlt">HiSS</span> scored similarly to conventional post-contrast MRI. On benign vs. malignant lesion separation, there was no statistically significant difference in ROC performance between <span class="hlt">HiSS</span> and conventional MRI, and <span class="hlt">HiSS</span> met a reasonable non-inferiority condition. CONCLUSION Pre-contrast <span class="hlt">HiSS</span> imaging is a promising approach for showing lesion morphology without blooming and other artifacts caused by contrast agents. <span class="hlt">HiSS</span> images could be used to guide subsequent dynamic contrast-enhanced MRI scans, to maximize spatial and temporal resolution in suspicious regions. <span class="hlt">HiSS</span> MRI without contrast agent injection may be particularly important for patients at risk for contrast-induced nephrogenic systemic fibrosis, or allergic reactions. PMID:21962476</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1239064-postmidnight-depletion-high-energy-tail-quiet-plasmasphere','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1239064-postmidnight-depletion-high-energy-tail-quiet-plasmasphere"><span>Postmidnight depletion of the high-energy tail of the quiet <span class="hlt">plasmasphere</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Sarno-Smith, Lois K.; Liemohn, Michael W.; Katus, Roxanne M.; ...</p> <p>2015-03-06</p> <p>The Van Allen Probes Helium Oxygen Proton Electron (HOPE) instrument measures the high energy tail of the thermal <span class="hlt">plasmasphere</span> allowing study of topside ionosphere and inner magnetosphere coupling. We statistically analyze a 22 month period of HOPE data, looking at quiet times with a Kp index of less than 3. We investigate the high energy range of the <span class="hlt">plasmasphere</span>, which consists of ions at energies between 1-10 eV and contains approximately 5% of total <span class="hlt">plasmaspheric</span> density. Both the fluxes and partial plasma densities over this energy range show H+ is depleted the most in the post-midnight sector (1-4 MLT), followedmore » by O+ and then He+. The relative depletion of each species across the post-midnight sector is not ordered by mass, which reveals ionospheric influence. We compare our results with keV energy electron data from HOPE and the Van Allen Probes Electric Fields and Waves (EFW) instrument spacecraft potential to rule out spacecraft charging. Our conclusion is that the post-midnight ion disappearance is due to diurnal ionospheric temperature variation and charge exchange processes« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1239064','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1239064"><span>Postmidnight depletion of the high-energy tail of the quiet <span class="hlt">plasmasphere</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sarno-Smith, Lois K.; Liemohn, Michael W.; Katus, Roxanne M.; Skoug, Ruth M.; Larsen, Brian A.; Thomsen, Michelle F.; Wygant, John R.; Moldwin, Mark B.</p> <p>2015-03-06</p> <p>The Van Allen Probes Helium Oxygen Proton Electron (HOPE) instrument measures the high energy tail of the thermal <span class="hlt">plasmasphere</span> allowing study of topside ionosphere and inner magnetosphere coupling. We statistically analyze a 22 month period of HOPE data, looking at quiet times with a Kp index of less than 3. We investigate the high energy range of the <span class="hlt">plasmasphere</span>, which consists of ions at energies between 1-10 eV and contains approximately 5% of total <span class="hlt">plasmaspheric</span> density. Both the fluxes and partial plasma densities over this energy range show H<sup>+</sup> is depleted the most in the post-midnight sector (1-4 MLT), followed by O<sup>+</sup> and then He<sup>+</sup>. The relative depletion of each species across the post-midnight sector is not ordered by mass, which reveals ionospheric influence. We compare our results with keV energy electron data from HOPE and the Van Allen Probes Electric Fields and Waves (EFW) instrument spacecraft potential to rule out spacecraft charging. Our conclusion is that the post-midnight ion disappearance is due to diurnal ionospheric temperature variation and charge exchange processes</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19990018405','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19990018405"><span>Convection of <span class="hlt">Plasmaspheric</span> Plasma into the Outer Magnetosphere and Boundary Layer Region: Initial Results</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ober, Daniel M.; Horwitz, J. L.</p> <p>1998-01-01</p> <p>We present initial results on the modeling of the circulation of <span class="hlt">plasmaspheric</span>-origin plasma into the outer magnetosphere and low-latitude boundary layer (LLBL), using a dynamic global core plasma model (DGCPM). The DGCPM includes the influences of spatially and temporally varying convection and refilling processes to calculate the equatorial core plasma density distribution throughout the magnetosphere. We have developed an initial description of the electric and magnetic field structures in the outer magnetosphere region. The purpose of this paper is to examine both the losses of <span class="hlt">plasmaspheric</span>-origin plasma into the magnetopause boundary layer and the convection of this plasma that remains trapped on closed magnetic field lines. For the LLBL electric and magnetic structures we have adopted here, the <span class="hlt">plasmaspheric</span> plasma reaching the outer magnetosphere is diverted anti-sunward primarily along the dusk flank. These plasmas reach X= -15 R(sub E) in the LLBL approximately 3.2 hours after the initial enhancement of convection and continues to populate the LLBL for 12 hours as the convection electric field diminishes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMSA31C..02H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMSA31C..02H"><span>The Impact of the Ionospheric Dynamo on the SAMI3 <span class="hlt">Plasmasphere</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huba, J. D.; Krall, J.</p> <p>2012-12-01</p> <p>The NRL SAMI3 ionosphere/<span class="hlt">plasmasphere</span> code is used to study the impact of the wind-driven ionospheric dynamo on the <span class="hlt">plasmasphere</span>. The SAMI3 ionosphere code includes 7 ion species (H+,He+,O+,N+,O2+,N2+,NO+), each treated as a separate fluid, with temperature equations being solved for H+, He+, O+ and e-. Winds in SAMI3 are provided by HWM07 and the wind-driven ionospheric dynamo potential is computed self-consistently, based on current conservation (∇ \\cdot J = 0). For this study SAMI3 is driven by either a Weimer or a Volland-Stern potential at high latitudes. The high-latitude potential in combination with losses imposed for `open' field lines (L > 7) produces a dynamic plasmapause. By performing SAMI3 runs with and without the wind-driven dynamo potential, we find that the wind-driven dynamo has a noticable impact on the shape and motion of the SAMI3 <span class="hlt">plasmasphere</span>. Research supported by NRL Base Funds and NASA.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014GeoRL..41..762F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014GeoRL..41..762F"><span>Storm time observations of <span class="hlt">plasmasphere</span> erosion flux in the magnetosphere and ionosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Foster, J. C.; Erickson, P. J.; Coster, A. J.; Thaller, S.; Tao, J.; Wygant, J. R.; Bonnell, J. W.</p> <p>2014-02-01</p> <p><span class="hlt">Plasmasphere</span> erosion carries cold dense plasma of ionospheric origin in a storm-enhanced density plume extending from dusk toward and through the noontime cusp and dayside magnetopause and back across polar latitudes in a polar tongue of ionization. We examine dusk sector (20 MLT) <span class="hlt">plasmasphere</span> erosion during the 17 March 2013 storm (Dst ~ -130 nT) using simultaneous, magnetically aligned direct sunward ion flux observations at high altitude by Van Allen Probes RBSP-A (at ~3.0 Re) and at ionospheric heights (~840 km) by DMSP F-18. Plasma erosion occurs at both high and low altitudes where the subauroral polarization stream flow overlaps the outer <span class="hlt">plasmasphere</span>. At ~20 UT, RBSP-A observed ~1.2E12 m-2 s-1 erosion flux, while DMSP F-18 observed ~2E13 m-2 s-1 sunward flux. We find close similarities at high and low altitudes between the erosion plume in both invariant latitude spatial extent and plasma characteristics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20100033477&hterms=isr&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Disr','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20100033477&hterms=isr&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Disr"><span>Remote Sensing of the Ionosphere and <span class="hlt">Plasmasphere</span> from Space Using Radiowaves</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mannucci, Anthony J.</p> <p>2008-01-01</p> <p>Topics include the scientific context, trans-ionospheric and sounding, small-scale structure, <span class="hlt">plasmasphere</span>, fast and slow tomography, and pseudo-imaging. Individual slides focus on where geospace science stands today, variability in inner magnetosphere electric fields, Appleton-Hartree formula, phase and range ionospheric observables, examples of leveling, large ionization changes during storms, new mid-latitude phenomena, ionospheric sounding, COSMIC CERTO/Tri-band beacon, LEO-ground radio tomography, irregularity measurements, COSMIC, critical sensor data from COSMIC GPS limb sounding, occultation geometry, comparison of calibrated slant TEC measurements for 26 June 2006, historic examples of Abel electron density profiles, comparison of UCAR and JPL Able profiles of 26 June 2006, validating UCAR and JPL Abel profiles using Arecibo ISR measurements for 26 June 2006, E-region from GPS/MET 1995, Abel versus gradient assisted retrieval, 3000 profiles/day, <span class="hlt">plasmasphere</span>, JASON TEC above satellite, GPS equatorial <span class="hlt">plasmasphere</span> measurements, April 2002 geomagnetic storm, and space-based GPS tomography.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.4252H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.4252H"><span>Ground based detection of the plasmapause and the density of the <span class="hlt">plasmasphere</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Heilig, Balázs; Darrouzet, Fabien; Friedel, Reinhard H.; Lichtenberger, János; Vellante, Massimo</p> <p>2014-05-01</p> <p>Although our knowledge on the <span class="hlt">plasmasphere</span> dynamics has improved greatly thanks to some recent space missions (IMAGE, Cluster), continuous monitoring of the plasmapause position and plasma density remains unsolved. Ground based observation of geomagnetic field line resonances (FLRs) has the potential to achieve this goal. A meridional array of properly spaced magnetometers, such as EMMA (European quasi - Meridional Magnetometer Array, setup in frame of the PLASMON EU FP7 project), can provide dayside plasma density profiles. Compared to VLF whistlers, the other ground based source of <span class="hlt">plasmasphere</span> density, FLRs have the advantage that they are often observed not only in the <span class="hlt">plasmasphere</span>, but also outside it, in the plasmatrough, making them suitable for the detection of the plasmapause. The detection of FLRs is based on the amplitude and phase gradient observed between stations closely spaced in North-South direction. At normal conditions FLRs can be identified by a maximum in the cross phase spectra. Under special conditions, near the plasmapause the phase difference is reverted giving a minimum at the resonance frequency. This feature yields another possibility for the detection of the plasmapause. We present some events to demonstrate how the motion of the plasmapause can be monitored by means of EMMA. Results are compared to in-situ plasma density/plasmapause observations (WHISPER data onboard Cluster, EMFISIS data onboard Van Allen Probe) and some empirical models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19980111127','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19980111127"><span>Convection of <span class="hlt">Plasmaspheric</span> Plasma into the Outer Magnetosphere and Boundary Layer Region: Initial Results</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ober, Daniel M.; Horwitz, J. L.; Gallagher, D. L.</p> <p>1998-01-01</p> <p>We present initial results on the modeling of the circulation of <span class="hlt">plasmaspheric</span>- origin plasma into the outer magnetosphere and low-latitude boundary layer (LLBL), using a dynamic global core plasma model (DGCPM). The DGCPM includes the influences of spatially and temporally varying convection and refilling processes to calculate the equatorial core plasma density distribution throughout the magnetosphere. We have developed an initial description of the electric and magnetic field structures in the outer magnetosphere region. The purpose of this paper is to examine both the losses of <span class="hlt">plasmaspheric</span>-origin plasma into the magnetopause boundary layer and the convection of this plasma that remains trapped on closed magnetic field lines. For the LLBL electric and magnetic structures we have adopted here, the <span class="hlt">plasmaspheric</span> plasma reaching the outer magnetosphere is diverted anti-sunward primarily along the dusk flank. These plasmas reach X = -15 R(sub E) in the LLBL approximately 3.2 hours after the initial enhancement of convection and continues to populate the LLBL for 12 hours as the convection electric field diminishes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRA..120.1646S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRA..120.1646S"><span>Postmidnight depletion of the high-energy tail of the quiet <span class="hlt">plasmasphere</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sarno-Smith, Lois K.; Liemohn, Michael W.; Katus, Roxanne M.; Skoug, Ruth M.; Larsen, Brian A.; Thomsen, Michelle F.; Wygant, John R.; Moldwin, Mark B.</p> <p>2015-03-01</p> <p>The Van Allen Probes Helium Oxygen Proton Electron (HOPE) instrument measures the high-energy tail of the thermal <span class="hlt">plasmasphere</span> allowing study of topside ionosphere and inner magnetosphere coupling. We statistically analyze a 22 month period of HOPE data, looking at quiet times with a Kp index of less than 3. We investigate the high-energy range of the <span class="hlt">plasmasphere</span>, which consists of ions at energies between 1 and 10 eV and contains approximately 5% of total <span class="hlt">plasmaspheric</span> density. Both the fluxes and partial plasma densities over this energy range show H+ is depleted the most in the postmidnight sector (1-4 magnetic local time), followed by O+ and then He+. The relative depletion of each species across the postmidnight sector is not ordered by mass, which reveals ionospheric influence. We compare our results with keV energy electron data from HOPE and the Van Allen Probes Electric Fields and Waves instrument spacecraft potential to rule out spacecraft charging. Our conclusion is that the postmidnight ion disappearance is due to diurnal ionospheric temperature variation and charge exchange processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5098185','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5098185"><span>Comparative morphological trade-offs between pre- and post-copulatory sexual selection in Giant <span class="hlt">hissing</span> cockroaches (Tribe: Gromphadorhini)</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Durrant, Kate L.; Skicko, Ian M.; Sturrock, Craig; Mowles, Sophie L.</p> <p>2016-01-01</p> <p>Sperm competition theory predicts that animals face a trade-off between investment in weaponry and investment in ejaculate composition. Within the Madagascan giant <span class="hlt">hissing</span> cockroaches (Tribe Gromphadorhini) differences in morphology exist that may indicate differing strategies of male-male competition. We compared relative pronotal horn length using high-resolution X-ray CT scanning data, relative testes mass, and male-male agonistic behaviour between two species of <span class="hlt">hissing</span> cockroaches, Gromphadorhina oblongonota and Aeluropoda insignis. The gross morphology and behaviour of these two species indicated that G. oblongonota is selected for pre-copulatory mate acquisition and that A. insignis is selected for post-copulatory sperm competition. We found evidence for a trade-off when investing in testes mass vs. horn length between the species. The large, aggressive G. oblongonota follows a strategy of greater investment in weapons at the expense of testes mass while the smaller, less-aggressive A. insignis invests in relatively greater testes mass and less in pronotal weapon length. We also found evidence of a trade-off within each species, where individuals invest more heavily in weapon length at the expense of testes mass. These findings support the predictions of pre- and post-copulatory competitive investment trade-offs for a relatively understudied Tribe of cockroaches. PMID:27819321</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6560414','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6560414"><span>Hazard ranking system evaluation of CERCLA inactive waste sites at Hanford: Volume 3: Unplanned-release sites (<span class="hlt">HISS</span> data base)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Jette, S.J.; Lamar, D.A.; McLaughlin, T.J.; Sherwood, D.R.; Van Houten, N.C.; Stenner, R.D; Cramer, K.H.; Higley, K.A.</p> <p>1988-10-01</p> <p>The purpose of this report is to formally document the assessment activities at the US Department of Energy (DOE) Hanford Site. These activities were carried out pursuant to the DOE orders that address the Comprehensive Environmental Response, and Liability Act (CERCLA) Program for the cleanup of inactive waste sites. The DOE orders incorporate the US Environmental Protection Agency methodology, which is based on the Superfund Amendments and Reauthorization Act of 1986. This methodology includes:PA/SI, remedial investigation/feasibility study, record of decision, design and implementation or remedial action, operation and monitoring, and verification monitoring. Volume 1 of this report discusses the CERCLA inactive waste-site evaluation process, assumptions, and results of the Hazard Ranking System methodology employed. Volume 2 presents the data on the individual CERCLA engineered-facility sites at Hanford, as contained in the Hanford Inactive Site Surveillance (<span class="hlt">HISS</span>) Data Base. Volume 3 presents the data on the individual CERCLA unplanned-release sites at Hanford, as contained in the <span class="hlt">HISS</span> Data Base. 13 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=animal+AND+language&pg=4&id=EJ955985','ERIC'); return false;" href="https://eric.ed.gov/?q=animal+AND+language&pg=4&id=EJ955985"><span>Look at That!: Using Madagascar <span class="hlt">Hissing</span> Cockroaches to Develop and Enhance the Scientific Inquiry Skill of Observation in Middle School Students</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Wagler, Ron</p> <p>2011-01-01</p> <p>Middle school students can develop and enhance their observation skills by participating in teacher-guided scientific inquiry (NRC 1996) activities where they observe animals that tend to act in known, predictable ways. Madagascar <span class="hlt">hissing</span> cockroaches ("Gromphadorhina portentosa") are one such animal. This article presents beginning, intermediate,…</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Madagascar&id=EJ955985','ERIC'); return false;" href="http://eric.ed.gov/?q=Madagascar&id=EJ955985"><span>Look at That!: Using Madagascar <span class="hlt">Hissing</span> Cockroaches to Develop and Enhance the Scientific Inquiry Skill of Observation in Middle School Students</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Wagler, Ron</p> <p>2011-01-01</p> <p>Middle school students can develop and enhance their observation skills by participating in teacher-guided scientific inquiry (NRC 1996) activities where they observe animals that tend to act in known, predictable ways. Madagascar <span class="hlt">hissing</span> cockroaches ("Gromphadorhina portentosa") are one such animal. This article presents beginning, intermediate,…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016cosp...41E.762G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016cosp...41E.762G"><span>Comparison of <span class="hlt">plasmaspheric</span> electron content over sea and land using Jason-2 observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gulyaeva, Tamara; Cherniak, Iurii; Zakharenkova, Irina</p> <p>2016-07-01</p> <p>The Global Ionospheric Maps of Total Electron Content, GIM-TEC, may suffer from model assumptions, in particular, over the oceans where relatively few measurements are available due to a scarcity of ground-based GPS receivers network only on seashores and islands which involve more assumptions or interpolations imposed on GIM mapping techniques. The GPS-derived TEC represents the total electron content integrated through the ionosphere, iTEC, and the <span class="hlt">plasmasphere</span>, pTEC. The sea/land differences in the F2 layer peak electron density, NmF2, and the peak height, hmF2, gathered with topside sounding data exhibit tilted ionosphere along the seashores with denser electron population at greater peak heights over the sea. Derivation of a sea/land proportion of total electron content from the new source of the satellite-based measurements would allow improve the mapping GIM-TEC products and their assimilation by the ionosphere-<span class="hlt">plasmasphere</span> IRI-Plas model. In this context the data of Jason-2 mission provided through the NOAA CLASS Website (http://www.nsof.class.noaa.gov/saa/products/catSearch) present a unique database of pTEC measured through the <span class="hlt">plasmasphere</span> over the Jason-2 orbit (1335 km) to GPS orbit (20,200 km) which become possible from GPS receivers placed onboard of Jason-2 with a zenith looking antenna that can be used not only for precise orbit determination (POD), but can also provide new data on the plasma density distribution in the <span class="hlt">plasmasphere</span>. Special interest represents possibility of the potential increase of the data volume in two times due to the successful launch of the Jason-3 mission on 17 January 2016. The present study is focused on a comparison of <span class="hlt">plasmasphere</span> electron content, pTEC, over the sea and land with a unique data base of the <span class="hlt">plasmasphere</span> electron content, pTEC, using measurements onboard Jason-2 satellite during the solar minimum (2009) and solar maximum (2014). Slant TEC values were scaled to estimate vertical pTEC using a geometric</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRA..121..492L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRA..121..492L"><span>A statistical study of <span class="hlt">plasmaspheric</span> plumes and ionospheric outflows observed at the dayside magnetopause</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, S. H.; Zhang, H.; Zong, Q.-G.; Otto, A.; Rème, H.; Liebert, E.</p> <p>2016-01-01</p> <p>We present a statistical study of <span class="hlt">plasmaspheric</span> plumes and ionospheric outflows observed by the Cluster spacecraft near the dayside magnetopause. <span class="hlt">Plasmaspheric</span> plumes are identified when the low-energy ions (<1 keV) with ˜90° pitch angle distributions are observed by the Cluster Ion Spectrometer/Hot Ion Analyzer instrument. The ionospheric outflows are characterized by unidirectional or bidirectional field-aligned pitch angle distributions of low-energy ions observed in the dayside magnetosphere. Forty-three (10%) <span class="hlt">plasmaspheric</span> plume events and 32 (7%) ionospheric outflow events were detected out of the 442 times that C3 crossed the dayside magnetopause between 2007 and 2009. The occurrence rate of plumes at duskside is significantly higher than that at dawnside. The occurrence rate of outflows shows a weak dawn-dusk asymmetry. We investigate the dependence of the occurrence rates of plumes and ionospheric outflows on geomagnetic activity and on solar wind/interplanetary magnetic field (IMF) conditions. The plume events tend to occur during southward IMF (duskward solar wind electric field) and moderate geomagnetic activity (Kp = 3,-30≤Dst <- 10 nT). However, the ionospheric outflow events tend to occur during northward IMF (dawnward solar wind electric field). The ionospheric outflows do not occur when Kp = 0, and the occurrence rate of the ionospheric outflows does not have a clear Dst dependence. Seventy-five percent (46%) of the outflows are observed in the duskside for negative (positive) IMF By. Conversely, 54% (25%) of the outflows are observed in the dawnside for positive (negative) IMF By. Finally, the occurrence rates of both plumes and outflows increase with solar wind dynamic pressure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002EGSGA..27..176B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002EGSGA..27..176B"><span>Use of Topside Sounding With Iri Model To Study The Electron Density In <span class="hlt">Plasmasphere</span> and Ionosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Beloff, N.; Denisenko, P. F.; Maltseva, O. A.; Gough, M. P.; Klimov, S. I.; Nozdrachev, M. N.; Alleyne, H.; Bates, I.</p> <p></p> <p>One of the major goals of near Earth space studies is a theoretical and experimen- tal investigation of the <span class="hlt">plasmaspheric</span> and ionospheric responses to variations of solar wind and IMF parameters. The experiments carried out in the scope of INTERBALL project allow one to trace the propagation of the CME up to its effects on Earth's mag- netosphere. When the topside sounding data and the measurements from low-orbit satellites such as MIR station are simultaneously available, it becomes possible to ob- serve the variations of electron density in <span class="hlt">plasmasphere</span> and ionosphere. In particular, such an observation is found to be useful for the empirical modeling of plasma dis- tribution. The most developed model of the ionosphere is the IRI model. However, the IRI model ensures high accuracy for the lower ionosphere, but yields significantly reduced accuracy for the top part. The largest errors occur near the satellite orbits lo- cated at the base level of the <span class="hlt">plasmaspheric</span> model. Therefore it is important to use both magnetospheric and ionospheric measurements. Authors recommend that: 1) the IRI model should be corrected using N(h)-profile parameters obtained from topside ionograms. Various schemes were considered: i) use the value of electron plasma frequency near the satellite only; ii) use only some points from N(h)-profile or the full profile; iii) use different coefficients to modify a thickness of lower and top parts of the ionosphere; 2) in addition, one should use MIR station measurements to estimate the correlation of electron density behavior at various heights during the disturbances.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JGRA..119.3724N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JGRA..119.3724N"><span>Estimation of the helium ion density distribution in the <span class="hlt">plasmasphere</span> based on a single IMAGE/EUV image</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nakano, S.; Fok, M.-C.; Brandt, P. C.; Higuchi, T.</p> <p>2014-05-01</p> <p>We have developed a technique by which to estimate the spatial distribution of <span class="hlt">plasmaspheric</span> helium ions based on extreme ultraviolet (EUV) data obtained from the IMAGE satellite. The estimation is performed using a linear inversion method based on the Bayesian approach. The global imaging data from the IMAGE satellite enable us to estimate a global two-dimensional distribution of the helium ions in the <span class="hlt">plasmasphere</span>. We applied this technique to a synthetic EUV image generated from a numerical model. This technique was confirmed to successfully reproduce the helium ion density that generated the synthetic EUV data. We also demonstrate how the proposed technique works for real data using two real EUV images.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009JASTP..71..158A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009JASTP..71..158A"><span>Kalman filter-based algorithms for monitoring the ionosphere and <span class="hlt">plasmasphere</span> with GPS in near-real time</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Anghel, Adela; Carrano, Charles; Komjathy, Attila; Astilean, Adina; Letia, Tiberiu</p> <p>2009-01-01</p> <p>Data collected from a GPS receiver located at low latitudes in the American sector are used to investigate the performance of the WinTEC algorithm [Anghel et al., 2008a, Kalman filter-based algorithm for near realtime monitoring of the ionosphere using dual frequency GPS data. GPS Solutions, accepted for publication; for different ionospheric modeling techniques: the single-shell linear, quadratic, and cubic approaches, and the multi-shell linear approach. Our results indicate that the quadratic and cubic approaches perform much better than the single-shell and multi-shell linear approaches in terms of post-fit residuals. The performance of the algorithm for the cubic approach is then further tested by comparing the vertical TEC predicted by WinTEC and USTEC [Spencer et al., 2004. Ionospheric data assimilation methods for geodetic applications. In: Proceedings of IEEE PLANS, Monterey, CA, 26-29 April, pp. 510-517] at five North American stations. In addition, since the GPS-derived total electron content (TEC) contains contributions from both ionospheric and <span class="hlt">plasmaspheric</span> sections of the GPS ray paths, in an effort to improve the accuracy of the TEC retrievals, a new data assimilation module that uses background information from an empirical <span class="hlt">plasmaspheric</span> model [Gallagher et al., 1988. An empirical model of the Earth's <span class="hlt">plasmasphere</span>. Advances in Space Research 8, (8)15-(8)24] has been incorporated into the WinTEC algorithm. The new Kalman filter-based algorithm estimates both the ionospheric and <span class="hlt">plasmaspheric</span> electron contents, the combined satellite and receiver biases, and the estimation error covariance matrix, in a single-site or network solution. To evaluate the effect of the <span class="hlt">plasmaspheric</span> component on the estimated biases and total TEC and to assess the performance of the newly developed algorithm, we compare the WinTEC results, with and without the <span class="hlt">plasmaspheric</span> term included, at three GPS receivers located at different latitudes in the American sector, during</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920072490&hterms=wave+electromagnetic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dwave%2Belectromagnetic','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920072490&hterms=wave+electromagnetic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dwave%2Belectromagnetic"><span>Poynting vector measurements of electromagnetic ion cyclotron waves in the <span class="hlt">plasmasphere</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Labelle, J.; Treumann, R. A.</p> <p>1992-01-01</p> <p>Results are presented from an analysis of the June 6, 1985 Pc 2 measurements for which E, B, and delta-N were all analyzed. The event occurred in the duskside overlap region between the <span class="hlt">plasmaspheric</span> bulge and the ion ring current. Results of the Poynting vector analysis of the R and L mode components show both of them to be characterized by northward Poynting vector, indicating energy flux away from the equator. The value of the Poynting vector was found to be about 3 microW/sq m.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19890062900&hterms=wake+measurement&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dwake%2Bmeasurement','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19890062900&hterms=wake+measurement&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dwake%2Bmeasurement"><span>Insight into theory-experiment comparisons of wake measurements in the <span class="hlt">plasmasphere</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Samir, U.; Comfort, R. H.; Singh, N.; Hwang, K. S.; Stone, N. H.</p> <p>1989-01-01</p> <p>Calculated results from a modified one-dimensional time-dependent plasma expansion model are compared with wake measurements of low-energy H(+) ions made in the <span class="hlt">plasmasphere</span> which consists of 77-90 percent H(+) and 23-10 percent He(+). The variation of the theoretical-to-experimental results with the H(+) ionic Mach number in the range 0.5-1.2 is shown. It is found that the theoretical model used overestimates the particle flux in the wake by factors of 2 to 6. Possible causes for these differences are examined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSA13B1960C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSA13B1960C"><span>Investigation of the <span class="hlt">plasmasphere</span> electron content on the base of radio-measurements</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cherniak, I.; Zakharenkova, I.; Krankowski, A.</p> <p>2013-12-01</p> <p>The electron densities in <span class="hlt">plasmasphere</span> are several orders of magnitude less than in ionosphere and the <span class="hlt">plasmasphere</span> is often ignored at analysis and estimation of GPS TEC data, however the <span class="hlt">plasmaspheric</span> contribution to the GPS TEC can became significant under certain conditions. This paper presents results of study of the <span class="hlt">plasmaspheric</span> electron content variations for such cases - period of very low solar activity and during strong geomagnetic storm. Estimates of IEC can be retrieved as a result of integration of ionospheric electron density profiles (EDP). For this aim one can use EDPs derived from satellite radio occultation (RO) or ground-based radio-physical measurements. For case of the extended solar minimum of 23/24 cycle, 2009 the PEC was estimated by combination of GPS TEC observations and FORMOSAT-3/COSMIC RO measurements. It was analyzed the monthly medians of TEC and PEC for different seasons (equinoxes and solstices). Results shows that for mid-latitudinal points PEC estimates varied weakly with the time of a day and reached the value of several TECU for the condition of solar minimum. Percentage contribution of PEC to GPS TEC indicated the clear dependence from the time with maximal values (more than 50-60%) during night-time and lesser values (25-45%) during day-time. The variations of PEC during strong geomagnetic storms at November 2004 were estimated by combining of mid-latitude Kharkov Incoherent Scatter Radar observations and GPS TEC data. The comparison between two independent measurements was performed by analysis of the height-temporal distribution for specific point corresponded to the mid-latitudes of Europe. Percentage contribution of PEC to GPS TEC indicated the clear dependence from the time with maximal values (more than 70%) during night-time and smaller values (30-45%) during day-time for weak disturbance and quite time and rather high values during strong negative storm (up to 90%) with small changes in time. These changes can be</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010cosp...38.2202K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010cosp...38.2202K"><span>Ion cooling in the <span class="hlt">plasmasphere</span> during magnetic storm initial phase: modeling the proton temperature dynamics.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kotova, Galina; Verigin, Mikhail; Bezrukikh, Vladilen</p> <p></p> <p>The effect of ion temperature decreasing at L ¡ 3 during geomagnetic storm development was recently revealed by INTERBALL 2 and MAGION 5 thermal plasma data. A model of proton drift outward from the Earth caused by magnetic field decreasing in the inner <span class="hlt">plasmasphere</span> is considered. Conservation of the first adiabatic invariant results in proton cooling during their outward motion. It is shown that model temperatures well agree with experimental data. The work is partially supported by the RAS programs P16 and OFN 15.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19960031945','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19960031945"><span>Effects of <span class="hlt">plasmaspheric</span> ion heating due to ionospheric and magnetospheric sources</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Comfort, Richard H.</p> <p>1996-01-01</p> <p>In an initial study, the He(+) observations from the Retarding Ion Mass Spectrometer on Dynamics Explorer 1 (RIMS/DE 1) was examined for more than 120 transits of the <span class="hlt">plasmasphere</span> in the fall of 1981. The He(+) to H(+) ratio was determined as it varied spatially over portions of the DE 1 orbit, and its variation with solar and magnetic activities and with local time, focusing specifically on the inner <span class="hlt">plasmasphere</span>. These variations were compared along the L = 2 field line with calculations made by the Field Line Interhemispheric Plasma (FLIP) code. In a recently submitted paper, the He(+) to H(+) density ratio was examined for all the available data from 1981 to 1984 from the RIMS on DE 1. There are two basic characteristics of the ratio: one is that the ratio decreases with radial distance in the <span class="hlt">plasmasphere</span>, and the other is the strong dependence of the density ratio on solar activity. In addition to the He(+)/H(+) ratio research, a phenomenon has been studied in the topside ionosphere which relates to the thermal coupling of the ionosphere to the <span class="hlt">plasmasphere</span>. There is little or no correlation with magnetic and solar activity here. Another study has been directed toward the relation of plasma properties to the density gradients forming the plasmapause. The study has followed a two-pronged approach. First, the observations have been analyzed to determine what happens to the plasma properties across these boundary layers (density gradients). Second, comparisons were made with FLIP model calculations to determine how well the model is able to treat these conditions. Among the significant lessons learned in these studies are two that bear directly on the direction of future investigations in this area. First, composition cannot be viewed independently of thermal structure. Second, solar and magnetic activity effects are real; but the causal relationship between activity and effects is frequently quite complicated because several different processes appear to be</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.5863R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.5863R"><span>EMMA/SANSA ground magnetometer network for studies of the <span class="hlt">plasmasphere</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reda, Jan; Vellante, Massimo; Heilig, Balazs; Raita, Tero; Collier, Andrew; Mandic, Igor; Neska, Mariusz</p> <p>2014-05-01</p> <p>We will present the actual state of the EMMA/SANSA ground magnetometer network which is in operation for the FP7 PLASMON project. This network is used to determine the <span class="hlt">plasmasphere</span> density with use of recording ULF pulsations. The network is established on the basis of earlier existing networks and magnetic stations. A very important element of the PLASMON activity is to establish new magnetic stations and to integrate old and new stations in one network providing real-time data. The integration and unification concerned data formats, time accuracy of recordings, delays in providing real-time data, as well as apparatus requirements e.g. analog filtration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSA23A2034M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSA23A2034M"><span>Modeling Sudden Stratospheric Warming Events Using the Ionosphere-<span class="hlt">Plasmasphere</span>-Electrodynamics (IPE) Model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Millholland, S. C.; Maruyama, N.; Maute, A. I.; Goncharenko, L. P.; Burns, A. G.; Richards, P. G.; Fang, T.; Fuller-Rowell, T. J.</p> <p>2013-12-01</p> <p>Sudden Stratospheric Warming (SSW) events are large meteorological disturbances where the northern winter stratospheric westerly winds slow down or reverse direction. The perturbation is associated with a breakdown in the northern polar vortex and has been observed to cause various anomalies in the upper atmosphere. SSW events occur nearly every year to varying degrees of strength. Understanding the connection between the terrestrial and space weathers during these events has become more important with increased solar activity, particularly in an effort to separate out forcing from the events and from geomagnetic and solar activities. In this work, the Ionosphere-<span class="hlt">Plasmasphere</span> Electrodynamics (IPE) model is used to investigate the response of the ionosphere during SSW events. The Jicamarca 150km echo observation is used to describe the main ionospheric forcing during the SSW event. The IPE model reproduces the observed ionospheric response to the large SSW event of January 2009. Our results illustrate the direct impact of the equatorial drift deviations during the SSW event on the variations of main ionospheric parameters. Furthermore, we evaluate the role of the coupling between ionosphere and <span class="hlt">plasmasphere</span> during the solar minimum in reproducing the observations. The global drift from Thermosphere-Ionosphere-Mesosphere-Electrodynamics General Circulation Model (TIMEGCM) is also used to evaluate the role of the latitudinal and local time variations of the ExB drift. Finally, we compare the ionospheric responses between 2009 and 2013 to understand the different ionospheric responses depending on the solar flux conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRA..122.4190S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRA..122.4190S"><span>Simultaneous space and ground-based observations of a <span class="hlt">plasmaspheric</span> virtual resonance</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shi, X.; Baker, J. B. H.; Ruohoniemi, J. M.; Hartinger, M. D.; Frissell, N. A.; Liu, Jiang</p> <p>2017-04-01</p> <p>We present simultaneous space and ground-based observations of Pi2 pulsations which occurred during a substorm on 25 September 2014. The timeline for this event starts at ˜06:04 UT when the THEMIS probe D located inside the <span class="hlt">plasmasphere</span> detected Pi2 pulsations in the electric and magnetic fields. Cross-spectral analysis shows the azimuthal electric field and compressional magnetic field oscillated nearly in quadrature, highly suggestive of a standing fast-mode wave. Simultaneous Pi2 observations from dayside and nightside ground magnetometers at low latitudes indicate a global wave mode. A latitudinal magnetometer chain on the nightside observed a phase reversal in the H component of the Pi2 pulsations when crossing the footprint of the plasmapause, estimated from THEMIS spacecraft measurements. Spectral analysis of data from ground magnetometers in this latitudinal chain showed fundamental and second harmonic spectral peaks in their H and D components. Similar pulsation signatures at comparable harmonic frequencies were observed by three midlatitude SuperDARN HF radars, both poleward and equatorward of the plasmapause ionospheric footprint. Finally, the longitudinal polarization pattern and azimuthal phase propagation of midlatitude Pi2 pulsations are consistent with previous observations of a <span class="hlt">plasmaspheric</span> virtual resonance being excited by a longitudinally localized source near midnight.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JGRA..119.4621R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JGRA..119.4621R"><span>Exploring the efficacy of different electric field models in driving a model of the <span class="hlt">plasmasphere</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ridley, A. J.; Dodger, A. M.; Liemohn, M. W.</p> <p>2014-06-01</p> <p>The dynamics of the <span class="hlt">plasmasphere</span> are strongly controlled by the inner magnetospheric electric field. In order to capture realistically the erosion of the nightside plasmapause and the formation of the drainage plume in a model of the <span class="hlt">plasmasphere</span>, the electric field must be accurate. This study investigates how well five different electric field models drive the Dynamic Global Core Plasma Model during eight storm periods. The five electric field models are the Volland-Stern analytic formula with Maynard-Chen Kpdependence, two versions of the Weimer statistical models (96 and 05), and two versions of the Assimilative Mapping of Ionospheric Electrodynamics (AMIE) technique using magnetometer and DMSP satellite data. Manually extracted plasmapause locations from images taken by the EUV instrument on the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) satellite, as described by Goldstein et al. (2005), were compared to the simulation results throughout the main phase of the eight events. Three methods of calculating the plasmapause were employed to determine the best fit to EUV data, using the maximum gradient, a constant density contour (fit method), and the location in which the modeled density fell significantly below the specified saturation density for the given radial position (saturation method). It was found that the simulations driven by the Weimer (1996) model produced the best fit overall and that the fit and saturation methods worked best for matching the model results to the observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5315403','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5315403"><span>Triaxial search coil measurements of ELF waves in the <span class="hlt">plasmasphere</span>: Initial results from EXOS-D</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kokubun, S.; Takami, M.; Hayashi, K. ); Kimura, I.; Sawada, A.; Kasahra, Y. ); Fukunishi, H.</p> <p>1991-02-01</p> <p>Triaxial search coil measurements of ELF waves in the frequency range below 50 Hz have been made with the polar orbiting satellite, EXOS-D (AKEBONO), in the <span class="hlt">plasmasphere</span>. Single component electric field measurements were also obtained along with measurements of the magnetic field. A survey of realtime telemetry data received for the period of March - October, 1989 reveals the existence of variety of plasma waves in the frequency range around ion gyrofrequencies near the equatorial region of the <span class="hlt">plasmasphere</span>. Electromagnetic noises with a multi-band structure were observed mostly above the local helium gyro-frequency (f{sub He{sup +}}), in the region of L values of 1.5{approximately}2.5. Multi-band ELF emission are common in the daytime and were observed in 49 out of 250 orbits examined here. Another type of electromagnetic ELF waves with a broad-band spectrum are also observed in the frequency range above the helium gyrofrequency in 10 orbits. Both types of wave spectra extend above the local proton gyrofrequency, but no absorption effect is observed at the local proton gyrofrequency. The electric field measurements clearly show spectral cut-off for both of these two types of waves near f {equals} (1.3{approximately}2.5) f{sub He{sup +}}. On the other hand, several spectral bands sometimes appear between the helium and oxygen gyrofrequencies in magnetic field components of multi-band emissions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/544806','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/544806"><span>Observations of inner <span class="hlt">plasmasphere</span> irregularities with a satellite-beacon radio-interferometer array</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Jacobson, A.R.; Hoogeveen, G.; Carlos, R.C.; Wu, G.; Fejer, B.G.; Kelley, M.C.</p> <p>1996-09-01</p> <p>A radio-interferometer array illuminated by 136-MHz beacons of several geosynchronous satellites has been used to study small ({ge}10{sup 13} m{sup {minus}2}) transient disturbances in the total electron content along the lines of sight to the satellites. High-frequency (f{gt}3 mHz) electron content oscillations are persistently observed, particularly during night and particularly during geomagnetically disturbed periods. The oscillations move across the array plane at speeds in the range 200{endash}2000 m/s, with propagation azimuths that are strongly peaked in lobes toward the western half-plane. Detailed analysis of this azimuth behavior, involving comparison between observations on various satellite positions, indicates compellingly that the phase oscillations originate in radio refraction due to geomagnetically aligned plasma density perturbations in the inner <span class="hlt">plasmasphere</span>. The motion of the phase perturbations across the array plane is caused by {bold EXB} drift of the plasma medium in which the irregularities are embedded. We review the statistics of 2.5 years of around-the-clock data on the local time, magnetic disturbance, seasonal, and line-of-sight variations of these observed irregularities. We compare the irregularities{close_quote} inferred electrodynamic drifts to what is known about midlatitude plasma drift from incoherent scatter. Finally, we show in detail how the observation of these irregularities provides a unique and complementary monitor of inner <span class="hlt">plasmasphere</span> irregularity incidence and zonal drift.{copyright} 1996 American Geophysical Union</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940030163','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940030163"><span>Studies on equatorial shock formation during <span class="hlt">plasmaspheric</span> refilling</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Singh, N.</p> <p>1994-01-01</p> <p>Investigations based on small-scale simulations of microprocesses occurring when a magnetic flux tube refills with a cold plasma are summarized. Results of these investigations are reported in the following attached papers: (1) 'Numerical Simulation of Filling a Magnetic Flux Tube with a Cold Plasma: The Role of Ion Beam-Driven Instabilities'; and (2) 'Numerical Simulation of Filling a Magnetic Flux Tube with a Cold Plasma: Effects of Magnetically Trapped Hot Plasma'. Other papers included are: '<span class="hlt">Interaction</span> of Field-Aligned Cold Plasma Flows with an Equatorially-Trapped Hot Plasma: Electrostatic Shock Formation'; and 'Comparison of Hydrodynamic and Semikinetic Treatments for a Plasma Flow along Closed Field Lines'. A proposal for further research is included.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSM43B2307T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSM43B2307T"><span>Van Allen Probes based investigation of storm time <span class="hlt">plasmasphere</span> erosion and earthward penetration of the convection electric field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thaller, S. A.; Wygant, J. R.; Dai, L.; Breneman, A. W.; Kersten, K.; Kletzing, C.; Kurth, W. S.; Bonnell, J. W.; De Pascuale, S.; Hospodarsky, G. B.; Bounds, S. R.</p> <p>2013-12-01</p> <p>Using the Van Allen Probes we investigate the erosion of the <span class="hlt">plasmasphere</span> as well as the evolution in location of the plasmapause during large storms (Dst < -100 nT). In addition, we also examine the penetration of the large scale storm-time convection electric field to low L ( < 3 RE) and its role in erosion of the <span class="hlt">plasmasphere</span>. The enhanced convection electric field penetrates to low L during large storms, and a tangible effect on <span class="hlt">plasmasphere</span> erosion is observed at low L. The plasmaspause is identified through the UHR line in EMFISIS high frequency spectral data and plasma densities determined from calibration fits to the spacecraft potential from the EFW instrument; such fits are also presented herein. During large storms the plasmapause can move to within L~1.9 RE of the earth. The erosion of the <span class="hlt">plasmasphere</span> and consequent inward movement of the plasmapause to low L from quite time locations (4-5 RE) occurs within less than one orbit period (~9hr).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1613719D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1613719D"><span>Detection of whistlers by the Belgian VLF antenna : Statistical analysis and comparison with Cluster data and a <span class="hlt">plasmaspheric</span> model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Darrouzet, Fabien; Ranvier, Sylvain; De Keyser, Johan; Lamy, Hervé; Pierrard, Viviane; Borremans, Kris; Décréau, Pierrette; Lichtenberger, Janos</p> <p>2014-05-01</p> <p>Whistlers are VLF (3-30 kHz) emissions initiated by lightning, propagating along magnetic field lines, observed on ground and in space. Whistler wave analysis is an effective tool for studying the <span class="hlt">plasmasphere</span>. Whistlers acquire particular frequency-time characteristics while they propagate through the magnetospheric plasma, and in particular through the <span class="hlt">plasmasphere</span>. Their propagation time depends on the plasma density along their propagation paths. It is possible to derive the <span class="hlt">plasmaspheric</span> electron density distribution from these propagation times. We therefore have started a project to detect whistlers with VLF measurements. A VLF antenna has been installed in 2011 in Humain, Belgium (50.11°N, 5.15°E). The VLF antenna is made of two perpendicular magnetic loops, oriented North-South and East-West, and with an area of approximately 50 m2 each. This antenna is part of AWDAnet, the Automatic Whistler Detector and Analyzer system's network. This network covers low, mid and high magnetic latitudes, including conjugate locations. We use the AWDA system to automatically retrieve electron density profiles from whistler measurements made in Belgium. On this poster, results of whistler occurrence are shown, as well as a comparison with density data obtained from the WHISPER instrument onboard Cluster and from a <span class="hlt">plasmaspheric</span> model. We also present the possibilities to install a similar VLF antenna at the Belgian Antarctica station.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1985JGR....90.1653M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1985JGR....90.1653M"><span>Enhanced ion outflows measured by the DE 1 high altitude plasma instrument in the dayside <span class="hlt">plasmasphere</span> during the recovery phase</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Menietti, J. D.; Winningham, J. D.; Burch, J. L.; Peterson, W. K.; Waite, J. H.; Weimer, D. R.</p> <p>1985-02-01</p> <p>Ion flow velocities both parallel and perpendicular to the magnetic field and including the effects of spacecraft charging and spacecraft velocity have been measured during the recovery phase of two large magnetic storms on October 14 and 21 of 1981. These measurements were made both inside and outside the <span class="hlt">plasmasphere</span> and indicate unreported yet substantial outflows of ions within the dayside <span class="hlt">plasmasphere</span> (October 14). Combined data from instruments on board the Dynamics Explorer satellite, including the high altitude plasma instrument (HAPI), the energetic ion composition spectrometer (EICS), the retarding ion mass spectrometer (RIMS) and the plasma wave instrument (PWI), indicate that these ions are most likely dominantly O+ at energies at least as low as 5 eV. The nightside pass (October 21), which occurred during the recovery phase of a similar storm, showed no <span class="hlt">plasmaspheric</span> outflows. the results indicate that a large contribution to the outflux into the dayside <span class="hlt">plasmasphere</span> during the recovery period is due to E>5 eV ions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5819124','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5819124"><span>Enhanced ion outflows measured by the DE 1 high altitude plasma instrument in the dayside <span class="hlt">plasmasphere</span> during the recovery phase</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Menietti, J.D.; Winningham, J.D.; Burch, J.L.; Peterson, W.K.; Waite J.H. Jr.; Weimer, D.R.</p> <p>1985-02-01</p> <p>Ion flow velocities both parallel and perpendicular to the magnetic field and including the effects of spacecraft charging and spacecraft velocity have been measured during the recovery phase of two large magnetic storms on October 14 and 21 of 1981. These measurements were made both inside and outside the <span class="hlt">plasmasphere</span> and indicate unreported yet substantial outflows of ions within the dayside <span class="hlt">plasmasphere</span> (October 14). Combined data from instruments on board the Dynamics Explorer satellite, including the high altitude plasma instrument (HAPI), the energetic ion composition spectrometer (EICS), the retarding ion mass spectrometer (RIMS) and the plasma wave instrument (PWI), indicate that these ions are most likely dominantly O/sup +/ at energies at least as low as 5 eV. The nightside pass (October 21), which occurred during the recovery phase of a similar storm, showed no <span class="hlt">plasmaspheric</span> outflows. the results indicate that a large contribution to the outflux into the dayside <span class="hlt">plasmasphere</span> during the recovery period is due to E>5 eV ions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004SPIE.5660....1M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004SPIE.5660....1M"><span>GPS-based remote sensing of the geospace environment: horizontal and vertical structure of the ionosphere and <span class="hlt">plasmasphere</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mannucci, Anthony J.; Hajj, George A.; Iijima, Byron A.; Komjathy, Attila; Meehan, Thomas K.; Pi, Xiao Qing; Srinivasan, Jeff; Tsurutani, Bruce T.; Wilson, Brian; Zhang, Liwei D.; Moldwin, Mark</p> <p>2004-12-01</p> <p>Transmissions of the Global Positioning System (GPS) satellites can be used to measure the total electron content (TEC) between a receiver and several GPS satellites in view. This simple observable is yielding a wealth of new scientific information about ionosphere and <span class="hlt">plasmasphere</span> dynamics. Data available from thousands of ground-based GPS receivers are used to image the large-scale and mesoscale ionospheric response to geospace forcings at high-precision covering all local times and latitudes. Complementary measurements from space-borne GPS receivers in low-Earth orbit provide information on both vertical and horizontal structure of the ionosphere/<span class="hlt">plasmasphere</span> system. New flight hardware designs are being developed that permit simultaneous measurement of integrated electron content along new raypath orientations, including zenith, cross-track and nadir antenna orientations (the latter via bistatic reflection of the GPS signal off ocean surfaces). We will discuss a new data assimilation model of ionosphere, the Global Assimilative Ionosphere Model (GAIM), capable of integrating measurements from GPS and other sensors with a physics-based ionospheric model, to provide detailed global nowcasts of ionospheric structure, useful for science and applications. Finally, we discuss efforts underway to combine GPS space-based observations of <span class="hlt">plasmaspheric</span> TEC, with ground-based magnetometer measurements, and satellite-based images from NASA's IMAGE satellite, to produce new dynamic models of the <span class="hlt">plasmasphere</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMSA32A..04S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMSA32A..04S"><span>COSMIC TEC tomographic vertical density reconstructions of the topside ionosphere and <span class="hlt">plasmasphere</span>: Differences between the American and African sectors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sibanda, P.; Moldwin, M.; Zou, S.; Yizengaw, E. K.</p> <p>2011-12-01</p> <p>Global Positioning System (GPS) navigation measurements have become useful in observing the ionospheric spatial electron density distribution TEC from ground-based receivers are biased by the high density around the F2 peak and therefore it is difficult to extract information about the topside ionosphere and <span class="hlt">plasmasphere</span>. GPS measurements onboard Low Earth Orbiting (LEO) satellites provide more detailed observations of the ionospheric electron density distribution from the orbit height of the LEO satellite to GPS orbit heights. We use GPS TEC measurements onboard COSMIC satellites to reconstruct the topside ionosphere and <span class="hlt">plasmasphere</span> electron density distribution for both geomagnetically quiet and disturbed conditions during over-flights of the American and African mid-latitude regions by the COSMIC spacecraft using algebraic tomographic reconstruction technique (ART). The reconstructions provide more detailed information of the longitudinal and vertical spatial structure of topside ionosphere and <span class="hlt">plasmasphere</span> during both geomagnetically quiet and disturbed conditions, and indicate the great potential of evaluating ionospheric models in the topside ionosphere/<span class="hlt">plasmasphere</span> altitude range.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001JASTP..63.1117C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001JASTP..63.1117C"><span>The study of bulk plasma motions and associated electric fields in the <span class="hlt">plasmasphere</span> by means of whistler-mode signals</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Carpenter, D. L.; Smith, A. J.</p> <p>2001-07-01</p> <p>Whistler-mode waves propagating to ground stations along geomagnetic-field-aligned paths provide powerful tools for investigating bulk motions of the magnetospheric plasma and thus the corresponding convection electric fields. Natural whistlers from lightning as well as signals from very low frequency (VLF) transmitters have been employed. The whistler method emphasizes measurement of temporal variations in the frequency versus time, or dispersion, properties of whistlers, while the transmitter method focuses upon measurement of the phase and group paths of fixed-frequency signal propagation. The methods depend upon wave properties that are sensitive to inhomogeneities in the geomagnetic field, and thus provide information on what are essentially cross-/L plasma motions in a frame of reference rotating with the Earth. In addition, whistler data on the duskside <span class="hlt">plasmasphere</span> bulge have been used to estimate values of the radial convection electric field (GSE /Y direction) near dusk. In this topical review we discuss the development, beginning in the 1960s, of the whistler and transmitter methods, as well as a few of their geophysical applications. Whistlers have provided substantial new information on the spatially and temporally structured manner in which convection electric fields penetrate the <span class="hlt">plasmasphere</span>, one example being the still unexplained reversal from inward to outward of the post-midnight radial flow direction following temporally isolated substorms. Whistlers have also been useful in identifying the <span class="hlt">plasmaspheric</span> drifts associated with quiet-day electric fields of ionospheric dynamo origin and in showing that the Ey (duskward), component of the convection electric field in the outer <span class="hlt">plasmasphere</span> is substantially larger near dusk than it is near mid-night. Whistler-mode signals from transmitters have been found to be a powerful means of tracking cross-/L motions in the <span class="hlt">plasmasphere</span> near /L=2.5 while separately identifying the effects of interchange</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AdSpR..55..170G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AdSpR..55..170G"><span>Validation of <span class="hlt">plasmasphere</span> electron density reconstructions derived from data on board CHAMP by IMAGE/RPI data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gerzen, T.; Feltens, J.; Jakowski, N.; Galkin, I.; Denton, R.; Reinisch, B.; Zandbergen, R.</p> <p>2015-01-01</p> <p><span class="hlt">Plasmaspheric</span> electron content is, beyond the ionosphere as major source, a significant contributor to the overall TEC budget affecting GNSS signals. The <span class="hlt">plasmasphere</span> can induce half or more of the GNSS range errors caused by atmospheric electrical charges, in particular at nighttime. At DLR Neustrelitz, Germany, GPS measurements recorded onboard the LEO satellite CHAMP were used to reconstruct the topside electron density distribution (ionosphere and <span class="hlt">plasmasphere</span>) up to GPS altitude, applying a model-based assimilation technique. In this paper, the potential of these CHAMP topside reconstructions for analyzing space weather related changes in the geo-plasma is investigated. For this purpose, comparisons are made between the CHAMP reconstructed profiles and electron densities derived from passive radio wave observations by the IMAGE RPI instrument for years 2001 till 2005. The comparison results indicate that an improvement, compared to the electron density of a background model, can be achieved by CHAMP data assimilation. The improvement is especially visible in the L-shell region below 3, which contributes notably to the GNSS signal delays. However, for the region around the plasmapause, systematical electron density underestimations of the background model w.r.t. the IMAGE data are detected. The rather limited CHAMP data coverage and the degraded observation geometry at these high altitudes seem to be not sufficient for complete compensation of this underestimation during the assimilation procedure. The results presented in this paper demonstrate the strengths of LEO TEC data assimilation, but at the same time illustrate the necessity to improve the modeling of the <span class="hlt">plasmasphere</span> region above 4 ER L-shell distances. Furthermore, they reveal the need of additional data to establish an appropriate data base for the modeling of the complete <span class="hlt">plasmasphere</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSM43B2315F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSM43B2315F"><span>Stormtime Observations of <span class="hlt">Plasmasphere</span> Erosion Flux in the Magnetosphere and Ionosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Foster, J. C.; Erickson, P. J.; Coster, A. J.; Thaller, S. A.; Tao, J.; Wygant, J. R.</p> <p>2013-12-01</p> <p><span class="hlt">Plasmasphere</span> erosion carries cold dense plasma of ionospheric origin toward the noontime cusp and dayside magnetopause. GPS TEC mapping shows the ionospheric footprint of this process as a continuous plume of storm enhanced density (SED) extending from the dusk sector into and through the cusp region and back across polar latitudes in a polar cap tongue of ionization. This circulation provides an enhanced source of ionospheric ions for injection into the magnetosphere, energization in the nighttime plasma sheet, and injection into the inner magnetosphere in the stormtime ring current. In this paper we examine dusk sector (18 MLT) <span class="hlt">plasmasphere</span> erosion with simultaneous direct observations of the sunward ion flux at high altitude by the Van Allen Probes spacecraft (RBSP A & B at ~3.5 Re) and at ionospheric heights (~830 km) by the DMSP spacecraft. Plasma flux is determined as the product of velocity and density and characteristic values for the sunward flux in the SED plume are 1.e13 - 1.e14 m-2s-1 as determined from Millstone Hill radar observations. Plasma erosion occurs where the sub auroral polarization stream (SAPS) flow overlaps the outer <span class="hlt">plasmasphere</span>. This relationship is seen clearly in both the high and low altitude observations. During the March 17, 2013 storm (Dst -130 nT), close magnetic field aligned coincidences between the Van Allen Probes and DMSP spacecraft occurred both during storm onset and in the main phase. At ~ 10 UT, several hours after storm onset, RBSP-B crossed the erosion plume observing a velocity of ~3200 m/s and sunward flux ~6.5 e12 m-2s-1. DMSP F-17 observed ionospheric velocity ~1800 m/s and flux of ~ 2.4 e14 m-2s-1. Later in the event at ~20 UT RBSP-A observed the high altitude erosion velocity to be ~2100 m/s and ~1.3e13 m_2s-1 flux while DMSP F-18 was seeing ionospheric velocity of ~1700 m/s and sunward flux of ~2.e13 m-2s-1. In both cases , the invariant latitude spatial extent and characteristics of the erosion plume in the high</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMAE33A0330K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMAE33A0330K"><span>Automatic Detection of Dispersion Curves of Lightning Whistlers Propagating in the <span class="hlt">Plasmasphere</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kasahara, Y.; Oike, Y.; Goto, Y.</p> <p>2013-12-01</p> <p>Akebono (EXOS-D) is a Japanese spacecraft that has been observing the Earth's <span class="hlt">plasmasphere</span> since 1989. The wide band analyzer (WBA) is a subsystem of the VLF instruments onboard Akebono, and it measures analogue waveform below 15 kHz of one component of the electric or magnetic field. When Akebono passed through the <span class="hlt">plasmasphere</span>, a series of lightning whistlers were frequently observed by the WBA. Lightning whistler is originated from lightning discharge and has a unique spectrum characterized by a discrete tone that decreases in frequency with time because of the velocity difference between higher and lower frequency components. This dispersive spectrum is quantified as 'dispersion', and it becomes larger when the path length is longer or electron density along the propagation path is denser. Thus the dispersion could be a very useful parameter to derive electron density profile in the <span class="hlt">plasmasphere</span> if we can derive these values along the propagation path. In the present paper, we introduce an automatic detection method of lightning whistlers from the analogue waveform data obtained by the WBA onboard Akebono. We first calibrate the waveform data referring the status of automatic gain controller implemented in the WBA. Second, a smoothing in the frequency domain and a simple noise filtering are applied to the spectrogram. Third, a recursive filter is applied to determine the threshold level for detection of lightning whistlers adapting the time varying back ground noise level. Finally a template matching method is adopted to achieve a rapid and simple detection of lightning whistlers. The developed method was applied to the VLF wide-band spectrum, whose maximum frequency is 20 kHz and the time and frequency resolution are 20msec and 50Hz, respectively. The results are satisfactory enough for the automatic detection of whistlers in a systematic way to analyze the trend of dispersion curve along the trajectory. Computation time for the analysis was practical enough</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26157626','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26157626"><span>Factor structure of the happiness-increasing strategies scales (<span class="hlt">H-ISS</span>): activities and coping strategies in relation to positive and negative affect.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Al Nima, Ali; Garcia, Danilo</p> <p>2015-01-01</p> <p>Background. Previous research (Tkach & Lyubomirsky, 2006) shows that there are eight general happiness-increasing strategies: social affiliation, partying, mental control, goal pursuit, passive leisure, active leisure, religion, and direct attempts. The present study investigates the factor structure of the happiness-increasing strategies scales (<span class="hlt">H-ISS</span>) and their relationship to positive and negative affect. Method. The present study used participants' (N = 1,050 and age mean = 34.21 sd = 12.73) responses to the <span class="hlt">H-ISS</span> in structural equation modeling analyses. Affect was measured using the Positive Affect Negative Affect Schedule. Results. After small modifications we obtained a good model that contains the original eight factors/scales. Moreover, we found that women tend to use social affiliation, mental control, passive leisure, religion, and direct attempts more than men, while men preferred to engage in partying and clubbing more than women. The <span class="hlt">H-ISS</span> explained significantly the variance of positive affect (R (2) = .41) and the variance of negative affect (R (2) = .27). Conclusions. Our study is an addition to previous research showing that the factor structure of the happiness-increasing strategies is valid and reliable. However, due to the model fitting issues that arise in the present study, we give some suggestions for improving the instrument.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4493682','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4493682"><span>Factor structure of the happiness-increasing strategies scales (<span class="hlt">H-ISS</span>): activities and coping strategies in relation to positive and negative affect</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2015-01-01</p> <p>Background. Previous research (Tkach & Lyubomirsky, 2006) shows that there are eight general happiness-increasing strategies: social affiliation, partying, mental control, goal pursuit, passive leisure, active leisure, religion, and direct attempts. The present study investigates the factor structure of the happiness-increasing strategies scales (<span class="hlt">H-ISS</span>) and their relationship to positive and negative affect. Method. The present study used participants’ (N = 1,050 and age mean = 34.21 sd = 12.73) responses to the <span class="hlt">H-ISS</span> in structural equation modeling analyses. Affect was measured using the Positive Affect Negative Affect Schedule. Results. After small modifications we obtained a good model that contains the original eight factors/scales. Moreover, we found that women tend to use social affiliation, mental control, passive leisure, religion, and direct attempts more than men, while men preferred to engage in partying and clubbing more than women. The <span class="hlt">H-ISS</span> explained significantly the variance of positive affect (R2 = .41) and the variance of negative affect (R2 = .27). Conclusions. Our study is an addition to previous research showing that the factor structure of the happiness-increasing strategies is valid and reliable. However, due to the model fitting issues that arise in the present study, we give some suggestions for improving the instrument. PMID:26157626</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950048216&hterms=plasma+explained&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dplasma%2Bexplained','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950048216&hterms=plasma+explained&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dplasma%2Bexplained"><span>On quasi-thermal fluctuations near the plasma frequency in the outer <span class="hlt">plasmasphere</span>: A case study</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lund, E. J.; Labelle, J.; Treumann, R. A.</p> <p>1994-01-01</p> <p>We present a derivation of the quasi-thermal electrostatic fluctuation power spectrum in a mult-Maxwellian plasma and show sample calculated spectra. We then apply this theory, which has been successfully applied in oter regions of space, to spectra from two Active Magnetospheric Particle Tracer Explorer/Ion Release Module (AMPTER IRM) passes through the duskside <span class="hlt">plasmasphere</span>. WE show that the plasma line that is often seen in this region is usually quasi-thermal in origin. We obtain a refined estimate of the plasma frequency and infer a cold electron temperature which is consistent within a factor of 2 with both models and previous meausurements by other techniques, but closer investigation reveals that details of the plasma line cannot be explained with the ususal two isotropic Maxwellian model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1991GeoRL..18..301K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1991GeoRL..18..301K"><span>Triaxial search coil measurements of ELF waves in the <span class="hlt">plasmasphere</span> - Initial results from EXOS-D</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kokubun, S.; Takami, M.; Hayashi, K.; Fukunishi, H.; Kimura, I.</p> <p>1991-02-01</p> <p>Measurements of ELF (below 50 Hz) waves in the near-equatorial region of the <span class="hlt">plasmasphere</span> are reported. Data obtained with the three-axis search-coil instruments of the Japanese EXOS-D satellite during March-October 1989 are presented graphically and briefly characterized. EM noise with multiband structure was detected mainly at frequencies above the local He(+) gyrofrequency in the region with L = 1.5-2.5 during daytime on 49 of 250 orbits, whereas broadband ELF noise in the same frequency range was detected on 10 orbits. No absorption at the local proton gyrofrequency was observed, and simultaneous electric-field measurements indicate a spectral cutoff at 1.3-2.5 times the He(+) gyrofrequency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010JASTP..72...90G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010JASTP..72...90G"><span>Magnetosphere-associated storms and the autonomous storms in the ionosphere-<span class="hlt">plasmasphere</span> environment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gulyaeva, T. L.; Stanislawska, I.</p> <p>2010-01-01</p> <p>Global GPS-derived ionosphere maps (GIM) of total electron content (TEC) were transformed into magnetic latitude (MLAT) versus magnetic local time (MLT) frame. TEC enhancement or depletion marked by W index show dominant electron content depressions and the ionosphere-<span class="hlt">plasmasphere</span> storms increasing by nighttime, at high magnetic latitudes and over the crests of equatorial anomaly. Based on W maps, the planetary Wp index was produced and used for derivation of a catalogue of more than 140 TEC storms during 1999-2009. In total 33 space weather intense storms and 35 moderate storms are revealed with four series of indices (AE, Ap, Dst and Wp) but more than half Wp storms were either partially overlapping in time with magnetic storm or observed autonomously under non-storm magnetosphere conditions. Relation between an annual number of intense Dst storms and Wp storms has been used for their prediction towards the peak of the forthcoming 24th solar cycle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JGRA..118.3077C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JGRA..118.3077C"><span>Sounding of the <span class="hlt">plasmasphere</span> by Mid-continent MAgnetoseismic Chain (McMAC) magnetometers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chi, P. J.; Engebretson, M. J.; Moldwin, M. B.; Russell, C. T.; Mann, I. R.; Hairston, M. R.; Reno, M.; Goldstein, J.; Winkler, L. I.; Cruz-Abeyro, J. L.; Lee, D.-H.; Yumoto, K.; Dalrymple, R.; Chen, B.; Gibson, J. P.</p> <p>2013-06-01</p> <p>We present a statistical analysis on the <span class="hlt">plasmaspheric</span> mass density derived from the field line resonance (FLR) observations by the Mid-continent MAgnetoseismic Chain (McMAC). McMAC consists of nine stations in the United States and Mexico along the 330° magnetic longitude, spanning L-values between 1.5 and 3.4. Using the gradient method and an automated procedure for FLR detection, we studied a full year of McMAC observations between July 2006 and June 2007. We find that the rate of FLR detection can reach as high as 56% around local noon at L = 2.7, and the detection rates at higher and lower L-values decline due to the occasional presence of the plasmapause and weaker FLR signals, respectively. At L-values between 1.8 and 3.1, the inferred equatorial plasma mass density follows the L-dependence of L-4. By comparing the mass density with the electron density, we found that the ion mass gradually decreased from 1.7 amu at L = 1.8 to 1 amu at L = 3.1. The plasma mass density exhibits an annual variation that maximizes in January, and at L = 2.4 the ratio between January and July densities is 1.6. Our observations also show a local time dependence of <span class="hlt">plasmaspheric</span> mass density that stays steady in the morning and rises postnoon, a phenomenon that may be attributed to the equatorial ionization anomaly as a part of the plasma neutral coupling at low latitude.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.9962M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.9962M"><span>Impact of the dipole tilt angle on the ionospheric plasma in the outer <span class="hlt">plasmasphere</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marchaudon, Aurelie; Blelly, Pierre-Louis</p> <p>2015-04-01</p> <p>We have developed a new interhemispheric 16-moment based ionosphere model. This model describes the field-aligned transport of the multi-species ionospheric plasma (6 ions) from one hemisphere to the other, taking into account source processes at low altitudes (photoionization, chemistry) and coupling with suprathermal electrons. We simulate the convection and corotation transport of closed flux tubes in the outer <span class="hlt">plasmasphere</span> for tilted/eccentric dipolar magnetic field configuration. We ran the model in solstice and equinox conditions and for two plasmapause boundary conditions: one corresponding to standard conditions with a stagnation point at 4.5 Earth radii (RE) and 15h Magnetic Local Time (MLT) and one corresponding to very quiet conditions with a stagnation point at 6 RE and 15h MLT. For each season/stagnation simulation, the model is run for 30 days before the equinox/solstice date in order to eliminate the transients. The goal is to study the combined effect of the tilt of the magnetic field and the rotation axis on the field-aligned dynamics and overall equilibrium of the subauroral ionosphere. In the classical representation of the <span class="hlt">plasmasphere</span>, the ionosphere only depends on angular MLT sector. We will show that due to the tilt effect, this view is erroneous and no real dynamic equilibrium is reached, in particular close to the stagnation point where we can observe large day-to-day variations in the ionospheric parameters. Finally, we will present the temperatures anisotropy development along the flux tube for different positions of the stagnation point.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22250722','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22250722"><span>Residual analysis of the water resonance signal in breast lesions imaged with high spectral and spatial resolution (<span class="hlt">HiSS</span>) MRI: A pilot study</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Weiss, William A. Medved, Milica; Karczmar, Gregory S.; Giger, Maryellen L.</p> <p>2014-01-15</p> <p>Purpose: High spectral and spatial resolution magnetic resonance imaging (<span class="hlt">HiSS</span> MRI) yields information on the local environment of suspicious lesions. Previous work has demonstrated the advantages of <span class="hlt">HiSS</span> (complete fat-suppression, improved image contrast, no required contrast agent, etc.), leading to initial investigations of water resonance lineshape for the purpose of breast lesion classification. The purpose of this study is to investigate a quantitative imaging biomarker, which characterizes non-Lorentzian components of the water resonance in <span class="hlt">HiSS</span> MRI datasets, for computer-aided diagnosis (CADx). Methods: The inhomogeneous broadening and non-Lorentzian or “off-peak” components seen in the water resonance of proton spectra of breast <span class="hlt">HiSS</span> images are analyzed by subtracting a Lorentzian fit from the water peak spectra and evaluating the difference spectrum or “residual.” The maxima of these residuals (referred to hereafter as “off-peak components”) tend to be larger in magnitude in malignant lesions, indicating increased broadening in malignant lesions. The authors considered only those voxels with the highest magnitude off-peak components in each lesion, with the number of selected voxels dependent on lesion size. Our voxel-based method compared the magnitudes and frequencies of off-peak components of all voxels from all lesions in a database that included 15 malignant and 8 benign lesions (yielding ∼3900 voxels) based on the lesions’ biopsy-confirmed diagnosis. Lesion classification was accomplished by comparing the average off-peak component magnitudes and frequencies in malignant and benign lesions. The area under the ROC curve (AUC) was used as a figure of merit for both the voxel-based and lesion-based methods. Results: In the voxel-based task of distinguishing voxels from malignant and benign lesions, off-peak magnitude yielded an AUC of 0.88 (95% confidence interval [0.84, 0.91]). In the lesion-based task of distinguishing malignant and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22250864','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22250864"><span>Residual analysis of the water resonance signal in breast lesions imaged with high spectral and spatial resolution (<span class="hlt">HiSS</span>) MRI: A pilot study</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Weiss, William A. Medved, Milica; Karczmar, Gregory S.; Giger, Maryellen L.</p> <p>2014-01-15</p> <p>Purpose: High spectral and spatial resolution magnetic resonance imaging (<span class="hlt">HiSS</span> MRI) yields information on the local environment of suspicious lesions. Previous work has demonstrated the advantages of <span class="hlt">HiSS</span> (complete fat-suppression, improved image contrast, no required contrast agent, etc.), leading to initial investigations of water resonance lineshape for the purpose of breast lesion classification. The purpose of this study is to investigate a quantitative imaging biomarker, which characterizes non-Lorentzian components of the water resonance in <span class="hlt">HiSS</span> MRI datasets, for computer-aided diagnosis (CADx). Methods: The inhomogeneous broadening and non-Lorentzian or “off-peak” components seen in the water resonance of proton spectra of breast <span class="hlt">HiSS</span> images are analyzed by subtracting a Lorentzian fit from the water peak spectra and evaluating the difference spectrum or “residual.” The maxima of these residuals (referred to hereafter as “off-peak components”) tend to be larger in magnitude in malignant lesions, indicating increased broadening in malignant lesions. The authors considered only those voxels with the highest magnitude off-peak components in each lesion, with the number of selected voxels dependent on lesion size. Our voxel-based method compared the magnitudes and frequencies of off-peak components of all voxels from all lesions in a database that included 15 malignant and 8 benign lesions (yielding ∼3900 voxels) based on the lesions’ biopsy-confirmed diagnosis. Lesion classification was accomplished by comparing the average off-peak component magnitudes and frequencies in malignant and benign lesions. The area under the ROC curve (AUC) was used as a figure of merit for both the voxel-based and lesion-based methods. Results: In the voxel-based task of distinguishing voxels from malignant and benign lesions, off-peak magnitude yielded an AUC of 0.88 (95% confidence interval [0.84, 0.91]). In the lesion-based task of distinguishing malignant and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20010039527&hterms=Archimedes&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DArchimedes','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20010039527&hterms=Archimedes&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DArchimedes"><span>The Large-Scale <span class="hlt">Plasmaspheric</span> Density Trough Associated With the 24 May 2000 Geomagnetic Storm: IMAGE EUV Observations and Global Core Plasma Modeling</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Adrian, M. L.; Gallagher, D. L.; Green, J. L.; Sandel, B. R.; Rose, M. Franklin (Technical Monitor)</p> <p>2001-01-01</p> <p>The IMAGE EUV imager observed a <span class="hlt">plasmaspheric</span> density, trough in association with a geomagnetically active period on 24 May 2000. In EUV, this density, trough appears as an Archimedes spiral extending from Earth's shadow to approximately 1900 MLT. We present an analysis of this density trough using simulated EUV images, Observational EUV images are subjected to edge analysis to establish the plasmapause L-shell and the location of the density trough in terms of L-shell, MLT extent, and radial width. The <span class="hlt">plasmaspheric</span> density distribution is modeled using both static and dynamic models for the <span class="hlt">plasmasphere</span>. The background <span class="hlt">plasmasphere</span> is then numerically simulated using the 4-parameter <span class="hlt">plasmaspheric</span> density model contained within the Global Core Plasma Model (GCPM) and the Dynamic Global Core Plasma Model (DGCPM). Simulated EUV images of the model <span class="hlt">plasmasphere</span> are produced once an artificial density, depletion, matching the observed MLT extent and width, has been removed. Once the azimuthal extent and width of the trough have been simulated, the depth of the artificial density depletion is iteratively adjusted to produce simulated EUV images that approximate observation. The results of this analysis and discussion of possible origins for this density trough will be presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20010039527&hterms=archimedes&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Darchimedes','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20010039527&hterms=archimedes&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Darchimedes"><span>The Large-Scale <span class="hlt">Plasmaspheric</span> Density Trough Associated With the 24 May 2000 Geomagnetic Storm: IMAGE EUV Observations and Global Core Plasma Modeling</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Adrian, M. L.; Gallagher, D. L.; Green, J. L.; Sandel, B. R.; Rose, M. Franklin (Technical Monitor)</p> <p>2001-01-01</p> <p>The IMAGE EUV imager observed a <span class="hlt">plasmaspheric</span> density, trough in association with a geomagnetically active period on 24 May 2000. In EUV, this density, trough appears as an Archimedes spiral extending from Earth's shadow to approximately 1900 MLT. We present an analysis of this density trough using simulated EUV images, Observational EUV images are subjected to edge analysis to establish the plasmapause L-shell and the location of the density trough in terms of L-shell, MLT extent, and radial width. The <span class="hlt">plasmaspheric</span> density distribution is modeled using both static and dynamic models for the <span class="hlt">plasmasphere</span>. The background <span class="hlt">plasmasphere</span> is then numerically simulated using the 4-parameter <span class="hlt">plasmaspheric</span> density model contained within the Global Core Plasma Model (GCPM) and the Dynamic Global Core Plasma Model (DGCPM). Simulated EUV images of the model <span class="hlt">plasmasphere</span> are produced once an artificial density, depletion, matching the observed MLT extent and width, has been removed. Once the azimuthal extent and width of the trough have been simulated, the depth of the artificial density depletion is iteratively adjusted to produce simulated EUV images that approximate observation. The results of this analysis and discussion of possible origins for this density trough will be presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006JGRA..111.6213P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006JGRA..111.6213P"><span>An entropy regularization method applied to the identification of wave distribution function for an ELF <span class="hlt">hiss</span> event</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Prot, Olivier; SantolíK, OndřEj; Trotignon, Jean-Gabriel; Deferaudy, Hervé</p> <p>2006-06-01</p> <p>An entropy regularization algorithm (ERA) has been developed to compute the wave-energy density from electromagnetic field measurements. It is based on the wave distribution function (WDF) concept. To assess its suitability and efficiency, the algorithm is applied to experimental data that has already been analyzed using other inversion techniques. The FREJA satellite data that is used consists of six spectral matrices corresponding to six time-frequency points of an ELF <span class="hlt">hiss</span>-event spectrogram. The WDF analysis is performed on these six points and the results are compared with those obtained previously. A statistical stability analysis confirms the stability of the solutions. The WDF computation is fast and without any prespecified parameters. The regularization parameter has been chosen in accordance with the Morozov's discrepancy principle. The Generalized Cross Validation and L-curve criterions are then tentatively used to provide a fully data-driven method. However, these criterions fail to determine a suitable value of the regularization parameter. Although the entropy regularization leads to solutions that agree fairly well with those already published, some differences are observed, and these are discussed in detail. The main advantage of the ERA is to return the WDF that exhibits the largest entropy and to avoid the use of a priori models, which sometimes seem to be more accurate but without any justification.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSM54B..06S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSM54B..06S"><span>Observational Results of Diurnal Variation in Quiet Time Inner <span class="hlt">Plasmasphere</span> Equatorial Noise Leading to Post-Midnight Ion Loss</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sarno-Smith, L. K.; Liemohn, M. W.; Skoug, R. M.; Morley, S.; Breneman, A. W.; Larsen, B.; Reeves, G. D.; Wygant, J. R.; Kletzing, C.; Hospodarsky, G. B.; Moldwin, M.; Katus, R. M.; Zou, S.</p> <p>2015-12-01</p> <p>After the discovery of the <span class="hlt">plasmaspheric</span> post-midnight 1-10 eV ion loss between L =2 and L =3, we have expanded upon these results and connected the observed ion loss with changes in plasma wave activity. Using the Van Allen Probes Helium, Oxygen, Proton, and Electron (HOPE) and the Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) instruments, we observed that diurnal variation in EMFISIS equatorial noise measurements was consistent with HOPE H+ thermal ion measurement variations. Through statistical studies and case studies, we present how enhanced dayside equatorial noise heats via cyclotron resonance to form the 1-10 eV ion population of the inner <span class="hlt">plasmasphere</span> during quiet time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5837489','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5837489"><span>The composition, temperature, and density structure of cold ions in the quiet terrestrial <span class="hlt">plasmasphere</span>: GEOS 1 results</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Farrugia, C.J.; Geiss, J.; Balsiger, H. ); Young, D.T. )</p> <p>1989-09-01</p> <p>The authors present a comprehensive study of the composition, and the density and temperature distributions of the thermal (energy {le} 110 eV) ion population in the terrestrial <span class="hlt">plasmasphere</span> under quiet geomagnetic conditions. The data were collected by the Ion Composition Experiment (ICE) on board the European Space Agency's GEOS 1 satellite and cover the period from June 1977 to May 1978. They find typical quiet time proton densities to vary smoothly between {approximately} 10{sup 2} cm{sup {minus}3} (L {approx} 6) and 2 {times} 10{sup 3} cm{sup {minus}3} (L {approx} 3). In the local time sector 1,700-2,200 the equatorial proton concentration obeys an inverse fourth power dependence with dipole L. He{sup +} is a major ionic component in all L ranges investigated. Its concentration relative to H{sup +} is highly variable, ranging from {approximately} 1% to, on occasion, over 100%. The averaged variation of He{sup +} with dipole L in the 1,700-2,200 local time range shows a somewhat more rapid decrease with increasing L than does H{sup +}. The temperature in the quiet <span class="hlt">plasmasphere</span> are between 4 {times} 10{sup 3} K and 1.5 {times} 10{sup 4} K and generally exhibit a slow increase with L value. The average radial temperature gradient near the equator is {approximately} 0.15 K/km. The main ionic constituents are usually in thermal equilibrium throughout the <span class="hlt">plasmasphere</span>. Using alternate passes in the same region, they discuss the poststorm recovery of the <span class="hlt">plasmasphere</span> on L shells > 4 for both H{sup +} and He{sup +}. Data are also presented on the minor ions O{sup +}, O{sup ++}, D{sup +}, and He{sup ++}.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSM33B..08J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSM33B..08J"><span>Warm Oxygen Enhancements in the Inner Magnetosphere and Their Relation to Geomagnetic Activity, <span class="hlt">Plasmasphere</span>, and Ring Current.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jahn, J. M.; Skoug, R. M.; Gkioulidou, M.; Bonnell, J. W.; Larsen, B.; Reeves, G. D.; Spence, H. E.</p> <p>2014-12-01</p> <p>Ionospheric oxygen plays an important role in the dynamics of Earth's magnetosphere. During geomagnetic storms, oxygen transported into the tail can experience significant energization and become a major contributor to the storm-time ring current. At very low energies, a dense cold oxygen torus straddles the outer <span class="hlt">plasmasphere</span>, frequently with O+/H+ ratios approaching unity. With the Radiation Belt Storm Probes we now also observe a third oxygen population in this region. In this paper we discuss the nature of "warm" (10's eV to few keV, i.e., between <span class="hlt">plasmasphere</span> and ring current ion energies) oxygen density enhancements over the course of the Van Allen Probes mission. We find that the composition of this warm thermal plasma is very dynamic throughout the inner magnetosphere. The warm oxygen density is highly responsive to changes in geomagnetic activity, varying by more than two orders of magnitude between quiet times and moderate storms. This variation at times is a greater than the variation of the corresponding proton density. The O+/H+ warm plasma density ration will frequently exceed unity, usually during the recovery phase of storms. The region of enhanced warm oxygen density reaches from the <span class="hlt">plasmasphere</span> boundary out to at least geosynchronous orbit (the largest L-shells covered by the Van Allen Probes). It can be observed at all local times. Barring other geomagnetic activity, warm oxygen density enhancements disappear typically within 5 days of their first detection, which is consistent with drift times through the inner magnetosphere along open drift paths. We are putting these characteristics in context of the composition, location, and evolution of the <span class="hlt">plasmasphere</span> and the ring current.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JGRA..119.3708N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JGRA..119.3708N"><span>Estimation of temporal evolution of the helium <span class="hlt">plasmasphere</span> based on a sequence of IMAGE/EUV images</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nakano, S.; Fok, M.-C.; Brandt, P. C.; Higuchi, T.</p> <p>2014-05-01</p> <p>We have developed a technique for estimating the temporal evolution of the <span class="hlt">plasmaspheric</span> helium ion density based on a sequence of extreme ultraviolet (EUV) data obtained from the IMAGE satellite. In the proposed technique, the estimation is obtained by incorporating EUV images from IMAGE into a two-dimensional fluid model of the <span class="hlt">plasmasphere</span> using a data assimilation approach based on the ensemble transform Kalman filter. Since the motion and the spatial structure of the helium <span class="hlt">plasmasphere</span> is strongly controlled by the electric field in the inner magnetosphere, the electric field around the plasmapause can also be estimated using the ensemble transform Kalman filter. We performed an experiment using synthetic images that were generated from the same numerical model under a certain condition. It was confirmed that the condition that generated the synthetic images was successfully reproduced. We also present some results obtained using real EUV imaging data. Finally, we discuss the possibility of estimating the density profile along a magnetic field line. Since each EUV image was taken from a different direction due to the motion of the IMAGE satellite, we could obtain the information on the density profile along a field line by combining multiple images.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20070031953&hterms=representation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Drepresentation','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20070031953&hterms=representation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Drepresentation"><span>TOPLA: A New Empirical Representation of the F-Region Topside and <span class="hlt">Plasmasphere</span> for the International Reference Ionosphere</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bilitza, D.; Reinisch, B.; Gallagher, D.; Huang, X.; Truhlik, V.; Nsumei, P.</p> <p>2007-01-01</p> <p>The goal of this LWS tools effort is the development of a new data-based F-region TOpside and <span class="hlt">PLAsmasphere</span> (TOPLA) model for the electron density (Ne) and temperature (Te) for inclusion in the International Reference Ionosphere (IRI) model using newly available satellite data and models for these regions. The IRI model is the de facto international standard for specification of ionospheric parameters and is currently being considered as an ISO Technical Specification for the ionosphere. Our effort is directed towards improving the topside part of the model and extending it into the <span class="hlt">plasmasphere</span>. Specifically we are planning to overcome the following shortcomings of the current IRI topside model: (I) overestimation of densities above 700 km by a factor of 2 and more, (3) unrealistically steep density profiles at high latitudes during very high solar activities, (4) no solar cycle variations and no semi-annual variations for the electron temperature, (5) discontinuities or unphysical gradients when merging with <span class="hlt">plasmaspheric</span> models. We will report on first accomplishments and on the current status of the project.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AdSpR..48.2036L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AdSpR..48.2036L"><span>A new inversion method of plasma density distribution of <span class="hlt">plasmasphere</span> in the geomagnetic equatorial plane from IMAGE data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Liang; Chen, Zhiqiang; Xu, Ronglan; Huang, Ya</p> <p>2011-12-01</p> <p>The plasma density distribution of <span class="hlt">plasmasphere</span> in the geomagnetic equatorial plane can help us study the magnetosphere like <span class="hlt">plasmasphere</span>, ionosphere and their kinetics. In this paper, we introduce a new inversion method, GE-ART, to calculate the plasma density distribution in the geomagnetic equatorial plane from the Extreme Ultraviolet (EUV) data of IMAGE satellite under the assumption that the plasma density is constant along each geomagnetic field line. The new GE-ART algorithm was derived from the traditional Algebraic Reconstruction Techniques (ART) in Computed Tomography (CT) which was different from the several existing methods. In this new method, each value of the EUV image data was back-projected evenly to the geomagnetic field lines intersected by this EUV sight. A 3-D inversion matrix was produced by the contributions of all the voxels contained in the <span class="hlt">plasmasphere</span> covered by the EUV sensor. That is, we considered that each value of the EUV image data was relative to the plasma densities of all the voxels passed through by the corresponding EUV radiation, which is the biggest difference to all the existing inversion methods. Finally, the GE-ART algorithm was evaluated by the real EUV data from the IMAGE satellite.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012cosp...39.2241Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012cosp...39.2241Z"><span>Estimation of the Ionosphere and <span class="hlt">Plasmasphere</span> Contribution to the GPS TEC under Solar Minimum Conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zakharenkova, Irina; Cherniak, Iurii; Krankowski, Andrzej; Shagimuratov, Irk; Sieradzki, Rafal</p> <p>2012-07-01</p> <p>The <span class="hlt">plasmaspheric</span> electron content (PEC) was estimated by comparison GPS observations and FORMOSAT-3/COSMIC radio occultation (RO) measurements at the extended solar minimum of cycle 23/24. GPS observations provide information about values of vertical total electron content (TEC) up to the metricconverterProductID20,200 km20,200 km. FORMOSAT-3/COSMIC now provides unprecedented global coverage of GPS RO measurements. Depending on the state of the constellation, COSMIC has been producing 1,500 -- 2,500 good soundings of the ionosphere and atmosphere per day, uniformly distributed around the globe. This number of RO is much higher than even before. In this study, COSMIC RO data for different seasons corresponded to equinoxes and solstices of 2007-2009 (March, June, September and December) were analyzed. All selected COSMIC RO electron density profiles were integrated up to the height of metricconverterProductID700 km700 km (altitude of COSMIC satellites), in that way the estimates of ionospheric electron content (IEC) were retrieved on a global scale. The final IGS combined global ionospheric maps (GIMs) were used to calculate the global maps of monthly medians of TEC values. As a result there were analyzed global distributions of GPS TEC and IEC estimates corresponded to the monthly median values for different seasons of 2007-2009. We consider the quantitative differences PEC = TEC -- IEC as a measure of the contribution of the PEC to GPS TEC. In order to analyze seasonal behaviour of PEC contribution to GPS TEC at the different regions we selected several specific points with coordinates, corresponded to the approximate positions of different, mid-latitude and low-latitude, ionospheric sounding stations. Such points were selected at Northern America, European and Asian regions, Southern America, Southern Africa and country-regionplaceAustralia. For each specific points GPS TEC, COSMIC IEC and PEC estimates were analyzed. Results of our comparative study revealed</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMSM23E..01D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMSM23E..01D"><span>Simulation of EMIC growth and propagation within the <span class="hlt">plasmaspheric</span> plume density irregularities</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>de Soria-Santacruz Pich, M.; Spasojevic, M.</p> <p>2012-12-01</p> <p>In situ data from the Magnetospheric Plasma Analyzer (MPA) instruments onboard the LANL spacecraft are used to study the growth and propagation of electromagnetic ion cyclotron (EMIC) waves in the presence of cold plasma irregularities in the <span class="hlt">plasmaspheric</span> plume. The data corresponds to the 9 June 2001 event, a period of moderate geomagnetic activity with highly irregular density structure within the plume as measured by the MPA instrument at geosynchoronus orbit. Theory and observations suggest that EMIC waves are responsible for energetic proton precipitation, which is stronger during geomagnetically disturbed intervals. These waves propagate below the proton gyrofrequency, and they appear in three frequency bands due to the presence of heavy ions, which strongly modify wave propagation characteristics. These waves are generated by ion cyclotron instability of ring current ions, whose temperature anisotropy provides the free energy required for wave growth. Growth maximizes for field-aligned propagation near the equatorial plane where the magnetic field gradient is small. Although the wave's group velocity typically stays aligned with the geomagnetic field direction, wave-normal vectors tend to become oblique due to the curvature and gradient of the field. On the other hand, radial density gradients have the capability of guiding the waves and competing against the magnetic field effect thus favoring wave growth conditions. In addition, enhanced cold plasma density reduces the proton resonant energy where higher fluxes are available for resonance, and hence explaining why wave growth is favored at higher L-shell regions where the ratio of plasma to cyclotron frequency is larger. The Stanford VLF 3D Raytracer is used together with path-integrated linear growth calculations to study the amplification and propagation characteristics of EMIC waves within the <span class="hlt">plasmaspheric</span> plume formed during the 9 June 2001 event. Cold multi-ion plasma is assumed for raytracing</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20110013493&hterms=signal+light&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsignal%2Blight*','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20110013493&hterms=signal+light&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsignal%2Blight*"><span>Large-Amplitude Transmitter-Associated and Lightning-Associated Whistler Waves in the Earth's Inner <span class="hlt">Plasmasphere</span> at L less than 2</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Breneman, A.; Cattell, C.; Wygant, J.; Kersten, K.; Wilson, L. B., III; Schreiner, S.; Kellogg, P. J.; Goetz, K.</p> <p>2011-01-01</p> <p>We report observations of very large amplitude whistler mode waves in the Earth fs nightside inner radiation belt enabled by the STEREO Time Domain Sampler. Amplitudes range from 30.110 mV/m (zero ]peak), 2 to 3 orders of magnitude larger than previously observed in this region. Measurements from the peak electric field detector (TDSMax) indicate that these large ]amplitude waves are prevalent throughout the <span class="hlt">plasmasphere</span>. A detailed examination of high time resolution electric field waveforms is undertaken on a subset of these whistlers at L < 2, associated with pump waves from lightning flashes and the naval transmitter NPM in Hawaii, that become unstable after propagation through the ionosphere and grow to large amplitudes. Many of the waveforms undergo periodic polarization reversals near the lower hybrid and NPM naval transmitter frequencies. The reversals may be related to finite plasma temperature and gradients in density induced by ion cyclotron heating of the plasma at 200 Hz, the modulation frequency of the continuous ]mode NPM naval transmitter signal. Test particle simulations using the amplitudes and durations of the waves observed herein suggest that they can <span class="hlt">interact</span> strongly with high ]energy (>100 keV) electrons on a time scale of <1 s and thus may be an important previously unaccounted for source of energization or pitch ]angle scattering in the inner radiation belt.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19352686','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19352686"><span>Role of permanent host association with the Madagascar <span class="hlt">hissing</span>-cockroach, Gromphadorhina portentosa, on the developmental water requirements of the mite, Gromphadorholaelaps schaeferi.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yoder, J A; Hedges, B Z; Benoit, J B; Keeney, G D</p> <p>2009-08-01</p> <p>We provide the first complete description of the water requirements for the <span class="hlt">hissing</span>-cockroach mite, Gromphadorholaelaps schaeferi, focusing on characteristics that result from the restriction of all stages to the Madagascar <span class="hlt">hissing</span>-cockroach (Gromphadorhina portentosa). Particularly, we determine how G. schaeferi spends its entire life on the same individual cockroach. This mite is not parasitic, rather they feed on cockroach saliva and other moist organic debris that accumulates between the cockroach's legs. Water balance characteristics of this mite show that it is extremely hydrophilic and that it must maintain a high percentage body water content to function properly despite being very porous (high net transpiration rate) and sensitive to water loss, tolerating only 20% loss of their water content before death. This hydrophilic trend starts with the larva and is retained into adulthood. Developmentally, a shift occurs during postlarval development from an emphasis on water gain (low critical equilibrium activity for water vapor absorption from drier air) in the protonymph to an emphasis on water retention (reduced net transpiration rate for water conservation) in the adult. The minute-sized larva is prevented from replenishing water stores by water vapor absorption or feeding because it lacks functional mouthparts, thus dries up rapidly. To avoid dehydration and survive, the larval stage utilizes a quick shoot-through molt to the protonymph that can feed and grow. Our conclusion is that the <span class="hlt">hissing</span>-cockroach creates an ideal, stable moisture-rich microhabitat that satisfies the high water demand for G. schaeferi during all stages, fixing this mite to a single cockroach as an ecological niche.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18040969','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18040969"><span>Endogenous and environmental factors influence the dietary fractionation of 13C and 15N in <span class="hlt">hissing</span> cockroaches Gromphadorhina portentosa.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>McCue, Marshall D</p> <p>2008-01-01</p> <p>Since DeNiro and Epstein's discovery that the (13)C and (15)N isotopic signatures of animals approximate those of their respective diets, the measurement of stable isotope signatures has become an important tool for ecologists studying the diets of wild animals. This study used Madagascar <span class="hlt">hissing</span> cockroaches (Gromphadorhina portentosa) to examine several preexisting hypotheses about the relationship between the isotopic composition of an animal and its diet. Contrary to my predictions, the results revealed that the tissues of adult cockroaches raised for two generations on a diet of known isotopic composition did not demonstrate enrichment of heavy stable isotopes. Moreover, the (15)N signatures of cockroaches were neither influenced by periods of rapid growth (i.e., 300-fold increase in dry body mass over 120 d) nor by imposed periods of starvation lasting up to 80 d. The offspring born to mothers raised on known diets were enriched in (15)N. Diet-switching experiments showed that turnover times of (13)C were highly correlated with age and ranged from 9 to 10 d to 60 to 75 d in subadults and adults, respectively. Adults subjected to diet switches differed from the subadults in that the adults achieved equilibrated isotopic signatures that were shifted approximately 1.0 per thousand toward their respective original diets. Lipid fractions of adult cockroaches averaged 2.9 per thousand more depleted in (13)C than in lipid-free fractions, but no changes in (13)C were observed in aging adults. Exposure to reduced ambient temperature from 33 degrees C to 23 degrees C over 120 d did not influence isotopic signatures of tissues. Overall, the results of this study reveal that different endogenous and exogenous factors can influence the isotopic signatures of cockroaches. These findings reinforce the need to conduct controlled studies to further examine environmental factors that influence the relationships between the isotopic signatures of animals and their diets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSM41F2554C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSM41F2554C"><span>Wave-wave and wave-particle <span class="hlt">interactions</span> in the inner magnetosphere measured with Van Allen Probes: cross coupling between wave modes and its effect on radiation belt dynamics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Colpitts, C. A.; Cattell, C. A.; Broughton, M.; Engebretson, M. J.</p> <p>2015-12-01</p> <p>We will show observations of waveform bursts using the Electric Field and Waves (EFW) burst data on the Van Allen Probes satellites with intermediate frequency waves such as whistler mode, magnetosonic and lower hybrid. These observations show very strong modulation of these waves by lower frequency waves such as EMIC or ULF. We are analyzing the burst data and cross coupling between wave modes to determine how prevalent the cross coupling between wave modes is and under what conditions it occurs. To supplement the EFW data, each satellite is also equipped with a full complement of particle instruments, including the HOPE instrument measuring lower energy (1 eV - 50 keV) particles and MagEIS instruments measuring higher energy (20 keV - 5 MeV) particles. The energy and angular resolution of these detectors are sufficient to resolve the scattering and energization arising from the distinct wave modes, using the signatures in the trapped electron populations predicted by theory for the various mechanisms. Comparison of the burst waveform data with the electron data from HOPE and MagEIS, for times with and without coupling between the wave modes, will allow us to identify how the cross coupling affects electron dynamics in the radiation belts. The significance of wave-particle <span class="hlt">interactions</span> in the formation and depletion of the radiation belts has long been established, but is still not completely understood. Specifically, pitch angle scattering from waves such as <span class="hlt">plasmaspheric</span> <span class="hlt">hiss</span> and electromagnetic ion cyclotron [EMIC] waves near the duskside plasmapause is known to contribute to electron loss from the radiation belts, primarily through precipitation into the atmosphere. Higher frequency waves such as whistler mode chorus and magnetosonic waves observed near the equator in the lower hybrid frequency range are widely believed to be primary means for electron energization. However, these and other competing processes often occur simultaneously, and an accurate model</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012cosp...39.2256Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012cosp...39.2256Z"><span>Remote sensing of the <span class="hlt">plasmasphere</span> mass density using ground magnetometers and the FLIP model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zesta, Eftyhia; Chi, Peter; Moldwin, Mark; Jorgensen, Anders; Richards, Phil; Boudouridis, Athanasios; Duffy, Jared</p> <p>2012-07-01</p> <p>The SAMBA (South American Meridional B-field Array) chain is a Southern Hemisphere meridional chain of 12 magnetometers, 11 of them at L=1.1 to L=2.5 along the coast of Chile and in the Antarctica peninsula, and one auroral station along the same meridian. SAMBA is ideal for low and mid-latitude studies of geophysical events and ULF waves. The MEASURE (Magnetometers along the Eastern Atlantic Seaboard for Undergraduate Research and Education) and McMAC (Mid-continent Magnetoseismic Chain) chains are Northern Hemisphere meridional chains in the same local time as SAMBA, but cover low to sub-auroral latitudes. SAMBA is partly conjugate to MEASURE and McMAC chains, offering unique opportunities for inter-hemispheric studies. We use 5 of the SAMBA stations and an even larger number of conjugate stations from the Northern hemisphere to determine the field line resonance (FLR) frequency of closely spaced flux tubes in the inner magnetosphere. Standard inversion techniques are used to derive the equatorial mass density of these flux tubes from the FLRs. We thus yield the mass density distribution of the <span class="hlt">plasmasphere</span> for specific events and compare our results with results from the FLIP thermosphere-ionosphere model model. We find that for moderate activity the model determined FLR radial distribution is in excellent agreement with the observed distribution. During storm time observations indicate stronger depletion than predicted by the model initial runs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMSA43B..06Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMSA43B..06Z"><span>Remote sensing of the <span class="hlt">plasmasphere</span> mass density using ground magnetometers and the FLIP model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zesta, E.; Boudouridis, A.; Moldwin, M.; Chi, P. J.; Jorgensen, A. M.; Duffy, J.; Richards, P. G.</p> <p>2011-12-01</p> <p>The SAMBA (South American Meridional B-field Array) chain is a Southern Hemisphere meridional chain of 12 magnetometers, 11 of them at L=1.1 to L=2.5 along the coast of Chile and in the Antarctica peninsula, and one auroral station along the same meridian. SAMBA is ideal for low and mid-latitude studies of geophysical events and ULF waves. The MEASURE (Magnetometers along the Eastern Atlantic Seaboard for Undergraduate Research and Education) and McMAC (Mid-continent Magnetoseismic Chain) chains are Northern Hemisphere meridional chains in the same local time as SAMBA, but cover low to sub-auroral latitudes. SAMBA is partly conjugate to MEASURE and McMAC chains, offering unique opportunities for inter-hemispheric studies. We use 5 of the SAMBA stations and an even larger number of conjugate stations from the Northern hemisphere to determine the field line resonance (FLR) frequency of closely spaced flux tubes in the inner magnetosphere. Standard inversion techniques are used to derive the equatorial mass density of these flux tubes from the FLRs. We thus yield the mass density distribution of the <span class="hlt">plasmasphere</span> for specific events and compare our results with results from the FLIP thermosphere-ionosphere model model. We find that for moderate activity the model determined FLR radial distribution is in excellent agreement with the observed distribution. During storm time observations indicate stronger depletion than predicted by the model initial runs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AdSpR..55.2248C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AdSpR..55.2248C"><span>Research on global <span class="hlt">plasmaspheric</span> electron content by using LEO occultation and GPS data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Peng; Yao, Yibin</p> <p>2015-05-01</p> <p>This paper investigates the characteristics of global <span class="hlt">plasmaspheric</span> electron content (pTEC) using COSMIC (Constellation Observing System for Meteorology, Ionosphere and Climate) occultation and GPS (Global Positioning System) data. The ionospheric electron content (iTEC) within 100-1000 km was obtained by fitting the COSMIC occultation electron density profiles, and the pTEC was obtained by subtracting the iTEC from CODE (Center for Orbit Determination in Europe) GIM (global ionosphere maps) TEC provided by University of Bern. This paper also investigates the characteristics of pTEC variations with local time, latitude and season. The results show that in 2011, the worldwide average of pTEC was 4.02 TECu, which is consistent with the findings of other studies. The pTEC shows significant diurnal variation characteristics, that is, pTEC is higher during daytime than during nighttime, but the percentage contribution of pTEC to GPS TEC is higher during nighttime than during daytime. The pTEC varies with the seasons, pTEC hemispheres symmetrically during spring and autumn, while pTEC in the summer hemisphere is higher than that in the winter hemisphere. Moreover, the percentage contribution of pTEC to GPS TEC (total electron content) is higher in winter hemisphere than in summer hemisphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015STP.....1c..49P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015STP.....1c..49P"><span>Forecasting characteristics of propagation of decameter radio waves using the global ionosphere and <span class="hlt">plasmasphere</span> model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ponomarchuk, Sergey; Kotovich, Galina; Romanova, Elena; Tashchilin, Anatoliy</p> <p>2015-09-01</p> <p>We present the results of forecasting maximum usable frequencies (MUF) on middle-latitude paths on the basis of complex algorithm including modules of the ionosphere and <span class="hlt">plasmasphere</span> global model (IPGM) and the model of radio wave propagation. The computation of propagation characteristics for decameter radio waves is carried out within the framework of normal wave technique. IPGM developed in ISTP SB RAS enables to compute electron concentration profiles and effective frequency of collisions using minimum number of input data and taking into account physical processes in the Earth's upper atmosphere. To estimate the efficiency of using IPGM in long-term forecast of radio wave propagation we computed MUF for radio communication in various heliogeophysical conditions. To obtain precision characteristics of MUF forecast we used experimental data of oblique sounding on Magadan-Irkutsk, Khabarovsk-Irkutsk, Norilsk-Irkutsk paths. The paths are equipped with modern ionosphere diagnostic hardware for oblique sounding by continuous chirp signal. We also compared results of MUF forecast using IPGM with computations carried out according IRI model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SZF.....1c..49P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SZF.....1c..49P"><span>Forecasting characteristics of propagation of decameter radio waves using the global ionosphere and <span class="hlt">plasmasphere</span> model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ponomarchuk, Sergey; Kotovich, Galina; Romanova, Elena; Tashchilin, Anatoliy</p> <p>2015-09-01</p> <p>We present the results of forecasting maximum usable frequencies (MUF) on middle-latitude paths on the basis of complex algorithm including modules of the ionosphere and <span class="hlt">plasmasphere</span> global model (IPGM) and the model of radio wave propagation. The computation of propagation characteristics for decameter radio waves is carried out within the framework of normal wave technique. IPGM developed in ISTP SB RAS enables to compute electron concentration profiles and effective frequency of collisions using minimum number of input data and taking into account physical processes in the Earth's upper atmosphere. To estimate the efficiency of using IPGM in long-term forecast of radio wave propagation we computed MUF for radio communication in various heliogeophysical conditions. To obtain precision characteristics of MUF forecast we used experimental data of oblique sounding on Magadan-Irkutsk, Khabarovsk-Irkutsk, Norilsk-Irkutsk paths. The paths are equipped with modern ionosphere diagnostic hardware for oblique sounding by continuous chirp signal. We also compared results of MUF forecast using IPGM with computations carried out according IRI model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AdSpR..55.2077K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AdSpR..55.2077K"><span>The global morphology of the <span class="hlt">plasmaspheric</span> electron content during Northern winter 2009 based on GPS/COSMIC observation and GSM TIP model results</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Klimenko, M. V.; Klimenko, V. V.; Zakharenkova, I. E.; Cherniak, Iu. V.</p> <p>2015-04-01</p> <p>We studied the contribution of the global <span class="hlt">plasmaspheric</span> and ionospheric electron content (PEC and IEC) into total electron content (TEC). The experimental PEC was estimated by comparison of GPS TEC observations and FORMOSAT-3/COSMIC radio occultation IEC measurements. Results are retrieved for the winter solstice (January and December 2009) conditions. Global maps of COSMIC-derived IEC, PEC and GPS TEC were compared with Global Self-consistent Model of the Thermosphere, Ionosphere and Protonosphere (GSM TIP) results. In addition, we used GSM TIP model results in order to estimate the contribution of <span class="hlt">plasmaspheric</span> electron content into TEC value at the different altitudinal regions. The advantages and problems of the outer ionospheric/<span class="hlt">plasmaspheric</span> parameters (O+/H+ transition height, TEC and electron density at height above F2 layer peak) representation by the IRI (International Reference Ionosphere) model are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMSA14A..03S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMSA14A..03S"><span>Imaging observation of the mesoscale structures in the Ionosphere, mesosphere, and <span class="hlt">plasmasphere</span> from the international space station</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Saito, A.; Yamazaki, A.; Sakanoi, T.; Yoshikawa, I.; Yamamoto, M.; Abe, T.; Suzuki, M.; Otsuka, Y.; Fujiwara, H.; Taguchi, M.; Nakamura, T.; Ejiri, M. K.; Masayuki, K.; Kawano, H.; Liu, H.; Sakanoi, K.; Ishii, M.; Kubota, M.; Tsugawa, T.; Hoshinoo, K.</p> <p>2012-12-01</p> <p>ISS-IMAP (Ionosphere, Mesosphere, upper Atmosphere, and <span class="hlt">Plasmasphere</span> mapping) mission is a space-borne mission to elucidate the mesoscale structures in the ionosphere, the mesosphere, and the <span class="hlt">plasmasphere</span> by imaging observations. It consists of two imaging instruments on the Exposed Facility of Japanese Experiment Module of the International Space Station, EF of ISS-JEM. The scientific instruments were delivered to ISS-JEM in July 2012. The observation was started in the summer of 2012. It will make imaging observation of the Earth's upper atmosphere with visible-light and infrared spectrum imager (VISI) and extra ultraviolet imager (EUVI). The objective of this mission is to clarify the energy transport process by the structures whose horizontal scale is 50-500km in the Earth's upper atmosphere, and the effect of the structures and disturbances on the space-borne engineering system. ISS-IMAP will measure the following three parameters in the lower latitude region than 50 degrees: (1) distribution of the atmospheric gravity wave in the mesopause (87km), the ionospheric E-region (95km), and the ionospheric F-region (250km) (2) distribution of the ionized atmosphere in the ionospheric F-region (3) distribution of O+ and He+ ions in the ionosphere and <span class="hlt">plasmasphere</span>. VISI will observe the airglow of 730nm (OH, Alt. 85km), 762nm (O2, Alt 95km), 630nm(O, Alt.250km) in the Nadir direction. EUVI will measure the resonant scattering of 30.4nm [He+] and 83.4nm [O+]. Its field-of-view is 15 degrees, and points the limb of the Earth to observe the vertical distribution of the ions. The scientific objectives and initial results of the ISS-IMAP mission will be introduced in the presentation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016cosp...41E2161Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016cosp...41E2161Z"><span>Longitudinal dependence of the seasonal variations of the topside ionospheric and <span class="hlt">plasmaspheric</span> electron content: observations and model results</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Man-Lian; Liu, Libo; Ning, Baiqi; Wan, Weixing</p> <p>2016-07-01</p> <p>Radio signals transmitted from GPS satellite going through the ionization zone above the Earth will be refracted by the ionized components in the ionosphere and the <span class="hlt">plasmasphere</span>, which would produce additional transfer delay and generate extra errors in satellite navigation and positioning, etc. These errors have strong relation with the total electron content (TEC) along the signal's travelling path. Therefore TEC is one of the most important parameters required by many users for different modern usage purposes. The topside ionospheric and <span class="hlt">plasmaspheric</span> electron content makes a large contribution to TEC. In the present study, data for the year 2008 of the topside ionospheric and <span class="hlt">plasmaspheric</span> electron content (PEC) between the height of 800-20200km above the Earth derived from the upward-looking TEC measurements of the precise orbit determination antenna on board the COSMIC low Earth orbit (LEO) satellites to the GPS signals are used to study the longitudinal dependence of the seasonal variations of PEC. A comparison study of the observed PEC with the IZMIRAN_Plas model results is also made. Our study showed that PEC shows different seasonal variations at different longitudinal sectors: for the 240°E-60°E longitudinal sector, PEC shows a strong annual variation with lowest value in the June solstice and highest value in the December solstice months; In contrast, very weak seasonal variations are observed for PEC at 60°E-240°E longitudinal sector; Comparison study showed that this longitudinal dependence feature of the observed PEC's seasonal variation is not well captured by the IZMIRAN_Plas model result. Acknowledgments This research was supported by the National Natural Science Foundation of China (NSFC No. 41274163)</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSM53A2206N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSM53A2206N"><span>Automated real-time monitoring of the <span class="hlt">plasmasphere</span> by means of ground-based magnetometer arrays in Europe and South Africa</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Neska, M.; Collier, A.; Heilig, B.; Jozwiak, W.; Raita, T.; Vellante, M.</p> <p>2013-12-01</p> <p>The EMMA (Europe) / SANSA (South Africa) magnetometer network created in the frame of the PLASMON project serves for determining the <span class="hlt">plasmasphere</span>'s mass distribution basing on the FLR (field line resonance) technique. This determination shall be done in a fully automated way and in real time. Current data from all stations are delivered to the PLASMON center within ca. 10 minutes. The central server performs a detection of FLR frequencies for appropriate magnetometer pairs according to the FLRID algorithm. Subsequently, the <span class="hlt">plasmasphere</span>'s mass is determined by the FLRINV algorithm. First results of the whole system's working are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001JASTP..63..605P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001JASTP..63..605P"><span>Comparison of the measured and modeled electron densities and temperatures in the ionosphere and <span class="hlt">plasmasphere</span> during the period 25-29 June 1990</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pavlov, A. V.; Abe, T.; Oyama, K.-I.</p> <p>2001-04-01</p> <p>We present a comparison of the electron density and temperature behavior measured in the ionosphere by the Millstone Hill incoherent-scatter radar during the period 25-29 June 1990, and in the <span class="hlt">plasmasphere</span> within the Millstone Hill magnetic field flux tube by the instruments on board of the EXOS-D satellite in the Northern Hemisphere between 02:07:56 UT and 02:11:08 UT on 28 June 1990 with numerical model calculations from a time-dependent mathematical model of the Earth's ionosphere and <span class="hlt">plasmasphere</span>. We have evaluated the value of the nighttime additional heating rate that should be added to the normal photoelectron heating in the electron energy equation in the <span class="hlt">plasmasphere</span> region above 5000 km along the magnetic field line to explain the high electron temperature measured by the instruments on board of the EXOS-D satellite. The additional heating brings the measured and modeled electron temperatures into agreement with the <span class="hlt">plasmasphere</span> and into very large disagreement with the ionosphere if the classical electron heat flux along magnetic field line is used in the model. The approach of Pavlov et al. (Annales Geophysicae 18 (2000) 1257-1272) based on an effective electron thermal conductivity coefficient along the magnetic field line, is used to explain the measured electron temperature in the ionosphere and <span class="hlt">plasmasphere</span>. This approach leads to a heat flux which is less than that given by the classical Spitzer-Harm theory. The evaluated additional heating of electrons in the <span class="hlt">plasmasphere</span> and the decrease of the thermal conductivity in the topside ionosphere and the greater part of the <span class="hlt">plasmasphere</span> allow the model to accurately reproduce the electron temperatures observed by the instruments on board of the EXOS-D satellite in the <span class="hlt">plasmasphere</span> and the Millstone Hill incoherent-scatter radar in the ionosphere. The resulting effect of vibrationally excited N2 and O2 on NmF2 is the decrease of the calculated daytime NmF2 up to a factor of 2. The modeled electron</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSM41H2577N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSM41H2577N"><span>Statistical analysis of <span class="hlt">plasmaspheric</span> magnetosonic mode waves from Van Allen Probes observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nomura, K.; Miyoshi, Y.; Keika, K.; Shoji, M.; Kurita, S.; Kitamura, N.; Machida, S.; Santolik, O.; Kletzing, C.; Boardsen, S. A.</p> <p>2015-12-01</p> <p>Magnetosonic waves (MSWs) are electromagnetic emissions whose properites can be described by the cold plasma extraordinary mode, which are typically generated at frequencies (f) between the proton cyclotron frequency (fcp) and the lower hybrid resonant frequency. It has been suggested that MSWs can contribute to the acceleration of relativistic electrons in the radiation belts. In this study, we investigate the Poynting vector of <span class="hlt">plasmaspheric</span> MSWs using the spectral matrix data from the EMFISIS instrument onboard the Van Allen Probes spacecraft. We derived the polarization and planarity from the spectrum matrix using the SVD method (Santolik et al., 2003) and also estimated the Poynting vector. The planarity is used as a proxy to distinguish presence of a single wave vector from mixture of waves propagating in different directions. The Poynting vector of MSWs with high planarity shows that the MSWs are observed to propagate radially as well as longitudinally. The occurrence probability of the propagation directions depends on the geomagnetic activities. During the geomagnetically quiet periods (Kp < 3), the percentage of inward, outward, and longitudinal propagations of MSWs at 60 Hz are 22%, 36% and 42% respectively. On the other hand, during the geomagnetically active periods (Kp > 5), the percentages are 53%, 21%, and 26%, respectively. The result indicates that the MSWs tend to propagate inward during the geomagnetically active periods. Since the fundamental frequency of the ion Bernstein mode would be local cyclotron frequency, we also investigate the source of MSWs from the minimum frequency of MSWs. It is found that a large number of MSWs tend to be generated at L=3.0-3.5 inside the plasmapause. We will also discuss the validity of the Poynting flux computation as a function of f/fcp.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AdSpR..50..427C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AdSpR..50..427C"><span><span class="hlt">Plasmaspheric</span> electron content derived from GPS TEC and FORMOSAT-3/COSMIC measurements: Solar minimum condition</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cherniak, Iu. V.; Zakharenkova, I. E.; Krankowski, A.; Shagimuratov, I. I.</p> <p>2012-08-01</p> <p>The <span class="hlt">plasmaspheric</span> electron content (PEC) was estimated by comparison of GPS TEC observations and FORMOSAT-3/COSMIC radio occultation measurements at the extended solar minimum of cycle 23/24. Results are retrieved for different seasons (equinoxes and solstices) of the year 2009. COSMIC-derived electron density profiles were integrated up to the height of 700 km in order to retrieve estimates of ionospheric electron content (IEC). Global maps of monthly median values of COSMIC IEC were constructed by use of spherical harmonics expansion. The comparison between two independent measurements was performed by analysis of the global distribution of electron content estimates, as well as by selection specific points corresponded to mid-latitudes of Northern America, Europe, Asia and the Southern Hemisphere. The analysis found that both kinds of observations show rather similar diurnal behavior during all seasons, certainly with GPS TEC estimates larger than corresponded COSMIC IEC values. It was shown that during daytime both GPS TEC and COSMIC IEC values were generally lower at winter than in summer solstice practically over all specific points. The estimates of PEC (h > 700 km) were obtained as a difference between GPS TEC and COSMIC IEC values. Results of comparative study revealed that for mid-latitudinal points PEC estimates varied weakly with the time of a day and reached the value of several TECU for the condition of solar minimum. Percentage contribution of PEC to GPS TEC indicated the clear dependence from the time with maximal values (more than 50-60%) during night-time and lesser values (25-45%) during day-time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMSA31B2157C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMSA31B2157C"><span>AUTOSCALA software improvements: topside-<span class="hlt">plasmasphere</span> profiles and TEC model assisted by AIS ionosonde measurements</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cesaroni, C.; Ippolito, A.; Scotto, C.; Ciraolo, L.</p> <p>2012-12-01</p> <p>The group of Upper Atmosphere Physics at INGV (Istituto Nazionale di Geofisica e Vulcanologia) developed Autoscala, a computer program for automatic scaling of the critical frequency foF2 and other ionospheric parameters derived from ionograms. Autoscala includes a routine that automatically estimates the electron density profile below F layer peak height hmF2, by adjusting the parameters of a model according to the recorded ionogram [Scotto (2009)]. Recently we have introduced a new algorithm for modeling upper ionosphere and <span class="hlt">plasmasphere</span> electron density profiles following the approach suggested by Kutiev et al. (2009). In particular, these model uses the parameters of F layer peak (foF2, hmF2, scale height at hmF2) to obtain scale heights that are useful to construct H- and O+ density profiles, and consequently N(h) profile (given as the sum of the former two). Integrating electron density profiles we are then able to obtain a real time TEC estimation above the considered ionospheric station. A first validation of the model is carried out for data measured at Rome ionospheric station (Italy, 41°54' N 12°28' E) using independent TEC measurements from GPS receivers. References: Scotto, C. (2009). Electron density profile calculation technique for Autoscala ionogram analysis. Advances in Space Research, 44(6), 756-766. doi:10.1016/j.asr.2009.04.037 Kutiev, I., Marinov, P., Belehaki, a., Reinisch, B., & Jakowski, N. (2009). Reconstruction of topside density profile by using the topside sounder model profiler and digisonde data. Advances in Space Research, 43(11), 1683-1687. doi:10.1016/j.asr.2008.08.017</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016AGUFMSA13B..05K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016AGUFMSA13B..05K"><span>Akebono (EXOS-D) sounder data archive for studies of the ionosphere and <span class="hlt">plasmasphere</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kumamoto, A.; Katoh, Y.; Obara, T.</p> <p>2016-12-01</p> <p>For the purpose of topside sounding of the ionosphere and active experiments of the plasma waves in geospace, a sounder system was installed on the Akebono (EXOS-D) satellite, which was operated in a period from 1989 to 2015. Through the long operation period, the sounder system was also operated successfully, and brought us 117,468 ionograms in a frequency range from 0.02-0.89 MHz and 31,936 ionograms in a frequency range from 0.3-11.4 MHz taken within 2.6 Re. In order to provide the data to world-wide researchers' use, we are preparing data archive of Akebono Sounder data in Common Data Format (CDF) and Planetary Data System (PDS) format. Calibrated ionograms will be provided as Level-2 data. In addition, we are going to perform echo trace of the ionograms, and derive the vertical profile of the electron number density below the satellite. The horizontal and vertical distribution of the number density of the topside ionosphere along the satellite path will be provided as Level-3 data. However, because we need some efforts in manual echo tracing with numerous ionograms, it will take some time to finish the release of Level-3 data. So, we are going to prepare another simplified Leve-3 data, which provides the horizontal and apparent (assuming light-speed propagation) vertical distribution of the reflection point of the echo at some fixed frequency. The dataset will be enough useful in finding irregular plasma structures around auroral ionosphere and storm-time <span class="hlt">plasmasphere</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSM43B2311Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSM43B2311Z"><span>Visualizing the fully three-dimensional <span class="hlt">plasmaspheric</span> and ring current distribution from global EUV and ENA imaging</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zimmerman, M. I.; Hsieh, S. W.; Brandt, P. C.; Vandegriff, J. D.; Stephens, G. K.; Toigo, A. D.; Keika, K.; Kusterer, M. B.; Demajistre, R.</p> <p>2013-12-01</p> <p>Extreme Ultra Violet (EUV) and Energetic neutral atom (ENA) imaging are powerful remote sensing tools utilized on, for example the IMAGE and TWINS missions, that provides global three-dimensional information about the structure, dynamics, and composition of Earth's <span class="hlt">plasmaspheric</span> He+ and ring current ion distributions. Numerical retrieval techniques provide 3D distributions of quantities such as pressure and ion flux from ring current ENA images and the He+ distribution from EUV <span class="hlt">plasmasphere</span> images. The tool includes an intuitive interface wnabling the user to select from a variety of prepared datasets, display and manipulate nested pressure isocontours, depict coincident spacecraft tracks and compare in-situ data with global distributions derived from images, and animate the pressure evolution of a magnetospheric storm. Therefore the tool is valuable for the validation and intercomparison between global and in-situ data and is broadly applicable to other derived global datasets and modeling results. Screenshot of the visualization tool including 3D isocontours of pressure inferred from IMAGE/HENA inversion data (left panel) and the equatorial inverted image intensity (right panel).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730013582','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730013582"><span>Two substorm studies of relations between westward electric fields in the outer <span class="hlt">plasmasphere</span>, auroral activity, and geomagnetic perturbations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Carpenter, D. L.; Akasofu, S.</p> <p>1972-01-01</p> <p>Temporal variations of the westward component of the magnetospheric convection electric field in the outer <span class="hlt">plasmasphere</span> were compared to auroral activity near L = 7, and to variations in the geomagnetic field at middle and high latitudes. The substorms occurred on July 29, 1965 near 0530 UT and on August 20, 1965 near 0730 UT. The results on westward electric field E(w) were obtained by the whistler method using data from Eights, Antarctica (L is approximately 4). All sky camera records were obtained from Byrd, Antarctica, (L is approximately 7), located within about 1 hour of Eights in magnetic local time. It was found that E(w) within the outer <span class="hlt">plasmasphere</span> increased rapidly to substorm levels about the time of auroral expansion at nearby longitudes. This behavior is shown to differ from results on E(w) from balloons, which show E(w) reaching enhanced levels prior to the expansion. A close temporal relation was found between the rapid, substorm associated increases in E(w) and a well known type of nightside geomagnetic perturbation. Particularly well defined was the correlation of E(w) rise and a large deviation of the D component at middle latitudes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSM43A4256J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSM43A4256J"><span>Observations of the coupling efficiency of VLF lightning-generated whistlers into the low-latitude <span class="hlt">plasmasphere</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jacobson, A. R.; Holzworth, R. H., II; Pfaff, R. F., Jr.; Heelis, R. A.</p> <p>2014-12-01</p> <p>The C/NOFS satellite [de La Beaujardiere, 2004] has provided a vast archive of multi-sensor data on the low-latitude ionosphere/<span class="hlt">plasmasphere</span> since 2008. As part of the project, the VEFI payload [Pfaff et al., 2010] has recorded the 3-D electric field from DC through 16 kHz with high fidelity. The relative calibrations track between the three E-field antennas with sufficient accuracy and stability to allow retrieval of the wave polarization for a wide range of lightning-generated whistler waves [Jacobson et al., 2014]. The wave polarization in turn allows retrieval of the wavevector (within a sign ambiguity), which in turn allows an inverse-raytrace of the whistler raypath from the satellite to the ionospheric entry point. We will compare the raytrace predictions with ground-truth from the WWLLN global lightning-monitoring system [Lay et al., 2004; Rodger et al., 2005; Rodger et al., 2004]. In addition to providing location and time of lightning strokes, WWLLN provides an estimate of the radiated radio energy in the whistler passband [Hutchins et al., 2012]. Finally, the CINDI payload [Heelis et al., 2009] on C/NOFS provides ion composition at the satellite, permitting the index of refraction to be inferred. We will compare these estimates to the Poynting fluence density observed by VEFI, thereby providing a direct test of the coupling of lightning radio energy into <span class="hlt">plasmaspheric</span> whistlers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSM13D2555R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSM13D2555R"><span><span class="hlt">Plasmasphere</span> pulsations observed simultaneously by midlatitude SuperDARN radars, ground magnetometers and THEMIS spacecraft during an auroral substorm</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ruohoniemi, J. M.; Shi, X.; Baker, J. B. H.; Frissell, N. A.; Hartinger, M.; Liu, J.</p> <p>2015-12-01</p> <p>We present simultaneous ground and space-based observations of ultra-low frequency (ULF) pulsations which occurred during an auroral substorm on September 25th, 2014. Expansion phase onset began at 06:04 UT at which time three midlatitude SuperDARN radars observed strong pulsations in the Pi2 frequency range with peak to peak amplitude reaching as high as 1km/s. Similar pulsations occurred during a later auroral intensification which started at 06:20 UT. Both sets of pulsations were detected in a region of radar backscatter located inside the subauroral polarization stream (SAPS) equatorward of the auroral oval specified by THEMIS all sky imagers and inside the midlatitude density trough as mapped by GPS/TEC measurements. The amplitude of the pulsations was large enough to reverse the direction of the SAPS flow from westward to eastward. Similar pulsations were detected by electric field instrument aboard the THEMIS probe D located inside the <span class="hlt">plasmasphere</span>. Simultaneous observations from several low-latitude ground magnetometers (some located on the dayside) further illustrate the global nature of the pulsations and suggest they may have been associated with a <span class="hlt">plasmaspheric</span> cavity resonance (PCR). Pulsed tailward plasma flow observed by THEMIS probe E at the geosynchronous orbit suggests that the compressional energy to generate the PCR was from the Bursty Bulk Flows (BBFs) braking against the magnetospheric dipolar region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017GeoRL..44.5928H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GeoRL..44.5928H"><span>SAMI3 prediction of the impact of the 21 August 2017 total solar eclipse on the ionosphere/<span class="hlt">plasmasphere</span> system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huba, J. D.; Drob, D.</p> <p>2017-06-01</p> <p>We present quantitative predictions of the impact of the upcoming total solar eclipse on the ionosphere and <span class="hlt">plasmasphere</span> using the Naval Research Laboratory (NRL) model Sami3 is Also a Model of the Ionosphere (SAMI3). The eclipse will occur over the continental United States on 21 August 2017. Our simulation results indicate that in the vicinity of the eclipse (1) the total electron content (TEC) decreases by up to ˜ 5 TEC units (TECU; 1 TECU = ×1016 m-2) which is a ˜ 35% decrease in TEC, (2) the electron density decreases by a factor of ˜ 50% in the F region, (3) the electron temperature decreases by up to ˜800 K in the <span class="hlt">plasmasphere</span>, and (4) the O+ velocity changes from ˜40 m s-1 upward to ˜20 m s-1 downward in the F region. Interestingly, the continental size modification of the ionospheric conductance modifies the global electric field, which should lead to measurable changes in the TEC in the southern conjugate hemisphere (≲1 TECU).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010cosp...38.2187Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010cosp...38.2187Z"><span>a New Method to Calculate the Density Map of Magnetic Equatorial Plane of the <span class="hlt">Plasmasphere</span> from the EUV Data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zheng, Jie</p> <p></p> <p>The Extreme Ultraviolet (EUV) data was collected by the EUV sensor on the American IMAGE satellite which represented the line integrals of the density of He+ along the EUV radiation. In this paper, we introduce a new method which can be used to calculate the density map of magnetic equatorial plane of the <span class="hlt">plasmasphere</span> from the EUV data. The new method is derived from the ART algorithm in computed tomography (CT) which is different from the several existing methods. The value of each element of the EUV data is back-projected to the corresponded L-curves. It is assumed that the He+ density is constant along L-curve. Different from the existing methods, each element of EUV data is considered as a sum of all the He+ densities on the L-curves which are passed though by the corresponding EUV radiation ray. Finally, the numerical experimental results are presented to verify our new method for the <span class="hlt">plasmasphere</span> density in the magnetic equatorial plane.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19860051618&hterms=Beats+waves&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DBeats%2Bwaves','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19860051618&hterms=Beats+waves&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DBeats%2Bwaves"><span>Recent research on magnetospheric wave-particle <span class="hlt">interactions</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Helliwell, R. A.; Inan, U. S.; Katsufrakis, J. P.; Carpenter, D. L.; Paschal, E. W.</p> <p>1985-01-01</p> <p>Highlights of recent Stanford University VLF research in the Antarctic include new observations of wave-induced particle precipitation and controlled experiments on nonlinear wave growth phenomena. Higher-than-expected levels of burst precipitation have been discovered inside the <span class="hlt">plasmasphere</span>, near L = 2, using subionospheric signal perturbations called 'Trimpi events'. Studies of burst precipitation have been extended to the region poleward of the plasmapause using the Siple transmitter signal as a waveguide probe. Experiments on the 'coherent wave instability', using the amplitude and frequency modulation capability of the new Siple transmitter, have produced exciting new results. Examples are: (1) better definition of the power threshold for the stimulation of temporal wave growth, (2) generation of strong sidebands by unamplified 'beat' waves and (3) generation of chorus-like elements within a band of simulated <span class="hlt">hiss</span>. Using a new digital processing technique developed at Stanford, new features of the phase behavior of growing waves have been found. Opportunities for extending these experiments are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010cosp...38.2186X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010cosp...38.2186X"><span>Global Density of the Earth <span class="hlt">Plasmasphere</span> Deduced from the Images of its Phantom by Using a Fbp and Art Computer Tomographic Techniques</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xu, Ronglan; Huang, Ya; Zhao, Hua; Li, Liang; Chen, Zhiqiang; Jin, Xin; Zheng, Jie; Zhang, Hua</p> <p></p> <p>The similarity of the projection in X ray Computer Tomography (CT) with the column density of the EUV Imager, provide the possibility to deduct the global density of <span class="hlt">Plasmasphere</span> from the image of <span class="hlt">plasmaspheric</span>, by using CT technique. Similar with the Medical CT, a phantom consists of <span class="hlt">plasmasphere</span> and ionosphere had been used. The boundary of the <span class="hlt">plasmasphere</span> is supposed as a dipole field line, with L= 4 Earth radii (Re), and the density within is equal to 1 and uniform. The ionosphere can be expected as a shell, with an inner and outer radius equal to 1.1 and 1. 2Re. And the density is supposed as 10.A Filtered Back-projection (FBP) Algorithm, and Algebraic Reconstruction Technique (ART) CT had been used. The FBP is the simplest and basic algorithm in CT Techniques by using parallel projections. It can be used in the lunar based Earth's <span class="hlt">Plasmaspheric</span> EUV Imager, since the field of view of the EUV Imager is small. In the EUV Imager of IMAGE satellite, since the imager is near to the Earth, so that the reconstruction algorithm will be a cone-beam. By using a cone beam to parallel beam rebinning, where the noise-ratio of cone beam versus parallel back-projection is acceptable, we can also use parallel back projection in the EUV Imager of IMAGE satellite. An improve accuracy of reconstruction algorithm is achieved by using a more complicate ART. The reconstruction quality is more efficient than FBP, when the image included the Earth's shelter and limit view angle imaging. To illustrate our result, we divide our reconstruction into some typical slices, parallel with the noon meridian plane of the Erath. For FBP, when the distance of the slice from the noon meridian plane is smaller than an Earth radius, we find some discrepancies between the reconstruction and the initial phantom, where ART is much better than FBT</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMSA31B1983S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMSA31B1983S"><span>Imaging observation of the Earth's upper atmosphere by Ionosphere, Mesosphere, upper Atmosphere, and <span class="hlt">Plasmasphere</span> mapping observation (ISS-IMAP) mission</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Saito, A.; Sakanoi, T.; Yoshikawa, I.; Yamazaki, A.; Abe, T.; Suzuki, M.; Otsuka, Y.; Nakamura, T.; Masayuki, K.; Ejiri, M. K.; Taguchi, M.; Yamamoto, M.; Kawano, H.; Fujiwara, H.; Ishii, M.; Kubota, M.; Sakanoi, K.; Hoshinoo, K.</p> <p>2011-12-01</p> <p>ISS-IMAP (Ionosphere, Mesosphere, upper Atmosphere, and <span class="hlt">Plasmasphere</span> mapping) mission is a scientific mission that will make imaging observation of the Earth's upper Atmosphere from the Exposed Facility of Japanese Experiment Module on the International Space Station (EF of ISS-JEM). It will be installed in Multi-mission Consolidated Equipment (MCE) on EF of ISS-JEM, and start the observation in 2012. It consists of two imager sets. Visible-light and infrared spectrum imager (VISI) will detect the airglow emission in the mesosphere and the thermosphere/ionosphere, and extra ultraviolet imager (EUVI) will detect the resonant scattering emission from the ions in the ionosphere and the <span class="hlt">plasmasphere</span>. The objective of this mission is to clarify the physical mechanism of the following three processes: (1) energy transport process by the atmospheric structures whose horizontal scale is 50-500km in the upper atmosphere (2) process of the plasma transport up to 20,000km altitude (3) effect of the upper atmosphere on the space-borne engineering system. ISS-IMAP will measure the following three parameters in the lower latitude region than 50 degrees: (1) distribution of the atmospheric gravity wave in the mesopause (87km), the ionospheric E-region (95km), and the ionospheric F-region (250km) (2) distribution of the ionized atmosphere in the ionospheric F-region (3) distribution of O+ and He+ ions in the ionosphere and <span class="hlt">plasmasphere</span>. VISI will observe the airglow of 730nm (OH, Alt. 85km), 762nm (O2, Alt 95km) and 630nm(O, Alt.250km) in the Nadir direction. Its field-of-view is 90-degree width perpendicular to the trajectory of ISS, and direct in two directions, forward and backward. The vertical structure of the airglow will be determined by stereo observation with these two slits. EUVI will measure the resonant scattering of 30.4nm [He+] and 83.4nm [O+] with 15 degrees of field-of-view. It points the limb of the Earth to observe the vertical distribution of the ions. The</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19820029721&hterms=plasma+Composition+Experiment&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dplasma%2BComposition%2BExperiment','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19820029721&hterms=plasma+Composition+Experiment&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dplasma%2BComposition%2BExperiment"><span>ISEE 1 observations of thermal plasma in the vicinity of the <span class="hlt">plasmasphere</span> during periods of quieting magnetic activity</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Horwitz, J. L.; Baugher, C. R.; Chappell, C. R.; Shelley, E. G.; Young, D. T.; Anderson, R. R.</p> <p>1981-01-01</p> <p>An investigation of thermal plasma behavior in the vicinity of the <span class="hlt">plasmasphere</span> during periods of quieting magnetic activity was conducted by combining thermal ion observations made with the plasma composition experiment on ISEE 1 with plasma density profiles obtained from plasma frequency measurements made with the same satellite's plasma wave experiment. During periods in which the magnetic activity quiets, the two regions characterized by H(+):He(+):O(+) (isotropic) and H(+):O(+):He(+) (field-aligned) ion species distributions (in order of dominance) are separated by a new region in which low-energy H(+) and He(+) are found flowing along the magnetic field lines. At other times, following quieting magnetic activity, distributions having peak fluxes at 90 deg pitch angle are observed in this region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1981JGR....86.9989H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1981JGR....86.9989H"><span>ISEE 1 observations of thermal plasma in the vicinity of the <span class="hlt">plasmasphere</span> during periods of quieting magnetic activity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Horwitz, J. L.; Baugher, C. R.; Chappell, C. R.; Shelley, E. G.; Young, D. T.; Anderson, R. R.</p> <p>1981-11-01</p> <p>An investigation of thermal plasma behavior in the vicinity of the <span class="hlt">plasmasphere</span> during periods of quieting magnetic activity was conducted by combining thermal ion observations made with the plasma composition experiment on ISEE 1 with plasma density profiles obtained from plasma frequency measurements made with the same satellite's plasma wave experiment. During periods in which the magnetic activity quiets, the two regions characterized by H(+):He(+):O(+) (isotropic) and H(+):O(+):He(+) (field-aligned) ion species distributions (in order of dominance) are separated by a new region in which low-energy H(+) and He(+) are found flowing along the magnetic field lines. At other times, following quieting magnetic activity, distributions having peak fluxes at 90 deg pitch angle are observed in this region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010cosp...38.1501T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010cosp...38.1501T"><span>Possible contribution of the OGO-5 ion composition measurement to an extension of IRI for the <span class="hlt">plasmasphere</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Truhlik, Vladimir; Triskova, Ludmila; Smilauer, Jan; Grebowsky, Joseph; Bilitza, Dieter; Benson, Robert</p> <p></p> <p>Orbiting Geophysical Observatory 5 (OGO 5) magnetospheric ion-composition data (H+, He+ and O+) from an ion spectrometer [Sharp, IEE Trans. in Geosci. Elect. V, GE-7, 93, 1969] have been retrieved from old magnetic tapes archived at the National Space Science Data Center (NSSDC). The highly compressed binary format was converted into a user-friendly ASCII for-mat and these data have now been made available from the NSSDC (http://nssdcftp.gsfc.nasa.gov). Additionally we have recovered the ephemeris information. Using these data we have inves-tigated altitude/field line distributions (derived by statistically analyzing all the data) of all measured ions inside the <span class="hlt">plasmasphere</span>. We discuss a possible extension of the current ion composition model in the International Reference Ionosphere (IRI) above its current upper boundary of validity (2500km). We also compare the locations of the OGO-5 H+ and He+ plasmapause positions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMSM31B2292L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMSM31B2292L"><span>Intra-<span class="hlt">plasmaspheric</span> wave power density deduced from long-term DEMETER measurements of terrestrial VLF transmitter wave amplitudes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lauben, D.; Cohen, M.; Inan, U.</p> <p>2012-12-01</p> <p>We deduce the 3d intra-<span class="hlt">plasmaspheric</span> distribution of VLF wave power between conjugate regions of strong VLF wave amplitudes as measured by DEMETER for high-power terrestrial VLF transmitters during its ~6-yr lifetime. We employ a mixed WKB/full-wave technique to solve for the primary and secondary electromagnetic and electrostatic waves which are transmitted and reflected from strong cold-plasma density gradients and posited irregularities, in order to match the respective end-point measured amplitude distributions. Energy arriving in the conjugate region and also escaping to other regions of the magnetosphere is note. The resulting 3d distribution allows improved estimates for the long-term average particle scattering induced by terrestrial VLF transmitters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012SPIE.8207E..2GI','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012SPIE.8207E..2GI"><span>Mucosal wave characteristics in three voice modes (fry, <span class="hlt">hiss</span> & overpressure) produced by a female speaker: a preliminary study using stroboscopy, HSDI and analyzed by kymography, P-FFT & Nyquist plots</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Izdebski, Krzysztof; Ward, Ronald R.; Yan, Yuling</p> <p>2012-02-01</p> <p>HSDI provides a whole new way to investigate visually intra-laryngeal behavior and posturing during phonation by providing detailed real-time information about laryngeal biomechanics that include observations about mucosal wave, wave motion directionality, glottic area wave form, asymmetry of vibrations within and across vocal folds and contact area of the glottis including posterior commissure closure. These observations are fundamental to our understanding and modeling of both normal and disordered phonation. In this preliminary report we focus on direct HSDI in vivo observations of not only the glottic region, but also on the entire supraglottic laryngeal posturing during fry, breathy/<span class="hlt">hiss</span> and over-pressured phonation modes produced in a non-pathological settings. Analysis included spatio-temporal vibration patterns of vocal folds, multi-line kymograms, spectral PFFT analysis, and Nyquist spatio-temporal plots. The presented examples reveal that supraglottic contraction assists in prolonged closed phase of the vibratory cycle, and that prolonged closed phase is longest in fry and overpressure and shortest albeit complex in <span class="hlt">hiss</span>. <span class="hlt">Hiss</span> also allows for vocal fold vibration despite glottis separation. These findings need to be compared to pathologic phonation representing the three voice modes to derive at better differential diagnosis.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSA51C..08S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSA51C..08S"><span>Preliminary results of the imaging observation of the MTI region by Ionosphere, Mesosphere, Upper Atmosphere, and <span class="hlt">Plasmasphere</span> Mapping Mission on the International Space Station</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Saito, A.; Yamazaki, A.; Sakanoi, T.; Yoshikawa, I.; Yamamoto, M.; Abe, T.; Suzuki, M.; Otsuka, Y.; Fujiwara, H.; Taguchi, M.; Nakamura, T.; Ejiri, M. K.; Kawano, H.; Liu, H.; Sakanoi, K.; Ishii, M.; Kubota, M.; Tsugawa, T.; Hoshinoo, K.</p> <p>2013-12-01</p> <p>ISS-IMAP (Ionosphere, Mesosphere, upper Atmosphere, and <span class="hlt">Plasmasphere</span> mapping) mission is a space-borne mission on the international space station (ISS) to investigate the mesoscale structures in the ionosphere, the mesosphere, and the <span class="hlt">plasmasphere</span> by imaging observations. It consists of two imaging instruments. Visible-light and infrared spectrum imager (VISI) observes the airglow in the MTI region. Extra ultraviolet imager (EUVI) observes the resonant scattering from ions in the ionosphere and the <span class="hlt">plasmasphere</span>. The objective of this mission is to clarify the energy transport process by the structures whose horizontal scale is 50-500km in the Earth's upper atmosphere, and the effect of the structures and disturbances on the space-borne engineering system. ISS-IMAP measures the following three parameters in the lower latitude region than 50 degrees: (1) distribution of the atmospheric gravity wave in the mesopause (87km), the ionospheric E-region (95km), and the ionospheric F-region (250km) (2) distribution of the ionized atmosphere in the ionospheric F-region (3) distribution of O+ and He+ ions in the ionosphere and <span class="hlt">plasmasphere</span>. Its continuous observation started in October 2012. The planned observational period is three years. VISI observes the airglow of 730nm (OH, Alt. 85km), 762nm (O2, Alt. 95km), and 630nm (O, Alt. 250km) in the Nadir direction. The global distributions of the airglow structures whose scale size is 50-500km in the nightside have been elucidated by the VISI observation. The topological dependence of AGW in the MTI region has been clarified by this novel space-borne observation. The preliminary results of the ISS-IMAP mission by VISI and EUVI will be introduced in the presentation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19720021630','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19720021630"><span>VHF/UHF technique for the determination of the columnar electron contents of the <span class="hlt">plasmasphere</span> and of the protonosphere using geostationary satellite transmission: Observations during magnetic storms</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Almeida, O. G.</p> <p>1972-01-01</p> <p>Measurements of the total electron content of the <span class="hlt">plasmasphere</span> up to geostationary heights were made using the beacon transmitters aboard the satellite ATS-3. The technique employed is a combination of the phase-path length difference and the Faraday rotation angle methods. Such a combination permits very accurate determination of the integration constant necessary to convert phase-path length difference data into information about the absolute value of the columnar content.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JPlPh..83c9006Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPlPh..83c9006Y"><span>Analytical research on the possibility of long orbital existence of submicron particles in the Earth's <span class="hlt">plasmasphere</span> by the methods of the KAM theory</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yakovlev, A. B.; Kolesnikov, E. K.; Chernov, S. V.</p> <p>2017-06-01</p> <p>Particles which move in the magnetosphere's plasma gain an electric charge which depends on the density and temperature of the plasma and the sunlight stream. If motion is slow enough, it is possible to consider that the micro-particle's electric charge is in quasi-equilibrium. For certain conditions, the Hamilton function can be written for the problem with a variable electric charge and, hence, the methods of the analysis of systems of Hamilton equations can be applied for research of such micro-particle motion. Although these conditions are strong enough, they correspond to the statement of many real problems. The spatial distribution of plasma in the Earth's <span class="hlt">plasmasphere</span> is described by a model of a two-component plasma. In the present paper, the capability of propagation of results which were received earlier for a case of the motion of a quasi-equilibrium electric charge in the Earth <span class="hlt">plasmasphere</span> has been shown. The received result shows that there is an opportunity for long orbital holding (not less than one month) of micro-particles of space dust in the Earth's <span class="hlt">plasmasphere</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMSA33A2185K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMSA33A2185K"><span>Use of ground-based and LEO GPS measurements to study the system of the ionosphere/<span class="hlt">plasmasphere</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Krankowski, A.; Zakharenkova, I.; Cherniak, I.</p> <p>2012-12-01</p> <p>The <span class="hlt">plasmaspheric</span> electron content (PEC) was estimated by comparison GPS observations and FORMOSAT-3/COSMIC radio occultation (RO) measurements at the extended solar minimum of cycle 23/24. GPS observations provide information about values of vertical total electron content (TEC) up to the metricconverterProductID20,200 km20,200 km. FORMOSAT-3/COSMIC now provides unprecedented global coverage of GPS RO measurements. Depending on the state of the constellation, COSMIC has been producing 1,500 - 2,500 good soundings of the ionosphere and atmosphere per day, uniformly distributed around the globe. This number of RO is much higher than even before. In this study, COSMIC RO data for different seasons corresponded to equinoxes and solstices of 2007-2009 (March, June, September and December) were analyzed. All selected COSMIC RO electron density profiles were integrated up to the height of metricconverterProductID700 km700 km (altitude of COSMIC satellites), in thatway the estimates of ionospheric electron content (IEC) were retrieved on a global scale. The final IGS combined global ionospheric maps (GIMs) were used to calculate the global maps of monthly medians of TEC values. As a result there were analyzed global distributions of GPS TEC and IEC estimates corresponded to the monthly median values for different seasons of 2007-2009. We consider the quantitative differences PEC = TEC - IEC as a measure of the contribution of the PEC to GPS TEC. In order to analyze seasonal behaviour of PEC contributionto GPS TEC at the different regions we selected several specific points with coordinates, corresponded to the approximate positions of different, mid-latitude and low-latitude, ionospheric sounding stations. Such points were selected at Northern America, European and Asian regions, Southern America, Southern Africa and country-region place Australia. For each specific points GPS TEC, COSMIC IEC and PEC estimates were analyzed. Results of our comparative study revealed that</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.4037C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.4037C"><span>Topside-<span class="hlt">plasmasphere</span> electron density profiles model by using AIS ionosonde measurements and calibrates GPS TEC data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cesaroni, Claudio; Scotto, Carlo; Ippolito, Alessandro; Ciraolo, Luigi</p> <p>2013-04-01</p> <p>The Upper Atmosphere Physics group at INGV (Istituto Nazionale di Geofisica e Vulcanologia) developed Autoscala, a computer program for automatic scaling of the critical frequency foF2 and other ionospheric parameters derived from ionograms. Autoscala includes a routine that automatically estimates the electron density profile below F layer peak height hmF2, by adjusting the parameters of a model according to the recorded ionogram [Scotto (2009)]. By integrating this profile we can estimate bottom-side total electron content (bTEC). By means of a calibration technique [Ciraolo et al. (2007)], we are able to obtain calibrated vertical TEC (vTEC) values from GPS measurements over a receiver station. This method permits to estimate biases of the received signal due to transmitter-receiver hardware configuration. These biases must be eliminated from the GPS data in order to calibrate the experimental slant total electron content (sTEC) along the satellite-receiver line-of-sight (LoS). The difference between vTEC and bottom-side TEC (bTEC) permits to evaluate electron content of the topside ionospheric region (tTEC). Starting from tTEC, bottom-side parameters (foF2, hmF2, scale height at hmF2) obtained by ionosonde and O+ - H+ transition level, we can solve a system of equations based on different ionospheric profiler (Chapman, sech-squared and exponential) the solution of which provides ion scale height [Stankov et al. (2003)]. This last factor is sufficient to establish the vertical distribution of electrons in topside and <span class="hlt">plasmasphere</span> regions. Obtained vertical profiles could be used to develop a new model for real time estimation of TEC and topside electron density distribution. References: Scotto, C. (2009). Electron density profile calculation technique for Autoscala ionogram analysis. Advances in Space Research, 44(6), 756-766. doi:10.1016/j.asr.2009.04.037 Ciraolo, L., et al. "Calibration errors on experimental slant total electron content (TEC) determined with</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160005845','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160005845"><span>The CuSPED Mission: CubeSat for GNSS Sounding of the Ionosphere-<span class="hlt">Plasmasphere</span> Electron Density</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gross, Jason N.; Keesee, Amy M.; Christian, John A.; Gu, Yu; Scime, Earl; Komjathy, Attila; Lightsey, E. Glenn; Pollock, Craig J.</p> <p>2016-01-01</p> <p>The CubeSat for GNSS Sounding of Ionosphere-<span class="hlt">Plasmasphere</span> Electron Density (CuSPED) is a 3U CubeSat mission concept that has been developed in response to the NASA Heliophysics program's decadal science goal of the determining of the dynamics and coupling of the Earth's magnetosphere, ionosphere, and atmosphere and their response to solar and terrestrial inputs. The mission was formulated through a collaboration between West Virginia University, Georgia Tech, NASA GSFC and NASA JPL, and features a 3U CubeSat that hosts both a miniaturized space capable Global Navigation Satellite System (GNSS) receiver for topside atmospheric sounding, along with a Thermal Electron Capped Hemispherical Spectrometer (TECHS) for the purpose of in situ electron precipitation measurements. These two complimentary measurement techniques will provide data for the purpose of constraining ionosphere-magnetosphere coupling models and will also enable studies of the local plasma environment and spacecraft charging; a phenomenon which is known to lead to significant errors in the measurement of low-energy, charged species from instruments aboard spacecraft traversing the ionosphere. This paper will provide an overview of the concept including its science motivation and implementation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSM51C2184O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSM51C2184O"><span>Building a Coupled Kinetic Framework for the Magnetosphere-Ionosphere-<span class="hlt">Plasmasphere</span>-Polar Wind-Superthermal Electron System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Omelchenko, Y.; Karimabadi, H.; Schunk, R. W.; Barakat, A. R.; Gardner, L. C.; Khazanov, G. V.; Glocer, A.; Kistler, L. M.</p> <p>2013-12-01</p> <p>Recent spacecraft observations have revealed that the critical plasma processes regulating mass and energy transfer in the magnetosphere take place at relatively thin ion-scale regions (e.g., bow shock, magnetopause, magnetotail) where kinetic ions control the physics. All parts of the magnetosphere are strongly coupled: the ionosphere's finite conductivity affects the field line tying as well as the size of the magnetosphere; multi-species ionospheric outflows limit the cross-polar cap potential, provide a sink for the energy flowing into the auroral region, modify the open/closed boundary during storms and substorms and determine the distribution of energetic particles in the ring current and plasma sheet. We propose to develop the next generation global modeling framework which will, for the first time, retain full ion kinetic effects throughout the entire magnetosphere. This will be achieved through coupling independent hybrid models for two separate parts of the magnetosphere: (i) the outer magnetosphere, modeled with a new asynchronous (event-driven) global hybrid code, HYPERS, and (ii) the ionosphere-<span class="hlt">plasmasphere</span>-polar-wind (IPPW) system, modeled with a different hybrid code coupled with a new superthermal electron (SE) transport model. Thus, in our asynchronous framework the HYPERS code will provide self-consistent electric field and ion flows (sinks) to the IPPW-SE model which will self-consistently compute ionospheric kinetic ion flows (sources) and conductivity to enable seamless continuation of the kinetic-ion physics towards the outer magnetosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoRL..43.2429M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoRL..43.2429M"><span>A new source of the midlatitude ionospheric peak density structure revealed by a new Ionosphere-<span class="hlt">Plasmasphere</span> model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Maruyama, Naomi; Sun, Yang-Yi; Richards, Phillip G.; Middlecoff, Jacques; Fang, Tzu-Wei; Fuller-Rowell, Timothy J.; Akmaev, Rashid A.; Liu, Jaun-Yeng; Valladares, Cesar E.</p> <p>2016-03-01</p> <p>The newly developed Ionosphere-<span class="hlt">Plasmasphere</span> (IP) model has revealed neutral winds as a primary source of the "third-peak" density structure in the daytime global ionosphere that has been observed by the low-latitude ionospheric sensor network GPS total electron content measurements over South America. This third peak is located near -30° magnetic latitude and is clearly separate from the conventional twin equatorial ionization anomaly peaks. The IP model reproduces the global electron density structure as observed by the FORMOSAT-3/COSMIC mission. The model reveals that the third peak is mainly created by the prevailing neutral meridional wind, which flows from the summer hemisphere to the winter hemisphere lifting the plasma along magnetic field lines to higher altitudes where recombination is slower. The same prevailing wind that increases the midlatitude density decreases the low-latitude density in the summer hemisphere by counteracting the equatorial fountain flow. The longitudinal variation of the three-peak structure is explained by the displacement between the geographic and geomagnetic equators.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AdSpR..38.1595S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AdSpR..38.1595S"><span>Enhancements of magnetospheric convection electric field associated with sudden commencements in the inner magnetosphere and <span class="hlt">plasmasphere</span> regions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shinbori, A.; Ono, T.; Iizima, M.; Kumamoto, A.; Nishimura, Y.</p> <p>2006-01-01</p> <p>Electric field variations in the inner magnetosphere and <span class="hlt">plasmasphere</span> regions associated with sudden commencements (SCs) are investigated by using the observation data of the Akebono satellite which has been carried out more than 15 years since 1989. 117 of 153 SC events in the low-latitude (MLAT < 45°) region, which occurred within a period from March 1989 to January 1996, showed a shift of the magnetospheric convection electric field with the magnitude of 0.1 3.2 mV/m about 1 min after the electric field signature with a bi-polar waveform due to the passage of fast-mode hydromagnetic (HM) waves. The increase of the convection electric field takes place in the entire magnetic local time sector in the inner magnetosphere. The amplitude does not depend on L-value and magnetic local time but is proportional to the SC amplitude measured at Kakioka. The majority of the electric field enhancements persist for about 4 14 min. The origin of the convection electric field in the inner magnetosphere is a plasma motion caused by the compression of the magnetosphere due to the solar wind shock and discontinuity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19740012354','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19740012354"><span>Studies of the structure of the <span class="hlt">plasmasphere</span> as seen by radiosounder measurements aboard the Alovetti-satellite</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Banks, P. M.; Doupnik, J. R.</p> <p>1973-01-01</p> <p>The structure of the <span class="hlt">plasmasphere</span> was studied as seen by radiosounder measurements aboard the Alovetti-2 satellite. Magnetic tape data files were obtained from the NASA Ames Research Center to give a reasonably complete set of high latitude electron density profiles. Considerable effort was expended to develop models of ion flow in the topside ionosphere. These models took both H(+) and O(+) into account and permitted various parameter studies to be made of the various factors which affect H(+) escape in polar wind flows. The results of these studies are included. Extensive computer programs were written to display the measured electron density profiles in ways useful to geophysical analysis. The expected mid-latitude trough was easily discernable in the nightime ionosphere at locations expected from similar observations of the plasmapause. In the dayside ionosphere, however, it proved extremely difficult to find any trough-like phenomena. Using the previously developed computer models, it was possible to study the region where the plasmapause appeared to be absent. It was found that over much of the dayside, large fluxes were computed well inside the plasmapause extending down to L-shells as low as 2.5.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18254744','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18254744"><span>The giant Madagascar <span class="hlt">hissing</span>-cockroach (Gromphadorhina portentosa) as a source of antagonistic moulds: concerns arising from its use in a public setting.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yoder, Jay A; Glenn, Brian D; Benoit, Joshua B; Zettler, Lawrence W</p> <p>2008-03-01</p> <p>Cockroaches and their excreta have been linked to allergies and childhood asthma. The giant Madagascar <span class="hlt">hissing</span>-cockroach (Gromphadorhina portentosa), heralded as an educational tool in classrooms, museums, zoos, is now available to the public as a children's pet raising health concerns. We provide a catalogue of potentially antagonistic moulds associated with this insect. Specimens were obtained from laboratories, classrooms, pet stores and private homes. Three different agar media were used to culture moulds from both internal and external cockroach surfaces. Pure cultures were obtained from hyphal tips excised by scalpel. A total of 14 mould taxa were obtained, mostly from external surfaces. The mycoflora was dominated by species of Rhizopus, Penicillium, Mucor, Trichoderma and Alternaria, and differed little among nymphs, adults, cast skins (exuviae) and faeces. A two-fold increase of Aspergillus niger isolates, however, was detected in exuviae and faeces. The mycoflora appeared to be equally distributed on the body regions in nymphs and adults alike. Most of the moulds recovered are common, well-known saprophytes with a prolific ability to produce asexual spores (e.g. conidia) when supplied with adequate moisture and an organic substrate (e.g. vegetable matter, pet food and exuviae). Cockroach rearing conditions thus serve as an ideal environment for mould growth and proliferation, and the subsequent use (handling) of these insects in a public forum increases the risk of inducing mould-related allergies in humans. Of special concern are moulds also capable of causing secondary infections (e.g. Rhizopus, Mucor, Aspergillus), gaining entry via open wounds and inhalation. This is mainly a point of public awareness aimed at individuals (especially children) prone to infections and allergies that might be exposed to this insect and/or its rearing conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27126627','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27126627"><span>First protein and peptide characterization of the tarsal adhesive secretions in the desert locust, Schistocerca gregaria, and the Madagascar <span class="hlt">hissing</span> cockroach, Gromphadorhina portentosa.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Betz, O; Maurer, A; Verheyden, A N; Schmitt, C; Kowalik, T; Braun, J; Grunwald, I; Hartwig, A; Neuenfeldt, M</p> <p>2016-10-01</p> <p>Peptides and proteins have been largely neglected in the analysis of insect tarsal adhesives. After extraction of the protein fraction of the tarsal secretion of the desert locust, Schistocerca gregaria, and Madagascar <span class="hlt">hissing</span> cockroach, Gromphadorhina portentosa, we combined Fourier transform infrared spectroscopy (FTIR), sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS) analyses for protein mass detection. In both these insects, SDS-PAGE analysis revealed several protein bands ranging from 8-190 kDa in both the tarsal secretion and the tibia control sample. Two (S. gregaria) and one (G. portentosa) protein bands exclusively occurred in the tarsal secretion and can be considered to belong to peptides and proteins specific to this secretion. MALDI-TOF analyses revealed 83 different proteins/peptides of 1-7 kDa in S. gregaria, and 48 of 1-11 kDa in G. portentosa. 59 (S. gregaria) and 27 (G. portentosa) proteins exclusively occurred in the tarsal secretion. In G. portentosa, a characteristic series of signal peaks occurred in the range of c. 10-12 kDa, each peak being approximately 160 Da apart. Such a pattern is indicative of proteins modified by glycosylation. Our approach demonstrates that extensive sampling involving considerable time and manpower to sample the adhesive fluid directly from the tarsi opens up a perspective for extracting peptides and proteins in sufficient quantities. This makes them accessible to the field of proteomics and thus to elucidate their possible function in the adhesive process. © 2016 The Royal Entomological Society.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMSA34A..04Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMSA34A..04Z"><span>Remote sensing of the <span class="hlt">plasmasphere</span> mass density using conjugate magnetometer chains SAMBA, MEASURE, and McMAC</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zesta, E.; Boudouridis, A.; Moldwin, M.; Chi, P. J.; Jorgensen, A. M.; McCarthy, N. M.</p> <p>2010-12-01</p> <p>The SAMBA (South American Meridional B-field Array) chain is a Southern Hemisphere meridional chain of 12 magnetometers, 11 of them at L=1.1 to L=2.5 along the coast of Chile and in the Antarctica peninsula, and one auroral station along the same meridian. SAMBA is ideal for low and mid-latitude studies of geophysical events and ULF waves. The MEASURE (Magnetometers along the Eastern Atlantic Seaboard for Undergraduate Research and Education) and McMAC (Mid-continent Magnetoseismic Chain) chains are Northern Hemisphere meridional chains in the same local time as SAMBA, but cover low to sub-auroral latitudes. SAMBA is partly conjugate to MEASURE and McMAC chains, offering unique opportunities for inter-hemispheric studies. We use 5 of the SAMBA stations and an even larger number of conjugate stations from the Northern hemisphere to determine the field line resonance (FLR) frequency of closely spaced flux tubes in the inner magnetosphere. Standard inversion techniques are used to derive the equatorial mass density of these flux tubes from the FLRs. We thus yield the mass density distribution of the <span class="hlt">plasmasphere</span> for specific events and compare our results with the empirical model of Berube and Moldwin [2005]. Limited prior results have shown that the derived mass density of closely spaced flux tubes, from L=1.6 to L=2.5, drops at a rate that cannot be predicted by any of the existing models or agree with past observations. We now assemble a much larger latitude range with better latitudinal spacing, that allow for more accurate comparisons. We also compare our derived mass density distribution with that predicted by the FLIP thermosphere-ionosphere model. We find that for moderate activity the model determined FLR radial distribution is in excellent agreement with the observed distribution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004JASTP..66...89P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004JASTP..66...89P"><span>Comparison of the measured and modeled electron densities and temperatures in the ionosphere and <span class="hlt">plasmasphere</span> during 14-16 May 1991</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pavlov, A. V.; Pavlova, N. M.</p> <p>2004-01-01</p> <p>The electron density and temperature in the ionosphere and <span class="hlt">plasmasphere</span> measured by the Millstone Hill incoherent-scatter radar and the instruments on board of the EXOS-D satellite are compared with calculations from a time-dependent mathematical model of the Earth's ionosphere and <span class="hlt">plasmasphere</span> during 14-16 May 1991. Use of [O]/[N2] correction factors with the NRLMSISE-00 model of the neutral atmosphere was found to bring the modeled and measured F-region main peak electron densities into agreement. It was found that the nighttime additional heating rate should be added to the normal photoelectron heating in the electron energy equation, in the nighttime <span class="hlt">plasmasphere</span> region, in order for the model to reproduce the observed high <span class="hlt">plasmaspheric</span> electron temperature within the Millstone Hill magnetic field flux tube in the Northern Hemisphere. The additional heating brings the measured and modeled electron temperatures into agreement in the <span class="hlt">plasmasphere</span> and into a very large disagreement in the ionosphere, if the classical electron heat flux along magnetic field lines is used. An approach of Pavlov et al. (2000, 2001) based on a new effective electron thermal conductivity coefficient along the magnetic field line and the evaluated additional heating of electrons in the <span class="hlt">plasmasphere</span> is used to explain the observed electron temperature in the ionosphere and <span class="hlt">plasmasphere</span>. This approach leads to a heat flux which is less than that given by the classical theory. The effects of the additional <span class="hlt">plasmaspheric</span> heating of electrons on the electron temperature and density are small at the F-region altitudes if the modified electron heat flux is used. We found that the resulting effect of vibrationally excited N2 and O2 on NmF2 is the decrease of the calculated NmF2 by up to a factor of about 2.7 by day and up to a factor of about 2.5 by night. The modeled electron temperature is very sensitive to the electron density, and this decrease in electron density results in an increase of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19790026580&hterms=test+particle+simulation+space+plasmas&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dtest%2Bparticle%2Bsimulation%2Bspace%2Bplasmas','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19790026580&hterms=test+particle+simulation+space+plasmas&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dtest%2Bparticle%2Bsimulation%2Bspace%2Bplasmas"><span>Modification of a very large thermal-vacuum test chamber for ionosphere and <span class="hlt">plasmasphere</span> simulation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pearson, O. L.</p> <p>1978-01-01</p> <p>No large-volume chamber existed which could simulate the ion and electron environment of near-earth space. A very large thermal-vacuum chamber was modified to provide for the manipulation of the test volume magnetic field and for the generation and monitoring of plasma. Plasma densities of 1 million particles per cu cm were generated in the chamber where a variable magnetic flux density of up to 0.00015 T (1.5 gauss) was produced. Plasma temperature, density, composition, and visual effects were monitored, and plasma containment and control were investigated. Initial operation of the modified chamber demonstrated a capability satisfactory for a wide variety of experiments and hardware tests which require an <span class="hlt">interaction</span> with the plasma environment. Potential for improving the quality of the simulation exists.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910001128','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910001128"><span>Properties of large scale plasma flow during the early stage of the <span class="hlt">plasmaspheric</span> refilling</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Singh, Nagendra; Craven, P.; Torr, D. G.; Richards, P. G.</p> <p>1990-01-01</p> <p>The objective is to better characterize the macroscopic properties of the interhemisphere plasma flow by solving a more complete set of hydrodynamic equations than that solved previously. Specifically, the ion continuity, momentum and energy equations were solved for the plasma flow along the closed magnetic field lines. During the initial stage of the supersonic outflow in the equatorial region, the ions cool substantially. Using the hydrodynamic model for the large-scale plasma flow, the dynamics of shocks was examined which form in the geomagnetic flux tubes during the early stages of refilling. These shocks are more like those forming in neutral gases than the electrostatic shocks driven by microinstabilities involving ion-ion <span class="hlt">interaction</span>. Therefore, the shocks seen in the hydrodynamic model are termed as hydrodynamic shocks. Such shocks are generally unsteady and therefore the usual shock jump conditions given by Rankine-Hugoniot relations are not strictly applicable to them. The density, flow velocity and temperature structures associated with the shocks are examined for both asymmetrical and symmetrical flows. In the asymmetrical flow the outflow from one of two conjugate ionospheres is dominant. On the other hand, in the symmetrical case outflows from the two ionospheric sources are identical. Both cases are treated by a two-stream model. In the late type of flow, the early-time refilling shows a relaxation type of oscillation, which is driven by the large-scale <span class="hlt">interactions</span> between the two identical streams. After this early stage, the resulting temperature structure shows some interesting features. In the equatorial region the streams are isothermal, but in the off-equatorial regions the streams have quite different temperatures, and also densities and flow velocities. The dense and slow stream is found to be warmer than the low-density fast stream. In the late stage of refilling, the temperature is found to steadily increase from the conjugate</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRA..12010640L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRA..12010640L"><span>Semiannual and solar activity variations of daytime plasma observed by DEMETER in the ionosphere-<span class="hlt">plasmasphere</span> transition region</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, L. Y.; Cao, J. B.; Yang, J. Y.; Berthelier, J. J.; Lebreton, J.-P.</p> <p>2015-12-01</p> <p>Using the plasma data of Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions (DEMETER) satellite and the NRLMSISE-00 atmospheric model, we examined the semiannual and solar activity variations of the daytime plasma and neutral composition densities in the ionosphere-<span class="hlt">plasmasphere</span> transition region (~670-710 km). The results demonstrate that the semiannually latitudinal variation of the daytime oxygen ions (O+) is basically controlled by that of neutral atomic oxygen (O), whereas the latitude distributions of the helium and hydrogen ions (He+ and H+) do not fully depend on the neutral atomic helium (He) and hydrogen (H). The summer enhancement of the heavy oxygen ions is consistent with the neutral O enhancement in the summer hemisphere, and the oxygen ion density has significantly the summer-dense and winter-tenuous hemispheric asymmetry with respect to the dip equator. Although the winter enhancements of the lighter He+ and H+ ions are also associated with the neutral He and H enhancements in the winter hemisphere, the high-density light ions (He+ and H+) and electrons (e-) mainly appear at the low and middle magnetic latitudes (|λ| < 50°). The equatorial accumulations of the light plasma species indicate that the light charged particles (He+, H+, and e-) are easily transported by some equatorward forces (e.g., the magnetic mirror force and centrifugal force). The frequent Coulomb collisions between the charged particles probably lead to the particle trappings at different latitudes. Moreover, the neutral composition densities also influence their ion concentrations during different solar activities. From the low-F10.7 year (2007-2008) to the high-F10.7 year (2004-2005), the daytime oxygen ions and electrons increase with the increasing neutral atomic oxygen, whereas the daytime hydrogen ions tend to decrease with the decreasing neutral atomic hydrogen. The helium ion density has no obvious solar activity variation, suggesting that the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003AnGeo..21.1601P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003AnGeo..21.1601P"><span>New method in computer simulations of electron and ion densities and temperatures in the <span class="hlt">plasmasphere</span> and low-latitude ionosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pavlov, A. V.</p> <p>2003-07-01</p> <p>A new theoretical model of the Earth’s low- and mid-latitude ionosphere and <span class="hlt">plasmasphere</span> has been developed. The new model uses a new method in ionospheric and <span class="hlt">plasmaspheric</span> simulations which is a combination of the Eulerian and Lagrangian approaches in model simulations. The electron and ion continuity and energy equations are solved in a Lagrangian frame of reference which moves with an individual parcel of plasma with the local plasma drift velocity perpendicular to the magnetic and electric fields. As a result, only the time-dependent, one-dimension electron and ion continuity and energy equations are solved in this Lagrangian frame of reference. The new method makes use of an Eulerian computational grid which is fixed in space co-ordinates and chooses the set of the plasma parcels at every time step, so that all the plasma parcels arrive at points which are located between grid lines of the regularly spaced Eulerian computational grid at the next time step. The solution values of electron and ion densities Ne and Ni and temperatures Te and Ti at the Eulerian computational grid are obtained by interpolation. Equations which determine the trajectory of the ionospheric plasma perpendicular to magnetic field lines and take into account that magnetic field lines are frozen in the ionospheric plasma are derived and included in the new model. We have presented a comparison between the modeled NmF2 and hmF2 and NmF2 and hmF2 which were observed at the anomaly crest and close to the geomagnetic equator simultaneously by the Huancayo, Chiclayo, Talara, Bogota, Panama, and Puerto Rico ionospheric sounders during the 7 October 1957 geomagnetically quiet time period at solar maximum. The model calculations show that there is a need to revise the model local time dependence of the equatorial upward E × B drift velocity given by Scherliess and Fejer (1999) at solar maximum during quiet daytime equinox conditions. Uncertainties in the calculated Ni , Ne , Te , and Ti</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1987ApJ...314..176M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1987ApJ...314..176M"><span>The <span class="hlt">HISS</span> of BL Lacertae</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moore, Richard L.; Schmidt, Gary D.; West, Steven C.</p> <p>1987-03-01</p> <p>The polarimetric variability of BL Lacertae is characterized by a random-walk noise spectrum on time scales of hours to weeks. The authors present here approximately 12 hr of polarimetric data obtained on three nights in 1983 - 1984 with the Hale 5 m telescope, which push our knowledge of the variability to the shortest time scales currently possible. During each of the runs, BL Lac was consistently variable. Power spectra of the variations in degree and position angle of polarization roughly follow power laws of index α ≈ 3±1 between time scales of 15 minutes to 3 hours. In the context of the "Christmas tree" model of variations, the steep spectrum at high frequencies suggests a lower limit near 1 light-hr for the size of individual components.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997PhRvC..56.1536C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997PhRvC..56.1536C"><span>Systematics of isotopic production cross sections from <span class="hlt">interactions</span> of relativistic 40Ca in hydrogen</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, C.-X.; Albergo, S.; Caccia, Z.; Costa, S.; Crawford, H. J.; Cronqvist, M.; Engelage, J.; Greiner, L.; Guzik, T. G.; Insolia, A.; Knott, C. N.; Lindstrom, P. J.; McMahon, M.; Mitchell, J. W.; Potenza, R.; Russo, G. V.; Soutoul, A.; Testard, O.; Tull, C. E.; Tuvé, C.; Waddington, C. J.; Webber, W. R.; Wefel, J. P.</p> <p>1997-09-01</p> <p>The isotopic production cross sections for 40Ca projectiles at 357, 565, and 763 MeV/nucleon <span class="hlt">interacting</span> in a liquid hydrogen target have been measured by the Transport Collaboration at the LBL <span class="hlt">HISS</span> facility. The systematics of these cross sections are studied, and the results indicate that nuclear structure effects are present in the isotope production process during the relativistic collisions. The newly measured cross sections are also compared with those predicted by semiempirical and parametric formulas, but the predictions do not fully describe the systematics such as the energy dependence. The consequences of the cross section systematics in galactic cosmic ray studies are also discussed.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1988AdSpR...8...25F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1988AdSpR...8...25F"><span>GEOS 1 observations of low-energy ions in the earth's <span class="hlt">plasmasphere</span> - A study on composition, and temperature and density structure under quiet geomagnetic conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Farrugia, C. J.; Geiss, J.; Balsiger, H.; Young, D. T.</p> <p></p> <p>Data are presented on the composition and the temperature (T) and density (N) distributions of the earth's <span class="hlt">plasmasphere</span> ionic population, obtained from GEOS 1 thermal-ion data. In deriving the N and T of the ions, a novel technique was employed, which is based on the modulation of the count rates by the spacecraft's spin. It was found that, for the major ion species H(+) and He(+), the relative density abundance He(+)/H(+) value of several percent was fairly common; the H(+) and He(+) ions are generally in thermal equilibrium, with temperatures varying between 4000 and 15,000 K, with a tendency to increase with L value. A comparison of the thermal structure obtained with those obtained by the Plasma Composition Experiment on ISEE and the Retarding Ion Mass Spectrometer on DE 1 showed no systematic difference between the 'energy' techniques used in these studies and the present 'angular' technique.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1985EOSTr..66.1181F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1985EOSTr..66.1181F"><span>Reply to [“Comment on “There is no magnestosphere...nor is there a <span class="hlt">plasmasphere</span>!’”</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fraser-Smith, A. C.</p> <p></p> <p>Despite the thorough introduction to four-letter words being given to our children at an early age by the television and recording industries, it is difficult to avoid the impression that accuracy in the use of words is declining in our society. Indeed, Orwellian doublespeak has become the norm at the leadership level: we all know what tax reform really means, for example. With this background, it is a pleasure to see Behannon and Anderson consulting their dictionaries and taking me to task for my literal interpretation of the “sphere” in magnetosphere and <span class="hlt">plasmasphere</span>. However, I had earlier rejected the “sphere of influence,” or “place or range of action or existence” connotation, and I continue to do so, for the following reasons.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AGUFMSA11B..02M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AGUFMSA11B..02M"><span>CRRES and DMSP Observations of Wave and Plasma Disturbances Associated with the Stormtime Ring Current in the <span class="hlt">Plasmasphere</span> and Topside Ionosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mishin, E. V.; Burke, W. J.</p> <p>2004-12-01</p> <p>We report on wave and plasma disturbances observed by Combined Release and Radiation Effects (CRRES) and Defense Meteorological Satellite Program (DMSP) satellites during the magnetic storm of June 5, 1991 in the region of ring current/<span class="hlt">plasmasphere</span> overlap and the conjugate topside ionosphere During three ring current nose encounters near L = 2.4, the <span class="hlt">plasmasphere</span> was highly-structured. A rich variety of wave phenomena were observed simultaneous with enhanced fluxes of low-energy (< ˜ 1 keV) electrons and ions, indicating the wave heating/acceleration source. Earthward of the plasma sheet boundary, which was near L = 5.5, wave-like structures in the dawn-to-dusk electric field with spatial wave-lengths from about 300 to 1000 km and magnitudes of ~1-3 mV/m were apparent. Mapped to ionospheric altitudes, these fields should produce broad irregular SAPS with average sunward velocities ~ 1 km/s. At about the same time DMSP F8, F9, and F10 indeed observed highly-structured SAPS in the topside ionosphere coincident with precipitating ring current ions, enhanced fluxes of suprathermal electrons and ions, elevated electron temperatures, and deep highly-irregular density troughs. Overall, these events represent the so-called strong wave-SAPS phenomenon [Mishin et al., JGR (2003), 108, 1309, 10.1029/2002JA009793]. Their importance for Space Weather is indicated by strong GPS phase and amplitude scintillations observed over the continental US [Basu et al., JGR, 106, 30389, 2001; Ledvina et al., GRL, 29, 10.1029/2002GL014770] coincident with similar events.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1394991-low-energy-lt-ev-electron-acceleration-ulf-waves-plasmaspheric-boundary-layer-van-allen-probes-observation','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1394991-low-energy-lt-ev-electron-acceleration-ulf-waves-plasmaspheric-boundary-layer-van-allen-probes-observation"><span>Low-energy (< 200 eV) electron acceleration by ULF waves in the <span class="hlt">plasmaspheric</span> boundary layer: Van Allen Probes observation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Ren, Jie; Zong, Q. G.; Miyoshi, Y.; ...</p> <p>2017-08-30</p> <p>Here, we report observational evidence of cold plamsmaspheric electron (< 200 eV) acceleration by ultra-low-frequency (ULF) waves in the <span class="hlt">plasmaspheric</span> boundary layer on 10 September 2015. Strongly enhanced cold electron fluxes in the energy spectrogram were observed along with second harmonic mode waves with a period of about 1 minute which lasted several hours during two consecutive Van Allen Probe B orbits. Cold electron (<200 eV) and energetic proton (10-20 keV) bi-directional pitch angle signatures observed during the event are suggestive of the drift-bounce resonance mechanism. The correlation between enhanced energy fluxes and ULF waves leads to the conclusions thatmore » <span class="hlt">plasmaspheric</span> dynamics is strongly affected by ULF waves. Van Allen Probe A and B, GOES 13, GOES 15 and MMS 1 observations suggest ULF waves in the event were strongest on the dusk-side magnetosphere. Measurements from MMS 1 contain no evidence of an external wave source during the period when ULF waves and injected energetic protons with a bump-on-tail distribution were detected by Van Allen Probe B. This suggests that the observed ULF waves were probably excited by a localized drift-bounce resonant instability, with the free energy supplied by substorm-injected energetic protons. The observations by Van Allen Probe B suggest that energy transfer between particle species in different energy ranges can take place through the action of ULF waves, demonstrating the important role of these waves in the dynamical processes of the inner magnetosphere.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002AGUFMSM51A0506Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002AGUFMSM51A0506Z"><span>Effects of Wave-Particle <span class="hlt">Interactions</span> on Radiation Belt Development</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zheng, Y.; Fok, M.; Khazanov, G. V.; Ober, D. M.; Gallagher, D. L.</p> <p>2002-12-01</p> <p>In this presentation, the effects of wave-particle <span class="hlt">interactions</span> on radiation belt development will be investigated. The tool of this investigation is the kinetic Radiation Belt model that solves the convection-diffusion equation of plasma distributions in the 10keV to MeV range, with the addition of a <span class="hlt">plasmasphere</span> model and a diffusion coefficient model. The boundary condtions of the Radiation Belt model are driven by solar wind and IMF. The purpose of the <span class="hlt">plasmasphere</span> model is to provide the density profile of the cold core plasma, which is used in the diffusion coefficient model for calculating the diffusion coefficients of different types of wave-particle <span class="hlt">interactions</span>. Therefore the effects of wave-particle <span class="hlt">interactions</span> on the development of the Radiation Belt can be incorporated and modeled in a more realistic fashion. We will present the model logic and the model validation by comparing measured particle fluxes with the model calculations for several magnetic storms. We hope, through this modeling effort, that the comparison study will shed light on the evolution of the Radiation Belt and on the contribution of different physical processes involved, particularly wave-particle <span class="hlt">interactions</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19750062163&hterms=cold+plasma&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dcold%2Bplasma','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19750062163&hterms=cold+plasma&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dcold%2Bplasma"><span>Hot-cold plasma <span class="hlt">interactions</span> in the earth's magnetosphere</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Williams, D. J.</p> <p>1975-01-01</p> <p>The paper gives a synopsis of observations and results obtained from the Explorer-45 satellite which pertain directly to the <span class="hlt">interaction</span> of the magnetospheric hot and cold plasma populations. The specific case discussed is the <span class="hlt">interaction</span> of the hot ring current plasma with the cold <span class="hlt">plasmaspheric</span> plasma in the evening to early morning local time sector during magnetic storm recovery phase. It was found that above the plasmapause region, the hot ring current plasma is stable with negligible losses due to pitch angle diffusion; the hot ring current plasma enters a moderate pitch angle regime in the plasmapause region, whereby the addition of cold plasma destabilizes the hot plasma. Analysis of the energy, spatial, and temporal dependence of the above destabilization along with the ion-cyclotron resonant energy equation, and comparison of this analysis with an in situ estimate of the plasma density strongly indicate that the mechanism responsible for destabilization of the hot plasma is the amplification of ion-cyclotron waves due to the <span class="hlt">interaction</span> of the cold <span class="hlt">plasmaspheric</span> plasma with the hot ring current plasma in a manner similar to that discussed by Cornwall et al. (1970).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19750062163&hterms=cold+hot&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dcold%2Bhot','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19750062163&hterms=cold+hot&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dcold%2Bhot"><span>Hot-cold plasma <span class="hlt">interactions</span> in the earth's magnetosphere</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Williams, D. J.</p> <p>1975-01-01</p> <p>The paper gives a synopsis of observations and results obtained from the Explorer-45 satellite which pertain directly to the <span class="hlt">interaction</span> of the magnetospheric hot and cold plasma populations. The specific case discussed is the <span class="hlt">interaction</span> of the hot ring current plasma with the cold <span class="hlt">plasmaspheric</span> plasma in the evening to early morning local time sector during magnetic storm recovery phase. It was found that above the plasmapause region, the hot ring current plasma is stable with negligible losses due to pitch angle diffusion; the hot ring current plasma enters a moderate pitch angle regime in the plasmapause region, whereby the addition of cold plasma destabilizes the hot plasma. Analysis of the energy, spatial, and temporal dependence of the above destabilization along with the ion-cyclotron resonant energy equation, and comparison of this analysis with an in situ estimate of the plasma density strongly indicate that the mechanism responsible for destabilization of the hot plasma is the amplification of ion-cyclotron waves due to the <span class="hlt">interaction</span> of the cold <span class="hlt">plasmaspheric</span> plasma with the hot ring current plasma in a manner similar to that discussed by Cornwall et al. (1970).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/956478','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/956478"><span>Electron loss rates from the outer radiation belt caused by the filling of the outer <span class="hlt">plasmasphere</span>: the calm before the storm</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Borovsky, Joseph E; Denton, Michael H</p> <p>2009-01-01</p> <p>Measurements from 7 spacecraft in geosynchronous orbit are analyzed to determine the decay rate of the number density of the outer electron radiation belt prior to the onset of high-speed-stream-driven geomagnetic storms. Superposed-data analysis is used wan(?) a collection of 124 storms. When there is a calm before the storm, the electron number density decays exponentially before the storm with a 3.4-day e-folding time: beginning about 4 days before storm onset, the density decreases from {approx}4x10{sup -4} cm{sup -3} to {approx}1X 10{sup -4} cm{sup -3}. When there is not a calm before the storm, the number-density decay is very smalL The decay in the number density of radiation-belt electrons is believed to be caused by pitch-angle scattering of electrons into the atmospheric loss cone as the outer <span class="hlt">plasmasphere</span> fills during the calms. While the radiation-belt electron density decreases, the temperature of the electron radiation belt holds approximately constant, indicating that the electron precipitation occurs equally at all energies. Along with the number density decay, the pressure of the outer electron radiation belt decays and the specific entropy increases. From the measured decay rates, the electron flux to the atmosphere is calculated and that flux is 3 orders of magnitude less than thermal fluxes in the magnetosphere, indicating that the radiation-belt pitch-angle scattering is 3 orders weaker than strong diffusion. Energy fluxes into the atmosphere are calculated and found to be insufficient to produce visible airglow.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUSMSA22A..04E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUSMSA22A..04E"><span>Matching CHAMP and C/NOFS Climatology at Low Latitudes with the ionosphere-thermosphere TIEGCM and the <span class="hlt">plasmasphere</span> GIP Models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Emery, B. A.; Bhaneja, P.; Bilitza, D.; Chau, J. L.; Coley, W. R.; Drob, D. P.; Fang, T.; Fejer, B. G.; Foster, B. T.; Haeusler, K.; Jones, M.; Klenzing, J.; Luhr, H.; Retterer, J. M.; Richmond, A. D.; Roddy, P. A.; Stoneback, R.; Su, Y.; Wu, Q.; Zhang, X.</p> <p>2013-05-01</p> <p>The equatorial orbiting Communications/Navigation Outage Forecasting System (C/NOFS) satellite observations from 400-800km started in mid-2008 in a period of deep solar minimum where the 10.7 cm solar radio flux flattened out around 67. By 2012, the solar flux increased to about 135. The polar orbiting CHAllenging Minisatellite Payload (CHAMP) satellite observations between about 410-310km above the equator are available from 2000 to 2010 from high to very low solar flux conditions. CHAMP Planar Langmuir Probe (PLP) observations of the electron density and temperature and the instrument measuring neutral cross-track winds (mostly zonal) are used. C/NOFS PLP, Ion Velocity Meter (IVM), and Vector Electric Field Instrument (VEFI) observations are used. The IVM package gives cross-track ExB ion drifts (meridional/upward and perpendicular) which can be mapped to the magnetic equator, along with a Retarding Potential Analyzer (RPA) for along-track ion drifts (zonal), plus [O+] composition and ion temperatures. VEFI also gives meridional/upward and zonal ion drifts. We compare climatological observations in equinox and winter with empirical models, and with the first-principles model estimates from the Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIEGCM), coupled with the Global Ionosphere-<span class="hlt">Plasmasphere</span> (GIP) model, with various tidal forcings from the lower atmosphere. We compare longitude variations as well as local time zonal averages between the observations and model results. We also compare with ground observations of the meridional/upward and zonal ion drifts from the magnetic equator at Jicamarca, Peru.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AdSpR..60..222Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AdSpR..60..222Z"><span>Comparison of the observed topside ionospheric and <span class="hlt">plasmaspheric</span> electron content derived from the COSMIC podTEC measurements with the IRI_Plas model results</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Man-Lian; Liu, Libo; Wan, Weixing; Ning, Baiqi</p> <p>2017-07-01</p> <p>In this paper, variations of the topside ionospheric and <span class="hlt">plasmaspheric</span> electron contents (TPEC) in the altitude range of ∼800 to 20,200 km are compared with the IRI_Plas model results for the low (2008) and high (2012) solar activity years using TEC data (podTEC) derived from the upward-looking precise orbit determination antenna on board COSMIC low Earth orbit (LEO) satellites tracking the GPS signals. For each year, the dataset were divided into groups according to four seasons: M-Equinox (March, April), J-Solstice (May June, July and August), S-Equinox (September, October) and D-Solstice (January, February, November, and December). Our study showed that the IRI_Plas model is able to reproduce reasonably well the main features of the observational TPEC's latitudinal, diurnal as well as seasonal variation tendency when no longitudinal difference is taken into account. However, there exist discrepancies between the observational TPEC and the model results. Except for the daytime hours in the Equinoctial seasons of the high solar activity year 2012 when the IRI_Plas model results showed an overestimation, in general, the IRI_Plas model results underestimate the observational ones, in particular at nighttime hours in the low-latitude region. When the longitudinal difference is taken into account, the comparison study showed that the longitudinal dependence effect shown in the observational TPEC's seasonal variations was not captured by the IRI_Plas model result. Moreover, the IRI_Plas model results tend to show a double-peak structure in the low-latitude region, a feature not appearing in the observational results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSM43B2306M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSM43B2306M"><span><span class="hlt">Interaction</span> of Substorm Injections with the Subauroral Geospace</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mishin, E. V.</p> <p>2013-12-01</p> <p>The subauroral geospace includes the ring current (RC), innermost part of the outer radiation belt, and <span class="hlt">plasmasphere</span> adjacent to the electron plasma sheet boundary and conjugate ionosphere. The purpose of this paper is to extend understanding of the active subauroral geospace by exploring subauroral events in the near-equatorial magnetosphere and conjugate ionosphere soon after the onsets of individual substorms. Their fast appearance is consistent with the propagation of substorm injections. The documented features in the premidnight sector are described in terms of the effect of a short circuit of substorm-injected plasma jets over the plasmapause. The short-circuiting occurs when the cold plasma density exceeds a critical value of 5-10 c.c. As the polarization field at the front of the hot plasma jet is shorten out, the hot electrons are arrested, while the hot ions yet move inward. This provides a natural explanation of the long-known dispersionless auroral electron precipitation boundary and the SAID location just interior to the plasmapause. Enhanced plasma turbulence provides anomalous circuit resistivity and magnetic diffusion leading to a turbulent boundary layer adjacent to the plasmapause. The hot ions' inward motion stops when their pressure gradient is balanced by the polarization electric field. Then, the ions experiencing gradient-curvature drift move westward and their <span class="hlt">interaction</span> with the <span class="hlt">plasmasphere</span> creates strong wave structures on the duskside.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25728659','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25728659"><span>Contact solid-phase microextraction with uncoated glass and polydimethylsiloxane-coated fibers versus solvent sampling for the determination of hydrocarbons in adhesion secretions of Madagascar <span class="hlt">hissing</span> cockroaches Gromphadorrhina portentosa (Blattodea) by gas chromatography-mass spectrometry.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gerhardt, Heike; Schmitt, Christian; Betz, Oliver; Albert, Klaus; Lämmerhofer, Michael</p> <p>2015-04-03</p> <p>Molecular profiles of adhesion secretions of Gromphadorrhina portentosa (Madagascar <span class="hlt">hissing</span> cockroach, Blattodea) were investigated by gas chromatography mass spectrometry with particular focus on a comprehensive analysis of linear and branched hydrocarbons. For this purpose, secretions from the tarsi (feet), possibly contributing to adhesion on smooth surfaces, and control samples taken from the tibiae (lower legs), which contain general cuticular hydrocarbons that are supposed to be not involved in the biological adhesion function, were analyzed and their molecular fingerprints compared. A major analytical difficulty in such a study constitutes the representative, spatially controlled, precise and reproducible sampling from a living insect as well as the minute quantities of insect secretions on both tarsi and tibiae. Thus, three different in vivo sampling methods were compared in terms of sampling reproducibility and extraction efficiency by replicate measurement of samples from tarsi and tibiae. While contact solid-phase microextraction (SPME) with a polydimethylsiloxane (PDMS) fiber showed higher peak intensities, a self-made uncoated glass fiber had the best repeatability in contact-SPME sampling. Chromatographic profiles of these two contact-SPME sampling methods were statistically not significantly different. Inter-individual variances were larger than potentially existing minor differences in molecular patterns of distinct sampling methods. Sampling by solvent extraction was time consuming, showed lower sensitivities and was less reproducible. In general, sampling by contact-SPME with a cheap glass fiber turned out to be a viable alternative to PDMS-SPME sampling. Hydrocarbon patterns of the tarsal adhesion secretions were qualitatively similar to those of epicuticular hydrocarbon profiles of the tibiae. However, hydrocarbons were in general less abundant in tarsal secretions than secretions from tibiae. Copyright © 2015 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25428500','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25428500"><span>An impenetrable barrier to ultrarelativistic electrons in the Van Allen radiation belts.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Baker, D N; Jaynes, A N; Hoxie, V C; Thorne, R M; Foster, J C; Li, X; Fennell, J F; Wygant, J R; Kanekal, S G; Erickson, P J; Kurth, W; Li, W; Ma, Q; Schiller, Q; Blum, L; Malaspina, D M; Gerrard, A; Lanzerotti, L J</p> <p>2014-11-27</p> <p>Early observations 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 studies 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 <span class="hlt">plasmasphere</span>, the outer boundary of which is called the plasmapause. The two-belt radiation structure was explained as arising from strong electron <span class="hlt">interactions</span> with <span class="hlt">plasmaspheric</span> <span class="hlt">hiss</span> just inside the plasmapause boundary, with the inner edge of the outer radiation zone corresponding to the minimum plasmapause location. Recent observations have revealed unexpected radiation belt morphology, especially at ultrarelativistic kinetic energies (more than five megaelectronvolts). Here we analyse an extended data set that reveals an exceedingly sharp inner boundary for the ultrarelativistic electrons. Additional, concurrently measured data reveal that this barrier to inward electron radial transport does not arise because of a physical boundary within the Earth's intrinsic magnetic field, and that inward radial diffusion is unlikely to be inhibited by scattering by electromagnetic transmitter wave fields. Rather, we suggest that exceptionally slow natural inward radial diffusion combined with weak, but persistent, wave-particle pitch angle scattering deep inside the Earth's <span class="hlt">plasmasphere</span> can combine to create an almost impenetrable barrier through which the most energetic Van Allen belt electrons cannot migrate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSA44A..05R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSA44A..05R"><span>Variation of <span class="hlt">Plasmaspheric</span> (90-4000 km) Field-aligned Electron Density and Ion Composition as a Function of Geomagnetic Storm Activity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reddy, A.; Sonwalkar, V. S.</p> <p>2015-12-01</p> <p>Whistler mode (WM) radio sounding from IMAGE has led to the first measurements of <span class="hlt">plasmaspheric</span> field-aligned electron density and ion composition as a function of geomagnetic storm activity during Aug-Sep 2005, a period that included several successive geomagnetic storms of varying strength. The plasmapause was located at L~2.4 during the onset and main phases of the storms. On the dayside, as a function of storm activity we found in general the following results: (1) The electron density, relative ion concentrations, and O+/H+ transition height had different temporal behavior. (2) Electron density in the first 1-2 days of the storm increased followed by a decrease in the recovery phase. (3) αH+ decreased during the onset, main and early recovery phase, and then it increased; αO+ increased in the early recovery phase, and then it decreased; αHe+ in general increased in the onset or main phase and decreased in the recovery phase. (4) O+/H+ transition height increased by ~200-300 km during the onset, main and early recovery phase. (5) When successive storms occurred in less than a day's span, the latter storms had little or no effect on the electron density and ion composition. On the nightside, WM sounding data was sparse. In the case of one moderate storm, we found that 3 days after the storm, electron density at F2 peak and relative ion concentrations (at all altitudes) were comparable to those before the storm, whereas electron density above O+/H+ transition height decreased. WM sounding results for the dayside and nightside were in agreement with measurements from CHAMP (350 km) and DMSP (850 km). WM sounding measurements coupled with physics-based models (e.g. SAMI2) will allow: (a) investigation of the role of thermospheric winds, dynamo and storm time electric fields in causing the variations in electron and ion densities, and (b) testing of current theories and validating physics-based models of the thermosphere-ionosphere-magnetosphere coupling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19820036453&hterms=ISIS&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DISIS','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19820036453&hterms=ISIS&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DISIS"><span>Global empirical models of ionospheric electron temperature in the upper F-region and <span class="hlt">plasmasphere</span> based on in situ measurements from the Atmosphere Explorer-C, ISIS-1 and ISIS-2 satellites</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Brace, L. H.; Theis, R. F.</p> <p>1981-01-01</p> <p>Langmuir probe measurements of electron temperature, T sub e, in the vicinity of 300, 400, 1400 and 3000 km from the Atmosphere Explorer-C and the ISIS satellites have been employed to construct empirical models of the global distribution of T sub e at each of these altitudes. Legendre polynomials are employed to describe the observations at solstice and equinox in terms of dip latitude and local time. Sources of T sub e variations, such as solar activity, magnetic activity and longitude are found to be of second order importance, although they are resolvable in some cases by comparisons of the data with the model. The behavior of T sub e at the altitudes of these models is discussed in terms of its implications for our understanding of the energy exchange between the F-region and the <span class="hlt">plasmasphere</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19820036453&hterms=Isis&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DIsis','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19820036453&hterms=Isis&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DIsis"><span>Global empirical models of ionospheric electron temperature in the upper F-region and <span class="hlt">plasmasphere</span> based on in situ measurements from the Atmosphere Explorer-C, ISIS-1 and ISIS-2 satellites</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Brace, L. H.; Theis, R. F.</p> <p>1981-01-01</p> <p>Langmuir probe measurements of electron temperature, T sub e, in the vicinity of 300, 400, 1400 and 3000 km from the Atmosphere Explorer-C and the ISIS satellites have been employed to construct empirical models of the global distribution of T sub e at each of these altitudes. Legendre polynomials are employed to describe the observations at solstice and equinox in terms of dip latitude and local time. Sources of T sub e variations, such as solar activity, magnetic activity and longitude are found to be of second order importance, although they are resolvable in some cases by comparisons of the data with the model. The behavior of T sub e at the altitudes of these models is discussed in terms of its implications for our understanding of the energy exchange between the F-region and the <span class="hlt">plasmasphere</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.6023B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.6023B"><span>The Upgraded European Digital Upper Atmosphere Server: new DIAS products for the high latitude ionosphere, the topside ionosphere and the <span class="hlt">plasmasphere</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Belehaki, Anna; Kutiev, Ivan; Zolesi, Bruno; Tsagouri, Ioanna; Dialetis, Dimitris; Marinov, Pencho; Fidanova, Stefka; Cander, Lili; Pietrella, Marco; Tziotziou, Kostas; Lykiardopoulos, Angelos</p> <p>2013-04-01</p> <p>Knowledge of the state of the upper atmosphere, and in particular its ionized part, is very important in several applications affected by space weather, especially the communications and navigation systems that rely on radio transmission. To better classify the ionosphere and forecast its disturbances over Europe, a data and model infrastructure platform called the European Digital Upper Atmosphere Server (DIAS) has been established in the National Observatory of Athens by a European consortium formed around eight ionospheric stations, and funded by the European Commission. The DIAS system operates since 2006 and the basic products that are delivered are real-time and historical ionograms, frequency plots and maps of the ionosphere on the foF2, M(3000)F2, MUF and bottomside electron density, as well as long term and short term forecasting up to 24 hour ahead. The DIAS system supports more than 500 subscribed users, including telecommunication companies, satellite operators, space agencies, radio amateurs, research organizations and the space weather scientific community. In 2012 the system has been upgraded, in close collaboration between the National Observatory of Athens, the Istituto Nazionale di Geofisica e Vulcanologia and the Bulgarian Academy of Sciences, with funding from the ESA/SSA Programme. The first group of new products results from the implementation of the TaD model (Topside Sounder Model assisted by Digisonde) that makes possible the generation of maps of the electron density at heights up to GNSS orbits, and of TEC and partial TEC maps (topside and <span class="hlt">plasmaspheric</span>) over Europe. The TaD is based on the simple empirical functions for the transition height, the topside electron density scale height and their ratio, based on the Alouette/ISIS database, and models separately the oxygen, hydrogen and helium ions density profiles. The model takes as input the plasma characteristics at the height of maximum electron concentration that are provided in real</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994PhRvC..49.3200C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994PhRvC..49.3200C"><span><span class="hlt">Interactions</span> in hydrogen of relativistic neon to nickel projectiles: Total charge-changing cross sections</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, C.-X.; Albergo, S.; Caccia, Z.; Costa, S.; Crawford, H. J.; Cronqvist, M.; Engelage, J.; Ferrando, P.; Fonte, R.; Greiner, L.; Guzik, T. G.; Insolia, A.; Jones, F. C.; Knott, C. N.; Lindstrom, P. J.; Mitchell, J. W.; Potenza, R.; Romanski, J.; Russo, G. V.; Soutoul, A.; Testard, O.; Tull, C. E.; Tuvé, C.; Waddington, C. J.; Webber, W. R.; Wefel, J. P.; Zhang, X.</p> <p>1994-06-01</p> <p>A liquid hydrogen target was used to study the nuclear fragmentation of beams of relativistic heavy ions, 22Ne to 58Ni, over an energy range 400 to 900 MeV/nucleon. The experiments were carried out at the Lawrence Berkeley Laboratory Bevalac <span class="hlt">HISS</span> facility, using the charge-velocity-rigidity method to identify the charged fragments. Here we describe the general concept of the experiment and present total charge-changing cross sections obtained from 17 separate runs. These new measured cross sections display an energy dependence which follows semiempirical model predictions. The mass dependence of the cross sections behaves as predicted by optical models, but within the experimental energy range, the optical model parameters display a clear energy dependence. The isospin of the projectile nuclei also appears to be an important factor in the <span class="hlt">interaction</span> process.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19940039118&hterms=greiner&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dgreiner','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19940039118&hterms=greiner&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dgreiner"><span>A program to measure new energetic particle nuclear <span class="hlt">interaction</span> cross sections</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Guzik, T. G.; Albergo, S.; Chen, C. X.; Costa, S.; Crawford, H. J.; Engelage, J.; Ferrando, P.; Flores, I.; Greiner, L.; Jones, F. C.</p> <p>1994-01-01</p> <p>The Transport Collaboration, consisting of researchers from institutions in France, Germany, Italy, and the USA, has established a program to make new measurements of nuclear <span class="hlt">interaction</span> cross sections for heavy projectiles (Z greater than or equal to 2) in targets of liquid H2, He and heavier materials. Such cross sections directly affect calculations of galactic and solar cosmic ray transport through matter and are needed for accurate radiation hazard assessment. To date, the collaboration has obtained data using the Lawrence Berkeley Laboratory Bevalac <span class="hlt">HISS</span> facility with 20 projectiles from He-4 to Ni-58 in the energy range 393-910 MeV/nucleon. Preliminary results from the analysis of these data are presented here and compared to other measurements and to cross section prediction formulae.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/7238775','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/7238775"><span><span class="hlt">Interactions</span> in hydrogen of relativistic neon to nickel projectiles: Total charge-changing cross sections</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chen, C.; Albergo, S.; Caccia, Z.; Costa, S.; Crawford, H.J.; Cronqvist, M.; Engelage, J.; Ferrando, P.; Fonte, R.; Greiner, L.; Guzik, T.G.; Insolia, A.; Jones, F.C.; Knott, C.N.; Lindstrom, P.J.; Mitchell, J.W.; Potenza, R.; Romanski, J.; Russo, G.V.; Soutoul, A.; Testard, O.; Tull, C.E.; Tuve, C.; Waddington, C.J.; Webber, W.R.; Wefel, J.P.; Zhang, X. Space Science Laboratory, University of California, Berkeley, California 94720 Service d'Astrophysique, Centre d'Etudes de Saclay, 91191 Gif-sur-Yvette, Cedex Dipartimento di Fisica, Universita di Catania, Istituto Nazionale di Fisica Nucleare, Sezione di Catania, Corso Italia 57, I 95129-Catania NASA</p> <p>1994-06-01</p> <p>A liquid hydrogen target was used to study the nuclear fragmentation of beams of relativistic heavy ions, [sup 22]Ne to [sup 58]Ni, over an energy range 400 to 900 MeV/nucleon. The experiments were carried out at the Lawrence Berkeley Laboratory Bevalac <span class="hlt">HISS</span> facility, using the charge-velocity-rigidity method to identify the charged fragments. Here we describe the general concept of the experiment and present total charge-changing cross sections obtained from 17 separate runs. These new measured cross sections display an energy dependence which follows semiempirical model predictions. The mass dependence of the cross sections behaves as predicted by optical models, but within the experimental energy range, the optical model parameters display a clear energy dependence. The isospin of the projectile nuclei also appears to be an important factor in the <span class="hlt">interaction</span> process.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/664489','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/664489"><span>Systematics of isotopic production cross sections from <span class="hlt">interactions</span> of relativistic {sup 40}Ca in hydrogen</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chen, C.; Guzik, T.G.; McMahon, M.; Wefel, J.P.; Albergo, S.; Caccia, Z.; Costa, S.; Insolia, A.; Potenza, R.; Russo, G.V.; Tuve, C.; Crawford, H.J.; Cronqvist, M.; Engelage, J.; Greiner, L.; Knott, C.N.; Waddington, C.J.; Lindstrom, P.J.; Tull, C.E.; Mitchell, J.W.; Webber, W.R.</p> <p>1997-09-01</p> <p>The isotopic production cross sections for {sup 40} Ca projectiles at 357, 565, and 763 MeV/nucleon <span class="hlt">interacting</span> in a liquid hydrogen target have been measured by the Transport Collaboration at the LBL <span class="hlt">HISS</span> facility. The systematics of these cross sections are studied, and the results indicate that nuclear structure effects are present in the isotope production process during the relativistic collisions. The newly measured cross sections are also compared with those predicted by semiempirical and parametric formulas, but the predictions do not fully describe the systematics such as the energy dependence. The consequences of the cross section systematics in galactic cosmic ray studies are also discussed. {copyright} {ital 1997} {ital The American Physical Society}</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19820014872','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19820014872"><span>High voltage space plasma <span class="hlt">interactions</span>. [charging the solar power satellites</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mccoy, J. E.</p> <p>1980-01-01</p> <p>Two primary problems resulted from plasma <span class="hlt">interactions</span>; one of concern to operations in geosynchronous orbit (GEO), the other in low orbits (LEO). The two problems are not the same. Spacecraft charging has become widely recognized as a problem, particularly for communications satellites operating in GEO. The very thin thermal plasmas at GEO are insufficient to bleed off voltage buildups due to higher energy charged particle radiation collected on outer surfaces. Resulting differential charging/discharging causes electrical transients, spurious command signals and possible direct overload damage. An extensive NASA/Air Force program has been underway for several years to address this problem. At lower altitudes, the denser plasmas of the <span class="hlt">plasmasphere</span>/ionosphere provide sufficient thermal current to limit such charging to a few volts or less. Unfortunately, these thermal plasma currents which solve the GEO spacecraft charging problem can become large enough to cause just the opposite problem in LEO.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.4869S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.4869S"><span>Influence of the electronic plasma density on the wave particle <span class="hlt">interaction</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sicard-Piet, Angelica; Boscher, Daniel</p> <p>2013-04-01</p> <p>The wave particle <span class="hlt">interaction</span>, which is well known to be a major phenomenon in the electron radiation belts dynamics, is based on two main parameters: the characteristics of the wave (type of wave, intensity,…) and the characteristics of the ambient plasma. In this work we studied the second parameter. On one side, the electronic plasma density can be derived from in-situ measurements. On the other side, several empirical models exist: GCPM, IZMIRAN or Carpenter models. Here, we compared electronic plasma densities derived from in-situ measurements each other and with existing models. Then, we investigated on the electronic plasma density distribution to distinguish the inside to the outside <span class="hlt">plasmasphere</span>. Finally, the effect of the electronic plasma density on the diffusion coefficients due to wave particle <span class="hlt">interaction</span> has been studied via a numerical code, called WAPI, based on quasi linear theory.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20170000980&hterms=Magnetosphere&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DMagnetosphere','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20170000980&hterms=Magnetosphere&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DMagnetosphere"><span>The Comprehensive Inner Magnetosphere-Ionosphere Model</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fok, M.-C.; Buzulukova, N. Y.; Chen, S.-H.; Glocer, A.; Nagai, T.; Valek, P.; Perez, J. D.</p> <p>2014-01-01</p> <p>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, <span class="hlt">plasmaspheric</span> density, Region 2 currents, convection potential, and precipitation in the ionosphere. It incorporates whistler mode chorus and <span class="hlt">hiss</span> wave diffusion of energetic electrons in energy, pitch angle, and cross terms. CIMI thus represents a comprehensive model that considers the effects of the ring current and <span class="hlt">plasmasphere</span> on the radiation belts. We have performed a CIMI simulation for the storm on 5-9 April 2010 and then compared our results with data from the Two Wide-angle Imaging Neutral-atom Spectrometers and Akebono satellites. We identify the dominant energization and loss processes for the ring current and radiation belts. We find that the <span class="hlt">interactions</span> with the whistler mode chorus waves are the main cause of the flux increase of MeV electrons during the recovery phase of this particular storm. When a self-consistent electric field from the CRCM is used, the enhancement of MeV electrons is higher than when an empirical convection model is applied. We also demonstrate how CIMI can be a powerful tool for analyzing and interpreting data from the new Van Allen Probes mission.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.1445B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.1445B"><span>Remarkable new results for high-energy protons and electrons in the inner Van Allen belt regions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Baker, Daniel N.</p> <p>2016-04-01</p> <p>Early observations 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 studies 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. The two-belt radiation structure was explained as arising from strong electron <span class="hlt">interactions</span> with <span class="hlt">plasmaspheric</span> <span class="hlt">hiss</span> just inside the plasmapause boundary with the inner edge of the outer radiation zone corresponding to the minimum plasmapause location.. Recent Van Allen Probes observations have revealed an unexpected radiation belt morphology, especially at ultrarelativistic kinetic energies (more than several megaelectronvolts). The data show an exceedingly sharp inner boundary for the ultrarelativistic electrons right at L=2.8. Additional, concurrently measured data reveal that this barrier to inward electron radial transport is likely due to scattering by powerful human electromagnetic transmitter (VLF) wave fields. We show that weak, but persistent, wave-particle pitch angle scattering deep inside the Earth's <span class="hlt">plasmasphere</span> due to manmade signals can act to create an almost impenetrable barrier through which the most energetic Van Allen belt electrons cannot migrate. Inside of this distance, the Van Allen Probes data show that high energy (20 -100 MeV) protons have a double belt structure with a stable peak of flux at L~1.5 and a much more variable belt peaking at L~2.3.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006cosp...36.1784R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006cosp...36.1784R"><span><span class="hlt">Plasmaspheric</span> electron content variation in the magnetic equatorial region during space weather events: Results from the CRABEX (Coherent Radio Beacon Experiment) using the beacon onboard the Indian geostationary satellite (GSAT - 2)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ravindran, Sudha; Manju, G.; Devasia, C. V.; Sridharan, R.; Thampi, S. V.; Sreelatha, P.; Sreeja, V.; Pant, T. K.; Raghava Reddi, C.</p> <p></p> <p>CRABEX is a national scientific program for the investigation of the unique features associated with the equatorial and low latitude ionosphere in the Indian zone using the technique of ionospheric tomography It consists of a beacon transmitter onboard the Indian geostationary satellite GSAT-2 which transmits four coherently generated frequencies - 150 012MHz 400 032MHz along with 1 MHz modulation of these frequencies i e 149 01192 MHz and 399 03192 MHz and a unique ground receiver system designed and set up at Trivandrum dip 0 3 r N to receive these beacon transmissions The data obtained from the measurement of the differential phase between 400 MHz and 150 MHz gives the relative Total Electron Content TEC along the line of sight between the satellite and the ground receiver and the measurement of modulation phase delay of 1 MHz on the above frequencies provides a coarse estimate of TEC These two measurements together give an accurate estimate of TEC along the line of sight from the satellite to the ground receiver and the Faraday rotation measurements give a reliable estimate of electron content upto sim 2000 km i e the ionospheric content IEC The simultaneous measurements of IEC and TEC upto the geo-stationary altitude of 36000 km is used to determine the <span class="hlt">plasmaspheric</span> electron content PEC The CRABEX program with its another segment consisting of a network of 6 receiver stations over the Indian subcontinent established along 77-78 r E meridian also makes use of the data obtained by receiving the 150 and 400 MHz</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993JGR....9813509V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993JGR....9813509V"><span>Proton whistler <span class="hlt">interactions</span> near the equator in the radiation belts</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Villalon, Elena; Burke, William J.</p> <p>1993-08-01</p> <p>The <span class="hlt">interactions</span> of energetic protons with whistlers propagating near the quasi-electrostatic limit are investigated using a test-particle Hamiltonian formalism. Near the equator the protons <span class="hlt">interact</span> with the waves which appear Doppler-shifted to some harmonic of their cyclotron frequency. In an inhomogeneous geomagnetic field the spacing between cyclotron harmonic resonances is very small. The Hamiltonian equations of motion are solved including multiple independent harmonics for each resonance. The wave frequency varies as a function of the distance along the field line, with only one frequency being resonant at a given point. Thus the inhomogeneity of the magnetic field is compensated by the frequency variation. The proton whistler <span class="hlt">interactions</span> satisfy the conditions for second-order resonances for all the harmonics. The resonances may also overlap in phase space, leading to significant changes in the protons energies and pitch angles. The combined contributions of positive and negative harmonics allow protons to diffuse toward smaller pitch angles. Numerical calculations applying this formalism to parameters relevant to the <span class="hlt">plasmasphere</span> and controlled VLF transmission experiments are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSM23C..03F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSM23C..03F"><span>Van Allen Probes Observations of Direct Wave Particle <span class="hlt">Interactions</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fennell, J. F.; Roeder, J. L.; Kurth, W. S.; Henderson, M. G.; Larsen, B.; Hospodarsky, G. B.; Blake, J. B.; Claudepierre, S. G.; Clemmons, J. H.; Spence, H.; Funsten, H. O.; Reeves, G. D.; Kletzing, C.; Wygant, J. R.</p> <p>2013-12-01</p> <p>We present observations of wave-particle <span class="hlt">interactions</span> observed on the Van Allen Probes during an interval of sporadic increases or bursts of 20-30 keV electron fluxes observed in conjunction with bursts of chorus activity. The electron flux and chorus burst occurred on a nearly one for one basis during an hour interval on January 13, 2013. The electron angular distributions changed during the burst events such that flux increases evolved from Sinn(α) type angular distributions to form maxima in the electron angular distributions at 75-80° local pitch angle with the fluxes at 90° and <60° remaining the same as in the pre and post burst distributions. These events occurred well outside the <span class="hlt">plasmasphere</span> following a minor plasma injection. They were observed on both Van Allen Probes spacecraft, which were relatively close together. The plasma density, electron gyro-frequency and pitch angle of peak flux in a burst was used to estimate the resonant electron energy. The result of ~25 keV is consistent with the energies of the electrons showing the flux enhancements observed by the ECT/MagEIS and ECT/HOPE spectrometers. These results will be described in detail and questions concerning the source of such events will be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1997ApJ...479..504C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1997ApJ...479..504C"><span>Relativistic <span class="hlt">Interaction</span> of 22Ne and 26Mg in Hydrogen and the Cosmic-Ray Implications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, C.-X.; Albergo, S.; Caccia, Z.; Costa, S.; Crawford, H. J.; Cronqvist, M.; Engelage, J.; Greiner, L.; Guzik, T. G.; Insolia, A.; Knott, C. N.; Lindstrom, P. J.; McMahon, M.; Mitchell, J. W.; Potenza, R.; Russo, G. V.; Soutoul, A.; Testard, O.; Tull, C. E.; Tuvé, C.; Waddington, C. J.; Webber, W. R.; Wefel, J. P.</p> <p>1997-04-01</p> <p>The isotopic production cross sections for 22Ne projectiles at 377,581, and 894 MeV nucleon-1 and 26Mg projectiles at 371 and 576 MeV nucleon-1 <span class="hlt">interacting</span> in a liquid hydrogen target have been measured by the Transport Collaboration at the Lawrence Berkeley Laboratory Heavy-Ion Spectrometer System (LBL <span class="hlt">HISS</span>) facility. These cross sections are compared with those predicted by semi-empirical formulae. The systematics are studied to develop suitable inputs for calculations of galactic cosmic-ray interstellar transport. These calculations are used to unfold the transport effects from available observations of cosmic-ray CNO isotopes to extract the underlying source composition. With these new cross section measurements, the previously reported enhancement of 18O at the cosmic-ray source, which is sensitive to the cross sections for production from 22Ne and 26Mg and the uncertainties in cross section prediction formulae, may be explained. There is no evidence for an enhancement of 18O when these new cross sections are used in a weighted slab propagation calculation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA109405','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA109405"><span>Helicopter Icing Spray System (<span class="hlt">HISS</span>) Nozzle Improvement Evaluation</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1981-09-01</p> <p>tests, most ice accretion on the spray boom resulted from leakage of loose fittings between nozzles and water manifolds, and from spray impingement...iuininging on the uplocks. Some ice accretion developed around nozzles when flow blocki-ge was experienced, but this was not a regular occurrence in...outriggers the estimated width of the cloud was 36 ft. "While less than any test aircraft rotor diameter, full span ice accretion was demon- strated on all</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA114435','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA114435"><span><span class="hlt">HISS</span> Calibration, Ice Phobics and FAA R/D Evaluations</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1981-08-01</p> <p>the existing direct curent (DC) generator had been replaced by a 30 kilovolt- ampere (KVA), 400 hertz alternating current (AC) generator. The AC...power was the engine-driven starter/generator. A 200 ampere transformer-rectifier to convert AC to DC power was installed as a standby DC system...velocity air flow over the ice collection probe and provide anti-icing. When the ice accu - mulation on the probe reached a preset level, the probe was</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA170732','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA170732"><span>Helicopter Icing Spray System (<span class="hlt">HISS</span>) Evaluation and Improvement</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1986-04-01</p> <p>reference If the disk-shaped water muwnifolds and associated plastic cubing to the nozz]_,ýs were replaced by stainless steel T-section manifolds, steel tubin ...b. Place: Icing test site, St. Paul, MI c. Date: 21-27 March 1982 d. Project No.: N/A e. Estimated Cost : Total $845. f. Other travelers: None 2...circulating air could be felt. The wind chill factor was the iain source of crew discomfort instead of actual temperature. The water pump, turbine</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/628684','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/628684"><span>Relativistic <span class="hlt">interaction</span> of {sup 22}Ne and {sup 26}Mg in hydrogen and the cosmic-ray implications</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chen, C.X.; Albergo, S.; Caccia, Z.; Costa, S.; Crawford, H.J.; Cronqvist, M.; Engelage, J.; Greiner, L.; Guzik, T.G.; Insolia, A.; Knott, C.N.; Lindstrom, P.J.; McMahon, M.; Mitchell, J.W.; Soutoul, A.; Testard, O.; Tull, C.E.; Tuve, C.; Waddington, C.J.; Webber, W.R.</p> <p>1997-04-01</p> <p>The isotopic production cross sections for {sup 22}Ne projectiles at 377,581, and 894 MeV nucleon{sup {minus}1} and {sup 26}Mg projectiles at 371 and 576 MeV nucleon{sup {minus}1} <span class="hlt">interacting</span> in a liquid hydrogen target have been measured by the Transport Collaboration at the Lawrence Berkeley Laboratory Heavy-Ion Spectrometer System (LBL <span class="hlt">HISS</span>) facility. These cross sections are compared with those predicted by semi-empirical formulae. The systematics are studied to develop suitable inputs for calculations of galactic cosmic-ray interstellar transport. These calculations are used to unfold the transport effects from available observations of cosmic-ray CNO isotopes to extract the underlying source composition. With these new cross section measurements, the previously reported enhancement of {sup 18}O at the cosmic-ray source, which is sensitive to the cross sections for production from {sup 22}Ne and {sup 26}Mg and the uncertainties in cross section prediction formulae, may be explained. There is no evidence for an enhancement of {sup 18}O when these new cross sections are used in a weighted slab propagation calculation. {copyright} {ital 1997} {ital The American Astronomical Society}</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRA..120..460R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRA..120..460R"><span>On long decays of electrons in the vicinity of the slot region observed by HEO3</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ripoll, J.-F.; Chen, Y.; Fennell, J. F.; Friedel, R. H. W.</p> <p>2015-01-01</p> <p>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 <span class="hlt">plasmaspheric</span> <span class="hlt">hiss</span>, 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 and Thorne in 1998 with the goal to assess whether they can reproduce lifetimes extracted from HEO observations. We show how <span class="hlt">hiss</span> dominantly affect high energy electrons (E > 2 MeV) for L in [2, 3.5] and VLF transmitter waves control residency times of low energy electrons (<0.4 MeV) around L = 2. These <span class="hlt">interactions</span> induce characteristic shapes of the lifetime profiles that will be discussed. We show how the wave amplitudes can be adjusted for the particular energy particles that are dominantly affected by one wave type only. Using these amplitudes, mean HEO lifetimes are reproduced within a factor 2 to 5. VLF occurrence rates and <span class="hlt">hiss</span> amplitude turn out significantly higher than those proposed by Abel and Thorne. The wide energy response of the sensors complicates the analysis because it blurs the electron lifetime dependence on energy, increases the overall lifetimes, and reduces the differences between the different channel lifetimes. In particular, our simulations suggest the flux measured by an integrated energy sensor aboard HEO has a variable slope, i.e., a variable lifetime, during 10-20 days in our data, due to the faster decay of the low residency time particles while slower decaying particles control the steady decay. It can explain some of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5414246','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5414246"><span><span class="hlt">Interactive</span> numerals</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2017-01-01</p> <p>Although Arabic numerals (like ‘2016’ and ‘3.14’) are ubiquitous, we show that in <span class="hlt">interactive</span> computer applications they are often misleading and surprisingly unreliable. We introduce <span class="hlt">interactive</span> numerals as a new concept and show, like Roman numerals and Arabic numerals, <span class="hlt">interactive</span> numerals introduce another way of using and thinking about numbers. Properly understanding <span class="hlt">interactive</span> numerals is essential for all computer applications that involve numerical data entered by users, including finance, medicine, aviation and science. PMID:28484609</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSM13F..03H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSM13F..03H"><span>Forecasting the Radiation Belts for Satellites Undergoing Electric-Orbit Raising</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Horne, R. B.; Glauert, S. A.; Meredith, N. P.; Kersten, T.; Heynderickx, D.; Maget, V.; Li, W.; Pitchford, D. A.; Wade, D.</p> <p>2015-12-01</p> <p>The introduction of commercial satellites with all-electric propulsion systems is nothing less than a revolution in the quest for low-cost access to space. As a consequence, it can take as long as 200 - 400 days to raise the perigee of the satellite to final geostationary orbit. During this time the satellites are exposed to the most intense part of the van Allen radiation belts where the electron radiation environment can vary by orders of magnitude as a result of changes in the solar wind. Here we describe briefly this new method of launch and discuss the importance of radiation protection, the need for real-time data on orbit and how physics based models can help supply this need. We describe the forecasting system that was developed in the European SPACECAST project, and is now continued in the SPACESTORM project, and how we use physics based models to forecast the electron flux throughout the outer radiation belt in real-time, updated hourly. We show that forecasts are much improved when the physics of wave-particle <span class="hlt">interactions</span> is included, and show comparisons between models using different wave models for <span class="hlt">plasmaspheric</span> <span class="hlt">hiss</span> and chorus waves. The results emphasise the importance of chorus wave amplitudes. Finally, we discuss some areas of research needed to improve the forecasts, such as the need to understand electron flux drop-outs and their relation to distortions of the geomagnetic field in the tail region, and the need for additional wave models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=many+AND+persons+AND+social+AND+media&pg=4&id=EJ190216','ERIC'); return false;" href="https://eric.ed.gov/?q=many+AND+persons+AND+social+AND+media&pg=4&id=EJ190216"><span>Media <span class="hlt">Interaction</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Nordlund, Jan-Erik</p> <p>1978-01-01</p> <p>Defines and operationalizes the concept of media <span class="hlt">interaction</span>, which implies that the audience member experiences "<span class="hlt">interaction</span>" with, and in many cases identifies with, persons in the media content. Presents a model of media <span class="hlt">interaction</span> and the results of surveys conducted to explore hypotheses derived form the model. (JMF)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/291181','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/291181"><span>Nuclear <span class="hlt">interactions</span> of high energy heavy ions and applications in astrophysics. Final technical report</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wefel, J.P.; Guzik, T.G.</p> <p>1998-06-25</p> <p>Projectile fragmentation experiments have been conducted at the LBL Bevalac accelerator, utilizing both the B40 and the <span class="hlt">HISS</span> facilities, to produce a dataset of 36 beam/energy combinations covering projectiles from {sup 4}He to {sup 58}Ni and various energies from 170--2100 MeV/nucleon. While some runs were subject to beam instabilities, magnet problems or low statistics, there remains a large dataset which is still being analyzed. The results will be used to investigate the physics of the intermediate energy fragmentation process and will find application in the astrophysics of cosmic ray propagation in the galaxy. An overview of the science goals and rationale is followed by presentation of the experimental techniques and apparatus that has been employed. Data analysis, including both detector subsystem and accelerator calibration, is discussed with emphasis on the unique features of the dataset and the analysis problems being addressed. Results from the experiments are presented throughout to illustrate the status of the analysis, e.g., momentum distribution widths. Total, Elemental and Isotopic cross sections from various beam/energy combinations are presented, including the first data on {sup 32}S fragmentation and the complete isotopic fragmentation cross sections for {sup 28}Si <span class="hlt">interacting</span> in both Carbon and Hydrogen targets. The new results are compared to any existing data and to formulae used to predict unmeasured cross sections. The size and complexity of the dataset and the required detail of the analysis precluded finishing the full analysis under the subject grant. Plans for additional analysis are presented, and these will be carried out in coming years as time and resources permit.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRA..120.4863N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRA..120.4863N"><span>Variability of the pitch angle distribution of radiation belt ultrarelativistic electrons during and following intense geomagnetic storms: Van Allen Probes observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ni, Binbin; Zou, Zhengyang; Gu, Xudong; Zhou, Chen; Thorne, Richard M.; Bortnik, Jacob; Shi, Run; Zhao, Zhengyu; Baker, Daniel N.; Kanekal, Shrikhanth G.; Spence, Harlan E.; Reeves, Geoffrey D.; Li, Xinlin</p> <p>2015-06-01</p> <p>Fifteen months of pitch angle resolved Van Allen Probes Relativistic Electron-Proton Telescope (REPT) measurements of differential electron flux are analyzed to investigate the characteristic variability of the pitch angle distribution of radiation belt ultrarelativistic (>2 MeV) electrons during storm conditions and during the long-term poststorm decay. By modeling the ultrarelativistic electron pitch angle distribution as sinnα, where α is the equatorial pitch angle, we examine the spatiotemporal variations of the n value. The results show that, in general, n values increase with the level of geomagnetic activity. In principle, ultrarelativistic electrons respond to geomagnetic storms by becoming more peaked at 90° pitch angle with n values of 2-3 as a supportive signature of chorus acceleration outside the <span class="hlt">plasmasphere</span>. High n values also exist inside the <span class="hlt">plasmasphere</span>, being localized adjacent to the plasmapause and exhibiting energy dependence, which suggests a significant contribution from electromagnetic ion cyclotron (EMIC) wave scattering. During quiet periods, n values generally evolve to become small, i.e., 0-1. The slow and long-term decays of the ultrarelativistic electrons after geomagnetic storms, while prominent, produce energy and L-shell-dependent decay time scales in association with the solar and geomagnetic activity and wave-particle <span class="hlt">interaction</span> processes. At lower L shells inside the <span class="hlt">plasmasphere</span>, the decay time scales τd for electrons at REPT energies are generally larger, varying from tens of days to hundreds of days, which can be mainly attributed to the combined effect of <span class="hlt">hiss</span>-induced pitch angle scattering and inward radial diffusion. As L shell increases to L~3.5, a narrow region exists (with a width of ~0.5 L), where the observed ultrarelativistic electrons decay fastest, possibly resulting from efficient EMIC wave scattering. As L shell continues to increase, τd generally becomes larger again, indicating an overall slower loss</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950057058&hterms=landau&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dlandau','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950057058&hterms=landau&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dlandau"><span>Landau damping of magnetospherically reflected whistlers</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Thorne, Richard M.; Horne, Richard B.</p> <p>1994-01-01</p> <p>Unducted VLF signals produced by lightning activity can form a population of magnetospherically reflected (MR) whistlers in the inner magnetosphere. It has been suggested recently that in the absence of significant attenuation such waves could merge into a broadband continuum with sufficient intensity to account for <span class="hlt">plasmaspheric</span> <span class="hlt">hiss</span>. To test this conjecture we have evaluated the path-integrated attenuation of MR whistlers along representative ray paths using the HOTRAY code. Using a realistic plasma distribution modeled on in-situ data, we find that the majority of MR waves experience significant damping after a few transits across the equator. This is primarily due to Landau resonance with suprathermal (0.1-1 keV) electrons. The attenuation is most pronounced for waves that propagate through the outer <span class="hlt">plasmasphere</span>; this can readily account for the infrequent occurrence of multiple-hop MR waves for L greater than or equal to 3.5. Selected waves that originate at intermediate latitudes (15 deg is less than or equal to lambda is less than or equal to 35 deg) and whose ray paths are confined to the inner plasma- sphere may experience up to 10 magnetospheric reflections before substantial attentuation occurs. These waves should form the population of observed MR waves. Wave attenuation becomes more pronounced at higher frequencies; this can account for the absence of multiple-hop waves above 5 kHz. Weakly attenuated MR waves tend to migrate outward to the L shell, where their frequency is comparable to the equatorial lower hybrid frequency. The enhanced concentration of waves due to a merging of ray paths would produce a spectral feature that rises in frequency at lower L. This is quite distinct from the reported properties of <span class="hlt">plasmaspheric</span> <span class="hlt">hiss</span>, which maintains a constant frequency band throughout the entire <span class="hlt">plasmasphere</span>. Furthermore, in the absence of mode conversion, waves below 500 Hz, which often form an important if not dominant part of the spectral properties</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JSG....97....1P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JSG....97....1P"><span><span class="hlt">Interacting</span> faults</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Peacock, D. C. P.; Nixon, C. W.; Rotevatn, A.; Sanderson, D. J.; Zuluaga, L. F.</p> <p>2017-04-01</p> <p>The way that faults <span class="hlt">interact</span> with each other controls fault geometries, displacements and strains. Faults rarely occur individually but as sets or networks, with the arrangement of these faults producing a variety of different fault <span class="hlt">interactions</span>. Fault <span class="hlt">interactions</span> are characterised in terms of the following: 1) Geometry - the spatial arrangement of the faults. <span class="hlt">Interacting</span> faults may or may not be geometrically linked (i.e. physically connected), when fault planes share an intersection line. 2) Kinematics - the displacement distributions of the <span class="hlt">interacting</span> faults and whether the displacement directions are parallel, perpendicular or oblique to the intersection line. <span class="hlt">Interacting</span> faults may or may not be kinematically linked, where the displacements, stresses and strains of one fault influences those of the other. 3) Displacement and strain in the <span class="hlt">interaction</span> zone - whether the faults have the same or opposite displacement directions, and if extension or contraction dominates in the acute bisector between the faults. 4) Chronology - the relative ages of the faults. This characterisation scheme is used to suggest a classification for <span class="hlt">interacting</span> faults. Different types of <span class="hlt">interaction</span> are illustrated using metre-scale faults from the Mesozoic rocks of Somerset and examples from the literature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRA..122.1871L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRA..122.1871L"><span>Coherently modulated whistler mode waves simultaneously observed over unexpectedly large spatial scales</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Jinxing; Bortnik, Jacob; Li, Wen; Thorne, Richard M.; Ma, Qianli; Chu, Xiangning; Chen, Lunjin; Kletzing, Craig A.; Kurth, William S.; Hospodarsky, George B.; Wygant, John; Breneman, Aaron; Thaller, Scott</p> <p>2017-02-01</p> <p>Utilizing simultaneous twin Van Allen Probes observations of whistler mode waves at variable separations, we are able to distinguish the temporal variations from spatial variations, determine the coherence spatial scale, and suggest the possible mechanism of wave modulation. The two probes observed coherently modulated whistler mode waves simultaneously at an unexpectedly large distance up to 4.3 RE over 3 h during a relatively quiet period. The modulation of 150-500 Hz <span class="hlt">plasmaspheric</span> <span class="hlt">hiss</span> was correlated with whistler mode waves measured outside the <span class="hlt">plasmasphere</span> across 3 h in magnetic local time and 3 L shells, revealing that the modulation was temporal in nature. We suggest that the coherent modulation of whistler mode waves was associated with the coherent ULF waves measured over a large scale, which modulate the <span class="hlt">plasmaspheric</span> density and result in the modulation of <span class="hlt">hiss</span> waves via local amplification. In a later period, the 500-1500 Hz periodic rising-tone whistler mode waves were strongly correlated when the two probes traversed large spatial regions and even across the plasmapause. These periodic rising-tone emissions recurred with roughly the same period as the ULF wave, but there was no one-to-one correspondence, and a cross-correlation analysis suggests that they possibly originated from large L shells although the actual cause needs further investigation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=turner&pg=5&id=EJ875635','ERIC'); return false;" href="https://eric.ed.gov/?q=turner&pg=5&id=EJ875635"><span>Imagined <span class="hlt">Interactions</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Honeycutt, James M.</p> <p>2010-01-01</p> <p>Social scientists have been studying imagined <span class="hlt">interactions</span> since the mid-1980s and have measured numerous physiological correlates (Honeycutt, 2010). In this commentary I assess the research reported in Crisp and Turner (May-June 2009) and highlight the underlying mechanisms of imagined <span class="hlt">interactions</span> that have empirically been laid out across…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=crisps&id=EJ875635','ERIC'); return false;" href="http://eric.ed.gov/?q=crisps&id=EJ875635"><span>Imagined <span class="hlt">Interactions</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Honeycutt, James M.</p> <p>2010-01-01</p> <p>Social scientists have been studying imagined <span class="hlt">interactions</span> since the mid-1980s and have measured numerous physiological correlates (Honeycutt, 2010). In this commentary I assess the research reported in Crisp and Turner (May-June 2009) and highlight the underlying mechanisms of imagined <span class="hlt">interactions</span> that have empirically been laid out across…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.lifesci.ucsb.edu/eemb/labs/kuris/pubs/Lafferty2010Science.pdf','USGSPUBS'); return false;" href="http://www.lifesci.ucsb.edu/eemb/labs/kuris/pubs/Lafferty2010Science.pdf"><span><span class="hlt">Interacting</span> parasites</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Lafferty, Kevin D.</p> <p>2010-01-01</p> <p>Parasitism is the most popular life-style on Earth, and many vertebrates host more than one kind of parasite at a time. A common assumption is that parasite species rarely <span class="hlt">interact</span>, because they often exploit different tissues in a host, and this use of discrete resources limits competition (1). On page 243 of this issue, however, Telfer et al. (2) provide a convincing case of a highly <span class="hlt">interactive</span> parasite community in voles, and show how infection with one parasite can affect susceptibility to others. If some human parasites are equally <span class="hlt">interactive</span>, our current, disease-by-disease approach to modeling and treating infectious diseases is inadequate (3).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://images.nasa.gov/#/details-PIA10391.html','SCIGOVIMAGE-NASA'); return false;" href="https://images.nasa.gov/#/details-PIA10391.html"><span><span class="hlt">Interacting</span> Galaxies</span></a></p> <p><a target="_blank" href="https://images.nasa.gov/">NASA Image and Video Library</a></p> <p></p> <p>2008-04-24</p> <p>This beautiful pair of <span class="hlt">interacting</span> galaxies consists of NGC 5754, the large spiral on the right, and NGC 5752, the smaller companion in the bottom left corner of the image. This image is from NASA Hubble Space Telescope.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhDT........16A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhDT........16A"><span>Wave-particle <span class="hlt">Interactions</span> in Space and Laboratory Plasmas</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>An, Xin</p> <p></p> <p>This dissertation presents a study of wave-particle <span class="hlt">interactions</span> in space and in the laboratory. To be concrete, the excitation of whistler-mode chorus waves in space and in the laboratory is studied in the first part. The relaxation of whistler anisotropy instability relevant to whistler-mode chorus waves in space is examined. Using a linear growth rate analysis and kinetic particle-in-cell simulations, the electron distributions are demonstrated to be well-constrained by the whistler anisotropy instability to a marginal-stability state, consistent with measurements by Van Allen Probes. The electron parallel beta beta ∥e separates the excited whistler waves into two groups: (i) quasi-parallel whistler waves for beta∥e > 0.02 and (ii) oblique whistler waves close to the resonance cone for beta∥e < 0.02. The saturated magnetic field energy of whistler waves roughly scales with the square of the electron beta beta∥e. 2, as shown in bothsatellite observations and particle-in-cell simulations. Motivated by the puzzles of chorus waves in space and by their recognized importance, the excitation of whistler-mode chorus waves is studied in the Large Plasma Device by the injection of a helical electron beam into a cold plasma. Incoherent broadband whistler waves similar to magnetospheric <span class="hlt">hiss</span> are observed in the laboratory plasma. Their mode structures are identified by the phase-correlation technique. It is demonstrated that the waves are excited through a combination of Landau resonance, cyclotron resonance and anomalous cyclotron resonance. To account for the finite size effect of the electron beam, linear unstable eigenmodes of whistler waves are calculated by matching the eigenmode solution at the boundary. It is shown that the perpendicular wave number inside the beam is quantized due to the constraint imposed by the boundary condition. Darwin particle-in-cell simulations are carried out to study the simultaneous excitation of Langmuir and whistler waves in a</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18752094','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18752094"><span><span class="hlt">Interactive</span> training.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Toogood, Sandy</p> <p>2008-09-01</p> <p>Active support (AS) was developed to help staff organise and deliver practical support for meaningful client engagement in everyday activities. Both the amount and momentary effectiveness of staff support for client engagement have been found to increase following AS training. Training typically consists of a combination of workshops and onsite coaching sessions. To date, onsite training procedures have not been described or evaluated independently of AS workshops. An onsite training procedure used in AS--<span class="hlt">interactive</span> training (IT)--was evaluated independently of AS workshops through direct observation of staff and client behaviour. Staff views were canvassed via a questionnaire. Following <span class="hlt">interactive</span> training, staff assistance and client engagement increased. Staff views on the experience were positive. Results from this preliminary study suggest that further research on the effectiveness of <span class="hlt">interactive</span> training is warranted.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/accomplishments/documents/fullText/ACC0451.pdf','DOE-RDACC'); return false;" href="http://www.osti.gov/accomplishments/documents/fullText/ACC0451.pdf"><span>Weak <span class="hlt">Interactions</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/accomplishments/fieldedsearch.html">DOE R&D Accomplishments Database</a></p> <p>Lee, T. D.</p> <p>1957-06-01</p> <p>Experimental results on the non-conservation of parity and charge conservation in weak <span class="hlt">interactions</span> are reviewed. The two-component theory of the neutrino is discussed. Lepton reactions are examined under the assumption of the law of conservation of leptons and that the neutrino is described by a two- component theory. From the results of this examination, the universal Fermi <span class="hlt">interactions</span> are analyzed. Although reactions involving the neutrino can be described, the same is not true of reactions which do not involve the lepton, as the discussion of the decay of K mesons and hyperons shows. The question of the invariance of time reversal is next examined. (J.S.R.)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009PhTea..47..460R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009PhTea..47..460R"><span><span class="hlt">Interacting</span> Compasses</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Riveros, Héctor G.; Betancourt, Julián</p> <p>2009-10-01</p> <p>The use of multiple compasses to map and visualize magnetic fields is well-known. The magnetic field exerts a torque on the compasses aligning them along the lines of force. Some science museums show the field of a magnet using a table with many compasses in a closely packed arrangement. However, the very interesting <span class="hlt">interactions</span> that occur between the compasses themselves are frequently neglected. In this paper we describe demonstrations, using arrays of compasses, that show these <span class="hlt">interactions</span> and model magnetic domains in ferromagnetic materials.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=laser+AND+technologies&pg=5&id=EJ454495','ERIC'); return false;" href="https://eric.ed.gov/?q=laser+AND+technologies&pg=5&id=EJ454495"><span><span class="hlt">Interactive</span> Video.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Boyce, Carol</p> <p>1992-01-01</p> <p>A workshop on <span class="hlt">interactive</span> video was designed for fourth and fifth grade students, with the goals of familiarizing students with laser disc technology, developing a cadre of trained students to train other students and staff, and challenging able learners to utilize higher level thinking skills while conducting a research project. (JDD)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=Hubble+AND+Space+AND+Telescope&id=EJ540140','ERIC'); return false;" href="https://eric.ed.gov/?q=Hubble+AND+Space+AND+Telescope&id=EJ540140"><span><span class="hlt">Interactive</span> Astronomy.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Martin, Jean K.</p> <p>1997-01-01</p> <p>Presents guiding principles for developing <span class="hlt">interactive</span> lessons for the World Wide Web. Describes "Amazing Space: Education Online from the Hubble Space Telescope", a program where students study spectacular Hubble Space Telescope images of stars and star-forming regions to learn about the life cycle of stars and the creation of atoms. (JRH)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=sewing+AND+machine&pg=4&id=ED224054','ERIC'); return false;" href="https://eric.ed.gov/?q=sewing+AND+machine&pg=4&id=ED224054"><span>Constructive <span class="hlt">Interaction</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Miyake, Naomi</p> <p></p> <p>To identify conditions that make a conversational <span class="hlt">interaction</span> constructive--in the sense that the participants can find the way toward the success of what they wanted to accomplish--two situations were examined. In one, a professional researcher explained her data to a statistician. In the other, three groups of two people cooperated with each…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=magnetic+AND+field&pg=4&id=EJ859376','ERIC'); return false;" href="http://eric.ed.gov/?q=magnetic+AND+field&pg=4&id=EJ859376"><span><span class="hlt">Interacting</span> Compasses</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Riveros, Hector G.; Betancourt, Julian</p> <p>2009-01-01</p> <p>The use of multiple compasses to map and visualize magnetic fields is well-known. The magnetic field exerts a torque on the compasses aligning them along the lines of force. Some science museums show the field of a magnet using a table with many compasses in a closely packed arrangement. However, the very interesting <span class="hlt">interactions</span> that occur…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=HUBBLE&pg=2&id=EJ540140','ERIC'); return false;" href="http://eric.ed.gov/?q=HUBBLE&pg=2&id=EJ540140"><span><span class="hlt">Interactive</span> Astronomy.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Martin, Jean K.</p> <p>1997-01-01</p> <p>Presents guiding principles for developing <span class="hlt">interactive</span> lessons for the World Wide Web. Describes "Amazing Space: Education Online from the Hubble Space Telescope", a program where students study spectacular Hubble Space Telescope images of stars and star-forming regions to learn about the life cycle of stars and the creation of atoms. (JRH)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=torque+AND+physics&pg=2&id=EJ859376','ERIC'); return false;" href="https://eric.ed.gov/?q=torque+AND+physics&pg=2&id=EJ859376"><span><span class="hlt">Interacting</span> Compasses</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Riveros, Hector G.; Betancourt, Julian</p> <p>2009-01-01</p> <p>The use of multiple compasses to map and visualize magnetic fields is well-known. The magnetic field exerts a torque on the compasses aligning them along the lines of force. Some science museums show the field of a magnet using a table with many compasses in a closely packed arrangement. However, the very interesting <span class="hlt">interactions</span> that occur…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920008475','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920008475"><span>Radio sky mapping from satellites at very low frequencies</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Storey, L. R. O.</p> <p>1991-01-01</p> <p>Wave Distribution Function (WDF) analysis is a procedure for making sky maps of the sources of natural electromagnetic waves in space plasmas, given local measurements of some or all of the three magnetic and three electric field components. The work that still needs to be done on this subject includes solving basic methodological problems, translating the solution into efficient algorithms, and embodying the algorithms in computer software. One important scientific use of WDF analysis is to identify the mode of origin of <span class="hlt">plasmaspheric</span> <span class="hlt">hiss</span>. Some of the data from the Japanese satellite Akebono (EXOS D) are likely to be suitable for this purpose.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017inma.book.....D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017inma.book.....D"><span><span class="hlt">Interactive</span> Macroeconomics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Di Guilmi, Corrado; Gallegati, Mauro; Landini, Simone</p> <p>2017-04-01</p> <p>Preface; List of tables; List of figures, 1. Introduction; Part I. Methodological Notes and Tools: 2. The state space notion; 3. The master equation; Part II. Applications to HIA Based Models: 4. Financial fragility and macroeconomic dynamics I: heterogeneity and <span class="hlt">interaction</span>; 5. Financial fragility and macroeconomic Dynamics II: learning; Part III. Conclusions: 6. Conclusive remarks; Part IV. Appendices and Complements: Appendix A: Complements to Chapter 3; Appendix B: Solving the ME to solve the ABM; Appendix C: Specifying transition rates; Index.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26072556','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26072556"><span>Sibling <span class="hlt">interaction</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Balsam, Rosemary H</p> <p>2013-01-01</p> <p>Sibling <span class="hlt">interactions</span> traditionally were conceived psychoanalytically in "vertical" and parentified oedipal terms and overlooked in their own right, for complicated reasons (Colonna and Newman 1983). Important work has been done to right this, from the 1980s and onward, with conferences and writings. Juliet Mitchell's 2000 and, in particular, her 2003 books, for example, have brought "lateral" sibling relations forcefully to the forefront of insights, especially about sex and violence, with the added interdisciplinary impact of illuminating upheaval in global community <span class="hlt">interactions</span> as well as having implications for clinicians. A clinical example from the analysis of an adult woman with a ten-years-younger sister will show here how we need both concepts to help us understand complex individual psychic life. The newer "lateral" sibling emphasis, including Mitchell's "Law of the Mother" and "seriality," can be used to inform the older "vertical" take, to enrich the full dimensions of intersubjective oedipal and preoedipal reciprocities that have been foundational in shaping that particular analysand's inner landscape. Some technical recommendations for heightening sensitivity to the import of these dynamics will be offered along the way here, by invoking Hans Loewald's useful metaphor of the analytic situation as theater.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24252529','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24252529"><span>[Pharmacokinetic <span class="hlt">interactions</span>].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Arazo Garcés, Piedad; de los Santos Gil, Ignacio</p> <p>2013-06-01</p> <p>Rilpivirine (RPV) is a nonnucleoside reverse transcriptase inhibitor (NNRTI) that has been approved for use in treatment-naïve patients and which has potent antiviral activity. Its adverse effects profile differs from that of first-generation NNRTs. The pharmacological <span class="hlt">interactions</span> produced by RPV are due to its effects on the CYP450 system; RPV is a substrate and mild inducer of CYP3A4. Moreover, in vitro, RPV inhibits glycoprotein-P. RPV has clinically significant pharmacological <span class="hlt">interactions</span>, especially with protease inhibitors (except boosted darunavir and lopinavir) and the NNRTIs efavirenz and nevirapine. Coadministration of RPV with drugs that increase gastric pH, such as omeprazole, or those inducing CYP3A4, such as rifampicin, can significantly reduce RPV concentrations and is contraindicated. The concomitant use of RPV with a CYP3A4 inhibitor (such as clarithromycin) can increase RPV concentrations. Administration of PRV with food is recommended to obtain better absorption and adequate plasma values. Copyright © 2013 Elsevier España, S.L. All rights reserved.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008eso..pres....2.','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008eso..pres....2."><span>Cosmic <span class="hlt">Interactions</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p></p> <p>2008-01-01</p> <p>An image based on data taken with ESO's Very Large Telescope reveals a triplet of galaxies intertwined in a cosmic dance. ESO PR Photo 02/08 ESO PR Photo 02/08 NGC 7173, 7174, and 7176 The three galaxies, catalogued as NGC 7173 (top), 7174 (bottom right) and 7176 (bottom left), are located 106 million light-years away towards the constellation of Piscis Austrinus (the 'Southern Fish'). NGC 7173 and 7176 are elliptical galaxies, while NGC 7174 is a spiral galaxy with quite disturbed dust lanes and a long, twisted tail. This seems to indicate that the two bottom galaxies - whose combined shape bears some resemblance to that of a sleeping baby - are currently <span class="hlt">interacting</span>, with NGC 7176 providing fresh material to NGC 7174. Matter present in great quantity around the triplet's members also points to the fact that NGC 7176 and NGC 7173 have <span class="hlt">interacted</span> in the past. Astronomers have suggested that the three galaxies will finally merge into a giant 'island universe', tens to hundreds of times as massive as our own Milky Way. ESO PR Photo 02/08 ESO PR Photo 02b/08 NGC 7173, 7174, and 7176 The triplet is part of a so-called 'Compact Group', as compiled by Canadian astronomer Paul Hickson in the early 1980s. The group, which is the 90th entry in the catalogue and is therefore known as HCG 90, actually contains four major members. One of them - NGC 7192 - lies above the trio, outside of this image, and is another peculiar spiral galaxy. Compact groups are small, relatively isolated, systems of typically four to ten galaxies in close proximity to one another. Another striking example is Robert's Quartet. Compact groups are excellent laboratories for the study of galaxy <span class="hlt">interactions</span> and their effects, in particular the formation of stars. As the striking image reveals, there are many other galaxies in the field. Some are distant ones, while others seem to be part of the family. Studies made with other telescopes have indeed revealed that the HCG 90 group contains 16 members</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6520728','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6520728"><span>Electroweak <span class="hlt">interactions</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bjorken, J.D.</p> <p>1980-10-01</p> <p>A point of view of the electroweak <span class="hlt">interaction</span> is presented. It begins phenomenologically and moves in stages toward the conventional gauge theory formalism containing elementary scalar Higgs-fields and then beyond. The purpose in so doing is that the success of the standard SU(2) x U(1) theory in accounting for low energy phenomena need not automatically imply success at high energies. It is deemed unlikely by most theorists that the predicted W/sup + -/ or Z/sup 0/ does not exist or does not have the mass and/or couplings anticipated in the standard model. However, the odds that the standard predictions will work are not 100%. Therefore there is some reason to look at the subject as one would were he forced by a wrong experimental outcome - to go back to fundamentals and ascertain what is the minimal amount of theory necessary to account for the data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940013051','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940013051"><span>Kinetic plasma processes occurring in the outer <span class="hlt">plasmasphere</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wilson, Gordon R.</p> <p>1992-01-01</p> <p>One area of data analysis work that was begun under this contract is the fitting of the perpendicular velocity distributions of equatorially trapped ions with a Kappa function. This type of characterization of the trapped ions will be very useful for comparison with velocity distributions produced by the model. A second area of data analysis is to study data from consecutive passes when DE 1's apogee was near the magnetic equator and the spacecraft was often skimming along nearly the same L shell. In 1982 three such periods occurred in May, June, and July. For these consecutive events we have Kp histories, density measurements from a number of sources (Whistler data, DE SFR, ISEE SFR) and consecutive samples of ion pitch angle distributions along field lines. It is clear from this data how the pitch angle distributions evolve during a flux tube refilling event. Our modeling of the flow of plasma along closed field lines is following two basic tracks. The first is a study of the basic refilling process without the effect of wave-particle heating near the equator or the effect of large or abrupt field-aligned electric potential drops. This model includes the effects of Coulomb self-collisions and collisions with the O+ ions in the topside ionosphere. The second track is a study of the effects of wave produced pitch-angle scattering and perpendicular heating occurring near the magnetic equator, in connection with the development of large potential drops that result from electron heating and the development of density gradients.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19860039650&hterms=population+control&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dpopulation%2Bcontrol','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19860039650&hterms=population+control&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dpopulation%2Bcontrol"><span>The hidden ion population - Revisited. [in outer <span class="hlt">plasmasphere</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Olsen, R. C.; Chappell, C. R.; Gallagher, D. L.; Green, J. L.; Gurnett, D. A.</p> <p>1985-01-01</p> <p>In an investigation conducted by Olsen (1982) on the basis of particle data taken with an electrostatic analyzer, it was found that a cold plasma population with a density between 10 and 100 per cu cm appeared suddenly when the satellite was eclipsed, but was hidden in sunlight. The present paper has the objective to show further measurements of ordinarily 'hidden' ion populations, in order to resolve some of the questions raised in connection with the Scatha satellite data reported by Olsen. It is found that the retarding ion mass spectrometer (RIMS) detector is capable of measuring the core of the plasma distribution in sunlight and eclipse, though the task is more easily done in eclipse. There are, however, limitations concerning the ability of the detector to measure all the plasma, all the time. It is, therefore, pointed out that continuous effective measurements of the 'hidden' ion population of the magnetosphere still awaits satellites with effective means of potential control.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA104362','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA104362"><span><span class="hlt">Plasmaspheric</span>, Faraday and Total Electron Contents, 1977 and 1978.</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>1980-12-01</p> <p>in) ’r cnj ON 0l ’N - ’ in U"- - ko -O r- j rn cc C) t i if LO nt U- - U)w r-- r-- 0 co j-’ w0’In’.ko D IfV) r- w cr w = Fl. r. o vino Co N r-f cj...Ito 10 mi O’O)C i )c)nf V, LONC IA koi o.2 L 101,vc c N- CIN-v O’-’CWi0)tW ONNC CDIN JCOS vInO ’.N O0%O J) *CD CD ~~~ ~ ~ (, N-f 44..-44- . 1 I- k</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=types+AND+quantitative+AND+research+AND+designs&id=EJ1107629','ERIC'); return false;" href="https://eric.ed.gov/?q=types+AND+quantitative+AND+research+AND+designs&id=EJ1107629"><span>Designing "<span class="hlt">Interaction</span>": How Do <span class="hlt">Interaction</span> Design Students Address <span class="hlt">Interaction</span>?</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Karlgren, Klas; Ramberg, Robert; Artman, Henrik</p> <p>2016-01-01</p> <p><span class="hlt">Interaction</span> design is usually described as being concerned with <span class="hlt">interactions</span> with and through artifacts but independent of a specific implementation. Design work has been characterized as a conversation between the designer and the situation and this conversation poses a particular challenge for <span class="hlt">interaction</span> design as <span class="hlt">interactions</span> can be elusive…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=artifact&pg=7&id=EJ1107629','ERIC'); return false;" href="http://eric.ed.gov/?q=artifact&pg=7&id=EJ1107629"><span>Designing "<span class="hlt">Interaction</span>": How Do <span class="hlt">Interaction</span> Design Students Address <span class="hlt">Interaction</span>?</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Karlgren, Klas; Ramberg, Robert; Artman, Henrik</p> <p>2016-01-01</p> <p><span class="hlt">Interaction</span> design is usually described as being concerned with <span class="hlt">interactions</span> with and through artifacts but independent of a specific implementation. Design work has been characterized as a conversation between the designer and the situation and this conversation poses a particular challenge for <span class="hlt">interaction</span> design as <span class="hlt">interactions</span> can be elusive…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=PIA06451&hterms=Cloud+technology&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DCloud%2Btechnology','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=PIA06451&hterms=Cloud+technology&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DCloud%2Btechnology"><span>Cloud <span class="hlt">Interactions</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2004-01-01</p> <p>[figure removed for brevity, see original site] <p/> Released 1 July 2004 The atmosphere of Mars is a dynamic system. Water-ice clouds, fog, and hazes can make imaging the surface from space difficult. Dust storms can grow from local disturbances to global sizes, through which imaging is impossible. Seasonal temperature changes are the usual drivers in cloud and dust storm development and growth. <p/> Eons of atmospheric dust storm activity has left its mark on the surface of Mars. Dust carried aloft by the wind has settled out on every available surface; sand dunes have been created and moved by centuries of wind; and the effect of continual sand-blasting has modified many regions of Mars, creating yardangs and other unusual surface forms. <p/> This image was acquired during mid-spring near the North Pole. The linear water-ice clouds are now regional in extent and often <span class="hlt">interact</span> with neighboring cloud system, as seen in this image. The bottom of the image shows how the <span class="hlt">interaction</span> can destroy the linear nature. While the surface is still visible through most of the clouds, there is evidence that dust is also starting to enter the atmosphere. <p/> Image information: VIS instrument. Latitude 68.4, Longitude 258.8 East (101.2 West). 38 meter/pixel resolution. <p/> Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time. <p/> NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSM53D2255K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSM53D2255K"><span>Multi-Spacecraft Data Assimilation and Reanalysis During the THEMIS and Van Allen Probes Era</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kellerman, A. C.; Shprits, Y.; Kondrashov, D. A.; Podladchikova, T.; Drozdov, A.; Subbotin, D.</p> <p>2013-12-01</p> <p>Earth's radiation belts are a dynamic system, controlled by competition between source, acceleration, loss and transport of particles. Solar wind pressure enhancements and outward transport are responsible for loss of electrons to the magnetopause, while wave-particle <span class="hlt">interactions</span> inside the magnetosphere, driven by solar wind pressure and velocity variations, may lead to acceleration and radial diffusion of 10's of keV to MeV energy electrons, and pitch-angle scattering loss to the atmosphere. An understanding of the mechanisms behind the observed dynamics is critical to accurate modeling and hence forecasting of radiation belt conditions, important for design, and protection of our space-borne assets. The Versatile Electron Radiation Belt (VERB) model solves the Fokker-Planck diffusion equation in three dimensional invariant coordinates, which allows one to more effectively separate adiabatic and non-adiabatic changes in the radiation belt electron population. The model includes geomagnetic storm intensity dependent parameterizations of the following dominant magnetospheric waves: day- and night-side chorus, <span class="hlt">plasmaspheric</span> <span class="hlt">hiss</span> (in the inner magnetosphere and inside the plume region), lightning and anthropogenic generated waves, and electro-magnetic ion cyclotron (EMIC) waves, also inside of <span class="hlt">plasmaspheric</span> plumes. The model is used to forecast the future state of the radiation belt electron population, while real-time data may be used to update the current state of the belts through assimilation with the model. The Kalman filter provides a computationally inexpensive method to assimilate data with a model, while taking into account the errors associated with each. System identification is performed to determine the model and observational bias and errors. The Kalman filter outputs an optimal estimate of the actual system state and the Kalman-gain weighted corrections (innovation) may be used to identify systematic differences between data and the model. Careful</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRA..121.2423B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRA..121.2423B"><span>A unified approach to inner magnetospheric state prediction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bortnik, J.; Li, W.; Thorne, R. M.; Angelopoulos, V.</p> <p>2016-03-01</p> <p>This brief technique paper presents a method of reconstructing the global, time-varying distribution of some physical quantity Q that has been sparsely sampled at various locations within the magnetosphere and at different times. The quantity Q can be essentially any measurement taken on the satellite including a variety of waves (chorus, <span class="hlt">hiss</span>, magnetosonic, and ion cyclotron), electrons of various energies ranging from cold to relativistic, and ions of various species and energies. As an illustrative example, we chose Q to be the electron number density (inferred from spacecraft potential) measured by three Time History of Events and Macroscale <span class="hlt">Interactions</span> during Substorms (THEMIS) probes between 2008 and 2014 and use the SYM-H index, taken at a 5 min cadence for the 5 h preceding each observed data point as the main regressor, although the predictor can also be any suitable geomagnetic index or solar wind parameter. Results show that the equatorial electron number density can be accurately reconstructed throughout the whole of the inner magnetosphere as a function of space and time, even capturing the dynamics of elementary <span class="hlt">plasmaspheric</span> plume formation and corotation, suggesting that the dynamics of various other physical quantities could be similarly captured. For our main model, we use a simple, fully connected feedforward neural network with two hidden layers having sigmoidal activation functions and an output layer with a linear activation function to perform the reconstruction. The training is performed using the Levenberg-Marquardt algorithm and gives typical RMS errors of ~1.7 and regression of >0.93, which is considered excellent. We also present a discussion on the different applications and future extensions of the present model, for modeling various physical quantities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRA..122..695T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRA..122..695T"><span>Investigating the source of near-relativistic and relativistic electrons in Earth's inner radiation belt</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Turner, D. L.; O'Brien, T. P.; Fennell, J. F.; Claudepierre, S. G.; Blake, J. B.; Jaynes, A. N.; Baker, D. N.; Kanekal, S.; Gkioulidou, M.; Henderson, M. G.; Reeves, G. D.</p> <p>2017-01-01</p> <p>Using observations from NASA's Van Allen Probes, we study the role of sudden particle enhancements at low L shells (SPELLS) as a source of inner radiation belt electrons. SPELLS events are characterized by electron intensity enhancements of approximately an order of magnitude or more in less than 1 day at L < 3. During quiet and average geomagnetic conditions, the phase space density radial distributions for fixed first and second adiabatic invariants are peaked at 2 < L < 3 for electrons ranging in energy from 50 keV to 1 MeV, indicating that slow inward radial diffusion is not the dominant source of inner belt electrons under quiet/average conditions. During SPELLS events, the evolution of electron distributions reveals an enhancement of phase space density that can exceed 3 orders of magnitude in the slot region and continues into the inner radiation belt, which is evidence that these events are an important - and potentially dominant - source of inner belt electrons. Electron fluxes from September 2012 through February 2016 reveal that SPELLS occur frequently ( 2.5/month at 200 keV), but the number of observed events decreases exponentially with increasing electron energy for ≥100 keV. After SPELLS events, the slot region reforms due to slow energy-dependent decay over several day time scales, consistent with losses due to <span class="hlt">interactions</span> with <span class="hlt">plasmaspheric</span> <span class="hlt">hiss</span>. Combined, these results indicate that the peaked phase space density distributions in the inner electron radiation belt result from an "on/off," geomagnetic-activity-dependent source from higher radial distances.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1345952-investigating-source-near-relativistic-relativistic-electrons-earth-inner-radiation-belt','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1345952-investigating-source-near-relativistic-relativistic-electrons-earth-inner-radiation-belt"><span>Investigating the source of near-relativistic and relativistic electrons in Earth's inner radiation belt</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Turner, Drew Lawson; O'Brien, T. P.; Fennell, J. F.; ...</p> <p>2017-01-30</p> <p>Using observations from NASA's Van Allen Probes, we study the role of sudden particle enhancements at low L shells (SPELLS) as a source of inner radiation belt electrons. SPELLS events are characterized by electron intensity enhancements of approximately an order of magnitude or more in less than 1 day at L < 3. During quiet and average geomagnetic conditions, the phase space density radial distributions for fixed first and second adiabatic invariants are peaked at 2 < L < 3 for electrons ranging in energy from ~50 keV to ~1 MeV, indicating that slow inward radial diffusion is not themore » dominant source of inner belt electrons under quiet/average conditions. During SPELLS events, the evolution of electron distributions reveals an enhancement of phase space density that can exceed 3 orders of magnitude in the slot region and continues into the inner radiation belt, which is evidence that these events are an important—and potentially dominant—source of inner belt electrons. Electron fluxes from September 2012 through February 2016 reveal that SPELLS occur frequently (~2.5/month at 200 keV), but the number of observed events decreases exponentially with increasing electron energy for ≥100 keV. After SPELLS events, the slot region reforms due to slow energy-dependent decay over several day time scales, consistent with losses due to <span class="hlt">interactions</span> with <span class="hlt">plasmaspheric</span> <span class="hlt">hiss</span>. Altogether, these results indicate that the peaked phase space density distributions in the inner electron radiation belt result from an “on/off,” geomagnetic-activity-dependent source from higher radial distances.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSM44B..03R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSM44B..03R"><span>Energy dependent dynamics of keV to MeV electrons in the inner zone, outer zone, and slot regions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reeves, G. D.; Friedel, R. H.; Larsen, B.; Skoug, R. M.; Funsten, H. O.; Claudepierre, S. G.; Fennell, J. F.; Turner, D. L.; Denton, M.; Spence, H. E.; Blake, J. B.; Baker, D. N.</p> <p>2015-12-01</p> <p>We present observations that illustrate the energy-dependence and L-shell dependence of radiation belt dynamics. We survey events in 2013 and analyze individual events in more detail. The survey data show: (a) Lower-energy electrons are enhanced more often than higher energies. (b) Events that fill the slot region are more common at lower energies. (c) Enhancements of electrons in the inner zone are more common at lower energies. And (d) even when events do not fully fill the slot region, enhancements at lower-energies tend to extend to lower L-shells than higher energies. The outer zone, inner zone, and slot region all occupy regions of space that are strongly energy dependent. During enhancement events the outer zone extends to lower L-shells at lower energies and higher L-shells at higher energies. The inner zone shows the opposite with an outer boundary at higher L-shells for lower energies. Both boundaries are nearly straight in log(energy) vs. L-shell space. At energies below a few hundred keV radiation belt electron penetration through the slot region into the inner zone is commonplace but the number and frequency of "slot filling" events decreases with increasing energy. The inner zone is enhanced only at energies that penetrate through the slot. Analysis shows that at least three processes may determine which electrons penetrate into the slot and inner zone: (1) enhanced convective electric fields at low L-shells, (2) impulsive, substorm-associated injections at low L-shells, and (3) slower radial diffusion and <span class="hlt">interaction</span> with <span class="hlt">plasmaspheric</span> <span class="hlt">hiss</span>. These new observations challenge some of our long-held pictures of what the radiation belts look like and how they behave.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=costanzo&pg=4&id=EJ385577','ERIC'); return false;" href="http://eric.ed.gov/?q=costanzo&pg=4&id=EJ385577"><span>Formation et <span class="hlt">interaction</span> (Teacher Education and <span class="hlt">Interaction</span>).</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Bertocchini, Paola; Costanzo, Edwige</p> <p>1989-01-01</p> <p>Effective <span class="hlt">interaction</span> is as important in inservice education programs for language teachers as it is in the foreign language classroom. Techniques are described for improving the quality of <span class="hlt">interaction</span> in teacher workshops through simulation exercises. (MSE)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19750057130&hterms=cold+plasma&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dcold%2Bplasma','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19750057130&hterms=cold+plasma&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dcold%2Bplasma"><span>Ionosphere-magnetosphere coupling. I - Thermal plasma</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chappell, C. R.</p> <p>1975-01-01</p> <p>The complex <span class="hlt">interaction</span> of the cold plasma of the <span class="hlt">plasmasphere</span> and ionosphere with the hot plasma of the ring current and the plasma sheet is studied. It is seen that a coupling, probably through wave particle <span class="hlt">interactions</span>, exists which seems to have a strong influence on the temperature of the plasma of the outer <span class="hlt">plasmasphere</span> and on the detailed dynamics of the bulge region, especially the formation of detached plasma regions or plasma tails. Also, there is evidence that the outer <span class="hlt">plasmasphere</span> may display very high temperatures, and that detached plasma regions are closely associated with ring current injections.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1933215','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1933215"><span>PIC: Protein <span class="hlt">Interactions</span> Calculator</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Tina, K. G.; Bhadra, R.; Srinivasan, N.</p> <p>2007-01-01</p> <p><span class="hlt">Interactions</span> within a protein structure and <span class="hlt">interactions</span> between proteins in an assembly are essential considerations in understanding molecular basis of stability and functions of proteins and their complexes. There are several weak and strong <span class="hlt">interactions</span> that render stability to a protein structure or an assembly. Protein <span class="hlt">Interactions</span> Calculator (PIC) is a server which, given the coordinate set of 3D structure of a protein or an assembly, computes various <span class="hlt">interactions</span> such as disulphide bonds, <span class="hlt">interactions</span> between hydrophobic residues, ionic <span class="hlt">interactions</span>, hydrogen bonds, aromatic–aromatic <span class="hlt">interactions</span>, aromatic–sulphur <span class="hlt">interactions</span> and cation–π <span class="hlt">interactions</span> within a protein or between proteins in a complex. <span class="hlt">Interactions</span> are calculated on the basis of standard, published criteria. The identified <span class="hlt">interactions</span> between residues can be visualized using a RasMol and Jmol interface. The advantage with PIC server is the easy availability of inter-residue <span class="hlt">interaction</span> calculations in a single site. It also determines the accessible surface area and residue-depth, which is the distance of a residue from the surface of the protein. User can also recognize specific kind of <span class="hlt">interactions</span>, such as apolar–apolar residue <span class="hlt">interactions</span> or ionic <span class="hlt">interactions</span>, that are formed between buried or exposed residues or near the surface or deep inside. PMID:17584791</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17584791','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17584791"><span>PIC: Protein <span class="hlt">Interactions</span> Calculator.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tina, K G; Bhadra, R; Srinivasan, N</p> <p>2007-07-01</p> <p><span class="hlt">Interactions</span> within a protein structure and <span class="hlt">interactions</span> between proteins in an assembly are essential considerations in understanding molecular basis of stability and functions of proteins and their complexes. There are several weak and strong <span class="hlt">interactions</span> that render stability to a protein structure or an assembly. Protein <span class="hlt">Interactions</span> Calculator (PIC) is a server which, given the coordinate set of 3D structure of a protein or an assembly, computes various <span class="hlt">interactions</span> such as disulphide bonds, <span class="hlt">interactions</span> between hydrophobic residues, ionic <span class="hlt">interactions</span>, hydrogen bonds, aromatic-aromatic <span class="hlt">interactions</span>, aromatic-sulphur <span class="hlt">interactions</span> and cation-pi <span class="hlt">interactions</span> within a protein or between proteins in a complex. <span class="hlt">Interactions</span> are calculated on the basis of standard, published criteria. The identified <span class="hlt">interactions</span> between residues can be visualized using a RasMol and Jmol interface. The advantage with PIC server is the easy availability of inter-residue <span class="hlt">interaction</span> calculations in a single site. It also determines the accessible surface area and residue-depth, which is the distance of a residue from the surface of the protein. User can also recognize specific kind of <span class="hlt">interactions</span>, such as apolar-apolar residue <span class="hlt">interactions</span> or ionic <span class="hlt">interactions</span>, that are formed between buried or exposed residues or near the surface or deep inside.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSM53A..04C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSM53A..04C"><span>Effect of Precipitating Electrons on Stormtime Inner Magnetospheric Electric Fields during the 17 March 2013 Storm</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, M.; Lemon, C. L.; Sazykin, S. Y.; Wolf, R.; Hecht, J. H.; Walterscheid, R. L.; Boyd, A. J.; Turner, D. L.</p> <p>2015-12-01</p> <p>We investigate how scattering of electrons by waves in the plasma sheet and <span class="hlt">plasmasphere</span> affects precipitating energy flux distributions and how the precipitating electrons modify the ionospheric conductivity and electric potentials during the large 17 March 2013 magnetic storm. Of particular interest is how electron precipitation in the evening sector affects the development of the Sub-auroral Polarization Stream (SAPS) electric field that is observed at sub-auroral latitudes in that sector. Our approach is to use the magnetically and electrically self-consistent Rice Convection Model - Equilibrium (RCM-E) of the inner magnetosphere to simulate the stormtime precipitating electron distributions and the electric field. We use parameterized rates of whistler-generated electron pitch-angle scattering from Orlova and Shprits [JGR, 2014] that depend on equatorial radial distance, magnetic activity (Kp), and magnetic local time (MLT) outside the simulated <span class="hlt">plasmasphere</span>. Inside the <span class="hlt">plasmasphere</span>, parameterized scattering rates due to <span class="hlt">hiss</span> [Orlova et al., GRL, 2014] are used. We compare simulated trapped and precipitating electron flux distributions with measurements from Van Allen Probes/MagEIS, POES/TED and MEPED, respectively, to validate the electron loss model. Ground-based (SuperDARN) and in-situ (Van Allen Probes/EFW) observations of electric fields are compared with the simulation results. We discuss the effect of precipitating electrons on the SAPS and inner magnetospheric electric field through the data-model comparisons.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28261555','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28261555"><span>Food and Drug <span class="hlt">Interactions</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Choi, Jong Hwan; Ko, Chang Mann</p> <p>2017-01-01</p> <p>Natural foods and vegetal supplements have recently become increasingly popular for their roles in medicine and as staple foods. This has, however, led to the increased risk of <span class="hlt">interaction</span> between prescribed drugs and the bioactive ingredients contained in these foods. These <span class="hlt">interactions</span> range from pharmacokinetic <span class="hlt">interactions</span> (absorption, distribution, metabolism, and excretion influencing blood levels of drugs) to pharmacodynamic <span class="hlt">interactions</span> (drug effects). In a quantitative respect, these <span class="hlt">interactions</span> occur mainly during metabolism. In addition to the systemic metabolism that occurs mainly in the liver, recent studies have focused on the metabolism in the gastrointestinal tract endothelium before absorption. Inhibition of metabolism causes an increase in the blood levels of drugs and could have adverse reactions. The food-drug <span class="hlt">interactions</span> causing increased blood levels of drugs may have beneficial or detrimental therapeutic effects depending on the intensity and predictability of these <span class="hlt">interactions</span>. It is therefore important to understand the potential <span class="hlt">interactions</span> between foods and drugs should and the specific outcomes of such <span class="hlt">interactions</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19960018544','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19960018544"><span>Electromagnetic Components of Auroral <span class="hlt">Hiss</span> and Lower Hybrid Waves in the Polar Magnetosphere</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wong, H. K.</p> <p>1995-01-01</p> <p>DE-1 has frequently observed waves in the whistler and lower hybrid frequencies range. Besides the electrostatic components, these waves also exhibit electromagnetic components. It is generally believed that these waves are excited by the electron acoustic instability and the electron-beam-driven lower hybrid instability. Because the electron acoustic and the lower hybrid waves are predominately electrostatic waves, they cannot account for the observed electromagnetic components. In this work, it is suggested that these electromagnetic components can be explained by waves that are generated near the resonance cone and that propagate away from the source. The role that these electromagnetic waves can play in particle acceleration processes at low altitude is discussed.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=history+AND+experiments+AND+animals&id=EJ997038','ERIC'); return false;" href="https://eric.ed.gov/?q=history+AND+experiments+AND+animals&id=EJ997038"><span>The Madagascar <span class="hlt">Hissing</span> Cockroach: A New Model for Learning Insect Anatomy</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Heyborne, William H.; Fast, Maggie; Goodding, Daniel D.</p> <p>2012-01-01</p> <p>Teaching and learning animal anatomy has a long history in the biology classroom. As in many fields of biology, decades of experience teaching anatomy have led to the unofficial selection of model species. However, in some cases the model may not be the best choice for our students. Our struggle to find an appropriate model for teaching and…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Anatomy&pg=2&id=EJ997038','ERIC'); return false;" href="http://eric.ed.gov/?q=Anatomy&pg=2&id=EJ997038"><span>The Madagascar <span class="hlt">Hissing</span> Cockroach: A New Model for Learning Insect Anatomy</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Heyborne, William H.; Fast, Maggie; Goodding, Daniel D.</p> <p>2012-01-01</p> <p>Teaching and learning animal anatomy has a long history in the biology classroom. As in many fields of biology, decades of experience teaching anatomy have led to the unofficial selection of model species. However, in some cases the model may not be the best choice for our students. Our struggle to find an appropriate model for teaching and…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760011293','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760011293"><span>Combustion of hydrogen injected into a supersonic airstream (a guide to the <span class="hlt">HISS</span> computer program)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Dyer, D. F.; Maples, G.; Spalding, D. B.</p> <p>1976-01-01</p> <p>A computer program based on a finite-difference, implicit numerical integration scheme is described for the prediction of hydrogen injected into a supersonic airstream at an angle ranging from normal to parallel to the airstream main flow direction. Results of calculations for flow and thermal property distributions were compared with 'cold flow data' taken by NASA/Langley and show excellent correlation. Typical results for equilibrium combustion are presented and exhibit qualitatively plausible behavior. Computer time required for a given case is approximately one minute on a CDC 7600. A discussion of the assumption of parabolic flow in the injection region is given which demonstrates that improvement in calculation in this region could be obtained by a partially-parabolic procedure which has been developed. It is concluded that the technique described provides an efficient and reliable means for analyzing hydrogen injection into supersonic airstreams and the subsequent combustion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22391031','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22391031"><span><span class="hlt">Interacting</span> dark sector with transversal <span class="hlt">interaction</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chimento, Luis P.; Richarte, Martín G.</p> <p>2015-03-26</p> <p>We investigate the <span class="hlt">interacting</span> dark sector composed of dark matter, dark energy, and dark radiation for a spatially flat Friedmann-Robertson-Walker (FRW) background by introducing a three-dimensional internal space spanned by the <span class="hlt">interaction</span> vector Q and solve the source equation for a linear transversal <span class="hlt">interaction</span>. Then, we explore a realistic model with dark matter coupled to a scalar field plus a decoupled radiation term, analyze the amount of dark energy in the radiation era and find that our model is consistent with the recent measurements of cosmic microwave background anisotropy coming from Planck along with the future constraints achievable by CMBPol experiment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=gestalt+AND+therapy&pg=2&id=EJ122391','ERIC'); return false;" href="http://eric.ed.gov/?q=gestalt+AND+therapy&pg=2&id=EJ122391"><span>Gestalt <span class="hlt">Interactional</span> Groups</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Harman, Robert L.; Franklin, Richard W.</p> <p>1975-01-01</p> <p>Gestalt therapy in groups is not limited to individual work in the presence of an audience. Describes several ways to involve gestalt groups <span class="hlt">interactionally</span>. <span class="hlt">Interactions</span> described focus on learning by doing and discovering, and are noninterpretive. (Author/EJT)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19840000014&hterms=wiring+harnesses&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dwiring%2Bharnesses','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19840000014&hterms=wiring+harnesses&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dwiring%2Bharnesses"><span>Computerized <span class="hlt">Interactive</span> Harness Engineering</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Billitti, J. W.</p> <p>1985-01-01</p> <p>Computerized <span class="hlt">interactive</span> harness engineering program inexpensive, <span class="hlt">interactive</span> system for learning and using engineering approach to interconnection systems. Basically data-base system that stores information as files of individual connectors and handles wiring information in circuit groups stored as records.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6929635','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6929635"><span><span class="hlt">Interactions</span> between magnetohydrodynamical discontinuities</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Dai, W.; Woodward, P.R. )</p> <p>1994-11-01</p> <p><span class="hlt">Interactions</span> between magnetohydrodynamical (MHD) discontinuities are studied through numerical simulations for the set of one-dimensional MHD equations. The <span class="hlt">interactions</span> include the impact of a shock on a contact discontinuity, the collision of two shocks, and the catchup of a shock over another shock. The shocks involved in the <span class="hlt">interactions</span> may be very strong. Each shock in an <span class="hlt">interaction</span> may be either a fast or a slow shock.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=control+AND+rod&pg=4&id=EJ561392','ERIC'); return false;" href="http://eric.ed.gov/?q=control+AND+rod&pg=4&id=EJ561392"><span><span class="hlt">Interactivity</span>: A Forgotten Art?</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Sims, Rod</p> <p>1997-01-01</p> <p>This paper promotes further discussion and analysis of <span class="hlt">interactivity</span> in learning environments and contains a classification of <span class="hlt">interaction</span> types appropriate for consideration in multimedia settings. Through an examination of related factors associated with navigation and control, a matrix of <span class="hlt">interactive</span> dimensions is proposed. (Author)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED116607.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED116607.pdf"><span><span class="hlt">Interactive</span> Reactor Simulation.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Nuttall, Herbert E., Jr.; Himmelblau, David M.</p> <p></p> <p>In the field of chemical engineering, <span class="hlt">interactive</span> process models can simulate the dynamic behavior and analysis of chemical processes. DYFLO was the process simulation program selected as a foundation for development of <span class="hlt">interactive</span> programs for computer-assisted instruction (CAI) in chemical engineering. <span class="hlt">Interactive</span> Computing and time sharing…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=interactive+AND+system&id=EJ857317','ERIC'); return false;" href="http://eric.ed.gov/?q=interactive+AND+system&id=EJ857317"><span>Dynamic <span class="hlt">Interactive</span> Learning Systems</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Sabry, Khaled; Barker, Jeff</p> <p>2009-01-01</p> <p>This paper reviews and discusses the notions of <span class="hlt">interactivity</span> and dynamicity of learning systems in relation to information technologies and design principles that can contribute to <span class="hlt">interactive</span> and dynamic learning. It explores the concept of dynamic <span class="hlt">interactive</span> learning systems based on the emerging generation of information as part of a…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=interaction+AND+design&id=EJ933726','ERIC'); return false;" href="http://eric.ed.gov/?q=interaction+AND+design&id=EJ933726"><span>Global <span class="hlt">Interaction</span> in Design</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Bennett, Audrey Grace</p> <p>2010-01-01</p> <p>Based on a virtual conference, Glide'08 (Global <span class="hlt">Interaction</span> in Design Education), that brought international design scholars together online, this special issue expands on the topics of cross-cultural communication and design and the technological affordances that support such <span class="hlt">interaction</span>. The author discusses the need for global <span class="hlt">interaction</span> in…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4971219','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4971219"><span>Evolving synergetic <span class="hlt">interactions</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wu, Bin; Arranz, Jordi; Du, Jinming; Zhou, Da; Traulsen, Arne</p> <p>2016-01-01</p> <p>Cooperators forgo their own interests to benefit others. This reduces their fitness and thus cooperators are not likely to spread based on natural selection. Nonetheless, cooperation is widespread on every level of biological organization ranging from bacterial communities to human society. Mathematical models can help to explain under which circumstances cooperation evolves. Evolutionary game theory is a powerful mathematical tool to depict the <span class="hlt">interactions</span> between cooperators and defectors. Classical models typically involve either pairwise <span class="hlt">interactions</span> between individuals or a linear superposition of these <span class="hlt">interactions</span>. For <span class="hlt">interactions</span> within groups, however, synergetic effects may arise: their outcome is not just the sum of its parts. This is because the payoffs via a single group <span class="hlt">interaction</span> can be different from the sum of any collection of two-player <span class="hlt">interactions</span>. Assuming that all <span class="hlt">interactions</span> start from pairs, how can such synergetic multiplayer games emerge from simpler pairwise <span class="hlt">interactions</span>? Here, we present a mathematical model that captures the transition from pairwise <span class="hlt">interactions</span> to synergetic multiplayer ones. We assume that different social groups have different breaking rates. We show that non-uniform breaking rates do foster the emergence of synergy, even though individuals always <span class="hlt">interact</span> in pairs. Our work sheds new light on the mechanisms underlying such synergetic <span class="hlt">interactions</span>. PMID:27466437</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AAS...204.1603D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AAS...204.1603D"><span>The <span class="hlt">Interactive</span> Learning Toolkit: supporting <span class="hlt">interactive</span> classrooms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dutta, S.; McCauley, V.; Mazur, E.</p> <p>2004-05-01</p> <p>Research-based <span class="hlt">interactive</span> learning techniques have dramatically improved student understanding. We have created the '<span class="hlt">Interactive</span> Learning Toolkit' (ILT), a web-based learning management system, to help implement two such pedagogies: Just in Time Teaching and Peer Instruction. Our main goal in developing this toolkit is to save the instructor time and effort and to use technology to facilitate the <span class="hlt">interaction</span> between the students and the instructor (and between students themselves). After a brief review of both pedagogies, we will demonstrate the many exciting new features of the ILT. We will show how technology can not only implement, but also supplement and improve these pedagogies. We would like acknowdge grants from NSF and DEAS, Harvard University</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24619146','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24619146"><span>[Drug-drug <span class="hlt">interactions</span>: <span class="hlt">interactions</span> between xenobiotics].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Haen, E</p> <p>2014-04-01</p> <p>Drug-drug <span class="hlt">interactions</span> (DDI) are a major topic in programs for continuous medical education (CME). Many physicians are afraid of being trapped into charges of malpractice; however, DDI cannot be avoided in many cases. They belong to routine medical practice and it is often impossible to avoid them. Moreover, they do not just occur between drugs but between any kind of foreign substance (xenobiotica), such as food (e.g. grapefruit juice, broccoli, barbecue) as well as legal (e.g. tobacco smoke, caffeine and alcohol) and illegal drugs. Therefore, the medical challenge is not just to avoid any <span class="hlt">interaction</span>. Instead the physician faces the question of how to proceed with drug treatment in the presence of such <span class="hlt">interactions</span>. Based on the medical education a physician has to judge first of all whether there is a risk for <span class="hlt">interactions</span> in the prescription being planned for an individual patient. The classification of <span class="hlt">interactions</span> proposed in this article (PD1-PD4, PK1-PK3) might help as a sort of check list. For more detailed information the physician can then consult one of the many databases available on the internet, such as PSIAConline (http://www.psiac.de) and MediQ (http://www.mediq.ch). Pharmacokinetic <span class="hlt">interactions</span> can be easily assessed, monitored and controlled by therapeutic drug monitoring (TDM). Besides these tools it is important to keep in mind that nobody knows everything; even physicians do not know everything. So take pride in asking someone who might help and for this purpose AGATE offers a drug information service AID (http://www.amuep-agate.de). Just good for nothing, without being based on any kind of medical approach are computer programs that judge prescriptions without taking into account a patient's individual peculiarities. In case these types of programs produce red exclamation marks or traffic lights to underline their judgment, they might even work in a contrapuntal way by just eliciting insecurity and fear.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3369190','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3369190"><span>The <span class="hlt">interactive</span> brain hypothesis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Di Paolo, Ezequiel; De Jaegher, Hanne</p> <p>2012-01-01</p> <p>Enactive approaches foreground the role of interpersonal <span class="hlt">interaction</span> in explanations of social understanding. This motivates, in combination with a recent interest in neuroscientific studies involving actual <span class="hlt">interactions</span>, the question of how <span class="hlt">interactive</span> processes relate to neural mechanisms involved in social understanding. We introduce the <span class="hlt">Interactive</span> Brain Hypothesis (IBH) in order to help map the spectrum of possible relations between social <span class="hlt">interaction</span> and neural processes. The hypothesis states that <span class="hlt">interactive</span> experience and skills play enabling roles in both the development and current function of social brain mechanisms, even in cases where social understanding happens in the absence of immediate <span class="hlt">interaction</span>. We examine the plausibility of this hypothesis against developmental and neurobiological evidence and contrast it with the widespread assumption that mindreading is crucial to all social cognition. We describe the elements of social <span class="hlt">interaction</span> that bear most directly on this hypothesis and discuss the empirical possibilities open to social neuroscience. We propose that the link between coordination dynamics and social understanding can be best grasped by studying transitions between states of coordination. These transitions form part of the self-organization of <span class="hlt">interaction</span> processes that characterize the dynamics of social engagement. The patterns and synergies of this self-organization help explain how individuals understand each other. Various possibilities for role-taking emerge during <span class="hlt">interaction</span>, determining a spectrum of participation. This view contrasts sharply with the observational stance that has guided research in social neuroscience until recently. We also introduce the concept of readiness to <span class="hlt">interact</span> to describe the practices and dispositions that are summoned in situations of social significance (even if not <span class="hlt">interactive</span>). This latter idea links <span class="hlt">interactive</span> factors to more classical observational scenarios. PMID:22701412</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=IWB+AND+mathematics&pg=2&id=EJ859741','ERIC'); return false;" href="http://eric.ed.gov/?q=IWB+AND+mathematics&pg=2&id=EJ859741"><span>How <span class="hlt">Interactive</span> Is the <span class="hlt">Interactive</span> Whiteboard?</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Quashie, Valerie</p> <p>2009-01-01</p> <p>An <span class="hlt">interactive</span> whiteboard (IWB) is simply a surface onto which a computer screen can be displayed, via a projector. It is touch-sensitive and lets one use a pen like a mouse, controlling the computer from the board itself. Everything that can be displayed on a computer can be displayed onto the whiteboard and, if the computer is linked to speakers…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=Different+AND+ways+AND+technological+AND+tools&pg=3&id=EJ895456','ERIC'); return false;" href="https://eric.ed.gov/?q=Different+AND+ways+AND+technological+AND+tools&pg=3&id=EJ895456"><span><span class="hlt">Interactive</span> Whiteboards: <span class="hlt">Interactive</span> or Just Whiteboards?</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Northcote, Maria; Mildenhall, Paula; Marshall, Linda; Swan, Paul</p> <p>2010-01-01</p> <p>Over the last decade, <span class="hlt">interactive</span> whiteboards have become popular teaching and learning tools, especially in primary school classrooms. Research studies from recent literature report on high levels of student motivation, teacher enthusiasm and whole-school support associated with these technological tools. Much research to date has reported on the…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1038932','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1038932"><span>Beam-Bem <span class="hlt">interactions</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kim, Hyung Jin; /Fermilab</p> <p>2011-12-01</p> <p>In high energy storage-ring colliders, the nonlinear effect arising from beam-beam <span class="hlt">interactions</span> is a major source that leads to the emittance growth, the reduction of beam life time, and limits the collider luminosity. In this paper, two models of beam-beam <span class="hlt">interactions</span> are introduced, which are weak-strong and strong-strong beam-beam <span class="hlt">interactions</span>. In addition, space-charge model is introduced.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22043389','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22043389"><span>Food-drug <span class="hlt">interactions</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bushra, Rabia; Aslam, Nousheen; Khan, Arshad Yar</p> <p>2011-03-01</p> <p>The effect of drug on a person may be different than expected because that drug <span class="hlt">interacts</span> with another drug the person is taking (drug-drug <span class="hlt">interaction</span>), food, beverages, dietary supplements the person is consuming (drug-nutrient/food <span class="hlt">interaction</span>) or another disease the person has (drug-disease <span class="hlt">interaction</span>). A drug <span class="hlt">interaction</span> is a situation in which a substance affects the activity of a drug, i.e. the effects are increased or decreased, or they produce a new effect that neither produces on its own. These <span class="hlt">interactions</span> may occur out of accidental misuse or due to lack of knowledge about the active ingredients involved in the relevant substances. Regarding food-drug <span class="hlt">interactions</span> physicians and pharmacists recognize that some foods and drugs, when taken simultaneously, can alter the body's ability to utilize a particular food or drug, or cause serious side effects. Clinically significant drug <span class="hlt">interactions</span>, which pose potential harm to the patient, may result from changes in pharmaceutical, pharmacokinetic, or pharmacodynamic properties. Some may be taken advantage of, to the benefit of patients, but more commonly drug <span class="hlt">interactions</span> result in adverse drug events. Therefore it is advisable for patients to follow the physician and doctors instructions to obtain maximum benefits with least food-drug <span class="hlt">interactions</span>. The literature survey was conducted by extracting data from different review and original articles on general or specific drug <span class="hlt">interactions</span> with food. This review gives information about various <span class="hlt">interactions</span> between different foods and drugs and will help physicians and pharmacists prescribe drugs cautiously with only suitable food supplement to get maximum benefit for the patient.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950059016&hterms=plasma+simulation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dplasma%2Bsimulation','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950059016&hterms=plasma+simulation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dplasma%2Bsimulation"><span>Kinetic simulation of plasma flows in the inner magnetosphere</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Miller, Ronald H.; Rasmussen, Craig E.; Gombosi, Tamas I.; Khazanov, Georgi V.; Winske, Dan</p> <p>1993-01-01</p> <p>A one-dimensional hybrid particle code is used to study the <span class="hlt">interactions</span> between upflowing thermal ions from conjugate ionospheres. The simulation model allows for multiple species, convection of <span class="hlt">plasmaspheric</span> flux tubes, and Coulomb self-collisions which conserve momentum and energy locally. The model incorporates a variable-flux boundary condition where the flux, at the boundaries, approaches zero as the <span class="hlt">plasmasphere</span> fills and equilibrium conditions are reached. The effects of two important processes on <span class="hlt">plasmaspheric</span> refilling have been considered. The first includes convection of the <span class="hlt">plasmaspheric</span> flux tube. The second is the <span class="hlt">interaction</span> of ionospheric thermal plasma and particle injection from an external source. Particle injection seems to play an important role in the evolution of the total particle distribution on the early timescales (t less than 1 hour); however, for late timescales (t larger than 8 days) the thermal plasma from the ionosphere dominates the particle distribution.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5332115','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5332115"><span>Food and Drug <span class="hlt">Interactions</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Choi, Jong Hwan; Ko, Chang Mann</p> <p>2017-01-01</p> <p>Natural foods and vegetal supplements have recently become increasingly popular for their roles in medicine and as staple foods. This has, however, led to the increased risk of <span class="hlt">interaction</span> between prescribed drugs and the bioactive ingredients contained in these foods. These <span class="hlt">interactions</span> range from pharmacokinetic <span class="hlt">interactions</span> (absorption, distribution, metabolism, and excretion influencing blood levels of drugs) to pharmacodynamic <span class="hlt">interactions</span> (drug effects). In a quantitative respect, these <span class="hlt">interactions</span> occur mainly during metabolism. In addition to the systemic metabolism that occurs mainly in the liver, recent studies have focused on the metabolism in the gastrointestinal tract endothelium before absorption. Inhibition of metabolism causes an increase in the blood levels of drugs and could have adverse reactions. The food-drug <span class="hlt">interactions</span> causing increased blood levels of drugs may have beneficial or detrimental therapeutic effects depending on the intensity and predictability of these <span class="hlt">interactions</span>. It is therefore important to understand the potential <span class="hlt">interactions</span> between foods and drugs should and the specific outcomes of such <span class="hlt">interactions</span>. PMID:28261555</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/582057','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/582057"><span>Two <span class="hlt">interacting</span> Hofstadter butterflies</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Barelli, A.; Bellissard, J.; Jacquod, P.; Shepelyansky, D.L.</p> <p>1997-04-01</p> <p>The problem of two <span class="hlt">interacting</span> particles in a quasiperiodic potential is addressed. Using analytical and numerical methods, we explore the spectral properties and eigenstates structure from the weak to the strong <span class="hlt">interaction</span> case. More precisely, a semiclassical approach based on noncommutative geometry techniques is used to understand the intricate structure of such a spectrum. An <span class="hlt">interaction</span> induced localization effect is furthermore emphasized. We discuss the application of our results on a two-dimensional model of two particles in a uniform magnetic field with on-site <span class="hlt">interaction</span>. {copyright} {ital 1997} {ital The American Physical Society}</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/973989','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/973989"><span>The Science of <span class="hlt">Interaction</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Pike, William A.; Stasko, John T.; Chang, Remco; O'Connell, Theresa</p> <p>2009-09-23</p> <p>There is a growing recognition with the visual analytics community that <span class="hlt">interaction</span> and inquiry are inextricable. It is through the <span class="hlt">interactive</span> manipulation of a visual interface – the analytic discourse – that knowledge is constructed, tested, refined, and shared. This paper reflects on the <span class="hlt">interaction</span> challenges raised in the original visual analytics research and development agenda and further explores the relationship between <span class="hlt">interaction</span> and cognition. It identifies recent exemplars of visual analytics research that have made substantive progress toward the goals of a true science of <span class="hlt">interaction</span>, which must include theories and testable premises about the most appropriate mechanisms for human-information <span class="hlt">interaction</span>. Six areas for further work are highlighted as those among the highest priorities for the next five years of visual analytics research: ubiquitous, embodied <span class="hlt">interaction</span>; capturing user intentionality; knowledge-based interfaces; principles of design and perception; collaboration; and interoperability. Ultimately, the goal of a science of <span class="hlt">interaction</span> is to support the visual analytics community through the recognition and implementation of best practices in the representation of and <span class="hlt">interaction</span> with visual displays.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15366276','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15366276"><span>Gender <span class="hlt">interactions</span> and success.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wiggins, Carla; Peterson, Teri</p> <p>2004-01-01</p> <p>Does gender by itself, or does gender's <span class="hlt">interaction</span> with career variables, better explain the difference between women and men's careers in healthcare management? US healthcare managers were surveyed regarding career and personal experiences. Gender was statistically <span class="hlt">interacted</span> with explanatory variables. Multiple regression with backwards selection systematically removed non-significant variables. All gender <span class="hlt">interaction</span> variables were non-significant. Much of the literature proposes that work and career factors impact working women differently than working men. We find that while gender alone is a significant predictor of income, it does not significantly <span class="hlt">interact</span> with other career variables.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4209935','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4209935"><span>Reconceptualizing sex, brain and psychopathology: <span class="hlt">interaction</span>, <span class="hlt">interaction</span>, <span class="hlt">interaction</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Joel, D; Yankelevitch-Yahav, R</p> <p>2014-01-01</p> <p>In recent years there has been a growing recognition of the influence of sex on brain structure and function, and in relation, on the susceptibility, prevalence and response to treatment of psychiatric disorders. Most theories and descriptions of the effects of sex on the brain are dominated by an analogy to the current interpretation of the effects of sex on the reproductive system, according to which sex is a divergence system that exerts a unitary, overriding and serial effect on the form of other systems. We shortly summarize different lines of evidence that contradict aspects of this analogy. The new view that emerges from these data is of sex as a complex system whose different components <span class="hlt">interact</span> with one another and with other systems to affect body and brain. The paradigm shift that this understanding calls for is from thinking of sex in terms of sexual dimorphism and sex differences, to thinking of sex in terms of its <span class="hlt">interactions</span> with other factors and processes. Our review of data obtained from animal models of psychopathology clearly reveals the need for such a paradigmatic shift, because in the field of animal behaviour whether a sex difference exists and its direction depend on the <span class="hlt">interaction</span> of many factors including, species, strain, age, specific test employed and a multitude of environmental factors. We conclude by explaining how the new conceptualization can account for sex differences in psychopathology. Linked Articles This article is part of a themed section on Animal Models in Psychiatry Research. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue-20 PMID:24758640</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23674575','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23674575"><span>Drug-nutrient <span class="hlt">interactions</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chan, Lingtak-Neander</p> <p>2013-07-01</p> <p>Drug-nutrient <span class="hlt">interactions</span> are defined as physical, chemical, physiologic, or pathophysiologic relationships between a drug and a nutrient. The causes of most clinically significant drug-nutrient <span class="hlt">interactions</span> are usually multifactorial. Failure to identify and properly manage drug-nutrient <span class="hlt">interactions</span> can lead to very serious consequences and have a negative impact on patient outcomes. Nevertheless, with thorough review and assessment of the patient's history and treatment regimens and a carefully executed management strategy, adverse events associated with drug-nutrient <span class="hlt">interactions</span> can be prevented. Based on the physiologic sequence of events after a drug or a nutrient has entered the body and the mechanism of <span class="hlt">interactions</span>, drug-nutrient <span class="hlt">interactions</span> can be categorized into 4 main types. Each type of <span class="hlt">interaction</span> can be managed using similar strategies. The existing data that guide the clinical management of most drug-nutrient <span class="hlt">interactions</span> are mostly anecdotal experience, uncontrolled observations, and opinions, whereas the science in understanding the mechanism of drug-nutrient <span class="hlt">interactions</span> remains limited. The challenge for researchers and clinicians is to increase both basic and higher level clinical research in this field to bridge the gap between the science and practice. The research should aim to establish a better understanding of the function, regulation, and substrate specificity of the nutrient-related enzymes and transport proteins present in the gastrointestinal tract, as well as assess how the incidence and management of drug-nutrient <span class="hlt">interactions</span> can be affected by sex, ethnicity, environmental factors, and genetic polymorphisms. This knowledge can help us develop a true personalized medicine approach in the prevention and management of drug-nutrient <span class="hlt">interactions</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA419068','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA419068"><span>Normal Shock Vortex <span class="hlt">Interaction</span></span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2003-03-01</p> <p>Figure 9: Breakdown map for normal-shock vortex-<span class="hlt">interaction</span>. References [1] O. Thomer, W. Schroder and M. Meinke , Numerical Simulation of Normal...and Oblique-Shock Vortex <span class="hlt">Interaction</span>, ZAMM Band 80, Sub. 1, pp. 181-184, 2000. [2] O. Thomer, E. Krause, W. Schroder and M. Meinke , Computational</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=teenagers&pg=7&id=EJ1089859','ERIC'); return false;" href="http://eric.ed.gov/?q=teenagers&pg=7&id=EJ1089859"><span>Let Social <span class="hlt">Interaction</span> Flourish</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Case, Anny Fritzen</p> <p>2016-01-01</p> <p>The author describes lessons learned--through a high school project that grouped English language learners with native speakers to create a video--about ways to foster respectful, productive <span class="hlt">interaction</span> among English learners and peers who are native speakers. The potential benefits of students who are just learning English <span class="hlt">interacting</span> socially…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/EJ1052538.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/EJ1052538.pdf"><span><span class="hlt">Interactive</span> Presentation of Content</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Magdin, Martin; Turcáni, Milan; Vrábel, Marek</p> <p>2009-01-01</p> <p>In the paper we discus about design of universal environment for solution of creating effective multimedia applications with accent on the implementation of <span class="hlt">interactive</span> elements with the possibility of using the adaptive systems (AS). We also discuss about possibilities of offline presentation of this <span class="hlt">interactive</span> multimedia adaptive animations…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=stp&pg=5&id=ED120266','ERIC'); return false;" href="https://eric.ed.gov/?q=stp&pg=5&id=ED120266"><span><span class="hlt">Interaction</span> Analysis in MANOVA.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Betz, M. Austin</p> <p></p> <p>Simultaneous test procedures (STPS for short) in the context of the unrestricted full rank general linear multivariate model for population cell means are introduced and utilized to analyze <span class="hlt">interactions</span> in factorial designs. By appropriate choice of an implying hypothesis, it is shown how to test overall main effects, <span class="hlt">interactions</span>, simple main,…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=storyboard&pg=4&id=EJ615259','ERIC'); return false;" href="http://eric.ed.gov/?q=storyboard&pg=4&id=EJ615259"><span>Storyboarding Multimedia <span class="hlt">Interactions</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Martin, Linda C.</p> <p>2000-01-01</p> <p>Understanding how to include <span class="hlt">interactivity</span> when designing multimedia-based training (MBT) storyboards is a major key for a successful MBT. Discusses the basic formats of <span class="hlt">interactions</span> and when to use each format. Describes how to storyboard and areas to address, including: the display area, prompts, branching, programming and graphics notes,…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Animation&pg=3&id=EJ1032402','ERIC'); return false;" href="http://eric.ed.gov/?q=Animation&pg=3&id=EJ1032402"><span>Visualizing Dispersion <span class="hlt">Interactions</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Gottschalk, Elinor; Venkataraman, Bhawani</p> <p>2014-01-01</p> <p>An animation and accompanying activity has been developed to help students visualize how dispersion <span class="hlt">interactions</span> arise. The animation uses the gecko's ability to walk on vertical surfaces to illustrate how dispersion <span class="hlt">interactions</span> play a role in macroscale outcomes. Assessment of student learning reveals that students were able to develop…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=visual+AND+basic+AND+programming&pg=3&id=EJ615259','ERIC'); return false;" href="https://eric.ed.gov/?q=visual+AND+basic+AND+programming&pg=3&id=EJ615259"><span>Storyboarding Multimedia <span class="hlt">Interactions</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Martin, Linda C.</p> <p>2000-01-01</p> <p>Understanding how to include <span class="hlt">interactivity</span> when designing multimedia-based training (MBT) storyboards is a major key for a successful MBT. Discusses the basic formats of <span class="hlt">interactions</span> and when to use each format. Describes how to storyboard and areas to address, including: the display area, prompts, branching, programming and graphics notes,…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Camilo&id=EJ955353','ERIC'); return false;" href="http://eric.ed.gov/?q=Camilo&id=EJ955353"><span><span class="hlt">Interactive</span> Visualization of Dependencies</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Moreno, Camilo Arango; Bischof, Walter F.; Hoover, H. James</p> <p>2012-01-01</p> <p>We present an <span class="hlt">interactive</span> tool for browsing course requisites as a case study of dependency visualization. This tool uses multiple <span class="hlt">interactive</span> visualizations to allow the user to explore the dependencies between courses. A usability study revealed that the proposed browser provides significant advantages over traditional methods, in terms of…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=Internet+AND+dependency&id=EJ955353','ERIC'); return false;" href="https://eric.ed.gov/?q=Internet+AND+dependency&id=EJ955353"><span><span class="hlt">Interactive</span> Visualization of Dependencies</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Moreno, Camilo Arango; Bischof, Walter F.; Hoover, H. James</p> <p>2012-01-01</p> <p>We present an <span class="hlt">interactive</span> tool for browsing course requisites as a case study of dependency visualization. This tool uses multiple <span class="hlt">interactive</span> visualizations to allow the user to explore the dependencies between courses. A usability study revealed that the proposed browser provides significant advantages over traditional methods, in terms of…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930013962','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930013962"><span>University-industry <span class="hlt">interaction</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hastings, Daniel E.</p> <p>1990-01-01</p> <p>It is posited that university industry <span class="hlt">interaction</span> is highly desirable from the viewpoint of the long term economic development of the country as well as being desirable for the Space Grant Programs. The present and future possible <span class="hlt">interactions</span> are reviewed for the three university levels namely, undergraduate, graduate, and faculty research.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=consumer+AND+electronics&pg=4&id=EJ561529','ERIC'); return false;" href="http://eric.ed.gov/?q=consumer+AND+electronics&pg=4&id=EJ561529"><span><span class="hlt">Interactive</span> TV: The Sequel.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Brown, Eric</p> <p>1998-01-01</p> <p>Examines the future of <span class="hlt">interactive</span> TV where consumers navigate the Internet on their TVs with WebTV set-top boxes. Focuses on competition between cable companies and computer and consumer electronics companies. Highlights nine companies and partnerships developing <span class="hlt">interactive</span> hardware and services. (PEN)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=dispersion&id=EJ1032402','ERIC'); return false;" href="https://eric.ed.gov/?q=dispersion&id=EJ1032402"><span>Visualizing Dispersion <span class="hlt">Interactions</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Gottschalk, Elinor; Venkataraman, Bhawani</p> <p>2014-01-01</p> <p>An animation and accompanying activity has been developed to help students visualize how dispersion <span class="hlt">interactions</span> arise. The animation uses the gecko's ability to walk on vertical surfaces to illustrate how dispersion <span class="hlt">interactions</span> play a role in macroscale outcomes. Assessment of student learning reveals that students were able to develop…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=english+AND+mind&pg=2&id=EJ1089859','ERIC'); return false;" href="https://eric.ed.gov/?q=english+AND+mind&pg=2&id=EJ1089859"><span>Let Social <span class="hlt">Interaction</span> Flourish</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Case, Anny Fritzen</p> <p>2016-01-01</p> <p>The author describes lessons learned--through a high school project that grouped English language learners with native speakers to create a video--about ways to foster respectful, productive <span class="hlt">interaction</span> among English learners and peers who are native speakers. The potential benefits of students who are just learning English <span class="hlt">interacting</span> socially…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=light+AND+daily+AND+life&pg=3&id=EJ875080','ERIC'); return false;" href="https://eric.ed.gov/?q=light+AND+daily+AND+life&pg=3&id=EJ875080"><span><span class="hlt">Interaction</span> Online: A Reevaluation</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Battalio, John</p> <p>2007-01-01</p> <p>Instructors commonly assume that the successful online course must replicate its live counterpart by including a variety of <span class="hlt">interactions</span> among student, instructor, and computer. Given the changing lifestyles prompted by an evolving Internet, an increasing student need for autonomy, and student learning styles, highly <span class="hlt">interactive</span> courses may not…</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6558591','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6558591"><span>Elementary particle <span class="hlt">interactions</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bugg, W.M.; Condo, G.T.; Handler, T.; Hart, E.L.; Ward, B.F.L.; Close, F.E.; Christophorou, L.G.</p> <p>1990-10-01</p> <p>This report discusses freon bubble chamber experiments exposed to {mu}{sup +} and neutrinos, photon-proton <span class="hlt">interactions</span>; shower counter simulations; SLD detectors at the Stanford Linear Collider, and the detectors at the Superconducting Super Collider; elementary particle <span class="hlt">interactions</span>; physical properties of dielectric materials used in High Energy Physics detectors; and Nuclear Physics. (LSP)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20674588','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20674588"><span>Electromagnetic cellular <span class="hlt">interactions</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cifra, Michal; Fields, Jeremy Z; Farhadi, Ashkan</p> <p>2011-05-01</p> <p>Chemical and electrical <span class="hlt">interaction</span> within and between cells is well established. Just the opposite is true about cellular <span class="hlt">interactions</span> via other physical fields. The most probable candidate for an other form of cellular <span class="hlt">interaction</span> is the electromagnetic field. We review theories and experiments on how cells can generate and detect electromagnetic fields generally, and if the cell-generated electromagnetic field can mediate cellular <span class="hlt">interactions</span>. We do not limit here ourselves to specialized electro-excitable cells. Rather we describe physical processes that are of a more general nature and probably present in almost every type of living cell. The spectral range included is broad; from kHz to the visible part of the electromagnetic spectrum. We show that there is a rather large number of theories on how cells can generate and detect electromagnetic fields and discuss experimental evidence on electromagnetic cellular <span class="hlt">interactions</span> in the modern scientific literature. Although small, it is continuously accumulating.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19750024877','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19750024877"><span>Spacelab user <span class="hlt">interaction</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1975-01-01</p> <p>The results of the third and final phase of a study undertaken to define means of optimizing the Spacelab experiment data system by <span class="hlt">interactively</span> manipulating the flow of data were presented. A number of payload applicable <span class="hlt">interactive</span> techniques and an integrated <span class="hlt">interaction</span> system for each of two possible payloads are described. These <span class="hlt">interaction</span> systems have been functionally defined and are accompanied with block diagrams, hardware specifications, software sizing and speed requirements, operational procedures and cost/benefits analysis data for both onboard and ground based system elements. It is shown that accrued benefits are attributable to a reduction in data processing costs obtained by, generally, a considerable reduction in the quantity of data that might otherwise be generated without <span class="hlt">interaction</span>. One other additional anticipated benefit includes the increased scientific value obtained by the quicker return of all useful data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002eaa..bookE2335R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002eaa..bookE2335R"><span>Venus: <span class="hlt">Interaction</span> with Solar Wind</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Russell, C.; Luhmann, J.; Murdin, P.</p> <p>2002-07-01</p> <p>The solar wind <span class="hlt">interaction</span> with VENUS provides the archetypal <span class="hlt">interaction</span> of a flowing magnetized PLASMA with a PLANETARY IONOSPHERE. Mars <span class="hlt">interacts</span> with the solar wind in much the same way as does Venus, while the rotating plasma in the Saturnian magnetosphere is believed to <span class="hlt">interact</span> similarly with its moon, Titan (see SATURN: MAGNETOSPHERE <span class="hlt">INTERACTION</span> WITH TITAN). The <span class="hlt">interaction</span> of the Jovian ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16414845','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16414845"><span>Cefuroxime antacid <span class="hlt">interactions</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sultana, N; Mubeen, T; Arayne, M S; Ifzal, R</p> <p>2001-01-01</p> <p>Cefuroxime sodium a second generation semi-synthetic cephalosporin is effective for treating meningitis, lower respiratory tract infections, gonorrhea, bone and joint infections and is approved for surgical prophylaxis. There are number of synergistic and as well as antagonistic drug <span class="hlt">interactions</span> reported for this antibiotic. Withstanding to gastric irritations caused by this antibiotic, antacids may possibly be co-administered with cefuroxime, which may result in severe adverse drug <span class="hlt">interaction</span>. The present work describes the effect of magnesium carbonate, magnesium hydroxide, magnesium trisilicate, megaldrate powder, sodium bicarbonate, aluminum oxide and simethicone suspension on the in vitro availability of cefuroxime sodium. The mechanism of <span class="hlt">interaction</span> between antibiotic and antacids was also studied.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3145460','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3145460"><span>Early <span class="hlt">Interactive</span> Emotional Development</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Messinger, Daniel S.; Mahoor, Mohammad H.; Cadavid, Steven; Chow, Sy-Miin; Cohn, Jeffrey F.</p> <p>2010-01-01</p> <p>Early infant emotional development concerns the <span class="hlt">interactive</span> emergence of emotional states that motivate approach and withdrawal. These are indexed by different patterns of infant facial expressions, vocalization, and gazing that emerge within parent-infant <span class="hlt">interactions</span> in the first 10 months of life. Specifically, the interface of a limited number of <span class="hlt">interactive</span> parameters creates complex real-time patterns which change over developmental time. These phenomena are described below using techniques from our laboratory such as statistical simulations, continuous ratings, and computer vision modeling. PMID:21804955</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3265267','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3265267"><span>Adverse Drug <span class="hlt">Interactions</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Becker, Daniel E.</p> <p>2011-01-01</p> <p>The potential for <span class="hlt">interactions</span> with current medications should always be considered when administering or prescribing any drug. Considering the staggering number of drugs patients may be taking, this task can be daunting. Fortunately, drug classes employed in dental practice are relatively few in number and therapy is generally brief in duration. While this reduces the volume of potential <span class="hlt">interactions</span>, there are still a significant number to be considered. This article will review basic principles of drug <span class="hlt">interactions</span> and highlight those of greatest concern in dental practice. PMID:21410363</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5632592','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5632592"><span>The ADAMS <span class="hlt">interactive</span> interpreter</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Rietscha, E.R.</p> <p>1990-12-17</p> <p>The ADAMS (Advanced DAta Management System) project is exploring next generation database technology. Database management does not follow the usual programming paradigm. Instead, the database dictionary provides an additional name space environment that should be <span class="hlt">interactively</span> created and tested before writing application code. This document describes the implementation and operation of the ADAMS Interpreter, an <span class="hlt">interactive</span> interface to the ADAMS data dictionary and runtime system. The Interpreter executes individual statements of the ADAMS Interface Language, providing a fast, <span class="hlt">interactive</span> mechanism to define and access persistent databases. 5 refs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015cam..book..147G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015cam..book..147G"><span><span class="hlt">Interactive</span> Design Activism</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Goulev, Petar; Farrer, Joan</p> <p></p> <p>The following sections are included: * Introduction * Computers and Human Well-being * To Fuzzy or Yes (No)! * <span class="hlt">Interactive</span> Design Activism * Sensing the Sun * Personalised Public Health Advice * Modifying Human Behaviour * Transdisciplinarity, Knowledge Transfer and Multi-domain</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994spas.book..210S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994spas.book..210S"><span>Electromagnetic and Weak <span class="hlt">Interactions</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Salam, A.; Ward, J. C.</p> <p></p> <p>One of the recurrent dreams in elementary particles physics is that of a possible fundamental synthesis between electro-magnetism and weak <span class="hlt">interactions</span> [1]. The idea has its origin in the following shared characteristics…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27631692','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27631692"><span>Chasing Ecological <span class="hlt">Interactions</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jordano, Pedro</p> <p>2016-09-01</p> <p>Basic research on biodiversity has concentrated on individual species-naming new species, studying distribution patterns, and analyzing their evolutionary relationships. Yet biodiversity is more than a collection of individual species; it is the combination of biological entities and processes that support life on Earth. To understand biodiversity we must catalog it, but we must also assess the ways species <span class="hlt">interact</span> with other species to provide functional support for the Tree of Life. Ecological <span class="hlt">interactions</span> may be lost well before the species involved in those <span class="hlt">interactions</span> go extinct; their ecological functions disappear even though they remain. Here, I address the challenges in studying the functional aspects of species <span class="hlt">interactions</span> and how basic research is helping us address the fast-paced extinction of species due to human activities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/823573','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/823573"><span>Atomic & Molecular <span class="hlt">Interactions</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p></p> <p>2002-07-12</p> <p>The Gordon Research Conference (GRC) on Atomic & Molecular <span class="hlt">Interactions</span> was held at Roger Williams University, Bristol, RI. Emphasis was placed on current unpublished research and discussion of the future target areas in this field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017LPICo1989.8054M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017LPICo1989.8054M"><span><span class="hlt">Interactive</span> Science on Mars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mercer, C. R.; Landis, G. A.</p> <p>2017-02-01</p> <p>Swarms of small citizen-driven rovers can conduct Mars surface science missions. Transportation and communication technology needed for human exploration can enable this new <span class="hlt">interactive</span> science mission architecture.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5025190','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5025190"><span>Chasing Ecological <span class="hlt">Interactions</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2016-01-01</p> <p>Basic research on biodiversity has concentrated on individual species—naming new species, studying distribution patterns, and analyzing their evolutionary relationships. Yet biodiversity is more than a collection of individual species; it is the combination of biological entities and processes that support life on Earth. To understand biodiversity we must catalog it, but we must also assess the ways species <span class="hlt">interact</span> with other species to provide functional support for the Tree of Life. Ecological <span class="hlt">interactions</span> may be lost well before the species involved in those <span class="hlt">interactions</span> go extinct; their ecological functions disappear even though they remain. Here, I address the challenges in studying the functional aspects of species <span class="hlt">interactions</span> and how basic research is helping us address the fast-paced extinction of species due to human activities. PMID:27631692</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920003229','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920003229"><span><span class="hlt">Interactive</span> Office user's manual</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Montgomery, Edward E.; Lowers, Benjamin; Nabors, Terri L.</p> <p>1990-01-01</p> <p>Given here is a user's manual for <span class="hlt">Interactive</span> Office (IO), an executive office tool for organization and planning, written specifically for Macintosh. IO is a paperless management tool to automate a related group of individuals into one productive system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002PhTea..40..140P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002PhTea..40..140P"><span><span class="hlt">Interactive</span> spectra demonstration</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Palmquist, Bruce C.</p> <p>2002-03-01</p> <p>This report describes an <span class="hlt">interactive</span> demonstration to help students qualitatively understand emission, continuous, and absorption spectra. Students throw colored balls at a person representing an electron that can move between discrete energy levels.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23373097','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23373097"><span>Grapefruit and drug <span class="hlt">interactions</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p></p> <p>2012-12-01</p> <p>Since the late 1980s, grapefruit juice has been known to affect the metabolism of certain drugs. Several serious adverse effects involving drug <span class="hlt">interactions</span> with grapefruit juice have been published in detail. The components of grapefruit juice vary considerably depending on the variety, maturity and origin of the fruit, local climatic conditions, and the manufacturing process. No single component accounts for all observed <span class="hlt">interactions</span>. Other grapefruit products are also occasionally implicated, including preserves, lyophylised grapefruit juice, powdered whole grapefruit, grapefruit seed extract, and zest. Clinical reports of drug <span class="hlt">interactions</span> with grapefruit juice are supported by pharmacokinetic studies, each usually involving about 10 healthy volunteers, in which the probable clinical consequences were extrapolated from the observed plasma concentrations. Grapefruit juice inhibits CYP3A4, the cytochrome P450 isoenzyme most often involved in drug metabolism. This increases plasma concentrations of the drugs concerned, creating a risk of overdose and dose-dependent adverse effects. Grapefruit juice also inhibits several other cytochrome P450 isoenzymes, but they are less frequently implicated in <span class="hlt">interactions</span> with clinical consequences. Drugs <span class="hlt">interacting</span> with grapefruit and inducing serious clinical consequences (confirmed or very probable) include: immunosuppressants, some statins, benzodiazepines, most calcium channel blockers, indinavir and carbamazepine. There are large inter-individual differences in enzyme efficiency. Along with the variable composition of grapefruit juice, this makes it difficult to predict the magnitude and clinical consequences of drug <span class="hlt">interactions</span> with grapefruit juice in a given patient. There is increasing evidence that transporter proteins such as organic anion transporters and P-glycoprotein are involved in <span class="hlt">interactions</span> between drugs and grapefruit juice. In practice, numerous drugs <span class="hlt">interact</span> with grapefruit juice. Although only a few</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1329215','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1329215"><span>Beam-Material <span class="hlt">Interaction</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mokhov, N. V.; Cerutti, F.</p> <p>2016-01-01</p> <p>Th is paper is motivated by the growing importance of better understanding of the phenomena and consequences of high-intensity energetic particle beam <span class="hlt">interactions</span> with accelerator, generic target, and detector components. It reviews the principal physical processes of fast-particle <span class="hlt">interactions</span> with matter, effects in materials under irradiation, materials response, related to component lifetime and performance, simulation techniques, and methods of mitigating the impact of radiation on the components and environment in challenging current and future applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16427500','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16427500"><span>LASER-tissue <span class="hlt">interactions</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Carroll, Lisa; Humphreys, Tatyana R</p> <p>2006-01-01</p> <p>As new laser devices continue to emerge, it becomes increasingly important for the clinical dermatologist to understand the basic principles behind their operation. A fundamental understanding of how lasers <span class="hlt">interact</span> with tissue will enable the physician to choose the most appropriate laser for a given clinical situation. Although the physical laws guiding laser design are vastly complex, the fundamental principles of laser-tissue <span class="hlt">interaction</span> can be summarized as they are applicable to the clinician.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19850000284&hterms=routine&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Droutine','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19850000284&hterms=routine&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Droutine"><span>An <span class="hlt">Interactive</span> Plotting Routine</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Tech