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Sample records for average interplanetary magnetic

  1. Interplanetary magnetic holes: Theory

    NASA Technical Reports Server (NTRS)

    Burlaga, L. F.; Lemaire, J. F.

    1978-01-01

    Magnetic holes in the interplanetary medium are explained as stationary, non-propagating, equilibrium structures in which there are field-aligned enhancements of the plasma density and/or temperature. Magnetic anti-holes are considered to be associated with depressions in the plasma pressure. In this model, the observed changes in the magnetic field intensity and direction are due to diamagnetic currents that are carried by ions which drift in a sheath as the result of gradients in the magnetic field and in the plasma pressure within the sheath. The thickness of the sheaths considered is approximately a few ion Larmor radii. An electric field is normal to the magnetic field in the sheath. Solutions of Vlasov's equation and Maxwell's equations are presented which account for several types of magnetic holes, including null-sheets, that were observed.

  2. Interplanetary magnetic field data book

    NASA Technical Reports Server (NTRS)

    King, J. H.

    1975-01-01

    An interplanetary magnetic field (IMF) data set is presented that is uniform with respect to inclusion of cislunar IMF data only, and which has as complete time coverage as presently possible over a full solar cycle. Macroscale phenomena in the interplanetary medium (sector structure, heliolatitude variations, solar cycle variations, etc.) and other phenomena (e.g., ground level cosmic-ray events) for which knowledge of the IMF with hourly resolution is necessary, are discussed. Listings and plots of cislunar hourly averaged IMP parameters over the period November 27, 1963, to May 17, 1974, are presented along with discussion of the mutual consistency of the IMF data used herein. The magnetic tape from which the plots and listings were generated, which is available from the National Space Science Data Center (NSSDC), is also discussed.

  3. On the angle between the average interplanetary magnetic field and the propagation direction of plane large amplitude Alfven waves

    NASA Technical Reports Server (NTRS)

    Lichtenstein, B. R.; Sonett, C. P.

    1979-01-01

    The paper shows that the experimentally observed close alignment of magnetic field minimum variance direction with the average magnetic field for Alfven waves in the solar wind is consistent with theoretically predicted properties of plane large amplitude Alfven waves in the MHD approximation. The theoretical properties of these Alfven waves constrain the time averaged magnetic field to cluster around the direction of minimum variance, which is aligned with the wave normal. Thus, spacecraft magnetometer observations in the solar wind of minimum variance directions strongly peaked about the average magnetic field direction are consistent with plane large amplitude Alfven waves which have wave normals aligned with the directions of minimum variance. This does not imply that geometrical hydromagnetic calculations for Alfven wave propagation direction in the solar wind are incorrect, but there is a discrepancy between geometrical hydromagnetics theory and observations that IMF minimum variance directions tend to be aligned with the ideal Parker spiral instead of the radial direction.

  4. Magnetic sails and interplanetary travel

    SciTech Connect

    Zubrin, R.M.; Andrews, D.G.

    1989-01-01

    A new concept, the magnetic sail, or 'magsail' is proposed which propels spacecraft by using the magnetic field generated by a loop of superconducting cable to deflect interplanetary or interstellar plasma winds. The performance of such a device is evaluated using both a plasma particle model and a fluid model, and the results of a series of investigations are presented. It is found that a magsail sailing on the solar wind at a radius of one astronautical unit can attain accelerations on the order of 0.01 m/sec squared, much greater than that available from a conventional solar lightsail, and also greater than the acceleration due to the sun's gravitational attraction. A net tangential force, or 'lift' can also be generated. Lift to drag ratios of about 0.3 appear attainable. Equations are derived whereby orbital transfers using magsail propulsion can be calculated analytically.

  5. Interplanetary magnetic field and geomagnetic Dst variations.

    NASA Technical Reports Server (NTRS)

    Patel, V. L.; Desai, U. D.

    1973-01-01

    The interplanetary magnetic field has been shown to influence the ring current field represented by Dst. Explorer 28 hourly magnetic field observations have been used with the hourly Dst values. The moderate geomagnetic storms of 60 gammas and quiet-time fluctuations of 10 to 30 gammas are correlated with the north to south change of the interplanetary field component perpendicular to the ecliptic. This change in the interplanetary field occurs one to three hours earlier than the corresponding change in the Dst field.

  6. Interplanetary stream magnetism - Kinematic effects

    NASA Technical Reports Server (NTRS)

    Burlaga, L. F.; Barouch, E.

    1976-01-01

    The particle density and the magnetic-field intensity and direction are calculated for volume elements of the solar wind as a function of the initial magnetic-field direction and the initial speed gradient. It is assumed that the velocity is constant and radial. These assumptions are approximately valid between about 0.1 and 1.0 AU for many streams. Time profiles of the particle density, field intensity, and velocity are calculated for corotating streams, neglecting effects of pressure gradients. The compression and rarefaction of the magnetic field depend sensitively on the initial field direction. By averaging over a typical stream, it is found that the average radial field intensity is inversely proportional to the square of the heliocentric distance, whereas the average intensity in the direction of the planets' motion does not vary in a simple way, consistent with deep space observations. Changes of field direction may be very large, depending on the initial angle; but when the initial angle at 0.1 AU is such that the base of the field line corotates with the sun, the spiral angle is the preferred direction at 1 AU. The theory is also applicable to nonstationary flows.

  7. Intermittent character of interplanetary magnetic field fluctuations

    SciTech Connect

    Bruno, Roberto; Carbone, Vincenzo; Chapman, Sandra; Hnat, Bogdan; Noullez, Alain; Sorriso-Valvo, Luca

    2007-03-15

    Interplanetary magnetic field magnitude fluctuations are notoriously more intermittent than velocity fluctuations in both fast and slow wind. This behavior has been interpreted in terms of the anomalous scaling observed in passive scalars in fully developed hydrodynamic turbulence. In this paper, the strong intermittent nature of the interplanetary magnetic field is briefly discussed comparing results performed during different phases of the solar cycle. The scaling properties of the interplanetary magnetic field magnitude show solar cycle variation that can be distinguished in the scaling exponents revealed by structure functions. The scaling exponents observed around the solar maximum coincide, within the errors, to those measured for passive scalars in hydrodynamic turbulence. However, it is also found that the values are not universal in the sense that the solar cycle variation may be reflected in dependence on the structure of the velocity field.

  8. Interplanetary Magnetic Field Guiding Relativistic Particles

    NASA Technical Reports Server (NTRS)

    Masson, S.; Demoulin, P.; Dasso, S.; Klein, K. L.

    2011-01-01

    The origin and the propagation of relativistic solar particles (0.5 to few Ge V) in the interplanetary medium remains a debated topic. These relativistic particles, detected at the Earth by neutron monitors have been previously accelerated close to the Sun and are guided by the interplanetary magnetic field (IMF) lines, connecting the acceleration site and the Earth. Usually, the nominal Parker spiral is considered for ensuring the magnetic connection to the Earth. However, in most GLEs the IMF is highly disturbed, and the active regions associated to the GLEs are not always located close to the solar footprint of the nominal Parker spiral. A possible explanation is that relativistic particles are propagating in transient magnetic structures, such as Interplanetary Coronal Mass Ejections (ICMEs). In order to check this interpretation, we studied in detail the interplanetary medium where the particles propagate for 10 GLEs of the last solar cycle. Using the magnetic field and the plasma parameter measurements (ACE/MAG and ACE/SWEPAM), we found widely different IMF configurations. In an independent approach we develop and apply an improved method of the velocity dispersion analysis to energetic protons measured by SoHO/ERNE. We determined the effective path length and the solar release time of protons from these data and also combined them with the neutron monitor data. We found that in most of the GLEs, protons propagate in transient magnetic structures. Moreover, the comparison between the interplanetary magnetic structure and the interplanetary length suggest that the timing of particle arrival at Earth is dominantly determined by the type of IMF in which high energetic particles are propagating. Finally we find that these energetic protons are not significantly scattered during their transport to Earth.

  9. Magnetic shielding for interplanetary spacecraft

    SciTech Connect

    Herring, J.S.; Merrill, B.J.

    1991-01-01

    The protection of spacecraft crews from the radiation produced by high energy electrons, protons and heavier ions in the space environment is a major health concern on long duration missions. Conventional approaches to radiation shielding in space have relied on thicker spacecraft walls to stop the high energy charged particles and to absorb the resulting gamma and bremsstrahlung photons. The shielding concept described here uses superconducting magnets to deflect charged particles before they collide with the spacecraft, thus avoiding the production of secondary particles. A number of spacecraft configurations and sizes have been analyzed, ranging from a small storm cellar'' for use during solar flares to continuous shielding for space stations having a crew of 15--25. The effectiveness of the magnetic shielding has been analyzed using a Monte Carlo program with incident proton energies from 0.5 to 1000 MeV. Typically the shield deflects 35--99 percent of the incident particles, depending, of course on particle energy and magnetic field strength. Further evaluation studies have been performed to assess weight comparisons between magnetic and conventional shielding; to determine magnet current distributions which minimize the magnetic field within the spacecraft itself; and to assess the potential role of ceramic superconductors. 2 figs., 8 tabs.

  10. Magnetic shielding for interplanetary spacecraft

    SciTech Connect

    Herring, J.S.; Merrill, B.J.

    1991-12-01

    The protection of spacecraft crews from the radiation produced by high energy electrons, protons and heavier ions in the space environment is a major health concern on long duration missions. Conventional approaches to radiation shielding in space have relied on thicker spacecraft walls to stop the high energy charged particles and to absorb the resulting gamma and bremsstrahlung photons. The shielding concept described here uses superconducting magnets to deflect charged particles before they collide with the spacecraft, thus avoiding the production of secondary particles. A number of spacecraft configurations and sizes have been analyzed, ranging from a small ``storm cellar`` for use during solar flares to continuous shielding for space stations having a crew of 15--25. The effectiveness of the magnetic shielding has been analyzed using a Monte Carlo program with incident proton energies from 0.5 to 1000 MeV. Typically the shield deflects 35--99 percent of the incident particles, depending, of course on particle energy and magnetic field strength. Further evaluation studies have been performed to assess weight comparisons between magnetic and conventional shielding; to determine magnet current distributions which minimize the magnetic field within the spacecraft itself; and to assess the potential role of ceramic superconductors. 2 figs., 8 tabs.

  11. Interplanetary planar magnetic structures associated with expanding active regions

    NASA Technical Reports Server (NTRS)

    Nakagawa, Tomoko; Uchida, Yutaka

    1995-01-01

    Planar magnetic structures are interplanetary objects whose magnetic field cannot be explained by Parker's solar wind model. They are characterized by two-dimensional structure of magnetic field that are highly variable and parallel to a plane which is inclined to the ecliptic plane. They appeared independently of interplanetary compression, solar flares, active prominences nor filament disappearances, but the sources often coincided with active regions. On the other hand, it has been discovered by the Yohkoh Soft X-ray telescope that active-region corona expand outwards at speeds of a few to a few tens of km/s near the Sun. The expansions occurred repeatedly, almost continually, even in the absence of any sizable flares. In the Yohkoh Soft X-ray images, the active-region corona seems to expand out into interplanetary space. Solar sources of interplanetary planar magnetic structures observed by Sakigake were examined by Yohkoh soft X-ray telescope. During a quiet period of the Sun from January 6 to November 11, 1993, there found 5 planar magnetic structures according to the criteria (absolute value of Bn)/(absolute value of B) less than 0.1 for planarity and (dB)/(absolute value of B) greater than 0.7 for variability of magnetic field, where Bn, dB, and the absolute value of B are field component normal to a plane, standard deviation, and average of the magnitude of the magnetic field, respectively. Sources of 4 events were on low-latitude (less than 5 degrees) active regions from which loop-like structures were expanding. The coincidence, 80%, is extremely high with respect to accidental coincidence, 7%, of Sakigake windows of solar wind observation with active regions. The last source was on loop-like features which seemed to be related with a mid-latitude (20 degrees) active region.

  12. Magnetic Reconnection in Interplanetary Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Fermo, R. L.; Opher, M.; Drake, J. F.

    2014-12-01

    Magnetic reconnection is a ubiquitous phenomenon in many varied space and astrophysical plasmas, and as such plays an important role in the dynamics of interplanetary coronal mass ejections (ICMEs). It is widely regarded that reconnection is instrumental in the formation and ejection of the initial CME flux rope, but reconnection also continues to affect the dynamics as it propagates through the interplanetary medium. For example, reconnection on the leading edge of the ICME, by which it interacts with the interplanetary medium, leads to flux erosion. However, recent in situ observations by Gosling et al. found signatures of reconnection exhausts in the interior. In light of this data, we consider the stability properties of systems with this flux rope geometry with regard to their minimum energy Taylor state. Variations from this state will result in the magnetic field relaxing back towards the minimum energy state, subject to the constraints that the toroidal flux and magnetic helicity remain invariant. In reversed field pinches, this relaxation is mediated by reconnection in the interior of the system, as has been shown theoretically and experimentally. By treating the ICME flux rope in a similar fashion, we show analytically that the the elongation of the flux tube cross section in the latitudinal direction will result in a departure from the Taylor state. The resulting relaxation of the magnetic field causes reconnection to commence in the interior of the ICME, in agreement with the observations of Gosling et al. We present MHD simulations in which reconnection initiates at a number of rational surfaces, and ultimately produces a stochastic magnetic field. If the time scales for this process are shorter than the propagation time to 1 AU, this result explains why many ICME flux ropes no longer exhibit the smooth, helical flux structure characteristic of a magnetic cloud.

  13. Regulation of the interplanetary magnetic flux

    SciTech Connect

    McComas, D.J.; Gosling, J.T.; Phillips, J.L.

    1991-01-01

    In this study we use a recently developed technique for measuring the 2-D magnetic flux in the ecliptic plane to examine (1) the long term variation of the magnetic flux in interplanetary space and (2) the apparent rate at which coronal mass ejections (CMEs) may be opening new flux from the Sun. Since there is a substantial variation ({approximately}50%) of the flux in the ecliptic plane over the solar cycle, we conclude that there must be some means whereby new flux can be opened from the Sun and previously open magnetic flux can be closed off. We briefly describe recently discovered coronal disconnections events which could serve to close off previously open magnetic flux. CMEs appear to retain at least partial magnetic connection to the Sun and hence open new flux, while disconnections appear to be likely signatures of the process that returns closed flux to the Sun; the combination of these processes could regulate the amount of open magnetic flux in interplanetary space. 6 refs., 3 figs.

  14. Coronal and interplanetary magnetic field models

    NASA Astrophysics Data System (ADS)

    Schatten, Kenneth H.

    1999-06-01

    We provide an historical perspective of coronal and interplanetary field models. The structure of the interplanetary medium is controlled by the coronal magnetic field from which the solar wind emanates. This field has been described with ``Source Surface'' (SS) and ``Heliospheric Current Sheet'' (HCS) models. The ``Source Surface'' model was the first to open the solar field into interplanetary space using volumetric coronal currents, which were a ``source'' for the IMF. The Heliospheric Current Sheet (HCS) model provided a more physically realistic solution. The field structure was primarily a dipole, however, without regard to sign, the shape appeared to be a monopole pattern (uniform field stress). Ulysses has observed this behavior. Recently, Sheeley and Wang have utilized the HCS field model to calculate solar wind structures fairly accurately. Fisk, Schwadron, and Zurbuchen have investigated small differences from the SS model. These differences allow field line motions reminiscent of a ``timeline'' or moving ``streakline'' in a flow field, similar to the smoke pattern generated by a skywriting plane. Differences exist in the magnetic field geometry, from the Parker ``garden hose'' model affecting both the ``winding angle'' as well as the amount of latitudinal ``wandering.''

  15. An interplanetary magnetic field ensemble at 1 AU

    NASA Technical Reports Server (NTRS)

    Matthaeus, W. H.; Goldstein, M. L.; King, J. H.

    1985-01-01

    A method for calculation ensemble averages from magnetic field data is described. A data set comprising approximately 16 months of nearly continuous ISEE-3 magnetic field data is used in this study. Individual subintervals of this data, ranging from 15 hours to 15.6 days comprise the ensemble. The sole condition for including each subinterval in the averages is the degree to which it represents a weakly time-stationary process. Averages obtained by this method are appropriate for a turbulence description of the interplanetary medium. The ensemble average correlation length obtained from all subintervals is found to be 4.9 x 10 to the 11th cm. The average value of the variances of the magnetic field components are in the approximate ratio 8:9:10, where the third component is the local mean field direction. The correlation lengths and variances are found to have a systematic variation with subinterval duration, reflecting the important role of low-frequency fluctuations in the interplanetary medium.

  16. Fractal structure of the interplanetary magnetic field

    NASA Technical Reports Server (NTRS)

    Burlaga, L. F.; Klein, L. W.

    1985-01-01

    Under some conditions, time series of the interplanetary magnetic field strength and components have the properties of fractal curves. Magnetic field measurements made near 8.5 AU by Voyager 2 from June 5 to August 24, 1981 were self-similar over time scales from approximately 20 sec to approximately 3 x 100,000 sec, and the fractal dimension of the time series of the strength and components of the magnetic field was D = 5/3, corresponding to a power spectrum P(f) approximately f sup -5/3. Since the Kolmogorov spectrum for homogeneous, isotropic, stationary turbulence is also f sup -5/3, the Voyager 2 measurements are consistent with the observation of an inertial range of turbulence extending over approximately four decades in frequency. Interaction regions probably contributed most of the power in this interval. As an example, one interaction region is discussed in which the magnetic field had a fractal dimension D = 5/3.

  17. EULERIAN DECORRELATION OF FLUCTUATIONS IN THE INTERPLANETARY MAGNETIC FIELD

    SciTech Connect

    Matthaeus, W. H.; Osman, K. T.; Dasso, S.; Weygand, J. M.; Kivelson, M. G.

    2010-09-20

    A method is devised for estimating the two-time correlation function and the associated Eulerian decorrelation timescale in turbulence. With the assumptions of a single decorrelation time and a frozen-in flow approximation for the single-point analysis, the method compares two-point correlation measurements with single-point correlation measurements at the corresponding spatial lag. This method is applied to interplanetary magnetic field measurements from the Advanced Composition Explorer and Wind spacecraft. An average Eulerian decorrelation time of 2.9 hr is found. This measures the total rate of distortion of turbulent fluid elements-including sweeping, nonlinear distortion, and wave propagation.

  18. Large-scale properties of the interplanetary magnetic field

    NASA Technical Reports Server (NTRS)

    Schatten, K. H.

    1972-01-01

    Early theoretical work of Parker is presented along with the observational evidence supporting his Archimedes spiral model. Variations present in the interplanetary magnetic field from the spiral angle are related to structures in the solar wind. The causes of these structures are found to be either nonuniform radial solar wind flow or the time evolution of the photospheric field. Coronal magnetic models are related to the connection between the solar magnetic field and the interplanetary magnetic field. Direct extension of the solar field-magnetic nozzle controversy is discussed along with the coronal magnetic models. Effects of active regions on the interplanetary magnetic field is discussed with particular reference to the evolution of interplanetary sectors. Interplanetary magnetic field magnitude variations are shown throughout the solar cycle. The percentage of time the field magnitude is greater than 10 gamma is shown to closely parallel sunspot number. The sun's polar field influence on the interplanetary field and alternative views of the magnetic field structure out of the ecliptic plane are presented. In addition, a variety of significantly different interplanetary field structures are discussed.

  19. Correlation length for interplanetary magnetic field fluctuations.

    NASA Technical Reports Server (NTRS)

    Fisk, L. A.; Sari, J. W.

    1973-01-01

    It is argued that it is necessary to consider two correlation lengths for interplanetary magnetic field fluctuations. For particles with gyroradii large enough to encounter and be scattered by large-scale tangential discontinuities in the field (particles with energies of above several GeV/nucleon) the appropriate correlation length is simply the mean spatial separation between the discontinuities. Particles with gyroradii much less than this mean separation appear to be unaffected by the discontinuities and respond only to smaller-scale field fluctuations. With this system of two correlation lengths the cosmic ray diffusion tensor may be altered from what was predicted by, for example, Jokipii and Coleman, and the objections raised recently by Klimas and Sandri to the diffusion analysis of Jokipii may apply only at relatively low energies (about 50 MeV/nucleon).

  20. Magnetic holes in the solar wind. [(interplanetary magnetic fields)

    NASA Technical Reports Server (NTRS)

    Turner, J. M.; Burlaga, L. F.; Ness, N. F.; Lemaire, J. F.

    1976-01-01

    An analysis is presented of high resolution interplanetary magnetic field measurements from the magnetometer on Explorer 43 which showed that low magnetic field intensities in the solar wind at 1 AU occur as distinct depressions or 'holes'. These magnetic holes are new kinetic-scale phenomena, having a characteristic dimension on the order of 20,000 km. They occurred at a rate of 1.5/day in the 18-day time span (March 18 to April 6, 1971) that was analyzed. Most of the magnetic holes are characterized by both a depression in the absolute value of the magnetic field, and a change in the magnetic field direction; some of these are possibly the result of magnetic merging. However, in other cases the magnetic field direction does not change; such holes are not due to magnetic merging, but might be a diamagnetic effect due to localized plasma inhomogeneities.

  1. Heliocentric distance dependence of the interplanetary magnetic field

    NASA Technical Reports Server (NTRS)

    Behannon, K. W.

    1977-01-01

    Recent and ongoing planetary missions have provided extensive observations of the variations of the Interplanetary Magnetic Field (IMF) both in time and with heliocentric distance from the sun. Large time variations in both the IMF and its fluctuations were observed. These are produced predominantly by dynamical processes in the interplanetary medium associated with stream interactions. Magnetic field variations near the sun are propagated to greater heliocentric distances, also contributing to the observed variablity of the IMF. Temporal variations on a time-scale comparable to or less than the corotation period complicate attempts to deduce radial gradients of the field and its fluctuations from the various observations. However, recent measurements inward to 0.46 AU and outward to 5 AU suggest that the radial component of the field on average decreases approximately as r to the minus second power, while the azimuthal component decreases more rapidly than the r to the minum first power dependence predicted by simple theory. This, and other observations, are discussed.

  2. A survey of long term interplanetary magnetic field variations

    NASA Technical Reports Server (NTRS)

    King, J. H.

    1975-01-01

    Interplanetary magnetic field data from 10 IMP, AIMP, and HEOS spacecraft were merged into a composite data set spanning 1963 to 1974. A consideration of the mutual consistency of the individual data sets reveals agreement typically to within 0.2 gamma. Composite data set analysis reveals: (1) whereas the yearly averaged magnitudes of all field vectors show virtually no solar cycle variation, the yearly averaged magnitudes of positive- and negative-polarity field vectors show separate solar cycle variations, consistent with variations in the average azimuthal angles of positive- and negative-polarity field vectors, (2) there is no heliolatitude dependence of long time average field magnitudes, (3) field vectors parallel to the earth-sun line are on the average 1 gamma less in magnitude than field vectors perpendicular to this line, and (4) the heliolatitude-dependent dominant polarity effect exhibits a complex sign reversal in the 1968 to 1971 period and a measure of symmetry in 1972 to 1974 not found in earlier data.

  3. Solar sources of the interplanetary magnetic field and solar wind

    NASA Technical Reports Server (NTRS)

    Levine, R. H.; Altschuler, M. D.; Harvey, J. W.

    1977-01-01

    Open magnetic field lines, those which extend from the solar photosphere to interplanetary space, are traced in the current-free (potential field) approximation using measured photospheric fields as a boundary condition. It is found that (1) only a relatively small fraction of the photospheric area connects via open field lines to the interplanetary magnetic field; (2) those photospheric areas which do contribute open field lines lie beneath coronal holes and within the boundaries of the holes as projected onto the photosphere or else between loop systems of an active region; (3) the interplanetary magnetic field in the plane of the sun's equator, essentially the field in the ecliptic plane, may connect to photospheric regions of high latitude; and (4) the fastest solar wind streams are correlated with those magnetic flux tubes which expand least in cross-sectional area over the distance between the photosphere and the coronal height where the solar wind begins.

  4. The spiral interplanetary magnetic field - A polarity and sunspot cycle variation

    NASA Technical Reports Server (NTRS)

    Svalgaard, L.; Wilcox, J. M.

    1974-01-01

    Spacecraft observations near the earth of the average direction of the interplanetary magnetic field during the sunspot maximum year 1968 showed a deviation from the spiral field of Parker's classical description. The included angle between the average field direction when the field polarity was away from the sun and the average direction when the field polarity was toward the sun was 168 deg, rather than 180 deg as predicted by Parker. This effect appears to have a sunspot cycle variation.

  5. The spiral interplanetary magnetic field: A polarity and sunspot cycle variation

    NASA Technical Reports Server (NTRS)

    Svalgaard, L.; Wilcox, J. M.

    1974-01-01

    Spacecraft observations near the earth of the yearly average direction of the interplanetary magnetic field during the sunspot maximum year 1968 showed a deviation from the spiral field. The angle between the average field direction when the field polarity was away from the sun and the average direction for toward polarity was 168 deg, rather than 180 deg. This effect appears to have a sunspot cycle variation.

  6. The regular interplanetary magnetic field during the 1980s

    NASA Technical Reports Server (NTRS)

    Kalinin, M. S.; Krainev, M. B.

    1995-01-01

    The regular magnetic field in the interplanetary space for 1980-1990 is calculated using the results of the Hoeksema-Zhao model for the radial magnetic field on the source surface. The unsteady radial component gives birth to the latitudinal and longitudinal components which could be of importance for, e.g., the galactic cosmic ray modulation.

  7. Interplanetary magnetic field effects on high latitude ionospheric convection

    NASA Technical Reports Server (NTRS)

    Heelis, R. A.

    1985-01-01

    Relations between the electric field and the electric current in the ionosphere can be established on the basis of a system of mathematical and physical equations provided by the equations of current continuity and Ohm's law. For this reason, much of the synthesis of electric field and plasma velocity data in the F-region is made with the aid of similar data sets derived from field-aligned current and horizontal current measurements. During the past decade, the development of a self-consistent picture of the distribution and behavior of these measurements has proceeded almost in parallel. The present paper is concerned with the picture as it applies to the electric field and plasma drift velocity and its dependence on the interplanetary magnetic field. Attention is given to the southward interplanetary magnetic field and the northward interplanetary magnetic field.

  8. The earth's magnetosphere under continued forcing - Substorm activity during the passage of an interplanetary magnetic cloud

    NASA Technical Reports Server (NTRS)

    Farrugia, C. J.; Freeman, M. P.; Burlaga, L. F.; Lepping, R. P.; Takahashi, K.

    1993-01-01

    Magnetic field and energetic particle observations from six spacecraft in the near-earth magnetotail are described and combined with ground magnetograms to document for the first time the magnetospheric substorm activity during a 30-hour long transit of an interplanetary cloud at 1 AU. During an earlier 11-hr interval when B(z) was continuously positive, the magnetosphere was quiescent, while in a later 18-hr interval when B(z) was uninterruptedly negative a large magnetic storm was set off. In the latter interval the substorm onsets recurred on average every 50 min. Their average recurrence frequency remained relatively undiminished even when the magnetic cloud B(z) and other measures of the interplanetary energy input decreased considerably. These results concur with current models of magnetospheric substorms based on deterministic nonlinear dynamics. The substorm onset occurred when the cloud's magnetic field had a persistent northward component but was predominantly westward pointing.

  9. How are Forbush decreases related to interplanetary magnetic field enhancements?

    NASA Astrophysics Data System (ADS)

    Arunbabu, K. P.; Antia, H. M.; Dugad, S. R.; Gupta, S. K.; Hayashi, Y.; Kawakami, S.; Mohanty, P. K.; Oshima, A.; Subramanian, P.

    2015-08-01

    Aims: A Forbush decrease (FD) is a transient decrease followed by a gradual recovery in the observed galactic cosmic ray intensity. We seek to understand the relationship between the FDs and near-Earth interplanetary magnetic field (IMF) enhancements associated with solar coronal mass ejections (CMEs). Methods: We used muon data at cutoff rigidities ranging from 14 to 24 GV from the GRAPES-3 tracking muon telescope to identify FD events. We selected those FD events that have a reasonably clean profile, and magnitude >0.25%. We used IMF data from ACE/WIND spacecrafts. We looked for correlations between the FD profile and that of the one-hour averaged IMF. We wanted to find out whether if the diffusion of high-energy protons into the large scale magnetic field is the cause of the lag observed between the FD and the IMF. Results: The enhancement of the IMF associated with FDs occurs mainly in the shock-sheath region, and the turbulence level in the magnetic field is also enhanced in this region. The observed FD profiles look remarkably similar to the IMF enhancement profiles. The FDs typically lag behind the IMF enhancement by a few hours. The lag corresponds to the time taken by high-energy protons to diffuse into the magnetic field enhancement via cross-field diffusion. Conclusions: Our findings show that high-rigidity FDs associated with CMEs are caused primarily by the cumulative diffusion of protons across the magnetic field enhancement in the turbulent sheath region between the shock and the CME. Appendices are available in electronic form at http://www.aanda.org

  10. SIGNATURES OF MAGNETIC RECONNECTION AT BOUNDARIES OF INTERPLANETARY SMALL-SCALE MAGNETIC FLUX ROPES

    SciTech Connect

    Tian Hui; Yao Shuo; Zong Qiugang; Qi Yu; He Jiansen

    2010-09-01

    The interaction between interplanetary small-scale magnetic flux ropes and the magnetic field in the ambient solar wind is an important topic in the understanding of the evolution of magnetic structures in the heliosphere. Through a survey of 125 previously reported small flux ropes from 1995 to 2005, we find that 44 of them reveal clear signatures of Alfvenic fluctuations and thus classify them as Alfven wave trains rather than flux ropes. Signatures of magnetic reconnection, generally including a plasma jet of {approx}30 km s{sup -1} within a magnetic field rotational region, are clearly present at boundaries of about 42% of the flux ropes and 14% of the wave trains. The reconnection exhausts are often observed to show a local increase in the proton temperature, density, and plasma beta. About 66% of the reconnection events at flux rope boundaries are associated with a magnetic field shear angle larger than 90{sup 0} and 73% of them reveal a decrease of 20% or more in the magnetic field magnitude, suggesting a dominance of anti-parallel reconnection at flux rope boundaries. The occurrence rate of magnetic reconnection at flux rope boundaries through the years 1995-2005 is also investigated and we find that it is relatively low around the solar maximum and much higher when approaching solar minima. The average magnetic field depression and shear angle for reconnection events at flux rope boundaries also reveal a similar trend from 1995 to 2005. Our results demonstrate for the first time that boundaries of a substantial fraction of small-scale flux ropes have properties similar to those of magnetic clouds, in the sense that both of them exhibit signatures of magnetic reconnection. The observed reconnection signatures could be related either to the formation of small flux ropes or to the interaction between flux ropes and the interplanetary magnetic fields.

  11. Dependence of the latitude of the cleft on the interplanetary magnetic field and substorm activity

    NASA Technical Reports Server (NTRS)

    Kamide, Y.; Burch, J. L.; Winningham, J. D.; Akasofu, S.-I.

    1976-01-01

    The latitudinal motion of the cleft (the polar cusp) associated with the southward interplanetary magnetic field (IMF) and substorm activity is examined. The cleft location is identified on the basis of the location of midday auroras and of electron precipitation by the OGO 4 and ISIS 1 satellites. It is found that the IMF and substorm activity control independently the latitude of the cleft and that they can shift the cleft location by 3 or 4 deg under average conditions.

  12. Analysis of ionospheric absorption associated with interplanetary magnetic clouds

    NASA Astrophysics Data System (ADS)

    Marcz, F.

    1991-04-01

    Based on an association of geomagnetic storm intervals with the passage of interplanetary magnetic clouds at the earth's magnetosphere, a post-storm increase of ionospheric absorption has been suggested for these passages. A significant and lasting increase of absorption was found in the case of magnetic clouds following shocks. A dependence on plasma characteristics has also been investigated. The proton temperature together with the solar wind velocity, as well as the durations of the clouds, seem to play an indirect role in the mechanism leading to the after-effect in absorption.

  13. Remnant Kronian and Interplanetary magnetic fields at Titan: Cassini observations

    NASA Astrophysics Data System (ADS)

    Bertucci, C.; Romanelli, N.; Achilleos, N. A.; Modolo, R.; Edberg, N. J.

    2013-12-01

    This work offers an interpretation to the unexpected magnetic field orientation found inside Titan's induced magnetosphere for Cassini flybys where excursions into the magnetosheath have been confirmed prior and at the time of closest approach. This interpretation is based on the concept of ';fossil fields' described in previous works. In particular, we report the first observation of remnant interplanetary magnetic field lines in Titan's ionosphere during flyby T39, and the second observation of remnant Kronian field lines while Titan is in Saturn's magnetosheath during flyby T85. In these cases, the ages of the fossil fields agree with those previously reported for flyby T32.

  14. Further study of the theta component of the interplanetary magnetic field.

    NASA Technical Reports Server (NTRS)

    Rosenberg, R. L.; Coleman, P. J., Jr.; Ness, N. F.

    1973-01-01

    Measurements of the interplanetary magnetic field taken with Imp 3, Pioneer 6, and Explorer 34 constitute a large portion of the data available at low and moderate solar activity and provide nearly continuous coverage from mid-1965 through 1966 without radial effects. Study of these observations provides further evidence for the following B sub theta effect initially discovered with Mariners 2, 4, and 5. At low or moderate solar activity, the mean value of B sub theta is negative (approximately northward in the observations) above the solar equatorial plane and positive below it for an interplanetary field directed outward from the sun, and vice versa for an inward field. Thus, for an outward field, the r-theta component of a line of magnetic force above or below the equatorial plane was skewed relative to the average value of r in the direction away from the equatorial plane. Comparisons between different spacecraft are discussed.

  15. Polarity of the interplanetary magnetic field and geomagnetic activity

    NASA Astrophysics Data System (ADS)

    Triskova, Ludmila

    The analysis of data from the years 1958 to 1980 has indicated that geomagnetic activity, expressed in terms of AE, Ap and Dst indices, is, on the average, controlled by the southward component of the interplanetary field on days with a definite IMF polarity. The effect of this component may sometimes be obscured by the effect of the dominant polarity. During boundary crossings, the Dst index is most conspicuously affected by this component. On the average, the effect of Hale boundary was not reflected in the response of the geomagnetic activity to the change of IMF polarity in the period 1970 to 1980.

  16. Magnetic Reconnection in the Interior of Interplanetary Coronal Mass Ejections

    NASA Astrophysics Data System (ADS)

    Fermo, R. L.; Opher, M.; Drake, J. F.

    2014-07-01

    Recent in situ observations of interplanetary coronal mass ejections (ICMEs) found signatures of reconnection exhausts in their interior or trailing edge. Whereas reconnection on the leading edge of an ICME would indicate an interaction with the coronal or interplanetary environment, this result suggests that the internal magnetic field reconnects with itself. In light of this data, we consider the stability properties of flux ropes first developed in the context of astrophysics, then further elaborated upon in the context of reversed field pinches (RFPs). It was shown that the lowest energy state of a flux rope corresponds to ∇×B=λB with λ a constant, the so-called Taylor state. Variations from this state will result in the magnetic field trying to reorient itself into the Taylor state solution, subject to the constraints that the toroidal flux and magnetic helicity are invariant. In reversed field pinches, this relaxation is mediated by the reconnection of the magnetic field, resulting in a sawtooth crash. If we likewise treat the ICME as a flux rope, any deviation from the Taylor state will result in reconnection within the interior of the flux tube, in agreement with the observations by Gosling et al. Such a departure from the Taylor state takes place as the flux tube cross section expands in the latitudinal direction, as seen in magnetohydrodynamic (MHD) simulations of flux tubes propagating through the interplanetary medium. We show analytically that this elongation results in a state which is no longer in the minimum energy Taylor state. We then present magnetohydrodynamic simulations of an elongated flux tube which has evolved away from the Taylor state and show that reconnection at many surfaces produces a complex stochastic magnetic field as the system evolves back to a minimum energy state configuration.

  17. Recurrent structures of the interplanetary magnetic field observed by Ulysses

    NASA Technical Reports Server (NTRS)

    Erdos, G.; Balogh, A.; Forsyth, R. J.; Smith, E. J.

    1995-01-01

    Since its launch in October 1990, Ulysses has provided good quality magnetic field data, practically covering the whole time interval until now. We have studied the very long time scale evolution of the interplanetary magnetic field, in particlular, we have search for recurrent disturbances in the magnetic field. The magnetic field vectors have been mapped back to the Sun along Parker spirals, in order to determine the Heliographic longitude of the source regions in the corona. It was found that the position of many high field sources drifts systematically relative to the corona assumed to rotate with the equatorial rotation period of the Sun. The results are compared to similar observations on the eastward drift of magnetic sectors observed after about June 1992. Changes associated with both the declining phase of the solar cycle and the latitudinal excursion of Ulysses are also discussed.

  18. Magnetic Fields in Interplanetary Space: A weak magnetic field pulled out from the sun has considerable influence on interplanetary processes.

    PubMed

    Cahill, L J

    1965-02-26

    The brief period between the conception of the interplanetary magnetic field and conclusive proof of its existence has been an exciting one. Imaginative theoretical developments and careful experimental verification have both been essential to rapid progress. From the various lines of evidence described here it is clear that an interplanetary magnetic field is always present, drawn out from the sun by the radially streaming solar wind. The field is stretched into a spiral pattern by the sun's rotation. The field appears to consist of relatively narrow filaments, the fields of adjacent filaments having opposite directions. At the earth's orbit the field points slightly below the ecliptic plane. The magnitude of the field is steady and near 5 gammas in quiet times, but it may rise to higher values at times of higher solar activity. A collision-free shock front is formed in the plasma flow around the earth. In the transition region between the shock front and the magnetopause the magnitude of the field is somewhat higher than it is in the interplanetary region, and large fluctuations in magnitude and direction are common. A shock front has also been observed in space between a slowly moving body of plasma and a faster, overtaking plasma stream. PMID:17813304

  19. Interplanetary gas. XXV - A solar wind and interplanetary magnetic field interpretation of cometary light outbursts

    NASA Technical Reports Server (NTRS)

    Niedner, M. B., Jr.

    1980-01-01

    Possible relationships of cometary brightness outbursts with the solar wind and interplanetary magnetic field are examined. Two types of outburst are distinguished: those which involve a significant brightening of both the head and the tail in a comet with a conspicuous plasma tail (Class I), and those involving the brightening of the central condensation of a previously faint comet with no detectable plasma tail (Class II). Class I bursts, as exemplified by Comet Morehouse 1908c, are attributed to the generation in the head of enhanced amounts of ions and their injection into the tail shortly before it disconnects, with ionization provided by sector boundary crossings. Class II events, as exhibited by Comet P/Tuttle-Giacobini-Kresak 1973b, are interpreted as the result of the bombardment of the nucleus by disturbed solar wind near corotated high-speed streams and sector boundaries, leading to highly exothermic chemical reactions.

  20. Interplanetary Magnetic Field Power Spectrum Variations: A VHO Enabled Study

    NASA Technical Reports Server (NTRS)

    Szabo, A.; Koval, A.; Merka, J.; Narock, T.

    2011-01-01

    The newly reprocessed high time resolution (11/22 vectors/sec) Wind mission interplanetary magnetic field data and the solar wind key parameter search capability of the Virtual Heliospheric Observatory (VHO) affords an opportunity to study magnetic field power spectral density variations as a function of solar wind conditions. In the reprocessed Wind Magnetic Field Investigation (MFI) data, the spin tone and its harmonics are greatly reduced that allows the meaningful fitting of power spectra to the 2 Hz limit above which digitization noise becomes apparent. The power spectral density is computed and the spectral index is fitted for the MHD and ion inertial regime separately along with the break point between the two for various solar wind conditions. The time periods of fixed solar wind conditions are obtained from VHO searches that greatly simplify the process. The functional dependence of the ion inertial spectral index and break point on solar wind plasma and magnetic field conditions will be discussed

  1. Interplanetary Magnetic Field Power Spectrum Variations: A VHO Enabled Study

    NASA Technical Reports Server (NTRS)

    Szabo, A.; Koval, A.; Merka, J.; Narock, T.

    2010-01-01

    The newly reprocessed high time resolution (11/22 vectors/sec) Wind mission interplanetary magnetic field data and the solar wind key parameter search capability of the Virtual Heliospheric Observatory (VHO) affords an opportunity to study magnetic field power spectral density variations as a function of solar wind conditions. In the reprocessed Wind Magnetic Field Investigation (MFI) data, the spin tone and its harmonics are greatly reduced that allows the meaningful fitting of power spectra to the approx.2 Hz limit above which digitization noise becomes apparent. The power spectral density is computed and the spectral index is fitted for the MHD and ion inertial regime separately along with the break point between the two for various solar wind conditions . The time periods of fixed solar wind conditions are obtained from VHO searches that greatly simplify the process. The functional dependence of the ion inertial spectral index and break point on solar wind plasma and magnetic field conditions will be discussed

  2. Ground state alignment as a tracer of interplanetary magnetic field

    NASA Astrophysics Data System (ADS)

    Yan, H.

    2012-12-01

    We demonstrate a new way of studying interplanetary magnetic field -- spectropolarimetry based on ground state alignment. Ground state alignment is a new promising way of sub-gausian magnetic fields in radiation-dominated environment. The polarization of spectral lines that are pumped by the anisotropic radiation from the sun is influenced by the magnetic alignment, which happens for sub-gausian magnetic field. As a result, the linear polarization becomes an excellent tracer of the embedded magnetic field. The method is illustrated by our synthetic obser- vation of the Jupiter's Io and comet Halley. A uniform density distribution of Na was considered and polar- ization at each point was then constructed. Both spa- tial and temporal variations of turbulent magnetic field can be traced with this technique as well. Instead of sending thousands of space probes, ground state alignment allows magnetic mapping with any ground telescope facilities equipped with spectrometer and polarimeter. For remote regions like the the boundary of interstellar medium, ground state alignment provides a unique diagnostics of magnetic field, which is crucial for understanding the physical processes such as the IBEX ribbons.

  3. Interplanetary magnetic field orientation for transient events in the outer magnetosphere

    NASA Technical Reports Server (NTRS)

    Sibeck, D. G.; Newell, P. T.

    1995-01-01

    It is generally believed that flux transfer events (FTEs) in the outer dayside magneosphere, usually identified by transient (approximately 1 min) bipolar magneitc field perturbations in the direction normal to the nominal magnetopause, occur when the magnetosheath magetic field has a southward component. We compare the results of three methods for determining the magnetosheath magnetic field orientationat the times of previously identified UKS/IRM events: (1) the average magnetosheath magnetic field orientation in the 30-min period adjacent to the nearest magnetopause crossing, (2) the magnetosheath magnetic field orientation observed just outside the magnetopause, and (3) the lagged interplanetary magnetic field (IMF) orientation at the time of the transient events. Whereas the results of method 2 indicate that the events tend to occur for a southward magnetosheath magnetic field, the results of methods 1 and 3 show no such tnedency. The fact that the three methods yield significantly diffeent results emphasizes the need for caution in future studies.

  4. Counterstreaming electrons in small interplanetary magnetic flux ropes

    NASA Astrophysics Data System (ADS)

    Feng, H. Q.; Zhao, G. Q.; Wang, J. M.

    2015-12-01

    Small interplanetary magnetic flux ropes (SIMFRs) are commonly observed by spacecraft at 1 AU, and their origin still remains disputed. We investigated the counterstreaming suprathermal electron (CSE) signatures of 106 SIMFRs measured by Wind during 1995-2005. We found that 79 (75%) of the 106 flux ropes contain CSEs, and the percentages of counterstreaming vary from 8% to 98%, with a mean value of 51%. CSEs are often observed in magnetic clouds (MCs), and this indicates these MCs are still attached to the Sun at both ends. CSEs are also related to heliospheric current sheets (HCSs) and the Earth's bow shock. We divided the SIMFRs into two categories: The first category is far from HCSs, and the second category is in the vicinity of HCSs. The first category has 57 SIMFRs, and only 7 of 57 ropes have no CSEs. This ratio is similar to that of MCs. The second category has 49 SIMFRs; however, 20 of the 49 events have no CSEs. This ratio is larger than that of MCs. These two categories have different origins. One category originates from the solar corona, and most ropes are still connected to the Sun at both ends. The other category is formed near HCSs in the interplanetary space.

  5. Transport of solar electrons in the turbulent interplanetary magnetic field

    NASA Astrophysics Data System (ADS)

    Ablaßmayer, J.; Tautz, R. C.; Dresing, N.

    2016-01-01

    The turbulent transport of solar energetic electrons in the interplanetary magnetic field is investigated by means of a test-particle Monte-Carlo simulation. The magnetic fields are modeled as a combination of the Parker field and a turbulent component. In combination with the direct calculation of diffusion coefficients via the mean-square displacements, this approach allows one to analyze the effect of the initial ballistic transport phase. In that sense, the model complements the main other approach in which a transport equation is solved. The major advancement is that, by recording the flux of particles arriving at virtual detectors, intensity and anisotropy-time profiles can be obtained. Observational indications for a longitudinal asymmetry can thus be explained by tracing the diffusive spread of the particle distribution. The approach may be of future help for the systematic interpretation of observations for instance by the solar terrestrial relations observatory (STEREO) and advanced composition explorer (ACE) spacecrafts.

  6. Three-dimensional interplanetary stream magnetism and energetic particle motion

    NASA Technical Reports Server (NTRS)

    Barouch, E.; Burlaga, L. F.

    1976-01-01

    Cosmic rays interact with mesoscale configurations of the interplanetary magnetic field. A technique is presented for calculating such configurations in the inner solar system, which are due to streams and source conditions near the sun, and maps of magnetic field are constructed for some plausible stream and source conditions. One effect of these mesoscale configurations on galactic cosmic rays is shown to be an out-of-the-ecliptic gradient drift sufficient to explain Forbush decreases. The effects on solar energetic particles include small polar drifts due to the field gradients and a possibly large modification of the time-intensity profiles and anisotropy characteristics due to the formation of mirror configurations in space. If a diffusion model is applicable to solar particles, the true diffusion coefficient will be masked by the effects of streams. A conceptual model which incorporates these ideas and those of several other models is presented.

  7. Interplanetary magnetic field enhancements in the solar wind Statistical properties at 1 AU

    NASA Technical Reports Server (NTRS)

    Arghavani, M. R.; Russell, C. T.; Luhmann, J. G.; Elphic, R. C.

    1985-01-01

    The present investigation is concerned with interplanetary magnetic field (IMF) enhancements which do not resemble any of the previously reported amplifications in the IMF. The magnetic field enhacements observed increase slowly at first and then more rapidly to a peak followed by a symmetrical decay. Interplanetary magnetic field enhacement observed by ISEE-3 on various dates are considered, giving attention to observations on June 5, 1979; September 8-9, 1980; February 5, 1981; and June 14-15, 1981. Interplanetary magnetic field enhancement observed with the aid of IMP-8 are also considered. A total of 45 events is found in surveying a 9-year period of magnetic field data.

  8. Inferring interplanetary magnetic field polarities from geomagnetic variations

    NASA Astrophysics Data System (ADS)

    Vokhmyanin, M. V.; Ponyavin, D. I.

    2012-06-01

    In this paper, we propose a modified procedure to infer the interplanetary magnetic field (IMF) polarities from geomagnetic observations. It allows to identify the polarity back to 1905. As previous techniques it is based on the well-known Svalgaard-Mansurov effect. We have improved the quality and accuracy of polarity inference compared with the previous results of Svalgaard (1975) and Vennerstroem et al. (2001) by adding new geomagnetic stations and extracting carefully diurnal curve. The data demonstrates an excess of one of the two IMF sectors within equinoxes (Rosenberg-Coleman rule) evidencing polar field reversals at least for the last eight solar cycles. We also found a predominance of the two-sector structure in late of descending phase of solar cycle 16.

  9. Magnetic shielding of interplanetary spacecraft against solar flare radiation

    NASA Technical Reports Server (NTRS)

    Cocks, Franklin H.; Watkins, Seth

    1993-01-01

    The ultimate objective of this work is to design, build, and fly a dual-purpose, piggyback payload whose function is to produce a large volume, low intensity magnetic field and to test the concept of using such a magnetic field (1) to protect spacecraft against solar flare protons, (2) to produce a thrust of sufficient magnitude to stabilize low satellite orbits against orbital decay from atmospheric drag, and (3) to test the magsail concept. These all appear to be capable of being tested using the same deployed high temperature superconducting coil. In certain orbits, high temperature superconducting wire, which has now been developed to the point where silver-sheathed high T sub c wires one mm in diameter are commercially available, can be used to produce the magnetic moments required for shielding without requiring any mechanical cooling system. The potential benefits of this concept apply directly to both earth-orbital and interplanetary missions. The usefulness of a protective shield for manned missions needs scarcely to be emphasized. Similarly, the usefulness of increasing orbit perigee without expenditure of propellant is obvious. This payload would be a first step in assessing the true potential of large volume magnetic fields in the US space program. The objective of this design research is to develop an innovative, prototype deployed high temperature superconducting coil (DHTSC) system.

  10. Evidence linking coronal mass ejections with interplanetary magnetic clouds

    NASA Technical Reports Server (NTRS)

    Wilson, R. M.; Hildner, E.

    1983-01-01

    Using proxy data for the occurrence of those mass ejections from the solar corona which are directed earthward, we investigate the association between the post-1970 interplanetary magnetic clouds of Klein and Burlaga and coronal mass ejections. The evidence linking magnetic clouds following shocks with coronal mass ejections is striking; six of nine clouds observed at Earth were preceded an appropriate time earlier by meter-wave type II radio bursts indicative of coronal shock waves and coronal mass ejections occurring near central meridian. During the selected periods when no clouds were detected near Earth, the only type II bursts reported were associated with solar activity near the limbs. Where the proxy solar data to be sought are not so clearly suggested, that is, for clouds preceding interaction regions and clouds within cold magnetic enhancements, the evidence linking the clouds and coronal mass ejections is not as clear; proxy data usually suggest many candidate mass-ejection events for each cloud. Overall, the data are consistent with and support the hypothesis suggested by Klein and Burlaga that magnetic clouds observed with spacecraft at 1 AU are manifestations of solar coronal mass ejection transients.

  11. North-south asymmetry of the interplanetary magnetic helicity

    NASA Technical Reports Server (NTRS)

    Smith, Charles W.; Bieber, John W.

    1995-01-01

    Previous analyses of the north-south asymmetry of the interplanetary magnetic helicity have used the omnitape dataset and have shown that there exists a persistent and statistically significant asymmetry in the handedness of the magnetic fluctuations at 1 AU. This asymmetry is concentrated in fluctuations with spacecraft frame frequencies less than 10-5 Hz (periods greater than 30 hours) at 1 AU. Attempts to extend these analyses to include data collected in the outer heliosphere require that we consider spacecraft frame periods many times greater than 30 hours. This raises interesting questions regarding homogeneity and stationarity of the datasets at this scale and brings into question the possible breakdown of the computed correlation functions due to the sector structure of the solar wind. The likely geometry of magnetic fluctuations in the outer heliosphere provides yet another complication in the analysis. These issues will be discussed in detail and the latest results from our studies of the Voyager 1 & 2 and Pioneer 10 & 11 datasets will be presented. The analysis of Pioneer-Venus Orbiter observations will be shown as well. The potential asymmetry between the magnetic helicity of the two hemispheres has significant and measurable implications for cosmic ray propagation in the heliosphere and these implications will be reviewed in light of the new results.

  12. Magnetic field directional discontinuities. I - Minimum variance errors. [of interplanetary magnetic field

    NASA Technical Reports Server (NTRS)

    Lepping, R. P.; Behannon, K. W.

    1980-01-01

    The paper deals with a statistical analysis of the errors associated with a minimum variance analysis of directional discontinuities by use of an idealized model of these discontinuities and various simulations, and also by an examination of actual Mariner 10 interplanetary magnetic field data. An empirical expression is derived for the magnitude of the error in an estimated discontinuity normal component, relative to the total field across the directional discontinuity. The analysis was performed primarily to aid in differentiating between interplanetary tangential and rotational discontinuities observed by Mariner 10.

  13. Polar cap magnetic variations and their relationship with the interplanetary magnetic sector structure.

    NASA Technical Reports Server (NTRS)

    Svalgaard, L.

    1973-01-01

    The relationship between polar geomagnetic variations and the polarity of the interplanetary magnetic sectors has been studied for the quiet year 1965. It is found that during the day hours a system of ionospheric currents encircles the magnetic poles on every day. The current system may extend up to 15 deg from the pole but is strongest at 8 to 10 deg invariant colatitude. The current direction as seen from near the magnetic poles is counterclockwise during interplanetary sectors with field pointing away from the sun and clockwise during toward sectors. The current strength is dependent on season, being strongest during local summer. When the magnetic pole is on the nightside of the earth, this polar cap current is absent or very weak.

  14. The Interplanetary Magnetic Field and Magnetospheric Current Systems

    NASA Technical Reports Server (NTRS)

    El-Alaoui, Mostafa

    2003-01-01

    We have performed systematic global magnetohydrodynamic (MHD) simulation studies driven by an idealized time series of solar wind parameters to establish basic cause and effect relationships between the solar wind variations and the ionosphere parameters. We studied six cases in which the interplanetary magnetic field (IMF) rotated from southward to northward in one minute. In three cases (cases A, B, and C) we ran five hours of southward IMF with Beta(sub Zeta) = 5 nT, followed by five hours of northward IMF with Beta(sub Zeta) = 5 nT. In the other three cases (cases D, E, and F) the magnetic field magnitude was increased to 10 nT. The solar wind parameters were: For cases A and D a density of 5 cm(exp -3), a thermal pressure of 3.3 nPa, and a solar wind speed 375 km/s, for cases B and E a density of 10 cm(exp -3), a thermal pressure of 9.9 nPa, and a solar wind speed 420 km/s, while for cases C and F a density of 15 cm(exp -3), a thermal pressure of 14.9 nPa, and a solar wind speed of 600 km/s.

  15. Interplanetary stream magnetism: Kinematic effects. [solar magnetic fields and wind

    NASA Technical Reports Server (NTRS)

    Burlaga, L. F.; Barouch, E.

    1974-01-01

    The particle density, and the magnetic field intensity and direction are calculated in corotating streams of the solar wind, assuming that the solar wind velocity is constant and radial and that its azimuthal variations are not two rapid. The effects of the radial velocity profile in corotating streams on the magnetic fields were examined using kinematic approximation and a variety of field configurations on the inner boundary. Kinematic and dynamic effects are discussed.

  16. The Bastille Day Magnetic Clouds and Upstream Shocks: Near Earth Interplanetary Observations

    NASA Technical Reports Server (NTRS)

    Lepping, R. P.; Berdichevsky, D. B.; Burlaga, L. F.; Lazarus, A. J.; Kasper, J.; Desch, M. D.; Wu, C.-C.; Reames, D. V.; Singer, H. J.; Singer, H. J.; Vondrak, Richard R. (Technical Monitor)

    2001-01-01

    The energetic charged particle, interplanetary magnetic field, and plasma characteristics of the 'Bastille Day' shock and ejecta/magnetic cloud events at 1 AU occurring over the days 14-16 July 2000 are described. Profiles of MeV (WIND/LEMT) energetic ions help to organize the overall sequence of events from the solar source to 1 AU. Stressed are analyses of an outstanding magnetic cloud (MC2) starting late on 15 July and its upstream shock about 4 hours earlier in WIND magnetic field and plasma data. Also analyzed is a less certain, but likely, magnetic cloud (MC1) occurring early on 15 July; this was separated from MC2 by its upstream shock and many heliospheric current sheet (HCS) crossings. Other HCS crossings occurred throughout the 3-day period. Overall this dramatic series of interplanetary events caused a large multi-phase magnetic storm with min Dst lower than -300 nT. The very fast solar wind speed (greater than or equal to 1100 km/s) in and around the front of MC2 (for near average densities) was responsible for a very high solar wind ram pressure driving in the front of the magnetosphere to geocentric distances estimated to be as low as approx. 5 R(sub E), much lower than the geosynchronous orbit radius. This was consistent with magnetic field observations from two GOES satellites which indicated they were in the magnetosheath for extended times. A static force free field model is used to fit the two magnetic cloud profiles providing estimates of the clouds' physical and geometrical properties. MC2 was much larger than MCI, but their axes were nearly antiparallel, and their magnetic fields had the same left-handed helicity. MC2's axis and its upstream shock normal were very close to being perpendicular to each other, as might be expected if the cloud were driving the shock at the time of observation. The estimated axial magnetic flux carried by MC2 was 52 x 10(exp 20) Mx, which is about 5 times the typical magnetic flux estimated for other magnetic clouds in the WIND data over its first 4 years and is 17 times the flux of MC1. This large flux is due to both the strong axially-directed field of MC2 (46.8 nT on the axis) and the large radius (R(sub 0) = 0.189 AU) of the flux tube. MC2's average speed is consistent with the expected transit time from a halo-CME to which it is apparently related.

  17. The Influence of the Interplanetary Magnetic Field (IMF) on Atmospheric Escape at Mars

    NASA Astrophysics Data System (ADS)

    Curry, S. M.; Luhmann, J. G.; Ma, Y.; Dong, C. F.; Brain, D. A.

    2014-07-01

    We present a study on the response of Mars’ atmosphere to changes in the interplanetary magnetic field (IMF) configuration, specifically with respect to the atmospheric escape rate via pick up ions and upcoming MAVEN observations.

  18. Experimental observations of the interplanetary magnetic field distribution in the inner heliosphere: controversial points

    NASA Astrophysics Data System (ADS)

    Khabarova, O. V.; Obridko, V. N.

    2012-04-01

    Interplanetary magnetic field (IMF) deviations from a Parker spiral are very often observed in the heliosphere at different distances from the Sun. Commonly, it is supposed that the IMF in the inner heliosphere corresponds to the Parker theory as a whole, but there is some turbulent component that impacts a full picture of the IMF spatial and temporal distribution and damages it. Meanwhile, the analysis of multipoint in-ecliptic IMF measurements from 0.23 AU to 5 AU shows that the radial IMF component in the inner heliosphere corresponds neither r-2 law nor the helicity assumption even under rough average. The next problematic point is an explanation of observational results on the in-ecliptic IMF distribution shape at different AU. It is shown that a bimodal (two-humped) view of Br, RTN (or Bx, By, GSE) distribution, well-known at 1 AU, is most brightly expressed at low heliolatitudes at 0.7-2 AU, but it disappears with an increasing heliocentric distance. The in-ecliptic IMF distribution shape becomes perfectly Gaussian-like at 3-4 AU. Such behaviour of the in-ecliptic IMF can not be explained by any theory of the IMF extension in space. Therefore, experimental results, accumulated for the space era, demonstrates the barest necessity of the 3-D interplanetary magnetic field picture revisiting, looking for new theories of plasma and IMF expansion from the Sun, as well as further development of new models of the inner heliosphere.

  19. The correlation length for interplanetary magnetic field fluctuations

    NASA Technical Reports Server (NTRS)

    Fisk, L. A.; Sari, J. W.

    1972-01-01

    It is argued that it is appropriate to consider two correlation lengths for interplanetary magnetic field fluctuations. For particles with gyro-radii large enough to encounter and be scattered by large-scale tangential discontinuities in the field (particles with energies greater than or approximately equal to several GeV/nucleon) the appropriate correlation length is simply the mean spatial separation between the discontinuities, L approximately 2 x 10 to the 11th power. Particles with gyro-radii much less than this mean separation (energies less than or approximately equal to 100 MeV/nucleon) appear to be unaffected by the discontinuities and respond only to smaller-scale field fluctuations. For these particles the correlation length is shown to be L approximately 10 to the 10th power cm. With this system of two correlation lengths the cosmic-ray diffusion tensor may be altered from what was predicted by, for example, Jokipii and Coleman, and the objections raised recently by Klimas and Sandri to the diffusion analysis of Jokipii may apply only at relatively low energies (approximately 50 MeV/nucleon).

  20. PUZZLES OF THE INTERPLANETARY MAGNETIC FIELD IN THE INNER HELIOSPHERE

    SciTech Connect

    Khabarova, Olga; Obridko, Vladimir

    2012-12-20

    Deviations of the interplanetary magnetic field (IMF) from Parker's model are frequently observed in the heliosphere at different distances r from the Sun. Usually, it is supposed that the IMF behavior corresponds to Parker's model overall, but there is some turbulent component that impacts and disrupts the full picture of the IMF spatial and temporal distribution. However, the analysis of multi-spacecraft in-ecliptic IMF measurements from 0.29 AU to 5 AU shows that the IMF radial evolution is rather far from expected. The radial IMF component decreases with the adiabatic power index (|B{sub r} | {proportional_to} r {sup -5/3}), the tangential component |B{sub r}| {proportional_to} r {sup -1}, and the IMF strength B {proportional_to} r {sup -1.4}. This means that the IMF is not completely frozen in the solar wind. It is possible that turbulent processes in the inner heliosphere significantly influence the IMF expansion. This is confirmed by the analysis of the B{sub r} distribution's radial evolution. B{sub r} has a well-known bimodal histogram only at 0.7-2.0 AU. The bimodality effect gradually disappears from 1 AU to 4 AU, and B{sub r} becomes quasi-normally distributed at 3-4 AU (which is a sign of rapid vanishing of the stable sector structure with heliocentric distance). We consider a quasi-continuous magnetic reconnection, occurring both at the heliospheric current sheet and at local current sheets inside the IMF sectors, to be a key process responsible for the solar wind turbulization with heliocentric distance as well as for the breakdown of the ''frozen-in IMF'' law.

  1. Variation with interplanetary sector of the total magnetic field measured at the OGO 2, 4, and 6 satellites

    NASA Technical Reports Server (NTRS)

    Langel, R. A.

    1973-01-01

    Variations in the scalar magnetic field (delta B) from the polar orbiting OGO 2, 4, and 6 spacecraft are examined as a function of altitude for times when the interplanetary magnetic field is toward the sun and for times when the interplanetary magnetic field away from the sun. This morphology is basically the same as that found when all data, irrespective of interplanetary magnetic sector, are averaged together. Differences in delta B occur, both between sectors and between seasons, which are similar in nature to variations in the surface delta Z found by Langel (1973c). The altitude variation of delta B at sunlit local times, together with delta Z at the earth's surface, demonstrates that the delta Z and delta B which varies with sector has an ionospheric source. Langel (1973b) showed that the positive delta B region in the dark portion of the hemisphere is due to at least two sources, the westward electrojet and an unidentified non-ionospheric source(s). Comparison of magnetic variations between season/sector at the surface and at the satellite, in the dark portion of the hemisphere, indicates that these variations are caused by variations in the latitudinally narrow electrojet currents and not by variations in the non-ionospheric source of delta B.

  2. Criteria of interplanetary parameters causing intense magnetic storms (Dst less than -100nT)

    NASA Technical Reports Server (NTRS)

    Gonzalez, Walter D.; Tsurutani, Bruce T.

    1987-01-01

    Ten intense storms occurred during the 500 days of August 16, 1978 to December 28, 1979. From the analysis of ISEE-3 field and plasma data, it is found that the interplanetary cause of these storms are long-duration, large and negative IMF B sub Z events, associated with interplanetary duskward-electric fields greater than 5 mV/m. Because a one-to-one relationship was found between these interplanetary events and intense storms, it is suggested that these criteria can, in the future, be used as predictors of intense storms by an interplanetary monitor such as ISEE-3. These B sub Z events are found to occur in association with large amplitudes of the IMF magnitude within two days after the onset of either high-speed solar wind streams or of solar wind density enhancement events, giving important clues to their interplanetary origin. Some obvious possibilities will be discussed. The close proximity of B sub Z events and magnetic storms to the onset of high speed streams or density enhancement events is in sharp contrast to interplanetary Alfven waves and HILDCAA events previously reported, and thus the two interplanetary features corresponding geomagnetic responses can be thought of as being complementary in nature. An examination of opposite polarity B sub Z events with the same criteria show that their occurrence is similar both in number as well as in their relationship to interplanetary disturbances, and that they lead to low levels of geomagnetic activity.

  3. A Scheme for finding the Front Boundary of an Interplanetary Magnetic Cloud

    NASA Technical Reports Server (NTRS)

    Lepping, Ronald P.; Narock, Thomas W.; Wu, Chin-Chun

    2006-01-01

    We developed a scheme for finding the front boundary of an interplanetary magnetic cloud (MC) based on criteria that depend on the possible existence of any one or all of six specific solar wind features. The features that the program looks for, within +/- 2 hours of a preliminarily determined time for the front boundary, estimated either by visual inspection or by an automatic MC identification scheme, are: (1) a sufficiently large directional discontinuity in the interplanetary magnetic field (IMF), (2) existence of a magnetic hole, (3) a significant proton plasma beta drop, (4) a significant proton temperature drop, (5) a marked increase in the IMF's intensity, and (6) a significant decrease in a normalized root-mean-square deviation (RMS)of the magnetic field - where the scheme was tested using 5, 10, 15, and 20 minute averages of the relevant physical quantities, in order to find the optimum average (and RMS) to use. Other criteria, besides these six, were examined and dismissed as not reliable, e.g., plasma speed. The scheme was developed specifically for aiding in forecasting the strength and timing of a geomagnetic storm due to the passage of an interplanetary MC in real-time, but can be used in post ground-data collection for imposition of consistency in choosing a MC's front boundary. The scheme has been extensively tested, first using 80 bona fide MCs over about 9 years of WIND data, and also for 121 MC-like structures as defined by a program that automatically identifies such structures over the same period. Optimum limits for various parameters in the scheme were found by statistical studies of the WIND MCs. The resulting limits can be user-adjusted for other data sets, if desired. Final testing of the 80 MCs showed that for 50 percent of the events the boundary estimates occurred within +/-10 minutes of visually determined times, 80 percent occurred within +/-30 minutes, and 91 percent occur within +/-60 minutes, and three or more individual boundary tests were passed for 88 percent of the total MCs. The scheme and its testing will be described.

  4. Relationships Among Geomagnetic Storms, Interplanetary Shocks, Magnetic Clouds, and Sunspot Number During 1995 - 2012

    NASA Astrophysics Data System (ADS)

    Wu, Chin-Chun; Lepping, Ronald P.

    2016-01-01

    During 1995 - 2012, the Wind spacecraft has recorded 168 magnetic clouds (MCs), 197 magnetic cloud-like structures (MCLs), and 358 interplanetary (IP) shocks. Ninety-four MCs and 56 MCLs had upstream shock waves. The following features are found: i) The averages of the solar wind speed, interplanetary magnetic field (IMF), duration (< Δ t >), the minimum of B_{min}, and intensity of the associated geomagnetic storm/activity (Dst_{min}) for MCs with upstream shock waves (MC_{shock}) are higher (or stronger) than those averages for the MCs without upstream shock waves (MC_{no-shock}). ii) The average < Δ t > of MC_{shock} events ({≈} 19.8 h) is 9 % longer than that for MC_{no-shock} events ({≈} 17.6 h). iii) For the MC_{shock} events, the average duration of the sheath (<Δ t_{sheath}>) is 12.1 h. These findings could be very useful for space weather predictions, i.e. IP shocks driven by MCs are expected to arrive at Wind (or at 1 AU) about 12 h ahead of the front of the MCs on average. iv) The occurrence frequency of IP shocks is well associated with sunspot number (SSN). The average intensity of geomagnetic storms measured by < Dst_{min}> for MC_{shock} and MC_{no-shock} events is -102 and -31 nT, respectively. The average values < {Dst}_{min} > are -78, -70, and -35 nT for the 358 IP shocks, 168 MCs, and 197 MCLs, respectively. These results imply that IP shocks, when they occur with MCs/MCLs, must play an important role in the strength of geomagnetic storms. We speculate about the reason for this. Yearly occurrence frequencies of MC_{shock} and IP shocks are well correlated with solar activity ( e.g., SSN). Choosing the correct Dst_{min} estimating formula for predicting the intensity of MC-associated geomagnetic storms is crucial for space weather predictions.

  5. Influence of interplanetary magnetic field and solar wind on auroral brightness in different regions

    NASA Astrophysics Data System (ADS)

    Yang, Y. F.; Lu, J. Y.; Wang, J.-S.; Peng, Z.; Zhou, L.

    2013-01-01

    Abstract<p label="1">By integrating and <span class="hlt">averaging</span> the auroral brightness from Polar Ultraviolet Imager auroral images, which have the whole auroral ovals, and combining the observation data of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) and solar wind from NASA Operating Missions as a Node on the Internet (OMNI), we investigate the influence of IMF and solar wind on auroral activities, and analyze the separate roles of the solar wind dynamic pressure, density, and velocity on aurora, respectively. We statistically analyze the relations between the <span class="hlt">interplanetary</span> conditions and the auroral brightness in dawnside, dayside, duskside, and nightside. It is found that the three components of the IMF have different effects on the auroral brightness in the different regions. Different from the nightside auroral brightness, the dawnside, dayside, and duskside auroral brightness are affected by the IMF Bx, and By components more significantly. The IMF Bx and By components have different effects on these three regional auroral brightness under the opposite polarities of the IMF Bz. As expected, the nightside aurora is mainly affected by the IMF Bz, and under southward IMF, the larger the |Bz|, the brighter the nightside aurora. The IMF Bx and By components have no visible effects. On the other hand, it is also found that the aurora is not intensified singly with the increase of the solar wind dynamic pressure: when only the dynamic pressure is high, but the solar wind velocity is not very fast, the aurora will not necessarily be intensified significantly. These results can be used to qualitatively predict the auroral activities in different regions for various <span class="hlt">interplanetary</span> conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19890049309&hterms=solar+storm&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsolar%2Bstorm','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19890049309&hterms=solar+storm&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsolar%2Bstorm"><span id="translatedtitle">Solar sources of <span class="hlt">interplanetary</span> southward Bz events responsible for major <span class="hlt">magnetic</span> storms (1978-1979)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tang, Frances; Tsurutani, Bruce T.; Smith, Edward J.; Gonzalez, Walter D.; Akasofu, Syun I.</p> <p>1989-01-01</p> <p>The solar sources of <span class="hlt">interplanetary</span> southward Bz events responsible for major <span class="hlt">magnetic</span> storms observed in the August 1978-December 1979 period were studied using a full complement of solar wind plasma and field data from ISEE 3. It was found that, of the ten major storms observed, seven were initiated by active region flares, and three were associated with prominence eruptions in solar quiet regions. Nine of the storms were associated with <span class="hlt">interplanetary</span> shocks. However, a comparison of the solar events' characteristics and those of the resulting <span class="hlt">interplanetary</span> shocks indicated that standard solar parameters did not correlate with the strengths of the resulting shocks at 1 AU.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19770027147','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19770027147"><span id="translatedtitle">Sources of <span class="hlt">magnetic</span> fields in recurrent <span class="hlt">interplanetary</span> streams</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Burlaga, L. F.; Behannon, K. W.; Hansen, S. F.; Pneuman, G. W.; Feldman, W. C.</p> <p>1977-01-01</p> <p>The sources of <span class="hlt">magnetic</span> fields in recurrent streams were examined. Most fields and plasmas at 1 AU were related to coronal holes, and the <span class="hlt">magnetic</span> field lines were open in those holes. Some of the <span class="hlt">magnetic</span> fields and plasmas were related to open field line regions on the sun which were not associated with known coronal holes, indicating that open field lines are more basic than coronal holes as sources of the solar wind. <span class="hlt">Magnetic</span> field intensities in five equatorial coronal holes ranged from 2G to 18G. <span class="hlt">Average</span> measured photospheric <span class="hlt">magnetic</span> fields along the footprints of the corresponding unipolar fields on circular equatorial arcs at 2.5 solar radii had a similar range and <span class="hlt">average</span>, but in two cases the intensities were approximately three times higher than the projected intensities. The coronal footprints of the sector boundaries on the source surface at 2.5 solar radii, meandered between -45 deg and +45 deg latitude, and their inclination ranged from near zero to near ninety degrees.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19770027122','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19770027122"><span id="translatedtitle"><span class="hlt">Interplanetary</span> medium data book, appendix</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>King, J. H.</p> <p>1977-01-01</p> <p>Computer generated listings of hourly <span class="hlt">average</span> <span class="hlt">interplanetary</span> plasma and <span class="hlt">magnetic</span> field parameters are given. Parameters include proton temperature, proton density, bulk speed, an identifier of the source of the plasma data for the hour, <span class="hlt">average</span> <span class="hlt">magnetic</span> field magnitude and cartesian components of the <span class="hlt">magnetic</span> field. Also included are longitude and latitude angles of the vector made up of the <span class="hlt">average</span> field components, a vector standard deviation, and an identifier of the source of <span class="hlt">magnetic</span> field data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5182344','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5182344"><span id="translatedtitle">Multifractal structure of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field: Voyager 2 observations near 25 AU, 1987 - 1988</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Burlaga, L.F. )</p> <p>1991-01-01</p> <p>This paper analyzes the large-scale fluctuations of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field strength observed by Voyager 2 from 23.3 AU to 27.8 AU during the period from day 190, 1987 to day 345, 1988. The q-th moments of B{sub {tau}} show scaling behavior in the range of scales from 16 hours to 21 days for {minus}10 {le} q {le} 10, i.e., <B{sub {tau}}{sup q}> {approximately} {tau}{sup s(q)} in this range. s(q) is approximately a quadratic function of q for {minus}4 {le} q {le} 4, as one expects for a distribution that is approximately lognormal, but the higher moments diverge from those of a lognormal distribution. The function D{sub q}(q) = 1 + s(q)/(q {minus} 1) has the form that is characteristic of multifractals. For a multifractal <span class="hlt">magnetic</span> field, the moments of the field should scale as {tau}{sup {alpha}} on a set with fractal dimension f({alpha}), where {alpha} has a continuum of values over some limited range. For the large-scale <span class="hlt">magnetic</span> field fluctuations, the function f({alpha}) computed from D{sub q}(q) is approximately a fourth order polynomial for {minus}10 {le} q {le} 10, and positive values of f({alpha}) occur for 0.8 {le} {alpha} {le} 1.2. The multifractional character of the <span class="hlt">magnetic</span> field strength fluctuations generalizes the concept that the <span class="hlt">magnetic</span> field is organized into interaction regions (regions in which the <span class="hlt">magnetic</span> field strength and pressure are higher than <span class="hlt">average</span> for several hours) and rarefaction regions (regions in which the <span class="hlt">magnetic</span> field strength and pressure are lower than <span class="hlt">average</span>). Near solar maximum the interaction regions in the distant heliosphere might be viewed as cluster of strong disturbed fields with considerable fine structure on various scales.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016Icar..263...10H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016Icar..263...10H"><span id="translatedtitle"><span class="hlt">Interplanetary</span> <span class="hlt">magnetic</span> field structure at Saturn inferred from nanodust measurements during the 2013 aurora campaign</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hsu, H.-W.; Kempf, S.; Badman, S. V.; Kurth, W. S.; Postberg, F.; Srama, R.</p> <p>2016-01-01</p> <p>Interactions between the solar wind and planetary magnetospheres provide important diagnostic information about the magnetospheric dynamics. The lack of monitoring of upstream solar wind conditions at the outer planets, however, restrains the overall scientific output. Here we apply a new method, using Cassini nanodust stream measurements, to derive the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field structure during the 2013 Saturn aurora campaign. Due to the complex dynamical interactions with the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field, a fraction of fast nanodust particles emerging from the Saturnian system is sent back into the magnetosphere and can be detected by a spacecraft located within. The time-dependent directionality caused by the variable <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field enable these particles to probe the solar wind structure remotely. Information about the arrival time of solar wind compression regions (coupled with the heliospheric current sheet crossings) as well as the field direction associated with the solar wind sector structure can be inferred. Here we present a tentative identification of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field sector structure based on Cassini nanodust and radio emission measurements during the 2013 Saturn aurora campaign. Our results show that, the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field near Saturn during 2013-080 to 176 was consistent with a two-sector structure. The intensifications of aurora and the radio emission on 2013-095, 112 and 140 coincide with the IMF sector boundaries, indicating that the encounter of the compressed solar wind is the main cause of the observed activities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AnGeo..23.1405B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AnGeo..23.1405B"><span id="translatedtitle"><span class="hlt">Interplanetary</span> <span class="hlt">magnetic</span> field control of Saturn's polar cusp aurora</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bunce, E. J.; Cowley, S. W. H.; Milan, S. E.</p> <p>2005-06-01</p> <p>Dayside UV emissions in Saturn's polar ionosphere have been suggested to be the first observational evidence of the kronian "cusp" (Gérard et al., 2004). The emission has two distinct states. The first is a bright arc-like feature located in the pre-noon sector, and the second is a more diffuse "spot" of aurora which lies poleward of the general location of the main auroral oval, which may be related to different upstream <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) orientations. Here we take up the suggestion that these emissions correspond to the cusp. However, direct precipitation of electrons in the cusp regions is not capable of producing significant UV aurora. We have therefore investigated the possibility that the observed UV emissions are associated with reconnection occurring at the dayside magnetopause, possibly pulsed, akin to flux transfer events seen at the Earth. We devise a conceptual model of pulsed reconnection at the low-latitude dayside magnetopause for the case of northwards IMF which will give rise to pulsed twin-vortical flows in the magnetosphere and ionosphere in the vicinity of the open-closed field-line boundary, and hence to bi-polar field-aligned currents centred in the vortical flows. During intervals of high-latitude lobe reconnection for southward IMF, we also expect to have pulsed twin-vortical flows and corresponding bi-polar field-aligned currents. The vortical flows in this case, however, are displaced poleward of the open-closed field line boundary, and are reversed in sense, such that the field-aligned currents are also reversed. For both cases of northward and southward IMF we have also for the first time included the effects associated with the IMF By effect. We also include the modulation introduced by the structured nature of the solar wind and IMF at Saturn's orbit by developing "slow" and "fast" flow models corresponding to intermediate and high strength IMF respectively. We then consider the conditions under which the plasma populations appropriate to either sub-solar reconnection or high-latitude lobe reconnection can carry the currents indicated. We have estimated the field-aligned voltages required, the resulting precipitating particle energy fluxes, and the consequent auroral output. Overall our model of pulsed reconnection under conditions of northwards and southwards IMF, and for varying orientations of IMF By, is found to produce a range of UV emission intensities and geometries which is in good agreement with the data presented by Gérard et al. (2004). The recent HST-Cassini solar wind campaign provides a unique opportunity to test the theoretical ideas presented here.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6371196','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6371196"><span id="translatedtitle">A study of an expanding interplantary <span class="hlt">magnetic</span> cloud and its interaction with the Earth's magnetosphere: The <span class="hlt">interplanetary</span> aspect</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Farrugia, C.J.; Burlaga, L.F.; Lepping, R.P. ); Osherovich, V.A. ); Richardson, I.G. Univ. of Maryland, College Park ); Freeman, M.P. ); Lazarus, A.J. )</p> <p>1993-05-01</p> <p>This is the first of three papers studying an expanding <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> cloud, and its interaction with the earth's magnetosphere. A <span class="hlt">magnetic</span> cloud is a very large scale <span class="hlt">interplanetary</span> phenomena which when viewed by an observer tied to the sun has certain characteristics: the <span class="hlt">magnetic</span> field direction rotates slowly over a period of a day through a large angle; the <span class="hlt">magnetic</span> field strength is larger than <span class="hlt">average</span>; and the proton pressure is much less than the <span class="hlt">magnetic</span> pressure. Here the authors interpret and discuss high time resolution measurements made by the IMP 8 spacecraft over roughly two days, at 1 AU, of interplantary <span class="hlt">magnetic</span> fields and plasma properties, on Jan 14-15, 1988. The observations are consistent with the model of <span class="hlt">magnetic</span> clouds as flux ropes of local cylindrical geometry. These clouds are large scale MHD configurations. As it evolves antisunward it expands. The authors modeled this behaviour. They also studied the question of the attachment of field lines in the cloud with the sun.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19910060875&hterms=Magnetic+interaction&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D20%26Ntt%3DMagnetic%2Binteraction','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19910060875&hterms=Magnetic+interaction&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D20%26Ntt%3DMagnetic%2Binteraction"><span id="translatedtitle"><span class="hlt">Interplanetary</span> <span class="hlt">magnetic</span> field control of the Mars bow shock - Evidence for Venuslike interaction</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zhang, T. L.; Schwingenschuh, K.; Lichtenegger, H.; Riedler, W.; Russell, C. T.</p> <p>1991-01-01</p> <p>The Mars bow shock location and shape have been determined by examining the Phobos spacecraft magnetometer data. Observations show that the position of the terminator bow shock varies with <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field orientation in the same way as at Venus. The shock is farthest from Mars in the direction of the <span class="hlt">interplanetary</span> electric field, consistent with the idea that mass loading plays an important role in the solar wind interaction with Mars. The shock cross section at the terminator plane is asymmetric and is controlled by the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field. The shock is farther from Mars during solar maximum. Thus the solar wind interaction with Mars appears to be Venuslike, with a <span class="hlt">magnetic</span> moment too small to affect significantly the solar wind interaction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5224461','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5224461"><span id="translatedtitle"><span class="hlt">Interplanetary</span> <span class="hlt">magnetic</span> field control of the Mars bow shock: Evidence for Venuslike interaction</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Zhang, T.L.; Schwingenschuh, K.; Lichtenegger, H.; Riedler, W. ); Russell, C.T.; Luhmann, J.G. )</p> <p>1991-07-01</p> <p>The Mars bow shock location and shape have been determined by examining the PHOBOS spacecraft magnetometer data. Observations show that the position of the terminator bow shock varies with <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field orientation in the same way as at Venus. The shock is farthest from Mars in the direction of the <span class="hlt">interplanetary</span> electric field, consistent with the idea that mass loading plays an important role in the solar wind interaction with Mars. The authors also find that the shock cross section at the terminator plane is asymmetric and is controlled by the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field as expected from the asymmetric propagation velocity of the fast magnetosonic wave. Comparing with earlier mission data, they show that the Mars shock location varies with solar activity. The shock is farther from Mars during solar maximum. Thus the solar wind interaction with Mars appears to be Venuslike, with a <span class="hlt">magnetic</span> moment too small to affect significantly the solar wind interaction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995SoPh..157..367A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995SoPh..157..367A"><span id="translatedtitle">The solar wind angular momentum and energy carried by the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alexander, P.; de La Torre, A.</p> <p>1995-03-01</p> <p>Solutions already found by one of the authors with a two-region model of the solar coronal expansion are used to analyze the transport of angular momentum and energy by the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field. In agreement with observations, it is predicted that the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field plays an insignificant role for the flux of energy, but carries a large amount of angular momentum. The appropriate description might be related to the replacement of classical transport coefficients by a collisionless heat flux equation in the outer region of the model. The Sun's loss of angular momentum may affect the strength of the solar rotation in the long term.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22270946','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22270946"><span id="translatedtitle">DECLINE AND RECOVERY OF THE <span class="hlt">INTERPLANETARY</span> <span class="hlt">MAGNETIC</span> FIELD DURING THE PROTRACTED SOLAR MINIMUM</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Smith, Charles W.; Schwadron, Nathan A.; DeForest, Craig E. E-mail: N.Schwadron@unh.edu</p> <p>2013-09-20</p> <p>The <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) is determined by the amount of solar <span class="hlt">magnetic</span> flux that passes through the top of the solar corona into the heliosphere, and by the dynamical evolution of that flux. Recently, it has been argued that the total flux of the IMF evolves over the solar cycle due to a combination of flux that extends well outside of 1 AU and is associated with the solar wind, and additionally, transient flux associated with coronal mass ejections (CMEs). In addition to the CME eruption rate, there are three fundamental processes involving conversion of <span class="hlt">magnetic</span> flux (from transient to wind-associated), disconnection, and interchange reconnection that control the levels of each form of <span class="hlt">magnetic</span> flux in the <span class="hlt">interplanetary</span> medium. This is distinct from some earlier models in which the wind-associated component remains steady across the solar cycle. We apply the model of Schwadron et al. that quantifies the sources, interchange, and losses of <span class="hlt">magnetic</span> flux to 50 yr of <span class="hlt">interplanetary</span> data as represented by the Omni2 data set using the sunspot number as a proxy for the CME eruption rate. We do justify the use of that proxy substitution. We find very good agreement between the predicted and observed <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> flux. In the absence of sufficient CME eruptions, the IMF falls on the timescale of ∼6 yr. A key result is that rising toroidal flux resulting from CME eruption predates the increase in wind-associated IMF.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/10702137','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/10702137"><span id="translatedtitle"><span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field Line Mixing Deduced from Impulsive Solar Flare Particles.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mazur; Mason; Dwyer; Giacalone; Jokipii; Stone</p> <p>2000-03-20</p> <p>We have studied fine-scale temporal variations in the arrival profiles of approximately 20 keV nucleon-1 to approximately 2 MeV nucleon-1 ions from impulsive solar flares using instrumentation on board the Advanced Composition Explorer spacecraft at 1 AU between 1997 November and 1999 July. The particle events often had short-timescale ( approximately 3 hr) variations in their intensity that occurred simultaneously across all energies and were generally not in coincidence with any local <span class="hlt">magnetic</span> field or plasma signature. These features appear to be caused by the convection of <span class="hlt">magnetic</span> flux tubes past the observer that are alternately filled and devoid of flare ions even though they had a common flare source at the Sun. Thus, we have used the particles to study the mixing of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field that is due to random walk. We deduce an <span class="hlt">average</span> timescale of 3.2 hr for these features, which corresponds to a length of approximately 0.03 AU. PMID:10702137</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19770038810&hterms=major+earth+event&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dmajor%2Bearth%2Bevent','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19770038810&hterms=major+earth+event&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dmajor%2Bearth%2Bevent"><span id="translatedtitle">The August 1972 solar-terrestrial events - <span class="hlt">Interplanetary</span> <span class="hlt">magnetic</span> field observations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Smith, E. J.</p> <p>1976-01-01</p> <p><span class="hlt">Interplanetary-magnetic</span>-field measurements made by Pioneers 9 and 10, HEOS 2, and Explorer 41 during early August 1972 are reviewed. It is noted that the two Pioneers were nearly radially aligned during the flare events, with Pioneer 9 at a distance of 0.78 AU from the sun and Pioneer 10 at a distance of 2.2 AU. The data obtained by Pioneer 9, Pioneer 10, and the two near-earth satellites are analyzed separately, and the major flare-associated shocks are identified. An attempt is made to identify corresponding shocks at the different locations and to determine their propagation velocities in the region between 0.8 and 2.2 AU. It is found that there was an obvious tendency for the <span class="hlt">average</span> shock velocities to decrease with increasing radial distance from the sun and that the local velocities at the Pioneer locations were significantly smaller than the appropriate <span class="hlt">average</span> values. A comparison of these local velocities indicates that there was a large deceleration of the shocks between the sun and some distance within 0.8 AU but little, if any, deceleration beyond that distance. A plot of <span class="hlt">average</span> shock velocities from the sun to 1.0 AU as a function of longitude separation between the flares and Pioneer 9 is shown to suggest a pronounced deviation of the shock fronts from spherical symmetry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AGUFMSH31A1178W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AGUFMSH31A1178W"><span id="translatedtitle">Orientation Of <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Clouds Associated With Filament Eruptions And Major Geomagnetic Storms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Y.; Ye, P.; Zhou, G.; Wang, S.; Wang, J.</p> <p>2004-12-01</p> <p>As a major source of non-recurrent geomagnetic storms, more than half of <span class="hlt">magnetic</span> clouds in the <span class="hlt">interplanetary</span> medium are associated with filament eruptions [Subramanian and Dere, 2001]. The strength of south component of the <span class="hlt">magnetic</span> field inside <span class="hlt">magnetic</span> cloud and its duration are consider the very important factors in causing geomagnetic storm. Obviously, these factors are related to the orientation of <span class="hlt">magnetic</span> cloud in terms of flux rope model. By investigating the observations of SOHO and ACE spacecraft from 2000 to 2003, the relationship between the orientation of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> clouds which were associated with filament eruptions and major geomagnetic storms are studied. Two issues are discussed: (1) the effect of <span class="hlt">magnetic</span> cloud's orientation on the intensity of geomagnetic storm, and (2) the possible factors in influencing the cloud's orientation. The results will be worked out.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSH41A2168K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSH41A2168K"><span id="translatedtitle">The Role Played by the <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field Topology in the Observed intensities of Solar Energetic Particle Events</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Karelitz, A. M.; Lario, D.</p> <p>2013-12-01</p> <p>The presence of large-scale solar wind structures in the <span class="hlt">interplanetary</span> medium may affect the transport of solar energetic particles (SEPs) in the heliosphere. In particular, the <span class="hlt">interplanetary</span> counterparts of coronal mass ejections (ICMEs) are able to modify the surrounding <span class="hlt">interplanetary</span> medium by introducing changes in the direction and strength of the <span class="hlt">magnetic</span> field as well as increasing the level of <span class="hlt">magnetic</span> field turbulence. Understanding the transport of SEPs in the heliosphere can lead to the increased capability in forecasting and predicting of the intensity of future SEP events. In this study, we classify paring SEP and ICME events from the 23rd solar cycle into six different categories based on when the peak of the SEP event occurred. For example, two different categories are: (1) the SEP peak occurred when an ICME was between the Sun and the Earth and (2) the SEP peak occurred after the ICME was beyond Earth. We perform a statistical analysis of the SEP peak intensities for each class of event and according to the characteristics of the solar x-ray flare or the CME associated with the origin of the SEP event For similar properties of the associated solar flare or CME we find that, on <span class="hlt">average</span>, events observed after the passage of an ICME have larger peak intensities than those events observed with an ICME between the Sun and Earth. Strict analysis and understanding of the influence that the dynamic <span class="hlt">interplanetary</span> solar wind has on the peak intensity of SEPs can enable space weather operational forecasters to better predict solar energetic particle intensities based on the occurrence of previous solar activity. By forecasting solar energetic particle events spacecraft, satellites, and humans in space, can be better protected from the impact of space weather.</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_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li class="active"><span>4</span></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_4 --> <div id="page_5" 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_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active"><span>5</span></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</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="81"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19720015727','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19720015727"><span id="translatedtitle">Effects of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field azimuth on auroral zone and polar cap <span class="hlt">magnetic</span> activity</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Burch, J. L.</p> <p>1972-01-01</p> <p>During relatively quiet times in the period 1964-1968, AE is found to be greater when the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (b sub IMF) is directed toward the sun in Jan., Feb., and Apr., and when B sub IMF is directed away from the sun in Oct. to Dec. Using Murmansk hourly H values and the AE components, AU and AL, it is shown that this sector dependence is present only in the negative H deviations. This observation supports the idea that negative bay magnitudes are determined chiefly by particle-produced ionization, while positive bay magnitudes are rather insensitive to increases in particle precipitation. The ratio of DP2-type <span class="hlt">magnetic</span> activity in the southern polar cap to that in the northern polar cap is found to be greater by a factor of about 1.75 for B sub IMF toward the sun.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19880060054&hterms=solar+storm&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsolar%2Bstorm','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19880060054&hterms=solar+storm&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsolar%2Bstorm"><span id="translatedtitle">Origin of <span class="hlt">interplanetary</span> southward <span class="hlt">magnetic</span> fields responsible for major <span class="hlt">magnetic</span> storms near solar maximum (1978-1979)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tsurutani, Bruce T.; Smith, Edward J.; Gonzalez, Walter D.; Tang, Frances; Akasofu, Syun I.</p> <p>1988-01-01</p> <p>Simultaneous ISEE-3 field and plasma data were used to examine <span class="hlt">interplanetary</span> phenomena associated with 10 major <span class="hlt">magnetic</span> storms detected from August 16, 1978, to December 28, 1979, in a study of Gonzalez and Tsurutani (1987), and, in particular to determine the origins of the southward <span class="hlt">magnetic</span> fields which caused the storms. In nine of the 10 cases, the responsible <span class="hlt">interplanetary</span> events were found, as expected, to be associated with the high <span class="hlt">magnetic</span> fields in the stream-stream interaction regions (sheaths) or driver gases, with the events following the <span class="hlt">interplanetary</span> shocks. The tenth event was found to be associated not with a high-speed stream, but with a noncompressional density-enhancement event. The results of this study indicate the equal importance of both the sheath fields or draped fields and the driver gas fields for the generation of major geomagnetic storms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19770027121','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19770027121"><span id="translatedtitle"><span class="hlt">Interplanetary</span> medium data book</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>King, J. H.</p> <p>1977-01-01</p> <p>Unresolved questions on the physics of solar wind and its effects on magnetospheric processes and cosmic ray propagation were addressed with hourly <span class="hlt">averaged</span> <span class="hlt">interplanetary</span> plasma and <span class="hlt">magnetic</span> field data. This composite data set is described with its content and extent, sources, limits of validity, and the mutual consistency studies and normalizations to which the input data were subjected. Hourly <span class="hlt">averaged</span> parameters were presented in the form of digital listings and 27-day plots. The listings are contained in a separately bound appendix.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110008573','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110008573"><span id="translatedtitle"><span class="hlt">Magnetic</span> Flux Circulation During Dawn-Dusk Oriented <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mitchell, E. J.; Lopez, R. E.; Fok, M.-C.; Deng, Y.; Wiltberger, M.; Lyon, J.</p> <p>2010-01-01</p> <p><span class="hlt">Magnetic</span> flux circulation is a primary mode of energy transfer from the solar wind into the ionosphere and inner magnetosphere. For southward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF), <span class="hlt">magnetic</span> flux circulation is described by the Dungey cycle (dayside merging, night side reconnection, and magnetospheric convection), and both the ionosphere and inner magnetosphere receive energy. For dawn-dusk oriented IMF, <span class="hlt">magnetic</span> flux circulation is not well understood, and the inner magnetosphere does not receive energy. Several models have been suggested for possible reconnection patterns; the general pattern is: dayside merging; reconnection on the dayside or along the dawn/dusk regions; and, return flow on dayside only. These models are consistent with the lack of energy in the inner magnetosphere. We will present evidence that the Dungey cycle does not explain the energy transfer during dawn-dusk oriented IMF. We will also present evidence of how <span class="hlt">magnetic</span> flux does circulate during dawn-dusk oriented IMF, specifically how the <span class="hlt">magnetic</span> flux reconnects and circulates back.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AdSpR..43.1575R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AdSpR..43.1575R"><span id="translatedtitle">Low-latitude geomagnetic response to the <span class="hlt">interplanetary</span> conditions during very intense <span class="hlt">magnetic</span> storms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rawat, R.; Alex, S.; Lakhina, G. S.</p> <p>2009-05-01</p> <p>The variations in the horizontal and declination components of the geomagnetic field in response to the <span class="hlt">interplanetary</span> shocks driven by fast halo coronal mass ejections, fast solar wind streams from the coronal hole regions and the dynamic pressure pulses associated with these events are studied. Close association between the field-aligned current density ( j∥) and the fluctuations in the declination component (Δ DABG) at Alibag is found for intense storm conditions. Increase in the dawn-dusk <span class="hlt">interplanetary</span> electric field ( Ey) and Δ DABG are generally in phase. However, when the magnetospheric electric field is directed from dusk to dawn direction, a prominent scatter occurs between the two. It is suggested that low-latitude ground <span class="hlt">magnetic</span> data may serve as a proxy for the <span class="hlt">interplanetary</span> conditions in the solar wind.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19730002064&hterms=ps&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dps','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19730002064&hterms=ps&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dps"><span id="translatedtitle">Comments on the measurement of power spectra of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Russell, C. T.</p> <p>1972-01-01</p> <p>Examination of possible noise sources in the measurement of the power spectrum of fluctuations in the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field shows that most measurements by fluxgate magnetometers are limited by digitization noise whereas the search coil magnetometer is limited by instrument noise. The folding of power about the Nyquist frequency or aliasing can be a serious problem at times for many magnetometers, but it is not serious during typical solar wind conditions except near the Nyquist frequency. Waves in the solar wind associated with the presence of the earth's bow shock can contaminate the <span class="hlt">interplanetary</span> spectrum in the vicinity of the earth. However, at times the spectrum in this region is the same as far from the earth. Doppler shifting caused by the convection of waves by the solar wind makes the interpretation of <span class="hlt">interplanetary</span> spectra difficult.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19720046848&hterms=Magnetic+interaction&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D50%26Ntt%3DMagnetic%2Binteraction','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19720046848&hterms=Magnetic+interaction&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D50%26Ntt%3DMagnetic%2Binteraction"><span id="translatedtitle">The effects of boundary condition asymmetries on the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field-moon interaction.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Reisz, A. C.; Paul, D. L.; Madden, T. R.</p> <p>1972-01-01</p> <p>Boundary condition asymmetries inherent in the solar wind flow past the moon are included in a cylindrical model of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field-moon interaction. Numerical examinations of the sunward side response of this model are compared in the frequency domain with those of symmetrically excited spherical and cylindrical models and two characteristic differences are observed: the response of the asymmetric model is depressed at low frequencies due to <span class="hlt">magnetic</span> diffusion around a conducting core, and is flattened at high frequencies because of the finite application time of the incident <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field. The diffusion of field lines around the core is also evident in the time response of the model in the antisolar cavity. The above features of the lunar response resulting from boundary condition asymmetries are shown to be evident in observational measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19930046797&hterms=cosmic+geometry&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dcosmic%2Bgeometry','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19930046797&hterms=cosmic+geometry&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dcosmic%2Bgeometry"><span id="translatedtitle">Long-term variations of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field spectra with implications for cosmic ray modulation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bieber, John W.; Chen, Jiasheng; Matthaeus, William H.; Smith, Charles W.; Pomerantz, Martin A.</p> <p>1993-01-01</p> <p>The paper calculates yearly <span class="hlt">averaged</span> power spectra of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field turbulence at 1 AU over the period 1965-1988 for fluctuations in the frequency range 5.8 x 10 exp -6 to 4.6 x 10 exp -5 Hz, corresponding to periods of 6-48 hr. The amplitudes of the spectra vary with the sunspot cycle and are inversely correlated with the intensity of about 10-GeV cosmic rays. The observed spectra are used to calculate a lower limit to the cosmic ray scattering mean free path employing resonant magnetostatic quasi-linear theory for both 'slab' and isotropic geometries of the turbulence. The mean free paths thus obtained are typically about 0.1 AU in the slab model and about 0.3 AU in the isotropic model, but they are not significantly correlated with the modulated galactic cosmic ray intensity recorded by neutron monitors. It is inferred that the scattering processes described by resonant magnetostatic theory play, at best, a very minor role in the solar modulation of about 10-GeV cosmic rays.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19810004452','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19810004452"><span id="translatedtitle"><span class="hlt">Magnetic</span> field directional discontinuities. 2: Characteristics between 0.46 and 1.0 AU. [<span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> fields</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lepping, R. P.; Benhannon, K. W.</p> <p>1980-01-01</p> <p>The characteristics of directional discontinuities (DD's) in the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field are studied using data from the Mariner 10 primary mission between 1.0 and 0.46 AU. Statistical and visual survey methods for DD identification resulted in a total of 644 events. Two methods were used to estimate the ratio of the number of tangential discontinuities (TD's) to the number of rotational discontinuities (RD's). Both methods show that the ratio of TD's to RD's varied with time and decreased with decreasing radial distance. A decrease in <span class="hlt">average</span> discontinuity thickness of approx. 40 percent was found between 1.0 and 0.72 AU and approx. 54 percent between 1.0 and 0.46 AU, independent of type (TD or RD). This decrease in thickness for decreasing r is in qualitative agreement with Pioneer 10 observations between 1 and 5 AU. When the individual DD thickness are normalized with respect to the estimated local proton gyroradius (RA sub L), the <span class="hlt">average</span> thickness at the three locations is nearly constant, 43 + or - 6 R sub L. This also holds true for both RD's and TD's separately. Statistical distributions of other properties, such as normal components and discontinuity plane angles, are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19770031631&hterms=pioneers+solar+power&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dpioneers%2Bsolar%2Bpower','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19770031631&hterms=pioneers+solar+power&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dpioneers%2Bsolar%2Bpower"><span id="translatedtitle"><span class="hlt">Interplanetary</span> <span class="hlt">magnetic</span> field power spectra - Mean field radial or perpendicular to radial</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sari, J. W.; Valley, G. C.</p> <p>1976-01-01</p> <p>A detailed frequency analysis of Pioneer-6 <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field data is carried out for 5 to 15 hour periods during which the mean <span class="hlt">interplanetary</span> field is approximately radial or perpendicular to radial. The reason why these data sets were chosen is that by making the usual assumption that the phase speed of any wave present is much less than the mean solar wind speed, the measured frequency spectra can be interpreted in terms of the wave number parallel or perpendicular to the mean field, without such additional assumptions as isotropy or the dominance of a particular mode and without measurements of velocity and density. The details of the calculation of the <span class="hlt">magnetic</span> field power spectra, coherencies, and correlation functions are discussed, along with results obtained directly from the data (such as spectra, slopes, anisotropies, and coherencies). The results are interpreted in terms of MHD theory, and are related to work in other areas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19960021310&hterms=balogh&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAuthor-Name%26N%3D0%26No%3D60%26Ntt%3Dbalogh','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19960021310&hterms=balogh&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAuthor-Name%26N%3D0%26No%3D60%26Ntt%3Dbalogh"><span id="translatedtitle">Correlated variations in the azimuthal and elevation angles of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Murphy, N.; Smith, E. J.; Goldstein, B.; Balogh, A.; Forsyth, R. J.</p> <p>1995-01-01</p> <p>Analysis of data collected during the in-ecliptic phase of the Ulysses mission shows that there are periods during which deviations from the Parker spiral direction in the azimuthal and elevation angles of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field are correlated. There are a number of solar wind structures which might be expected to introduce such a correlation into the data, e.g., CMEs, Stream-stream interfaces or helicity carried by the solar wind. These potential sources fall into two categories: Those produced at or close to the solar wind source region and those produced by extended interactions as the solar wind expands. We will distinguish the contributions of these two source categories and assess the impact on the evolution on the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19750062208&hterms=earth+day+1970&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dearth%2Bday%2B1970','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19750062208&hterms=earth+day+1970&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dearth%2Bday%2B1970"><span id="translatedtitle">Comparison of inferred and observed <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field polarities, 1970-1972</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wilcox, J. M.; Svalgaard, L.; Hedgecock, P. C.</p> <p>1975-01-01</p> <p>The inferred polarity (toward or away from the sun) of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field at earth using polar observations of the geomagnetic field has been compared with spacecraft observations. A list published by Svalgaard (1974) of the inferred field polarities in the period from 1970 to 1972 is found to be correct on 82% of the days. A near real-time (same day) method of inferring the polarity of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field using geomagnetic observations at Vostok and Thule is in use at the NOAA Space Environment Laboratory, Boulder, Colorado. During 1972, this method is found to be correct on 87% of the days. A list of 'well-defined' sector boundaries at earth from 1970 to 1972 is given.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009GeoRL..3611103L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009GeoRL..3611103L"><span id="translatedtitle">Tsallis distribution of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field at 0.72 AU: Venus Express observation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, X. Y.; Wang, C.; Zhang, T. L.</p> <p>2009-06-01</p> <p>Previous work shows that Probability Distribution Functions (PDFs) of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field strength differences can be described by a single function - Tsallis distribution at Earth and beyond. Launch of Venus Express enables us to extend the application of Tsallis distribution to the inner heliosphere at 0.72 AU. This paper analyzes the distributions of increments of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field magnitude on scales from 1 hour to 211 hours (˜85.3 days), and fit all these PDFs to Tsallis distribution. The entropy index q value of all the PDFs on these scales at 0.72 AU are in the range of 1.5 to 1.7, which implies the non-Gaussianality of the PDFs. The variation of the statistical parameters such as cumulants, variance and kurtosis with scales is also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19800031782&hterms=15926&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3D15926','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19800031782&hterms=15926&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3D15926"><span id="translatedtitle">Empirical relationships between <span class="hlt">interplanetary</span> conditions, magnetospheric flux transfer, and the AL index. [auroral zone <span class="hlt">magnetic</span> index</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Slavin, J. A.; Holzer, R. E.</p> <p>1979-01-01</p> <p>Holzer and Slavin (1978) have found that the transfer of <span class="hlt">magnetic</span> flux to and from the dayside magnetosphere as inferred from observed displacements of the magnetopause surface is correlated with both the magnitude of the auroral zone <span class="hlt">magnetic</span> index AL and the incident flux of southward IMF. Empirical expressions specifying the rate at which <span class="hlt">magnetic</span> flux is eroded in terms of <span class="hlt">interplanetary</span> parameters and the rate of <span class="hlt">magnetic</span> flux return as a function of AL have been developed. These relations are then used to predict magnetotail <span class="hlt">magnetic</span> field enhancements from <span class="hlt">interplanetary</span> and ground based data during an interval of substorm activity. The total <span class="hlt">magnetic</span> flux in the tail is increased during intervals when the amount of flux transferred into its volume by dayside erosion exceeds the flux lost to the dayside by magnetospheric convection. Using Ogo-5 tail observations it is found for the sample events considered that these <span class="hlt">magnetic</span> field enhancements can be described by empirical expressions for the <span class="hlt">magnetic</span> flux transfer rates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19770024113','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19770024113"><span id="translatedtitle">On the existence of finite amplitude, transverse Alfven waves in the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sari, J. W.</p> <p>1977-01-01</p> <p><span class="hlt">Interplanetary</span> <span class="hlt">magnetic</span> field data from the Mariner 10 spacecraft were examined for evidence of small and finite amplitude transverse Alfven waves, general finite amplitude Alfven waves, and magnetosonic waves. No evidence for transverse Alfven waves was found. Instead, the field fluctuations were found to be dominated by the general finite amplitude Alfven wave. Such wave modes correspond to non-plane-wave solutions of the nonlinear magnetohydrodynamic equations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19860064504&hterms=low+frequency+noise&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dlow%2Bfrequency%2Bnoise','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19860064504&hterms=low+frequency+noise&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dlow%2Bfrequency%2Bnoise"><span id="translatedtitle">Low-frequency 1/f noise in the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Matthaeus, W. H.; Goldstein, M. L.</p> <p>1986-01-01</p> <p>Spacecraft observations of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field at 1 AU are shown to have frequency spectra with a 1/f dependence in the range 2.7-80 microHz. It is suggested that the 1/f spectrum results from the superposition of uncorrelated samples of solar surface turbulence that have log-normal distributions of correlation lengths corresponding to a scale-invariant distribution of correlation times over an appropriate range of parameters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19880053447&hterms=kuala+lumpur&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dkuala%2Blumpur','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19880053447&hterms=kuala+lumpur&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dkuala%2Blumpur"><span id="translatedtitle">Transport equations for low-energy solar particles in evolving <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> fields</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ng, C. K.</p> <p>1988-01-01</p> <p>Two new forms of a simplified Fokker-Planck equation are derived for the transport of low-energy solar energetic particles in an evolving <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field, carried by a variable radial solar wind. An idealized solution suggests that the 'invariant' anisotropy direction reported by Allum et al. (1974) may be explained within the conventional theoretical framework. The equations may be used to relate studies of solar particle propagation to solar wind transients, and vice versa.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013LRSP...10....4L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013LRSP...10....4L"><span id="translatedtitle">Reconstruction and Prediction of Variations in the Open Solar <span class="hlt">Magnetic</span> Flux and <span class="hlt">Interplanetary</span> Conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lockwood, Mike</p> <p>2013-09-01</p> <p>Historic geomagnetic activity observations have been used to reveal centennial variations in the open solar flux and the near-Earth heliospheric conditions (the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field and the solar wind speed). The various methods are in very good agreement for the past 135 years when there were sufficient reliable <span class="hlt">magnetic</span> observatories in operation to eliminate problems due to site-specific errors and calibration drifts. This review underlines the physical principles that allow these reconstructions to be made, as well as the details of the various algorithms employed and the results obtained. Discussion is included of: the importance of the <span class="hlt">averaging</span> timescale; the key differences between ``range'' and ``interdiurnal variability'' geomagnetic data; the need to distinguish source field sector structure from heliospherically-imposed field structure; the importance of ensuring that regressions used are statistically robust; and uncertainty analysis. The reconstru! ctions are exceedingly useful as they provide calibration between the in-situ spacecraft measurements from the past five decades and the millennial records of heliospheric behaviour deduced from measured abundances of cosmogenic radionuclides found in terrestrial reservoirs. Continuity of open solar flux, using sunspot number to quantify the emergence rate, is the basis of a number of models that have been very successful in reproducing the variation derived from geomagnetic activity. These models allow us to extend the reconstructions back to before the development of the magnetometer and to cover the Maunder minimum. Allied to the radionuclide data, the models are revealing much about how the Sun and heliosphere behaved outside of grand solar maxima and are providing a means of predicting how solar activity is likely to evolve now that the recent grand maximum (that had prevailed throughout the space age) has come to an end.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..12.6371B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..12.6371B"><span id="translatedtitle">Study of <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Reconnection with Circularly Polarized Light</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Boehle, Anna</p> <p>2010-05-01</p> <p>Modern grain alignment theory predicts that Zodiacal dust must be aligned and the scattering of solar light on it should result in circularly polarized light. We analyze the existing circularly polarized data and observe that the pattern of observed polarization can be explained only if substantial deviations from the Parker spiral are present. We conjecture that turbulent <span class="hlt">magnetic</span> reconnection may influence the observed <span class="hlt">magnetic</span> field pattern.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930005148','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930005148"><span id="translatedtitle">Venus internal <span class="hlt">magnetic</span> field and its interaction with the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Knudsen, W. C.</p> <p>1992-01-01</p> <p>In a previous study, Knudsen et al. suggested that Venus has a weak internal <span class="hlt">magnetic</span> dipole field of the order of 7 x 10 + 20 G cm(exp -3) that is manifested in the form of <span class="hlt">magnetic</span> flux tubes threading the ionospheric holes in the Venus nightside ionosphere. They pointed out that any internal field of Venus, dipole or multipole, would be weakened in the subsolar region and concentrated in the antisolar region of the planet by the supersonic transterminator convection of the dayside ionosphere into the nightside hemisphere. The inferred magnitude of the dipole field does not violate the upper limit for an internal <span class="hlt">magnetic</span> field established by the Pioneer Venus magnetometer experiment. The most compelling objection to the model suggested by Knudsen et al. has been the fact that it does not explain the observed <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) control of the polarity of the ionospheric hole flux tubes. In this presentation I suggest that a <span class="hlt">magnetic</span> reconnection process analogous to that occurring at earth is occurring at Venus between the IMF and a weak internal dipole field. At Venus in the subsolar region, the reconnection occurs within the ionosphere. At Earth it occurs at the magnetopause. Reconnection will occur only when the IMF has an appropriate orientation relative to that of the weak internal field. Thus, reconnection provides a process for the IMF to control the flux tube polarity. The reconnection in the subsolar region takes place in the ionosphere as the barrier <span class="hlt">magnetic</span> field is transported downward into the lower ionosphere by downward convection of ionospheric plasma and approaches the oppositely directed internal <span class="hlt">magnetic</span> field that is diffusing upward. The reconnected flux tubes are then transported anti-Sunward by the anti-Sunward convecting ionospheric plasma as well as by the anti-Sunward-flowing solar wind. Reconnection will also occur in the Venus <span class="hlt">magnetic</span> tail region, somewhat analogously to the reconnection that occurs in the magnetotail of the Earth. The possibility that reconnection is occurring between the IMF and an internal dipole field may be tested by measuring the orientation of the IMF projected into a plane perpendicular to the solar wind velocity during time intervals for which ionospheric holes are observed. The orientations of the IMV components should fall within a 180 deg angle.</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_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active"><span>5</span></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_5 --> <div id="page_6" 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_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</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="101"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19750025912','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19750025912"><span id="translatedtitle">The large-scale <span class="hlt">magnetic</span> field in the solar wind. [<span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> fields/solar activity effects</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Burlaga, L. F.; Ness, N. F.</p> <p>1975-01-01</p> <p>A large-scale, three dimensional <span class="hlt">magnetic</span> field in the <span class="hlt">interplanetary</span> medium with an expected classical spiral pattern to zeroth order is discussed. Systematic and random deviations which are expected are treated. The sector structure which should be evident at high latitudes is examined. <span class="hlt">Interplanetary</span> streams are discussed as determining the patterns of <span class="hlt">magnetic</span> field intensity. It was proposed that the large-scale spiral field can induce a meridional flow which might alter the field geometry somewhat. The nonuniformities caused by streams will probably significantly influence the motion of solar and galactic particles. It was concluded that knowledge of the 3-dimensional field and its dynamical effects can be obtained by in situ measurements by a probe which goes over the sun's poles. Diagrams of the <span class="hlt">magnetic</span> fields are given.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19950046378&hterms=solar+wind+magnetic+field&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsolar%2Bwind%2Bmagnetic%2Bfield','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950046378&hterms=solar+wind+magnetic+field&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsolar%2Bwind%2Bmagnetic%2Bfield"><span id="translatedtitle">The population of the magnetosphere by solar winds ions when the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field is northward</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Richard, Robert L.; Walker, Raymond J.; Ashour-Abdalla, Maha</p> <p>1994-01-01</p> <p>We have examined some possible entry mechanisms of solar wind ions into the magnetosphere by calculating the trajectories of thousands of non-interacting ions in the <span class="hlt">magnetic</span> and electric fields from a three dimensional global magnetohydrodynamic (MHD) simulation of the magnetosphere and the magnetosheath, under northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) conditions. Particles, launched in the solar wind, entered the magnetosphere and formed the low latitude boundary layer (LLBL), plasma sheet and a region of trapped particles near the Earth. The densities and temperatures we obtained in these regions were realistic, with the exception of trapped particle densities. The dominant entry mechanism was convection into the magnetosphere on reconnecting field lines.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AdSpR..37.1777K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AdSpR..37.1777K"><span id="translatedtitle"><span class="hlt">Interplanetary</span> origin of <span class="hlt">magnetic</span> storms and their F2-region responses at the equatorial anomaly</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kumar, S.; Sharma, S.; Chandra, H.</p> <p></p> <p>The <span class="hlt">interplanetary</span> origin of 102 storms (Dst ⩽ -50 nT) of varying strength that occurred during the period of 1997 2001, have been studied. The shock compression, <span class="hlt">magnetic</span> clouds, and shock compression followed by <span class="hlt">magnetic</span> clouds are most probable sources of intense southward component BS of IMF in the <span class="hlt">interplanetary</span> medium causing the <span class="hlt">magnetic</span> storms. Thirty five percent of <span class="hlt">magnetic</span> storms were associated with the <span class="hlt">magnetic</span> clouds. The main phase of 60% intense and very intense <span class="hlt">magnetic</span> storms associated with the <span class="hlt">magnetic</span> clouds, occurred through the multi-step growth in the ring current during the main phase evolution of the storms. The storms were associated with enhanced IMF intensity, proton bulk velocity, ion dynamic pressure and ion density, in the solar wind, in general, with increase in strength of the storms, but not linearly. The storm-time effects in the ionospheric F2-region during 51 <span class="hlt">magnetic</span> storms during 1997 2001, at Ahmedabad (23.2°N, 72.4°E, dip angle 30.7° at sub-ionospheric points), a station at the ionization anomaly crest in the Indian region, are also studied. The negative ionospheric effects are more pronounced than the positive ionospheric effects. While the prompt penetration of high-latitude electric fields and the electric fields generated by the disturbance dynamo play important role in F2-region response by changing E × B drifts at low latitude, the storm-induced transport of gas with depleted ratio of [O]/[N2] may also be responsible for the post-midnight large decrease in foF2, during strong <span class="hlt">magnetic</span> storms (Dst < 100 nT).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19910055756&hterms=Magnetic+interaction&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D30%26Ntt%3DMagnetic%2Binteraction','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19910055756&hterms=Magnetic+interaction&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D30%26Ntt%3DMagnetic%2Binteraction"><span id="translatedtitle">The interaction of a very large <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> cloud with the magnetosphere and with cosmic rays</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lepping, R. P.; Burlaga, L. F.; Ogilvie, K. W.; Tsurutani, B. T.; Lazarus, A. J.</p> <p>1991-01-01</p> <p>The observation of one of the largest <span class="hlt">magnetic</span> clouds ever observed at a distance of 1 AU, with a diameter of greater than about 0.4 AU, is reported. The cloud is shown to be almost unchanged structurally by interaction with the earth bow shock. The first observations are reported of an auroral activity response to the passage of a <span class="hlt">magnetic</span> cloud, with a nearly immediate increase in auroral activity when the IMF theta(B) angle reversed polarity to negative near the cloud center. The results provide strong evidence that turbulent <span class="hlt">magnetic</span> fields behind <span class="hlt">interplanetary</span> shocks are a possible cause of Forbush decreases, but contest the idea that relatively smooth, strong fields in clouds are a cause of such decreases. The cloud field modeling supports the existence of <span class="hlt">magnetic</span> force-free fields in describing cloud structure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUFMSH13B..06M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUFMSH13B..06M"><span id="translatedtitle">New Insights into The Structure of the Turbulent <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Matthaeus, W. H.; Giacalone, J.; Jokipii, J. R.</p> <p>2005-12-01</p> <p>We present new insights into the structure of the turbulent <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field. Various authors [1,2] have studied field line random walk associated with <span class="hlt">interplanetary</span> fields consisting of smooth mean fields and fluctuations. One possible way to generate fluctuations [3,4] is at a source surface near the solar surface, by random transverse plasma motions (such as supergranulation at the solar photosphere or perhaps reconnection), together with a uniform radial outflow at a specified solar wind speed. In this approach, the structure of the <span class="hlt">magnetic</span> field fluctuations is controlled by the temporal and spatial dependence of the footpoint velocity field. These combine to regulate the spatial structure observed in the <span class="hlt">interplanetary</span> field. Further dynamical processing is ignored in this view, which is therefore most appropriate for large scale fluctuations. Comparison of this picture with observations from the magnetometer on the Ulysses spacecraft has shown good agreement. A quite different approach to modeling the spatial structure of <span class="hlt">interplanetary</span> fluctuations is embodied in the so-called two component model, This was introduced [5,6,7] as a useful simplified parameterization of <span class="hlt">interplanetary</span> fluctuations, and, since it is associated with no specific generation mechanism, this approach is consistent with either solar-surface or in situ generation of turbulence. This also shows good agreement with observations. Here, we show that these two apparently different ways of modeling turbulent fields can be closely related. In particular, we show that by properly choosing the temporal and spatial dependence of the transverse velocity field at the solar source surface, we can generate the two component model (as well as many other possible models). The consequences of this insight for our understanding of turbulence and energetic-particle transport are discussed. [1] Jokipii and Parker, Phys. Rev. Lett, 21, 44, 1968 [2] Matthaeus et al, Phys. Rev Lett. 75, 2136, 1995 [3] Jokipii and Kota Geophys. Res. Lett., 16, 1, 1989 [4] Giacalone and Jokipii, Astrophys. J. 616, 573, 2004 [5] Matthaeus, Goldstein and Roberts, JGR, 95, 20673, 1990 [6] Tu and Marsch, 98, 1257, 1993 [7] Bieber etal, Atrophys. J., 420, 294, 1994</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19850029359&hterms=bifurcation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dbifurcation','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850029359&hterms=bifurcation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dbifurcation"><span id="translatedtitle">A magnetohydrodynamic simulation of the bifurcation of tail lobes during intervals with a northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ogino, T.; Walker, R. J.</p> <p>1984-01-01</p> <p>The interaction of the solar wind with the earth's magnetosphere during a northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field was studied by using a three-dimensional magneto-hydrodynamic model. For a northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field on 5 nT, the plasma sheet thickens near the noon-midnight meridian plane. When projected onto the polar cap this appears as a narrow channel extending from midnight towards noon. This plasma pattern is associated with three pairs of convection cells. The high latitude sunward convection and northern B(z) Birkeland current are caused by <span class="hlt">magnetic</span> merging in the polar region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19960021432&hterms=helios&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dhelios','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19960021432&hterms=helios&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dhelios"><span id="translatedtitle">The effects of 8 Helios observed solar proton events of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field fluctuations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>ValdezGalicia, J. F.; Alexander, P.; Otaola, J. A.</p> <p>1995-01-01</p> <p>There have been recent suggestions that large fluxes during solar energetic particle events may produce their own turbulence. To verify this argument it becomes essential to find out whether these flows cause an enhancement of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field fluctuations. In the present work, power and helicity spectra of the IMF before, during and after 8 Helios-observed solar proton events in the range 0.3 - 1 AU are analyzed. In order to detect proton self generated waves, the time evolution of spectra are followed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/17815417','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/17815417"><span id="translatedtitle"><span class="hlt">Interplanetary</span> <span class="hlt">magnetic</span> field enhancements and their association with the asteroid 2201 oljato.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Russell, C T; Aroian, R; Arghavani, M; Nock, K</p> <p>1984-10-01</p> <p>Comparison of the times of occurrence of a newly discovered type of disturbance in the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field at 0.72 astronomical unit with the passage of the small Venus-crossing asteroid, 2201 Oljato, reveals a possible association, but the source of these disturbances appears to be associated with outgassing material in the Oljato orbit some distance behind the asteroid and not with the asteroid itself. This suggested association can account for one quarter of the total number of events seen in eight Venus years. PMID:17815417</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19790012789','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19790012789"><span id="translatedtitle">Contributions to the Fourth Solar Wind Conference. [<span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> fields and medium</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Acuna, M. H.; Behannon, K. W.; Burlaga, L. F.; Lepping, R.; Ness, N.; Ogilvie, K.; Pizzo, J.</p> <p>1979-01-01</p> <p>Recent results in <span class="hlt">interplanetary</span> physics are examined. These include observations of shock waves and post-shock <span class="hlt">magnetic</span> fields made by Voyager 1, 2; observations of the electron temperature as a function of distance between 1.36 AU and 2.25 AU; and observations of the structure of sector boundaries observed by Helios 1. A theory of electron energy transport in the collisionless solar wind is presented, and compared with observations. Alfven waves and Alvenic fluctuations in the solar wind are also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22364987','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22364987"><span id="translatedtitle">Structures of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> flux ropes and comparison with their solar sources</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hu, Qiang; Dasgupta, B.; Khare, A.; Webb, G. M. E-mail: qiu@physics.montana.edu</p> <p>2014-09-20</p> <p>Whether a <span class="hlt">magnetic</span> flux rope is pre-existing or formed in situ in the Sun's atmosphere, there is little doubt that <span class="hlt">magnetic</span> reconnection is essential to release the flux rope during its ejection. During this process, the question remains: how does <span class="hlt">magnetic</span> reconnection change the flux-rope structure? In this work, we continue with the original study of Qiu et al. by using a larger sample of flare-coronal mass ejection (CME)-<span class="hlt">interplanetary</span> CME (ICME) events to compare properties of ICME/<span class="hlt">magnetic</span> cloud (MC) flux ropes measured at 1 AU and properties of associated solar progenitors including flares, filaments, and CMEs. In particular, the <span class="hlt">magnetic</span> field-line twist distribution within <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> flux ropes is systematically derived and examined. Our analysis shows that, similar to what was found before, for most of these events, the amount of twisted flux per AU in MCs is comparable with the total reconnection flux on the Sun, and the sign of the MC helicity is consistent with the sign of the helicity of the solar source region judged from the geometry of post-flare loops. Remarkably, we find that about half of the 18 <span class="hlt">magnetic</span> flux ropes, most of them associated with erupting filaments, have a nearly uniform and relatively low twist distribution from the axis to the edge, and the majority of the other flux ropes exhibit very high twist near the axis, up to ≳ 5 turns per AU, which decreases toward the edge. The flux ropes are therefore not linearly force-free. We also conduct detailed case studies showing the contrast of two events with distinct twist distribution in MCs as well as different flare and dimming characteristics in solar source regions, and discuss how reconnection geometry reflected in flare morphology may be related to the structure of the flux rope formed on the Sun.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5976541','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5976541"><span id="translatedtitle">Electron heat flux dropouts in the solar wind: evidence for <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field reconnection</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>McComas, D. J.; Gosling, J. T.; Phillips, J. L.; Bame, S. J.; Luhmann, J. G.; Smith, E. J.</p> <p>1989-06-01</p> <p>Electron heat flux dropout events have been observed in the solar wind using the ISEE 3 plasma electron data set. These events manifest themselves as dropouts of the solar wind halo electrons which are normally found streaming outward along the local <span class="hlt">magnetic</span> field. These dropouts leave nearly isotropic distributions of solar wind halo electrons, and consequently, the heat flux in these events is reduced to near the observational noise level. We have examined ISEE 3 data from shortly after launch (August 16, 1978) through the end of 1978 and identified 25 such events ranging in duration from 20 min to over 11 hours. Comparison with the ISEE 3 magnetometer data indicates that these intervals nearly always occur in conjunction with large rotations of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field. Statistical analyses of the plasma and <span class="hlt">magnetic</span> field data for the 25 dropout intervals indicate that heat flux dropouts generally occur in association with high plasma densities low plasma velocities, low ion and electron temperatures, and low <span class="hlt">magnetic</span> field magnitudes. A second set of 25 intervals chosen specifically to lie at large field rotations, but at times at which not heat flux dropouts were observed, do not show these characteristic plalsma variations. This suggests that the dropout intervals comprise a unique set of events. Since the hot halo electrons normally found streaming outward from the Sun along the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (the solar wind electron heat flux) are a result of direct <span class="hlt">magnetic</span> connection to the hot solar corona, heat flux dropout intervals may indicate that the spacecraft is sampling plasma regimes which are <span class="hlt">magnetically</span> disconnected from the Sun and instead are connected to the outer heliosphere at both ends.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20030014815','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20030014815"><span id="translatedtitle"><span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field Control of the Entry of Solar Energetic Particles into the Magnetosphere</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Richard, R. L.; El-Alaoui, M.; Ashour-Abdalla, M.; Walker, R. J.</p> <p>2002-01-01</p> <p>We have investigated the entry of energetic ions of solar origin into the magnetosphere as a function of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field orientation. We have modeled this entry by following high energy particles (protons and 3 He ions) ranging from 0.1 to 50 MeV in electric and <span class="hlt">magnetic</span> fields from a global magnetohydrodynamic (MHD) model of the magnetosphere and its interaction with the solar wind. For the most part these particles entered the magnetosphere on or near open field lines except for some above 10 MeV that could enter directly by crossing field lines due to their large gyroradii. The MHD simulation was driven by a series of idealized solar wind and <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) conditions. It was found that the flux of particles in the magnetosphere and transport into the inner magnetosphere varied widely according to the IMF orientation for a constant upstream particle source, with the most efficient entry occurring under southward IMF conditions. The flux inside the magnetosphere could approach that in the solar wind implying that SEPs can contribute significantly to the magnetospheric energetic particle population during typical SEP events depending on the state of the magnetosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010cosp...38.3039D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010cosp...38.3039D"><span id="translatedtitle">Onset time of solar energetic particles under the influence of scattering by <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> turbulence</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Diaz, Ismael; Zhang, Ming; Rassoul, Hamid</p> <p></p> <p>When a solar flare or CME occurs, solar energetic particles (SEP) are produced and can quickly travel along the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field lines, some of which connect the sun to the earth. Because these particles are extremely hazardous to astronauts or sensitive microelectronics on spacecraft, it is an important to predict their arrival and provide a window of time when the danger will subsist. Analysis of onset time of SEP arrival has been carried out by many researchers in the community (e.g., Reames, 2009). Assuming that first arrival particles have traveled nearly scatter-free, one can determine the length of the connecting <span class="hlt">magnetic</span> field line since the onset time will be linearly proportional to 1/v. The proportionality constant of the linear relation is the length of the field line. At Earth the nominal Parker field line length is 1.12 AU, but many onset time analyses yield larger estimates, sometimes, up to twice that length. In this paper we present a calculation of SEP onset times from a model that solves the focused transport equation that allows for particle scattering during the <span class="hlt">interplanetary</span> transport (Zhang et. al., 2009). With typical mean free paths found in SEP observations (Bieber et al., 1994) we found that the onset time of SEP flux is delayed compared to scatter-free transport. The time delay depends on the particle rigidity. Under most reasonable ranges of mean free path and its rigidity dependence, the onset time appears to be linearly proportional to 1/v. Such a property may easily mislead researchers to think the transport is scatter-free and derive larger field line lengths than the expected Parker field line. The smaller the mean free path the longer the field line length will be derived. The model results show how <span class="hlt">interplanetary</span> scattering can severely affect the onset times of SEP's.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19790045591&hterms=Longitude&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DLongitude','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19790045591&hterms=Longitude&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DLongitude"><span id="translatedtitle"><span class="hlt">Interplanetary</span> <span class="hlt">magnetic</span> field polarity and the size of low-pressure troughs near 180 deg W longitude</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wilcox, J. M.; Duffy, P. B.; Schatten, K. H.; Svalgaard, L.; Scherrer, P. H.; Roberts, W. O.; Olson, R. H.</p> <p>1979-01-01</p> <p>The relationship between <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field polarity and the area of low pressure (300 mbar) troughs near 180 deg W longitude is examined. For most of the winters from 1951 to 1973, the trough size, as indicated by the vorticity area index, is found to be significantly greater when the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field is directed away from the sun than when the field is directed towards the sun. This relationship is shown to hold for various combinations of winters and for most months within a winter, and be most pronounced at the time when polarity was determined. It is suggested that the phenomenon is caused by merging of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field lines, when polarity is directed away from the sun, with geomagnetic field lines in the Northern Hemisphere (where these measurements were made), allowing energetic particle fluxes to have access to the north polar region</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19930053282&hterms=Magnetic+interaction&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D20%26Ntt%3DMagnetic%2Binteraction','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19930053282&hterms=Magnetic+interaction&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D20%26Ntt%3DMagnetic%2Binteraction"><span id="translatedtitle">A study of an expanding interplanatary <span class="hlt">magnetic</span> cloud and its interaction with the earth's magnetosphere - The <span class="hlt">interplanetary</span> aspect</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Farrugia, C. J.; Burlaga, L. F.; Osherovich, V. A.; Richardson, I. G.; Freeman, M. P.; Lepping, R. P.; Lazarus, A. J.</p> <p>1993-01-01</p> <p>High time resolution <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field and plasma measurements of an <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> cloud and its interaction with the earth's magnetosphere on January 14/15, 1988 are interpreted and discussed. It is argued that the data are consistent with the theoretical model of <span class="hlt">magnetic</span> clouds as flux ropes of local straight cylindrical geometry. The data also suggest that this cloud is aligned with its axis in the ecliptic plane and pointing in the east-west direction. Evidence consisting of the intensity and directional distribution of energetic particle in the <span class="hlt">magnetic</span> cloud argues in favor of the connectedness of the <span class="hlt">magnetic</span> field lines to the sun's surface. The intensities of about 0.5 MeV ions is rapidly enhanced and the particles stream in a collimated beam along the <span class="hlt">magnetic</span> field preferentially from the west of the sun. The particles travel form a flare site along the cloud <span class="hlt">magnetic</span> field lines, which are thus presumably still attached to the sun.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6720643','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6720643"><span id="translatedtitle">Sudden impulses at low-latitude stations: Steady state response for northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Russell, C.T.; Ginskey, M.; Petrinec, S.M. )</p> <p>1994-01-01</p> <p>An examination of the response of the low-latitude H component of the Earth's <span class="hlt">magnetic</span> field during the passage of <span class="hlt">interplanetary</span> shocks when the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field is northward reveals that this response can be understood quantitatively in terms of the compression of a simple vacuum magnetospheric model. The compression at the surface of the Earth at 20[degrees] latitude at noon in the absence of equatorial electrojet effects is found to be 18.4 nT/(nPa)[sup 1/2]. Stations below 15[degrees] latitude and above 40[degrees] appear to have additional but variable sources of current which magnify this effect. The diurnal variation of the compression is larger than expected from the simple vacuum magnetosphere, [+-]20% about the mean instead of [+-]10%. The authors interpret this difference to indicate that tail currents, not in the vacuum model, are as important as the magnetopause currents in determining the diurnal variation of the field at the surface of the Earth. 21 refs., 10 figs., 3 tabs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.6315K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.6315K"><span id="translatedtitle">Analysis of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field observations at different heliocentric distances</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Khabarova, Olga</p> <p>2013-04-01</p> <p>Multi-spacecraft measurements of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) from 0.29 AU to 5 AU along the ecliptic plane have demonstrated systematic deviations of the observed IMF strength from the values predicted on the basis of the Parker-like radial extension models (Khabarova, Obridko, 2012). In particular, it was found that the radial IMF component |Br| decreases with a heliocentric distance r with a slope of -5/3 (instead of r-2 expansion law). The current investigation of multi-point observations continues the analysis of the IMF (and, especially, Br) large-scale behaviour, including its latitudinal distribution. Additionally, examples of the mismatches between the expected IMF characteristics and observations at smaller scales are discussed. It is shown that the observed effects may be explained by not complete IMF freezing-in to the solar wind plasma. This research was supported by the Russian Fund of Basic Researches' grants Nos.11-02-00259-a, and 12-02-10008-K. Khabarova Olga, and Obridko Vladimir, Puzzles of the <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field in the Inner Heliosphere, 2012, Astrophysical Journal, 761, 2, 82, doi:10.1088/0004-637X/761/2/82, http://arxiv.org/pdf/1204.6672v2.pdf</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003EAEJA.....7961P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA.....7961P"><span id="translatedtitle">The dependence of solar wind ion entry on the direction of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Peroomian, V.</p> <p>2003-04-01</p> <p>We have investigated the entry characteristics of solar wind ions into the magnetosphere by tracing particle orbits in time-dependent electric and <span class="hlt">magnetic</span> fields obtained from a three-dimensional global magnetohydrodynamic (MHD) simulation of the magnetosphere. The MHD simulation used in the study began with a 2-hour period of northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF). The IMF then rotated by 45^o every two hours. The final four hours of the simulation had southward IMF. Millions of ions were launched in the solar wind, upstream of the bowshock, at x = 17 R_E, at time intervals corresponding to the midpoint of each IMF interval and collected after crossing the magnetopause current layer. We found that the region of the upstream solar wind that mapped to the magnetopause entry regions was parallel to the y z orientation of the IMF. Moreover, ions entry into the magnetosphere was in general agreement with the regions identified by Luhmann et al. [1984]. However, there were significant asymmetries in the entry locations due to the direction of the <span class="hlt">interplanetary</span> electric field and the acceleration experienced by ions in crossing the magnetopause current layer. In all cases the ions entering the magnetosphere did so in sufficient numbers to account for the plasma observed within that region and successfully populated the plasma sheet and ring current regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014FlDy...49..270K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014FlDy...49..270K"><span id="translatedtitle">Collision of an <span class="hlt">interplanetary</span> shock wave with the Earth's bow shock. Hydrodynamic parameters and <span class="hlt">magnetic</span> field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Korolev, A. S.; Pushkar, E. A.</p> <p>2014-03-01</p> <p>Hydrodynamic parameters and <span class="hlt">magnetic</span> field generated in each of the waves in neighborhood of the Earth's bow shock when an <span class="hlt">interplanetary</span> shock wave impinges on it and propagates along its surface are found in the three-dimensional non-plane-polarized formulation within the framework of the ideal magnetohydrodynamic model. The interaction pattern is constructed in the quasi-steady-state formulation as a mosaic of exact solutions, obtained by means of a computer, to the Riemann problem of breakdown of a discontinuity between the states downstream of the impinging wave and the bow shock on the traveling line of intersection of their fronts. The calculations are carried out for typical parameters of the quiescent solar wind and the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field in the Earth's orbit when the plane front of a shock wave moves along the Sun-Earth radius with various given velocities. The solutions obtained can be used to interpret measurements carried out by spacecraft in the solar wind and in neighborhood of the Earth's magnetosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22270882','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22270882"><span id="translatedtitle">AN ANALYSIS OF MAGNETOHYDRODYNAMIC INVARIANTS OF <span class="hlt">MAGNETIC</span> FLUCTUATIONS WITHIN <span class="hlt">INTERPLANETARY</span> FLUX ROPES</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Telloni, D.; Perri, S.; Carbone, V.; Bruno, R.; D Amicis, R.</p> <p>2013-10-10</p> <p>A statistical analysis of <span class="hlt">magnetic</span> flux ropes, identified by large-amplitude, smooth rotations of the <span class="hlt">magnetic</span> field vector and a low level of both proton density and temperature, has been performed by computing the invariants of the ideal magnetohydrodynamic (MHD) equations, namely the <span class="hlt">magnetic</span> helicity, the cross-helicity, and the total energy, via <span class="hlt">magnetic</span> field and plasma fluctuations in the <span class="hlt">interplanetary</span> medium. A technique based on the wavelet spectrograms of the MHD invariants allows the localization and characterization of those structures in both scales and time: it has been observed that flux ropes show, as expected, high <span class="hlt">magnetic</span> helicity states (|σ{sub m}| in [0.6: 1]), but extremely variable cross-helicity states (|σ{sub c}| in [0: 0.8]), which, however, are not independent of the <span class="hlt">magnetic</span> helicity content of the flux rope itself. The two normalized MHD invariants observed within the flux ropes tend indeed to distribute, neither trivially nor automatically, along the √(σ{sub m}{sup 2}+σ{sub c}{sup 2})=1 curve, thus suggesting that some constraint should exist between the <span class="hlt">magnetic</span> and cross-helicity content of the structures. The analysis carried out has further showed that the flux rope properties are totally independent of their time duration and that they are detected either as a sort of interface between different portions of solar wind or as isolated structures embedded in the same stream.</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_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_6 --> <div id="page_7" 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_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</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="121"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/227129','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/227129"><span id="translatedtitle">Anomalous magnetosheath properties during Earth passage of an <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> cloud</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Farrugia, C.J.; Erkaev, N.V.; Burlaga, L.F.</p> <p>1995-10-01</p> <p>In this work the authors present a model for the behavior of the magnetosheath during the passage of the earth thru an <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> cloud. They study the variation of plasma flow and field values as a result of this encounter. The unique feature of such encounters is that they present substantial changes in the solar wind conditions along the bow shock and magnetopause for periods of 1 to 2 days. The mach number upstream of the bow shock can be as low as 3, compared to normal value of 8 to 10. The mach number and <span class="hlt">magnetic</span> shear across the magnetopause have a major impact on the magnetosheath properties. The authors use the encounter of January 14-15, 1988, as a basis for their model, and apply ideal MHD equations, by means of a boundary layer technique, to study changes in field and plasma flow patterns.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22304094','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22304094"><span id="translatedtitle">Simulation of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field B{sub y} penetration into the magnetotail</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Guo, Jiuling; Shen, Chao; Liu, Zhenxing</p> <p>2014-07-15</p> <p>Based on our global 3D magnetospheric MHD simulation model, we investigate the phenomena and physical mechanism of the B{sub y} component of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) penetrating into the magnetotail. We find that the dayside reconnected <span class="hlt">magnetic</span> field lines move to the magnetotail, get added to the lobe fields, and are dragged in the IMF direction. However, the B{sub y} component in the plasma sheet mainly originates from the tilt and relative slippage of the south and north lobes caused by plasma convection, which results in the original B{sub z} component in the plasma sheet rotating into a B{sub y} component. Our research also shows that the penetration effect of plasma sheet B{sub y} from the IMF B{sub y} during periods of northward IMF is larger than that during periods of southward IMF.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20020088125','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20020088125"><span id="translatedtitle">Long-term Trends in <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field Strength and Solar Wind Structure during the 20th Century</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Richardson, I. G.; Cliver, E. W.; Cane, H. V.; White, Nicholas E. (Technical Monitor)</p> <p>2002-01-01</p> <p>Lockwood et al have recently reported an approximately 40% increase in the radial component of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) at Earth between 1964 and 1996. We argue that this increase does not constitute a secular trend but is largely the consequence of lower than <span class="hlt">average</span> fields during solar cycle 20 (1964-1976) in comparison with surrounding cycles. For times after 1976 the <span class="hlt">average</span> IMF strength has actually decreased slightly. Examination of the cosmic ray intensity, an indirect measure of the IMF strength, over the last five solar cycles (19-23) also indicates that cycle <span class="hlt">averages</span> of the IMF strength have been relatively constant since approximately 1954. We also consider the origin of the well-documented increase in the geomagnetic alphaalpha index that occurred primarily during the first half of the twentieth century. We surmise that the coronal mass ejection (CME) rate for recent solar cycles was approximately twice as high as that for solar cycles 100 years ago. However, this change in the CME rate and the accompanying increase in 27-day recurrent storm activity reported by others are unable to account completely for the increase in alphaalpha. Rather, the CMEs and recurrent high-speed streams at the beginning of the twentieth century must have been embedded in a background of slow solar wind that was less geoeffective (having, for example, lower IMF strength and/or flow speed) than its modern counterpart.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19860056292&hterms=dbs&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Ddbs','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19860056292&hterms=dbs&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Ddbs"><span id="translatedtitle">On the association of <span class="hlt">magnetic</span> clouds with disappearing filaments. [<span class="hlt">interplanetary</span> phenomena associated with coronal mass ejection</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wilson, R. M.; Hildner, E.</p> <p>1986-01-01</p> <p>Evidence is presented that an <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> cloud preceding an interaction region, observed at earth on January 24, 1974, is associated with the eruptive filament of disparition brusque (DB) near central meridian on January 18. The DB was also associated with a long-decay soft X ray transient and a long-duration gradual-rise-and-fall radio burst. To assess whether <span class="hlt">magnetic</span> clouds are generally associated with DBs, results from statistical testing of the relation of 33 <span class="hlt">magnetic</span> clouds (and 33 control samples without <span class="hlt">magnetic</span> clouds) to disappearing filaments near central meridian (approximately less than 45 deg central meridian distance) are presented. The hypothesis that <span class="hlt">magnetic</span> cloud are the 1-AU counterparts of either eruptive filaments or the coronal mass ejections which probably accompany them is supported. The major result is that disappearing filaments occur more frequently on the days when <span class="hlt">magnetic</span> clouds are launched than on control days, a result obtained with greater than 99 pct confidence. There is a suggestion that clouds following shocks, probably launched at times of solar flares, are not as strongly associated with disappearing filaments as are clouds launched less violently.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015P%26SS..119..264V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015P%26SS..119..264V"><span id="translatedtitle">The effect of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field orientation on the solar wind flux impacting Mercury's surface</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Varela, J.; Pantellini, F.; Moncuquet, M.</p> <p>2015-12-01</p> <p>The aim of this paper is to study the plasma flows on the Mercury surface for different <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field orientations on the day side of the planet. We use a single fluid MHD model in spherical coordinates to simulate the interaction of the solar wind with the Hermean magnetosphere for six solar wind realistic configurations with different <span class="hlt">magnetic</span> field orientations: Mercury-Sun, Sun-Mercury, aligned with the <span class="hlt">magnetic</span> axis of Mercury (Northward and Southward) and with the orbital plane perpendicular to the previous cases. In the Mercury-Sun (Sun-Mercury) simulation the Hermean <span class="hlt">magnetic</span> field is weakened in the South-East (North-East) of the magnetosphere leading to an enhancement of the flows on the South (North) hemisphere. For a Northward (Southward) orientation there is an enhancement (weakening) of the Hermean <span class="hlt">magnetic</span> field in the nose of the bow shock so the fluxes are reduced and drifted to the poles (enhanced and drifted to the equator). If the solar wind <span class="hlt">magnetic</span> field is in the orbital plane the magnetosphere is tilted to the West (East) and weakened at the nose of the shock, so the flows are enhanced and drifted to the East (West) in the Northern hemisphere and to the West (East) in the Southern hemisphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140016484','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140016484"><span id="translatedtitle">The B-dot Earth <span class="hlt">Average</span> <span class="hlt">Magnetic</span> Field</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Capo-Lugo, Pedro A.; Rakoczy, John; Sanders, Devon</p> <p>2013-01-01</p> <p>The <span class="hlt">average</span> Earth's <span class="hlt">magnetic</span> field is solved with complex mathematical models based on mean square integral. Depending on the selection of the Earth <span class="hlt">magnetic</span> model, the <span class="hlt">average</span> Earth's <span class="hlt">magnetic</span> field can have different solutions. This paper presents a simple technique that takes advantage of the damping effects of the b-dot controller and is not dependent of the Earth <span class="hlt">magnetic</span> model; but it is dependent on the <span class="hlt">magnetic</span> torquers of the satellite which is not taken into consideration in the known mathematical models. Also the solution of this new technique can be implemented so easily that the flight software can be updated during flight, and the control system can have current gains for the <span class="hlt">magnetic</span> torquers. Finally, this technique is verified and validated using flight data from a satellite that it has been in orbit for three years.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19790061224&hterms=media+relations&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dmedia%2Brelations','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19790061224&hterms=media+relations&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dmedia%2Brelations"><span id="translatedtitle">Spatial distribution of large-scale solar <span class="hlt">magnetic</span> fields and their relation to the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Levine, R. H.</p> <p>1979-01-01</p> <p>The spatial organization of the observed photospheric <span class="hlt">magnetic</span> field as well as its relation to the polarity of the IMF have been studied using high resolution magnetograms from the Kitt Peak National Observatory. Systematic patterns in the large scale field are due to contributions from both concentrated flux and more diffuse flux. The polarity of the photospheric field, determined on various spatial scales, correlates with the polarity of the IMF. Analyses based on several spatial scales in the photosphere suggest that new flux in the <span class="hlt">interplanetary</span> medium is often due to relatively small photospheric features which appear in the photosphere up to one month before they are manifest at the earth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110023374','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110023374"><span id="translatedtitle"><span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field Power Spectrum Variations in the Inner Heliosphere: A Wind and MESSENGER Study</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Szabo, Adam; Koval, A.</p> <p>2011-01-01</p> <p>The newly reprocessed high time resolution (11/22 vectors/sec) Wind mission <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field data and the similar observations made by the MESSENGER spacecraft in the inner heliosphere affords an opportunity to compare <span class="hlt">magnetic</span> field power spectral density variations as a function of radial distance from the Sun under different solar wind conditions. In the reprocessed Wind <span class="hlt">Magnetic</span> Field Investigation (MFI) data, the spin tone and its harmonics are greatly reduced that allows the meaningful fitting of power spectra to the approx.2 Hz limit above which digitization noise becomes apparent. The powe'r spectral density is computed and the spectral index is fitted for the MHD and ion inertial regime separately along with the break point between the two for various solar wind conditions. Wind and MESSENGER <span class="hlt">magnetic</span> fluctuations are compared for times when the two spacecraft are close to radial and Parker field alignment. The functional dependence of the ion inertial spectral index and break point on solar wind plasma and <span class="hlt">magnetic</span> field conditions will be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22039339','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22039339"><span id="translatedtitle"><span class="hlt">MAGNETIC</span> VARIANCES AND PITCH-ANGLE SCATTERING TIMES UPSTREAM OF <span class="hlt">INTERPLANETARY</span> SHOCKS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Perri, Silvia; Zimbardo, Gaetano E-mail: gaetano.zimbardo@fis.unical.it</p> <p>2012-07-20</p> <p>Recent observations of power-law time profiles of energetic particles accelerated at <span class="hlt">interplanetary</span> shocks have shown the possibility of anomalous, superdiffusive transport for energetic particles throughout the heliosphere. Those findings call for an accurate investigation of the <span class="hlt">magnetic</span> field fluctuation properties at the resonance frequencies upstream of the shock's fronts. Normalized <span class="hlt">magnetic</span> field variances, indeed, play a crucial role in the determination of the pitch-angle scattering times and then of the transport regime. The present analysis investigates the time behavior of the normalized variances of the <span class="hlt">magnetic</span> field fluctuations, measured by the Ulysses spacecraft upstream of corotating interaction region (CIR) shocks, for those events which exhibit superdiffusion for energetic electrons. We find a quasi-constant value for the normalized <span class="hlt">magnetic</span> field variances from about 10 hr to 100 hr from the shock front. This rules out the presence of a varying diffusion coefficient and confirms the possibility of superdiffusion for energetic electrons. A statistical analysis of the scattering times obtained from the <span class="hlt">magnetic</span> fluctuations upstream of the CIR events has also been performed; the resulting power-law distributions of scattering times imply long range correlations and weak pitch-angle scattering, and the power-law slopes are in qualitative agreement with superdiffusive processes described by a Levy random walk.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AdSpR..55..401K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AdSpR..55..401K"><span id="translatedtitle">Variations of solar, <span class="hlt">interplanetary</span>, and geomagnetic parameters with solar <span class="hlt">magnetic</span> multipole fields during Solar Cycles 21-24</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kim, Bogyeong; Lee, Jeongwoo; Yi, Yu; Oh, Suyeon</p> <p>2015-01-01</p> <p>In this study we compare the temporal variations of the solar, <span class="hlt">interplanetary</span>, and geomagnetic (SIG) parameters with that of open solar <span class="hlt">magnetic</span> flux from 1976 to 2012 (from Solar Cycle 21 to the early phase of Cycle 24) for a purpose of identifying their possible relationships. By the open flux, we mean the <span class="hlt">average</span> <span class="hlt">magnetic</span> field over the source surface (2.5 solar radii) times the source area as defined by the potential field source surface (PFSS) model of the Wilcox Solar Observatory (WSO). In our result, most SIG parameters except the solar wind dynamic pressure show rather poor correlations with the open solar <span class="hlt">magnetic</span> field. Good correlations are recovered when the contributions from individual multipole components are counted separately. As expected, solar activity indices such as sunspot number, total solar irradiance, 10.7 cm radio flux, and solar flare occurrence are highly correlated with the flux of <span class="hlt">magnetic</span> quadrupole component. The dynamic pressure of solar wind is strongly correlated with the dipole flux, which is in anti-phase with Solar Cycle (SC). The geomagnetic activity represented by the Ap index is correlated with higher order multipole components, which show relatively a slow time variation with SC. We also found that the unusually low geomagnetic activity during SC 23 is accompanied by the weak open solar fields compared with those in other SCs. It is argued that such dependences of the SIG parameters on the individual multipole components of the open solar <span class="hlt">magnetic</span> flux may clarify why some SIG parameters vary in phase with SC and others show seemingly delayed responses to SC variation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1983JGR....88.4005N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1983JGR....88.4005N"><span id="translatedtitle">Response of nightside auroral-oval boundaries to the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nakai, H.; Kamide, Y.</p> <p>1983-05-01</p> <p>The size of the auroral oval varies dynamically in association with geomagnetic activity and with the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF). The present investigation can be regarded as an extension of studies conducted by Kamide and Winningham (1977), Gussenhoven et al. (1981), and Hardy et al. (1981). These investigators have reported on the relationship of the location of the auroral oval, as recorded by satellite borne electron spectrometers, with the intensity of the solar wind and magnetospheric electric fields. In the current investigation it is attempted to determine the most probable time scale of the auroral oval response to the IMF variations. Aurora imagery data for the nightside auroral oval recorded by three Defense Meteorological Satellite Program (DMSP) satellites are utilized. IMF data with high-time resolution are utilized to explain a detailed role of the solar wind parameters regarding changes in the auroral oval location at midnight.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009GeoRL..3618112S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009GeoRL..3618112S"><span id="translatedtitle">Anomalous magnetosheath flows and distorted subsolar magnetopause for radial <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> fields</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shue, J.-H.; Chao, J.-K.; Song, P.; McFadden, J. P.; Suvorova, A.; Angelopoulos, V.; Glassmeier, K. H.; Plaschke, F.</p> <p>2009-09-01</p> <p>On 12 August 2007 from 1436 to 1441 UT, when the five THEMIS probes (THA, THB, THC, THD, and THE) were located near the subsolar magnetopause, a sunward flow was observed in the magnetosheath. A fast anti-sunward flow (-280 km/s) was observed in the magnetosheath before the sunward flow. Although THA observed this fast anti-sunward flow, THC and THD, which were also in the magnetosheath, instead observed a slow flow, indicating that the fast flow was small in scale. With the observed flow vectors and the magnetopause normal directions estimated from tangential discontinuity analysis, we conclude that this fast flow creates an indentation on the magnetopause, 1 R E deep and 2 R E wide. The magnetopause subsequently rebounds, rotating the flow direction sunward along the surface of the magnetopause. The fast flow is likely related to the radial <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFMSM31B1525S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFMSM31B1525S"><span id="translatedtitle">Anomalous Magnetosheath Flows and Distorted Subsolar Magnetopause for Radial <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Fields</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shue, J.; Chao, J. K.; Song, P.; McFadden, J. P.; Suvorova, A.; Angelopoulos, V.; Glassmeier, K.; Plaschke, F.</p> <p>2009-12-01</p> <p>On 12 August 2007 from 1436 to 1441 UT, when the five THEMIS probes (THA, THB, THC, THD, and THE) were located near the subsolar magnetopause, a sunward flow was observed in the magnetosheath. A fast anti-sunward flow (-280 km/s) was observed in the magnetosheath before the sunward flow. Although THA observed this fast anti-sunward flow, THC and THD, which were also in the magnetosheath, instead observed a slow flow, indicating that the fast flow was small in scale. With the observed flow vectors and the magnetopause normal directions estimated from tangential discontinuity analysis, we conclude that this fast flow creates an indentation on the magnetopause, 1 Re deep and 2 Re wide. The magnetopause subsequently rebounds, rotating the flow direction sunward along the surface of the magnetopause. The fast flow is likely related to the radial <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20040171460&hterms=solar+wind+magnetic+field&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dsolar%2Bwind%2Bmagnetic%2Bfield','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20040171460&hterms=solar+wind+magnetic+field&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dsolar%2Bwind%2Bmagnetic%2Bfield"><span id="translatedtitle">In-Situ Solar Wind and <span class="hlt">Magnetic</span> Field Signatures of <span class="hlt">Interplanetary</span> Coronal Mass Ejections</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zurbuchen, Thomas H.; Richardson, Ian G.</p> <p>2004-01-01</p> <p>The heliospheric counterparts of coronal mass ejections (CMEs) at the Sun, <span class="hlt">interplanetary</span> coronal mass ejections (ICMEs), can be identified in-situ based on a number of <span class="hlt">magnetic</span> field, plasma, compositional and energetic particle signatures, as well as combinations thereof. Although many of these signatures have been recognized since the early space era, recent observations from improved instrumentation on spacecraft such as Ulysses, Wind, and ACE, in conjunction with solar observations from SOHO, have advanced our understanding of the characteristics of ICMEs and their solar counterparts. We summarize these signatures and their implications for understanding the nature of these structures and the physical properties of coronal mass ejections. We conclude that our understanding of ICMEs is far from complete, and formulate several challenges that, if addressed, would substantially improve our knowledge of the relationship between CMEs at the Sun and in the heliosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19780029186&hterms=GSM&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DGSM','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19780029186&hterms=GSM&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DGSM"><span id="translatedtitle">Characteristics of the association between the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field and substorms</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Caan, M. N.; Mcpherron, R. L.; Russell, C. T.</p> <p>1977-01-01</p> <p>The geomagnetic response to changes in the orientation of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) has been investigated for 18 IMF events. These events consisted of clear southward shifts of the IMF when the IMF Bz(GSM) component had been northward for more than two hours. It was found that when the IMF thus shifted southward and remained southward for at least two hours, a magnetospheric substorm always ensued. Several properties of this subsequent geomagnetic activity were determined to be associated with IMF parameters. The amplitude of auroral negative bays was confirmed to be a function of the southward IMF flux preceding the onsets. Auroral bay activity was also observed to cease abruptly coincident with permanent northward recoveries in the IMF. Finally, it was observed that many of the ground expansion onsets were associated with either IMF northward fluctuations or partial northward recoveries, which is interpreted as indicative of the existence of a class of IMF-triggered substorms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1985ICRC....5...42H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1985ICRC....5...42H"><span id="translatedtitle">The effect of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field on sidereal variations observed at medium depth underground detectors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Humble, J. E.; Fenton, A. G.</p> <p>1985-08-01</p> <p>It has been known for some years that the intensity variations in sidereal time observed by muon detectors at moderate underground depths are sensitive to the polarity of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (ipmf) near the Earth. There are differences in the response to these anisotropies as observed in the Norhtern and southern hemispheres. When fully understood, the nature of the anisotropy seems likely to provide information on the 3-dimensional structure of the heliomagnetosphere, its time variations, and its linking with the local interstellar field. The summation harmonic dials for the sidereal diurnal variation during 1958 to 1982 show that there is a strong dependence on whether the ipmf near the Earth is directed outwards from the Sun or inwards it.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012cosp...39...49A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012cosp...39...49A"><span id="translatedtitle">Substorm aurora and <span class="hlt">magnetic</span> tail dynamics during <span class="hlt">interplanetary</span> shock compression: THEMIS observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Angelopoulos, Vassilis; Zhou, Xiaoyan</p> <p>2012-07-01</p> <p>Fast and forward <span class="hlt">interplanetary</span> shocks compress and squeeze the Earth magnetosphere and cause a series of magnetospheric and ionospheric reactions. In addition to the enhancement of chorus, electromagnetic ion cyclotron (EMIC) waves and magnetospheric hiss, the ionospheric convection is enhanced as well. Shock aurora is generated, which is a phenomenon first an auroral brightness onset near local noon right after the shock impingement then followed by a fast anti-sunward auroral propagation along the oval. It has been found that substorm auroral activity can be significantly intensified by the shock compression when the shock upstream <span class="hlt">magnetic</span> field was in southward in a certain period of time. This paper will present recent results based on the THEMIS spacecraft and ground-based observations. With multiple spacecraft in the magnetotail, the complex dynamics of the compressed tail is identified and analyzed. Correlations between the tail dynamics and substorm auroral variations will be discussed. *On-leave from Jet Propulsion Laboratory</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015Ge%26Ae..55..938V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015Ge%26Ae..55..938V"><span id="translatedtitle">Radiocarbon version of 11-year variations in the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field since 1250</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Volobuev, D. M.; Makarenko, N. G.</p> <p>2015-12-01</p> <p>It is known that the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF), which is controlled by solar activity, modulates the flux of galactic cosmic rays (GCRs). Because GCRs are the only source of the 14C isotope in the atmosphere before the era of atmospheric nuclear tests, the formation rate of this isotope in the atmosphere is one of the few reliable sources of information on solar activity before the initiation of regular telescopic observations. In this study, we solve the inverse problem for the equation of radiocarbon diffusion from the atmosphere into the ocean by calibrating the radiocarbon content in tree rings from 1510 to 1950. We obtain an approximation of 11-year IMF cycles represented by the IDV index from 1872 to 1950. The model extrapolation to the calibration curve for the Korean Peninsula over the time period from 1250 to 1650 makes it possible to calculate the sequence of minima of quasi-11-year cycles since 1250.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ApJ...812..152Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ApJ...812..152Z"><span id="translatedtitle">Strong Solar Wind Dynamic Pressure Pulses: <span class="hlt">Interplanetary</span> Sources and Their Impacts on Geosynchronous <span class="hlt">Magnetic</span> Fields</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zuo, Pingbing; Feng, Xueshang; Xie, Yanqiong; Wang, Yi; Xu, Xiaojun</p> <p>2015-10-01</p> <p>In this investigation, we first present a statistical result of the <span class="hlt">interplanetary</span> sources of very strong solar wind dynamic pressure pulses (DPPs) detected by WIND during solar cycle 23. It is found that the vast majority of strong DPPs reside within solar wind disturbances. Although the variabilities of geosynchronous <span class="hlt">magnetic</span> fields (GMFs) due to the impact of positive DPPs have been well established, there appears to be no systematic investigations on the response of GMFs to negative DPPs. Here, we study both the decompression effects of very strong negative DPPs and the compression from strong positive DPPs on GMFs at different <span class="hlt">magnetic</span> local time sectors. In response to the decompression of strong negative DPPs, GMFs on the dayside near dawn and near dusk on the nightside, are generally depressed. But near the midnight region, the responses of GMF are very diverse, being either positive or negative. For part of the events when GOES is located at the midnight sector, the GMF is found to abnormally increase as the result of magnetospheric decompression caused by negative DPPs. It is known that under certain conditions <span class="hlt">magnetic</span> depression of nightside GMFs can be caused by the impact of positive DPPs. Here, we find that a stronger pressure enhancement may have a higher probability of producing the exceptional depression of GMF at the midnight region. Statistically, both the decompression effect of strong negative DPPs and the compression effect of strong positive DPPs depend on the <span class="hlt">magnetic</span> local time, which are stronger at the noon sector.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRA..120.3328J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRA..120.3328J"><span id="translatedtitle">Comparing generic models for <span class="hlt">interplanetary</span> shocks and <span class="hlt">magnetic</span> clouds axis configurations at 1 AU</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Janvier, M.; Dasso, S.; Démoulin, P.; Masías-Meza, J. J.; Lugaz, N.</p> <p>2015-05-01</p> <p><span class="hlt">Interplanetary</span> coronal mass ejections (ICMEs) are the manifestation of solar transient eruptions, which can significantly modify the plasma and <span class="hlt">magnetic</span> conditions in the heliosphere. They are often preceded by a shock, and a <span class="hlt">magnetic</span> flux rope is detected in situ in a third to half of them. The main aim of this study is to obtain the best quantitative shape for the flux rope axis and for the shock surface from in situ data obtained during spacecraft crossings of these structures. We first compare the orientation of the flux rope axes and shock normals obtained from independent data analyses of the same events, observed in situ at 1 AU from the Sun. Then we carry out an original statistical analysis of axes/shock normals by deriving the statistical distributions of their orientations. We fit the observed distributions using the distributions derived from several synthetic models describing these shapes. We show that the distributions of axis/shock orientations are very sensitive to their respective shape. One classical model, used to analyze <span class="hlt">interplanetary</span> imager data, is incompatible with the in situ data. Two other models are introduced, for which the results for axis and shock normals lead to very similar shapes; the fact that the data for MCs and shocks are independent strengthens this result. The model which best fits all the data sets has an ellipsoidal shape with similar aspect ratio values for all the data sets. These derived shapes for the flux rope axis and shock surface have several potential applications. First, these shapes can be used to construct a consistent ICME model. Second, these generic shapes can be used to develop a quantitative model to analyze imager data, as well as constraining the output of numerical simulations of ICMEs. Finally, they will have implications for space weather forecasting, in particular, for forecasting the time arrival of ICMEs at the Earth.</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_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_7 --> <div id="page_8" 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_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</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="141"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21562644','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21562644"><span id="translatedtitle">DETECTION OF CURRENT SHEETS AND <span class="hlt">MAGNETIC</span> RECONNECTIONS AT THE TURBULENT LEADING EDGE OF AN <span class="hlt">INTERPLANETARY</span> CORONAL MASS EJECTION</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chian, Abraham C.-L.; Munoz, Pablo R. E-mail: pablocus@gmail.com</p> <p>2011-06-01</p> <p>The relation between current sheets, turbulence, and <span class="hlt">magnetic</span> reconnections at the leading edge of an <span class="hlt">interplanetary</span> coronal mass ejection detected by four Cluster spacecraft on 2005 January 21 is studied. We report the observational evidence of two <span class="hlt">magnetically</span> reconnected current sheets in the vicinity of a front <span class="hlt">magnetic</span> cloud boundary layer with the following characteristics: (1) a Kolmogorov power spectrum in the inertial subrange of the <span class="hlt">magnetic</span> turbulence, (2) the scaling exponent of structure functions of <span class="hlt">magnetic</span> fluctuations exhibiting multi-fractal scaling predicted by the She-Leveque magnetohydrodynamic model, and (3) bifurcated current sheets with the current density computed by both single-spacecraft and multi-spacecraft techniques.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SoPh..290..553L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SoPh..290..553L"><span id="translatedtitle">Yearly Comparison of <span class="hlt">Magnetic</span> Cloud Parameters, Sunspot Number, and <span class="hlt">Interplanetary</span> Quantities for the First 18 Years of the Wind Mission</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lepping, R. P.; Wu, C.-C.; Berdichevsky, D. B.</p> <p>2015-02-01</p> <p>In the scalar part of this study, we determine various statistical relationships between estimated <span class="hlt">magnetic</span> cloud (MC) model fit-parameters and sunspot number (SSN) for the interval defined by the Wind mission, i.e., early 1995 until the end of 2012, all in terms of yearly <span class="hlt">averages</span>. The MC-fitting model used is that of Lepping, Jones, and Burlaga ( J. Geophys. Res. 95, 11957 - 11965, <CitationRef CitationID="CR19">1990). We also statistically compare the MC fit-parameters and other derived MC quantities [ e.g., axial <span class="hlt">magnetic</span> flux (ΦO) and total axial current density ( J O)] with some associated ambient <span class="hlt">interplanetary</span> quantities (including the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field ( B IMF), proton number density ( N P), and others). Some of the main findings are that the minimum SSN is nearly simultaneous with the minimum in the number of MCs per year ( N MC), which occurs in 2008. There are various fluctuations in N MC and the MC model-fit quality ( Q') throughout the mission, but the last four years (2009 - 2012) are markedly different from the others; Q' is low and N MC is large over these four years. N MC is especially large for 2012. The linear correlation coefficient (c.c.≈0.75) between the SSN and each of the three quantities J O, MC diameter (2 R O), and B IMF, is moderately high, but none of the MC parameters track the SSN well in the sense defined in this article. However, there is good statistical tracking among the following: MC axial field, B IMF, 2 R O, <span class="hlt">average</span> MC speed ( V MC), and yearly <span class="hlt">average</span> solar wind speed ( V SW) with relatively high c.c.s among most of these. From the start of the mission until late 2005, J O gradually increases, with a slight violation in 2003, but then a dramatic decrease (by more than a factor of five) occurs to an almost steady and low value of ≈ 3 μA km-2 until the end of the interval of interest, i.e., lasting for at least seven years. This tends to split the overall 18-year interval into two phases with a separator at the end of 2005. There is good tracking between 2 R O and the total axial current density, as expected. The MC duration is also correlated well with these two quantities. ΦO shows marked variations throughout the mission, but has no obvious trend. N P, B IMF, V MC, Q', and V SW are all quite steady over the full 18 years and have markedly low relative variation. Concerning vector quantities, we examine the distribution of MC type for the 18 years, where type refers to the field directional change through a given MC starting at first encounter ( i.e., North-to-South, or South-to-North, All South, All North, etc.). Combining all 18 years of MC types shows that the occurrence rate varies strongly across the various MC types, with N-to-S being most prevalent, with a 27 % occurrence rate (of all MCs), and S-to-N being second, with a 23 % occurrence. Then All N and All S come next at 16 % and 10 % occurrence rate, respectively. All others are at 7 % or lower. For the variation of MC types with time, the southern types ( i.e., those that start with a southern <span class="hlt">magnetic</span> field, a negative B Z in geocentric-solar-ecliptic coordinates) decrease, as the northern types ( i.e., those that start with a northern field) increase, apparently consistent with the specific timing of the polarity change of the solar <span class="hlt">magnetic</span> field, as predicted by Bothmer and Rust (in Crooker, N., Joselyn, J., Feynman J. (eds), Geophys. Monogr., 139 - 146, <CitationRef CitationID="CR3">1997).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19990056482&hterms=Ulysses&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DUlysses','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19990056482&hterms=Ulysses&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DUlysses"><span id="translatedtitle">Self-similar evolution of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> clouds and Ulysses measurements of the polytropic index inside the cloud</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Osherovich, Vladimir A.; Fainberg, J.; Stone, R. G.; MacDowall, R. J.; Berdichevsky, D.</p> <p>1997-01-01</p> <p>A self similar model for the expanding flux rope is developed for a magnetohydrodynamic model of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> clouds. It is suggested that the dependence of the maximum <span class="hlt">magnetic</span> field on the distance from the sun and the polytropic index gamma has the form B = r exp (-1/gamma), and that the ratio of the electron temperature to the proton temperature increases with distance from the sun. It is deduced that ion acoustic waves should be observed in the cloud. Both predictions were confirmed by Ulysses observations of a 1993 <span class="hlt">magnetic</span> cloud. Measurements of gamma inside the cloud demonstrate sensitivity to the internal topology of the <span class="hlt">magnetic</span> field in the cloud.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19820005721','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19820005721"><span id="translatedtitle">Large-scale variations of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field: Voyager 1 and 2 observations between 1-5 AU</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Burlaga, L. F.; Lepping, R. P.; Behannon, K. W.; Klein, L. W.; Neubauer, F. M.</p> <p>1981-01-01</p> <p>Observations by the Voyager 1 and 2 spacecraft of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field between 1 and 5 AU were used to investigate the large scale structure of the IMF in a period of increasing solar activity. The Voyager spacecraft found notable deviations from the Parker axial model. These deviations are attributed both to temporal variations associated with increasing solar activity, and to the effects of fluctuations of the field in the radial direction. The amplitude of the latter fluctuations were found to be large relative to the magnitude of the radial field component itself beyond approximately 3 AU. Both Voyager 1 and Voyager 2 observed decreases with increasing heliocentric distance in the amplitude of transverse fluctuations in the <span class="hlt">averaged</span> field strength (B) which are consistent with the presence of predominantly undamped Alfven waves in the solar wind, although and necessarily implying the presence of them. Fluctuations in the strength of B (relative to mean field strength) were found to be small in amplitude, with a RMS which is approximately one third of that for the transverse fluctuations and they are essentially independent of distance from the Sun.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRA..120.8327Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRA..120.8327Z"><span id="translatedtitle">Excitation of dayside chorus waves due to <span class="hlt">magnetic</span> field line compression in response to <span class="hlt">interplanetary</span> shocks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhou, Chen; Li, Wen; Thorne, Richard M.; Bortnik, Jacob; Ma, Qianli; An, Xin; Zhang, Xiao-jia; Angelopoulos, Vassilis; Ni, Binbin; Gu, Xudong; Fu, Song; Zhao, Zhengyu</p> <p>2015-10-01</p> <p>The excitation of magnetospheric whistler-mode chorus in response to <span class="hlt">interplanetary</span> (IP) shocks is investigated using wave data from the Time History of Events and Macroscale Interactions during Substorms (THEMIS) spacecraft. As an example, we show a typical chorus wave excitation following an IP shock event that was observed by THEMIS in the postnoon sector near the magnetopause on 3 August 2010. We then analyze characteristic changes during this event and perform a survey of similar events during the period 2008-2014 using the THEMIS and OMNI data set. Our statistical analysis demonstrates that the chorus wave excitation/intensification in response to IP shocks occurs only at high L shells (L > 8) on the dayside. We analyzed the variations of <span class="hlt">magnetic</span> curvature following the arrival of the IP shock and found that IP shocks lead to more homogeneous background <span class="hlt">magnetic</span> field configurations in the near-equatorial dayside magnetosphere; and therefore, the threshold of nonlinear chorus wave growth is likely to be reduced, favoring chorus wave generation. Our results provide the observational evidence to support the concept that the geomagnetic field line configuration plays a key role in the excitation of dayside chorus.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19970026617','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19970026617"><span id="translatedtitle">Penetration of the <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field B(sub y) into Earth's Plasma Sheet</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hau, L.-N.; Erickson, G. M.</p> <p>1995-01-01</p> <p>There has been considerable recent interest in the relationship between the cross-tail <span class="hlt">magnetic</span> field component B(sub y) and tail dynamics. The purpose of this paper is to give an overall description of the penetration of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) B(sub y) into the near-Earth plasma sheet. We show that plasma sheet B(sub y) may be generated by the differential shear motion of field lines and enhanced by flux tube compression. The latter mechanism leads to a B(sub y) analogue of the pressure-balance inconsistency as flux tubes move from the far tail toward the Earth. The growth of B(sub y), however, may be limited by the dawn-dusk asymmetry in the shear velocity as a result of plasma sheet tilting. B(sub y) penetration into the plasma sheet implies field-aligned currents flowing between hemispheres. These currents together with the IMF B(sub y) related mantle field-aligned currents effectively shield the lobe from the IMF B(sub y).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19840051826&hterms=magnetic+control+satellite&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dmagnetic%2Bcontrol%2Bsatellite','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19840051826&hterms=magnetic+control+satellite&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dmagnetic%2Bcontrol%2Bsatellite"><span id="translatedtitle">Dependence of the spectrum of Pc 3-4 pulsations on the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Takahashi, K.; Mcpherron, R. L.; Terasawa, T.</p> <p>1984-01-01</p> <p>Dependence of the power spectrum of Pc 3-4 <span class="hlt">magnetic</span> pulsations observed at the ATS 6 geosynchronous satellite on the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) has been studied. Pulsation events that were observed near noon and exhibited harmonic structure are chosen for analysis. Further selected are pulsation events with identical fundamental frequency to study dependence of the power of pulsations at different harmonic bands on the IMF. A weak negative correlation is observed between the IMF cone angle theta-XB and the power of pulsations in the frequency range 20-70 mHz. Also, a positive correlation between the intensity of the IMF B(IMF) and the power of pulsations at 50-70 mHz is found. This B(IMF) control is present at all ranges of the cone angle. A comparison is conducted of this observation with the frequency of bow shock associated upstream waves predicted from a model of wave generation by a cyclotron resonance of ions reflected at the bow shock. The predicted frequency depends on the IMF as B(IMF) (cos theta-XB)-squared. Although this relation gives a proportionality between the frequency and B(IMF) qualitatively consistent with the observation, it does not explain the most obvious IMF control of the spectrum of the pulsations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.8709Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.8709Y"><span id="translatedtitle">Dependence of efficiency of <span class="hlt">magnetic</span> storm generation on the types of <span class="hlt">interplanetary</span> drivers.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yermolaev, Yuri; Nikolaeva, Nadezhda; Lodkina, Irina</p> <p>2015-04-01</p> <p>To compare the coupling coefficients between the solar-wind electric field Ey and Dst (and corrected Dst*) index during the <span class="hlt">magnetic</span> storms generated by different types of <span class="hlt">interplanetary</span> drivers, we use the Kyoto Dst-index data, the OMNI data of solar wind plasma and <span class="hlt">magnetic</span> field measurements, and our "Catalog of large scale phenomena during 1976-2000" (published in [1] and presented on websites: ftp://ftp.iki.rssi.ru/pub/omni/). Both indexes at the main phase of <span class="hlt">magnetic</span> storms are approximated by the linear dependence on the following solar wind parameters: integrated electric field of solar wind (sumEy), solar wind dynamic pressure (Pd), and the level of <span class="hlt">magnetic</span> field fluctuations (sB), and the fitting coefficients are determined by the technique of least squares. We present the results of the main phase modelling for <span class="hlt">magnetic</span> storms with Dst<-50 nT induced by 4 types of the solar wind streams: MC (10 events), CIR (41), Sheath (26), Ejecta (45). Our analysis [2, 3] shows that the coefficients of coupling between Dst and Dst* indexes and integral electric field are significantly higher for Sheath (for Dst*and Dst they are -3.4 and -3.3 nT/V m-1 h, respectively) and CIR (-3.0 and -2.8) than for MC (-2.0 and -2.5) and Ejecta (-2.1 and -2.3). Thus we obtained additional confirmation of experimental fact that Sheath and CIR have higher efficiency in generation of <span class="hlt">magnetic</span> storms than MC and Ejecta. This work was supported by the RFBR, project 13-02-00158a, and by the Program 9 of Presidium of Russian Academy of Sciences. References 1. Yu. I. Yermolaev, N. S. Nikolaeva, I. G. Lodkina, and M. Yu. Yermolaev, Catalog of Large-Scale Solar Wind Phenomena during 1976-2000, Cosmic Research, 2009, Vol. 47, No. 2, pp. 81-94. 2. N.S. Nikolaeva, Yu.I. Yermolaev, I.G. Lodkina, Modeling of Dst-index temporal profile on the main phase of the <span class="hlt">magnetic</span> storms generated by different types of solar wind, Cosmic Research, 2013, Vol. 51, No. 6, pp. 401-412 3. Nikolaeva N.S., Yermolaev Yu.I., Lodkina I.G., Modeling of corrected Dst-index temporal profile on the main phase of the <span class="hlt">magnetic</span> storms generated by different types of solar wind, Cosmic Research, 2015, Vol.53, No. 2, 81, DOI: 10.7868/S0023420615020077</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRA..120.7737R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRA..120.7737R"><span id="translatedtitle">Dependence of the location of the Martian <span class="hlt">magnetic</span> lobes on the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field direction: Observations from Mars Global Surveyor</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Romanelli, N.; Bertucci, C.; Gómez, D.; Mazelle, C.</p> <p>2015-09-01</p> <p>We use magnetometer data from the Mars Global Surveyor (MGS) spacecraft during portions of the premapping orbits of the mission to study the variability of the Martian-induced magnetotail as a function of the orientation of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF). The time spent by MGS in the magnetotail lobes during periods with positive solar wind flow-aligned IMF component B∥IMF suggests that their location as well as the position of the central polarity reversal layer (PRL) are displaced in the direction antiparallel to the IMF cross-flow component B⊥IMF. Analogously, in the cases where B∥IMF is negative, the lobes are displaced in the direction of B⊥IMF. This behavior is compatible with a previously published analytical model of the IMF draping, where for the first time, the displacement of a complementary reversal layer (denoted as IPRL for inverse polarity reversal layer) is deduced from first principles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015TESS....140503K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015TESS....140503K"><span id="translatedtitle">The <span class="hlt">magnetic</span> flux excess effect as a consequence of non-Parker radial evolution of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Khabarova, Olga</p> <p>2015-04-01</p> <p>The “<span class="hlt">magnetic</span> flux excess” effect is exceeding of <span class="hlt">magnetic</span> flux Fs=4π|Br|r2 measured by distant spacecraft over the values obtained through measurements at the Earth’s orbit (Owens et al., JGR, 2008). Theoretically, its conservation should take place at any heliocentric distance r further than 10 solar radii, which means that the difference between the flux measured at 1 AU and Fs observed in another point in the heliosphere should be zero. However, the difference is negative closer to the Sun and increasingly positive at larger heliocentric distances. Possible explanations of this effect are continuously discussed, but the consensus is yet not reached.It is shown that a possible source of this effect is the solar wind expansion not accordingly with the Parker solution at least at low heliolatitudes. The difference between the experimentally found (r-5/3) and commonly used (r-2) radial dependence of the radial component of the IMF Br may lead to mistakes in the IMF point-to-point recalculations (Khabarova & Obridko, ApJ, 2012; Khabarova, Astronomy Reports, 2013). Using the observed Br (r) dependence, it is easy to find the variation of difference between the <span class="hlt">magnetic</span> flux Fs(r) at certain heliocentric distance r and Fs_1AU at 1 AU, which can be calculated as Fs(r)-Fs_1AU =4π·(B1AU /[1AU]-5/3) (r2-5/3 -[1AU]2-5/3) (Khabarova, Astronomy Reports, 2013).The possible influence of presence of the heliospheric current sheet near the ecliptic plane on the picture of <span class="hlt">magnetic</span> field lines and consequent deviation from the Parker's model is discussed.- Khabarova Olga, and Obridko Vladimir, Puzzles of the <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field in the Inner Heliosphere, 2012, Astrophysical Journal, 761, 2, 82, doi:10.1088/0004-637X/761/2/82, http://arxiv.org/pdf/1204.6672v2.pdf- Olga V. Khabarova, The <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field: radial and latitudinal dependences. Astronomy Reports, 2013, Vol. 57, No. 11, pp. 844-859, http://arxiv.org/ftp/arxiv/papers/1305/1305.1204.pdf</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSM23A2222R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSM23A2222R"><span id="translatedtitle">Auroral intensity asymmetries associated with the x-component of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field in the two polar hemispheres</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reistad, J. P.; Ostgaard, N.; Laundal, K.; Haaland, S.; Oksavik, K.</p> <p>2013-12-01</p> <p>We present a statistical study of the <span class="hlt">average</span> response of the two auroral ovals to an x-component in the <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field (IMF) during non-substorm and negative IMF Bz conditions. Event studies using simultaneous global imaging of the entire auroral ovals have suggested that non-conjugate features of the aurora, meaning a significant difference of auroral intensity in conjugate regions, could be related to hemispheric differences in energy transfer from the Solar Wind (SW). The energy transfer mechanism is referred to as the SW dynamo. In the presence of an x-component in the IMF, open field lines will experience different <span class="hlt">magnetic</span> tension forces in the two hemispheres. In order to investigate the importance of this asymmetry only identified in events studies earlier, we derive <span class="hlt">average</span> patterns of the auroral oval brightness for two extreme (+/- IMF Bx) situations where other effects have been excluded as good as possible in the selection of data. This is achieved using global imaging. In the Northern Hemisphere we use the IMAGE FUV-WIC camera and in the Southern Hemisphere the Polar VIS Earth camera. The most evident difference is found in the Northern Hemisphere between the positive and negative IMF Bx situations. Here the data coverage is excellent during the first years of the IMAGE mission (2000-2003). We find that there seems to be a significant difference in <span class="hlt">average</span> intensity in the dusk/pre-midnight sector between the two situations (+/- IMF Bx) in which the negative IMF Bx situation is the brighter one. This is consistent with the arguments on IMF Bx dependence on <span class="hlt">magnetic</span> tension on open field-lines in the two hemispheres. However, how this mechanism could possibly affect closed field-lines is still unclear. The same analysis is performed for the Southern Hemisphere oval. Although an opposite asymmetry is expected for the proposed mechanism, our results are somehow ambiguous due to the poor coverage compared to the Northern Hemisphere. Our analysis will hopefully address whether this is an hemispheric asymmetry or an effect just evident in the Northern Hemisphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006JGRA..11110209S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006JGRA..11110209S"><span id="translatedtitle">Spatiotemporal structure of the reconnecting magnetosphere under By-dominated <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> cloud conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sandholt, P. E.; Farrugia, C. J.</p> <p>2006-10-01</p> <p>In this study we discuss the spatiotemporal structure of the reconnecting magnetosphere under a steady external field which was pointing southward (Bz = -5 nT), but with a strong eastward component (By = 20 nT; clock angle = 100°). The relevant conditions refer to a three hour long interval midway through the passage at Earth of an <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> cloud on 17 April 1999. The quasi-steady parameters provided by the <span class="hlt">magnetic</span> cloud is what allow us to probe the detailed magnetospheric/ionospheric structure under these conditions. We document the presence of a specific configuration of cusp and oval-aligned polar arcs with associated merging and lobe convection cells in both hemispheres. Strong signatures of pulsed ionospheric flows (PIFs) are present in high-latitude ground magnetometer records from Svalbard and Greenland. Particle data obtained from Polar/HYDRA during an overflight of the southern hemisphere cusp at 0800-0900 MLT show the presence of polar arcs and an inverse energy versus latitude dispersion of precipitating ions on the poleward side of the merging cell and the plasma regimes of mantle, cusp, and BPS. Furthermore, observations by Polar, DMSP, and SuperDARN document the precipitation, field-aligned current and ion flow pattern in the south. The presence of "double cusp" in the north and polar arcs in both hemispheres (mirror images about noon) during the actual IMF Bz negative (By-dominated) conditions and the implications on solar wind-magnetosphere coupling are discussed. The <span class="hlt">magnetic</span> cloud conditions at ACE included a very low proton plasma β (˜0.01) and a low Alfven Mach number (˜2) near the center of the cloud. We speculate that these conditions may have given rise to a plasma depletion at the high-latitude magnetopause and favored the excitation of lobe reconnection under the prevailing Bz negative conditions. The reported observations are placed in the context of recent studies of the spatiotemporal structure of the dayside aurora.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011epsc.conf...93L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011epsc.conf...93L"><span id="translatedtitle">Collisions in Space: Observations of Disturbances in the <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field Caused by Destructive Collisions of Small Bodies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lai, H. R.; Russell, C. T.; Delzanno, G. L.; Jia, Y. D.</p> <p>2011-10-01</p> <p>Collisions between small <span class="hlt">interplanetary</span> bodies can produce clouds of dust particles, which rapidly become charged in the solar wind plasma. A wide range of particle sizes will be produced and the smallest nanoscale particles can be accelerated to solar wind speed in minutes. Our multi-fluid MHD simulation with charged dust as one fluid shows a three-dimensional disturbance in the <span class="hlt">magnetic</span> field with compression and draping in the flow direction and bending in the direction perpendicular to both the flow and unperturbed <span class="hlt">magnetic</span> field, producing a current sheet orthogonal to the flow. The Lorentz force of this current balances the transverse momentum of the gyrating dust particles and the solar gravity force balances the <span class="hlt">magnetic</span> pressure gradient force. Thus the <span class="hlt">magnetic</span> gradient force is proportional to the mass of the picked up dust and allows us to weigh the dust cloud. The <span class="hlt">magnetic</span> field behavior in the simulation results qualitatively resembles the phenomenon called an <span class="hlt">interplanetary</span> field enhancement (IFE), which is featured by a cuspshaped <span class="hlt">magnetic</span> field enhancement lasting from several minutes to hours, with a sharp discontinuity in at least one component of the <span class="hlt">magnetic</span> field. The association between IFE appearance and dust production was first inferred from PVO data in the 1980s, but the IFE formation process has been unclear until now. In this paper, we will gather the statistics of IFEs and use the <span class="hlt">magnetic</span> compression to weigh the mass of the dust cloud. We will also estimate the volume over which individual events may be sensed. Using this volume together with the IFE occurrence rate we can calculate the inferred collision rate. We find for the IFE with mass about 107 kg, this rate approximately agrees with the estimated rate of collision of <span class="hlt">interplanetary</span> bodies which can produce dust within the same mass range.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4497471','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4497471"><span id="translatedtitle">Saturn's dayside ultraviolet auroras: Evidence for morphological dependence on the direction of the upstream <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Meredith, C J; Alexeev, I I; Badman, S V; Belenkaya, E S; Cowley, S W H; Dougherty, M K; Kalegaev, V V; Lewis, G R; Nichols, J D</p> <p>2014-01-01</p> <p>We examine a unique data set from seven Hubble Space Telescope (HST) “visits” that imaged Saturn's northern dayside ultraviolet emissions exhibiting usual circumpolar “auroral oval” morphologies, during which Cassini measured the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) upstream of Saturn's bow shock over intervals of several hours. The auroras generally consist of a dawn arc extending toward noon centered near ∼15° colatitude, together with intermittent patchy forms at ∼10° colatitude and poleward thereof, located between noon and dusk. The dawn arc is a persistent feature, but exhibits variations in position, width, and intensity, which have no clear relationship with the concurrent IMF. However, the patchy postnoon auroras are found to relate to the (suitably lagged and <span class="hlt">averaged</span>) IMF Bz, being present during all four visits with positive Bz and absent during all three visits with negative Bz. The most continuous such forms occur in the case of strongest positive Bz. These results suggest that the postnoon forms are associated with reconnection and open flux production at Saturn's magnetopause, related to the similarly interpreted bifurcated auroral arc structures previously observed in this local time sector in Cassini Ultraviolet Imaging Spectrograph data, whose details remain unresolved in these HST images. One of the intervals with negative IMF Bz however exhibits a prenoon patch of very high latitude emission extending poleward of the dawn arc to the <span class="hlt">magnetic</span>/spin pole, suggestive of the occurrence of lobe reconnection. Overall, these data provide evidence of significant IMF dependence in the morphology of Saturn's dayside auroras. Key Points We examine seven cases of joint HST Saturn auroral images and Cassini IMF data The persistent but variable dawn arc shows no obvious IMF dependence Patchy postnoon auroras are present for northward IMF but not for southward IMF PMID:26167441</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19720018182','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19720018182"><span id="translatedtitle">Precipitation of low energy electrons at high latitudes: Effects of substorms, <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field and dipole tilt angle</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Burch, J. L.</p> <p>1972-01-01</p> <p>Data from the auroral particles experiment on OGO-4 were used to study effects of substorm activity, <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field latitutde, and dipole tilt angle on high-latitude precipitation of 700 eV electrons. It was found that: (1) The high-latitude zone of 700 eV electron precipitation in late evening and early morning hours moves equatorward by 5 to 10 deg during substorms. (2) The low-latitude boundary of polar cusp electron precipitation at 9 to 15 hours MLT also moves equatorward by several degrees during substorms and, in the absence of significant substorm activity, after a period of southward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field. (3) With times containing substorm activity or a southward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field eliminated, the low-latitude boundary of polar cusp electron precipitation is found to move by approximately 4 deg over the total yearly range of tilt angles. At maximum winter and summer conditions the invariant latitude of the boundary is shown to shift by approximately -3 deg and +1 deg respectively from its equinox location.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19870055304&hterms=different+association&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Ddifferent%2Bassociation','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19870055304&hterms=different+association&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Ddifferent%2Bassociation"><span id="translatedtitle"><span class="hlt">Interplanetary</span> <span class="hlt">magnetic</span> field enhancements - Further evidence for an association with asteroid 2201 Oljato</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Russell, C. T.</p> <p>1987-01-01</p> <p>In 1980 and 1983 the asteroid 2201 Oljato passed inside the orbit of Venus, respectively 65 and 21 days prior to the passage of Venus, apparently causing disturbances in the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field, possibly through the interaction of its debris trail with the solar wind. In July 1986 the asteroid passed through the inner solar system 25 days after Venus and it is expected to find similar disturbances if the debris trail extended in front of the asteroid. The expected disturbances were observed. All data from the longitude range of the disturbances have been examined for all Venus years as well as from a control period over the same solar longitudes but at different ecliptic longitudes. No enhancements in the rate of occurrence of events were seen in the control periods during 1980, 1983 and 1986, and the rate was uniformly low at all other times. The new data reaffirm the association of solar wind disturbances with the asteroidal passage and imply a debris trail that extends perhaps 1 AU both in front of and behind the asteroid.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMSM23B..06R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMSM23B..06R"><span id="translatedtitle">Understanding the geoeffective properties of rapid changes in the solar wind and <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (Invited)</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.; Yu, Y.; Liemohn, M. W.; Dodger, A. M.</p> <p>2010-12-01</p> <p>The magnetosphere is strongly driven by the state of the solar wind and <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF). When these change, the magnetosphere reacts in different ways depending on the specific change. For example, when the IMF reorients, the reconnection site needs to move and become reestablished. After this, Alfven waves propagate to the ionosphere, communicating the change. Overall, this alteration can take many minutes to initialize and 10-20 minutes to set up a new potential pattern. Conversely, when the solar wind changes and the magnetopause position alters, a fast-mode wave propagates throughout the system communicating the new state. During this time period, the ionospheric convection can become significantly enhanced for a few to tens of minutes. This has a ramification on the geoeffectiveness of highly structured solar wind and IMF, as occurs during the sheath of a coronal mass ejection. Namely, the magnetosphere acts as a low pass filter on the highly variable IMF, but reacts strongly to the strongly varying solar wind density. We present systematic simulation results that demonstrate these properties of the magnetosphere, and discuss the effectiveness of the different frequencies of variations that may encounter the magnetosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSH42A..05R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSH42A..05R"><span id="translatedtitle">Propagation and Evolution of <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Clouds: Global Simulations and Comparisons with Observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Riley, P.; Ben-Nun, M.; Linker, J.; Torok, T.; Lionello, R.; Downs, C.</p> <p>2014-12-01</p> <p>In this talk, we explore the evolution of <span class="hlt">interplanetary</span> coronal mass ejections (ICMEs), and fast <span class="hlt">magnetic</span> clouds (MCs) in particular. We address three specific issues. First, What are the large-scale forces acting on ejecta as they travel from the Sun to 1 AU through a realistic ambient solar wind, and how does they affect the large-scale structure of the event? Second, what are the dominant waves/shocks associated with fast ICMEs? And third, how are the properties of ICMEs different during cycle 24 than during the previous cycle? To accomplish these objectives, we employ a variety of numerical approaches, including global resistive MHD models that incorporate realistic energy transport processes. We also compare and contrast model results with both remote solar and in-situ measurements of ICMEs at 1 AU and elsewhere, including the so-called ``Bastille Day'' event of July 14, 2000, and the more recent ``extreme ICME'' observed by STEREO-A on July 23, 2012.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMSM41A1999D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMSM41A1999D"><span id="translatedtitle">Solar Wind Energy Input during Prolonged, Intense Northward <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Fields: A New Coupling Function</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Du, A.; Tsurutani, B.; Sun, W.</p> <p>2011-12-01</p> <p>Substorm activity during intense (B > 10 nT), long duration (T > 3 hr) northward (Bz > 0 nT = N) IMF <span class="hlt">magnetic</span> clouds (MCs) during solar cycle 23 (SC23) have been examined in detail. The MCs with northward-then-southward (NS) IMFs were analyzed separately from MCs with southward-then-northward (SN) configurations. It is found that there is a lack of substorms during the N field intervals of NS clouds. In sharp contrast, substorms do occur during the N field portions of SN MCs. From the above two results it is reasonable to conclude that the latter substorms represent residual energy remaining from the preceding S portions of the SN MCs. We use this scenario to derive a new solar wind-magnetosphere coupling function during northward IMFs: E_(NIMF) = ? N^(-1/12) V^(7/3) B^(1/2)+? V |Dst_(min)|. The first term on the right-hand side of the equation represents the energy input via "viscous interaction", and the second term indicates the residual energy stored in the magnetotail. It was empirically found that the magnetosphere/magnetotail can store energy for ~ 4 hrs before it dissipates away. The concept of magnetosphere/magnetotail short term energy storage should prove to be useful to predict when <span class="hlt">interplanetary</span> shocks will and will not trigger substorms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JGRA..119.3130J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JGRA..119.3130J"><span id="translatedtitle"><span class="hlt">Interplanetary</span> <span class="hlt">magnetic</span> field control of the ionospheric field-aligned current and convection distributions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Juusola, L.; Milan, S. E.; Lester, M.; Grocott, A.; Imber, S. M.</p> <p>2014-04-01</p> <p>Patterns of the high-latitude ionospheric convection and field-aligned current (FAC) are a manifestation of the solar wind-magnetosphere-ionosphere coupling. By observing them we can acquire information on magnetopause reconnection, a process through which solar wind energy enters the magnetosphere. We use over 10 years of <span class="hlt">magnetic</span> field and convection data from the CHAMP satellite and Super Dual Auroral Radar Network radars, respectively, to display combined distributions of the FACs and convection for different <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) orientations and amplitudes. During southward IMF, convection follows the established two-cell pattern with associated Region 1 and Region 2 FACs, indicating subsolar reconnection. During northward IMF, superposed on a weak two-cell pattern there is a reversed two-cell pattern with associated Region 0 and Region 1 FACs on the dayside, indicating lobe reconnection. For dominant IMF Bx, the sign of Bz determines whether lobe or subsolar reconnection signatures will be observed, but Bx will weaken the signatures compared to pure northward or southward IMF. When the IMF rotates from northward to duskward or dawnward, the distinct reversed and forward two-cell patterns start to merge into a distorted two-cell pattern. This is in agreement with the IMF By displacing the reconnection location from the open lobe field lines to closed dawn or dusk field lines, even though IMF Bz>0. As the IMF continues to rotate southward, the distorted pattern transforms smoothly to that of the symmetric two-cell pattern. While the IMF direction determines the configuration of the FACs and convection, the IMF amplitude affects their intensity.</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_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_8 --> <div id="page_9" 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_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</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="161"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730018611','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730018611"><span id="translatedtitle">The relation between the azimuthal component of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field and the geomagnetic field in the polar caps</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Svalgaard, L.</p> <p>1973-01-01</p> <p>The recently discovered relation between the azimuthal component of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field and <span class="hlt">magnetic</span> variations in the earth's polar caps is reviewed. When the IMF azimuthal component is positive (typical of an <span class="hlt">interplanetary</span> sector with <span class="hlt">magnetic</span> field directed away from the sun) geomagnetic perturbations directed away from the earth are observed within 8 deg from the corrected geomagnetic pole. When the IMF azimuthal component is negative (typically within toward sectors) the geomagnetic perturbations are directed towards the earth at both poles. These perturbations can also be described by an equivalent current flowing at a constant <span class="hlt">magnetic</span> latitude of 80 - 82 deg clockwise around the <span class="hlt">magnetic</span> poles during toward sectors and counterclockwise during away sectors. This current fluctuates in magnitude and direction with the azimuthal component of the IMF, with a delay time of the order of 20 minutes. The importance of this effect for understanding of both solar <span class="hlt">magnetism</span> and magnetospheric physics is stressed in view of the possibility for investigating the solar sector structure during the last five sunspot cycles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20110023536&hterms=MCS&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DMCS','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20110023536&hterms=MCS&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DMCS"><span id="translatedtitle"><span class="hlt">Magnetic</span> Field-Line Lengths in <span class="hlt">Interplanetary</span> Coronal Mass Ejections Inferred from Energetic Electron Events</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kahler, S. W.; Haggerty, D. K.; Richardson, I. G.</p> <p>2011-01-01</p> <p>About one quarter of the observed <span class="hlt">interplanetary</span> coronal mass ejections (ICMEs) are characterized by enhanced <span class="hlt">magnetic</span> fields that smoothly rotate in direction over timescales of about 10-50 hr. These ICMEs have the appearance of <span class="hlt">magnetic</span> flux ropes and are known as "<span class="hlt">magnetic</span> clouds" (MCs). The total lengths of MC field lines can be determined using solar energetic particles of known speeds when the solar release times and the I AU onset times of the particles are known. A recent examination of about 30 near-relativistic (NR) electron events in and near 8 MCs showed no obvious indication that the field-line lengths were longest near the MC boundaries and shortest at the MC axes or outside the MCs, contrary to the expectations for a flux rope. Here we use the impulsive beamed NR electron events observed with the Electron Proton and Alpha Monitor instrument on the Advanced Composition Explorer spacecraft and type III radio bursts observed on the Wind spacecraft to determine the field-line lengths inside ICMEs included in the catalog of Richardson & Cane. In particular, we extend this technique to ICMEs that are not MCs and compare the field-line lengths inside MCs and non-MC ICMEs with those in the ambient solar wind outside the ICMEs. No significant differences of field-line lengths are found among MCs, ICMEs, and the ambient solar wind. The estimated number of ICME field-line turns is generally smaller than those deduced for flux-rope model fits to MCs. We also find cases in which the electron injections occur in solar active regions CARs) distant from the source ARs of the ICMEs, supporting CME models that require extensive coronal <span class="hlt">magnetic</span> reconnection with surrounding fields. The field-line lengths are found to be statistically longer for the NR electron events classified as ramps and interpreted as shock injections somewhat delayed from the type III bursts. The path lengths of the remaining spike and pulse electron events are compared with model calculations of solar wind field-line lengths resulting from turbulence and found to be in good agreement.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21578263','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21578263"><span id="translatedtitle"><span class="hlt">MAGNETIC</span> FIELD-LINE LENGTHS IN <span class="hlt">INTERPLANETARY</span> CORONAL MASS EJECTIONS INFERRED FROM ENERGETIC ELECTRON EVENTS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kahler, S. W.; Haggerty, D. K.; Richardson, I. G.</p> <p>2011-08-01</p> <p>About one quarter of the observed <span class="hlt">interplanetary</span> coronal mass ejections (ICMEs) are characterized by enhanced <span class="hlt">magnetic</span> fields that smoothly rotate in direction over timescales of about 10-50 hr. These ICMEs have the appearance of <span class="hlt">magnetic</span> flux ropes and are known as '<span class="hlt">magnetic</span> clouds' (MCs). The total lengths of MC field lines can be determined using solar energetic particles of known speeds when the solar release times and the 1 AU onset times of the particles are known. A recent examination of about 30 near-relativistic (NR) electron events in and near 8 MCs showed no obvious indication that the field-line lengths were longest near the MC boundaries and shortest at the MC axes or outside the MCs, contrary to the expectations for a flux rope. Here we use the impulsive beamed NR electron events observed with the Electron Proton and Alpha Monitor instrument on the Advanced Composition Explorer spacecraft and type III radio bursts observed on the Wind spacecraft to determine the field-line lengths inside ICMEs included in the catalog of Richardson and Cane. In particular, we extend this technique to ICMEs that are not MCs and compare the field-line lengths inside MCs and non-MC ICMEs with those in the ambient solar wind outside the ICMEs. No significant differences of field-line lengths are found among MCs, ICMEs, and the ambient solar wind. The estimated number of ICME field-line turns is generally smaller than those deduced for flux-rope model fits to MCs. We also find cases in which the electron injections occur in solar active regions (ARs) distant from the source ARs of the ICMEs, supporting CME models that require extensive coronal <span class="hlt">magnetic</span> reconnection with surrounding fields. The field-line lengths are found to be statistically longer for the NR electron events classified as ramps and interpreted as shock injections somewhat delayed from the type III bursts. The path lengths of the remaining spike and pulse electron events are compared with model calculations of solar wind field-line lengths resulting from turbulence and found to be in good agreement.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19950046667&hterms=solar+wind+magnetic+field&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsolar%2Bwind%2Bmagnetic%2Bfield','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950046667&hterms=solar+wind+magnetic+field&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsolar%2Bwind%2Bmagnetic%2Bfield"><span id="translatedtitle">Magnetopause shape as a bivariate function of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field B(sub z) and solar wind dynamic pressure</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Roelof, Edmond C.; Sibeck, David G.</p> <p>1993-01-01</p> <p>We present a new method for determining the shape of the magnetopause as a bivariate function of the hourly <span class="hlt">averaged</span> solar wind dynamic pressure (p) and the north-south component of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) B(sub z). We represent the magnetopause (for X(sub GSE) greater than -40 R(sub E)) as an ellipsoid of revolution in solar-wind-aberrated coordinates and express the (p, B(sub z)) dependence of each of the three ellipsoid parameters as a second-order (6-term) bivariate expansion in Inp and B(sub z). We define 12 overlapping bins in a normalized dimensionless (p, B(sub z)) `control space' and fit an ellipsoid to those magnetopause crossings having (p, B(sub z)) values within each bin. We also calculate the bivariate (Inp, B(sub z)) moments to second order over each bin in control space. We can then calculate the six control-space expansion coefficients for each of the three ellipsoid parameters in configuration space. From these coefficients we can derive useful diagnosis of the magnetopause shape as joint functions of p and B(sub z): the aspect ratio of the ellipsoid's minor-to-major axes; the flank distance, radius of curvature, and flaring angle (at X(sub GSE) = 0); and the subsolar distance and radius of curvature. We confirm and quantify previous results that during periods of southward B(sub z) the subsolar magnetopause moves inward, while at X(sub GSE) = 0 the flank magnetopause moves outward and the flaring angle increases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016P%26SS..120...78V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016P%26SS..120...78V"><span id="translatedtitle">Parametric study of the solar wind interaction with the Hermean magnetosphere for a weak <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Varela, J.; Pantellini, F.; Moncuquet, M.</p> <p>2016-01-01</p> <p>The aim of this study is to simulate the interaction of the solar wind with the Hermean magnetosphere when the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field is weak, performing a parametric study for all the range of hydrodynamic values of the solar wind predicted on Mercury for the ENLIL + GONG WSA + Cone SWRC model: density from 12 to 180 cm-3, velocity from 200 to 500 km/s and temperatures from 2 ·104 to 18 ·104 K, and compare the results with a real MESSENGER orbit as reference case. We use the code PLUTO in spherical coordinates and an asymmetric multipolar expansion for the Hermean <span class="hlt">magnetic</span> field. The study shows for all simulations a stand off distance larger than the Mercury radius and the presence of close <span class="hlt">magnetic</span> field lines on the day side of the planet, so the dynamic pressure of the solar wind is not high enough to push the magnetopause on the planet surface if the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field is weak. The simulations with large dynamic pressure lead to a large compression of the Hermean <span class="hlt">magnetic</span> field modifying its topology in the inner magnetosphere as well as the plasma flows from the magnetosheath towards the planet surface.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AdSpR..52.2112A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AdSpR..52.2112A"><span id="translatedtitle">Sunspot numbers, <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field, and cosmic ray intensity at earth: Nexus for the twentieth century</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ahluwalia, H. S.</p> <p>2013-12-01</p> <p>The pivotal role played by the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (B) in modulating galactic cosmic ray (GCR) intensity in the heliosphere is described. We show that the inverse correlation observed by Forbush (1958) between GCRs and sunspot numbers (SSNs) is reflected in high correlation between SSNs and B (cc = 0.94). The SSN data are available since 1700 and the derived B data since 1835. The paleo-cosmic ray data are available for several millennia in the form of 10Be radionuclide sequestered in polar ice. The data of the ion chambers (ICs) at the Cheltenham-Fredericksburg-Yakutsk (CFY) sites are combined to create a data string for 1937-1988. In turn, these data are used to extend the measurements of the low energy GCR ions (>0.1 GeV) at balloon altitudes at high latitudes in Russia to 1937. These data are then correlated to B and the fit parameters are used to extend the low energy ion data to 1900, creating the instrumental era GCR time series for the twentieth century. The derived GCR time series is compared to 10Be measured at two sites in Greenland, namely Dye 3 and NGRIP for 1900-2000 to check the internal consistency of datasets for the long-term trend. We find that the annual mean rate (%) for 1965 at NGRIP is an outlier. We replace it with the mean of 1964 and 1965 rates and construct a new re-normalized time series at NGIP, improving the agreement with the derived instrumental era GCR time series for the twentieth century as well. This should encourage its use by heliophysics community for varied applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JASTP.115...52C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JASTP.115...52C"><span id="translatedtitle">IMF By-controlled field-aligned currents in the magnetotail during northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cheng, Z. W.; Shi, J. K.; Dunlop, M.; Liu, Z. X.</p> <p>2014-08-01</p> <p>The influence of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) By component on the field-aligned currents (FACs) in the plasma sheet boundary layer (PSBL) in the magnetotail during the northward IMF were investigated using the data from Cluster. There are 748 FACs cases selected to do analysis. We present that the IMF By component plays a very important role in controlling the flow direction of the FACs in the PSBL in the magnetotail. In the northern hemisphere, the influence of the positive (negative) IMF By is an earthward (tailward) FACs. To the contrary, in the southern hemisphere, the effect of the positive (negative) IMF By is a tailward (earthward) FACs. There is a clear north-south asymmetry of the polarity of the FACs in the PSBL when IMF By is positive or negative, and this asymmetry of the polarity is more distinct when IMF By is positive. The FAC density is controlled by IMF By only when |IMF By| is large. When |IMF By| is more than 10 nT the absolute FAC density in the PSBL has an obvious positive correlation with the |IMF By|. When |IMF By| is less than 10 nT, there is no correlation between the absolute FAC density and |IMF By|. There is a clear dusk-dawn asymmetry in the current densities for the FACs in the PSBL, with the dawn currents appearing larger than the dusk currents. The FAC with the largest (smallest) density is located in the range of 0100≤MLT<0200 (2100≤MLT<2200).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20110007245&hterms=Butterfly&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DButterfly','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20110007245&hterms=Butterfly&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DButterfly"><span id="translatedtitle">Solar Sources and Geospace Consequences of <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Clouds Observed During Solar Cycle 23</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gopalswamy, N.; Akiyama, S.; Yashiro, S.; Michalek, G.; Lepping, R. P.</p> <p>2007-01-01</p> <p>We present results of a statistical investigation of 99 <span class="hlt">magnetic</span> clouds (MCs) observed during 1995-2005. The MC-associated coronal mass ejections (CMEs) are faster and wider on the <span class="hlt">average</span> and originate within +/-30deg from the solar disk center. The solar sources of MCs also followed the butterfly diagram. The correlation between the <span class="hlt">magnetic</span> field strength and speed of MCs was found to be valid over a much wider range of speeds. The number of south-north (SN) MCs was dominant and decreased with solar cycle, while the number of north-south (NS) MCs increased confirming the odd-cycle behavior. Two-thirds of MCs were geoeffective; the Dst index was highly correlated with speed and <span class="hlt">magnetic</span> field in MCs as well as their product. Many (55%) fully northward (FN) MCs were geoeffective solely due to their sheaths. The non-geoeffective MCs were slower (<span class="hlt">average</span> speed approx. 382 km/s), had a weaker southward <span class="hlt">magnetic</span> field (<span class="hlt">average</span> approx. -5.2nT), and occurred mostly during the rise phase of the solar activity cycle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760009906','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760009906"><span id="translatedtitle">Observations of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field between 0.46 and 1 A.U. by the Mariner 10 spacecraft. Ph.D. Thesis - Catholic Univ. of Am.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Behannon, K. W.</p> <p>1976-01-01</p> <p>Almost continuous measurement of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) at a sampling rate of 25 vectors/sec was performed by the <span class="hlt">magnetic</span> field experiment onboard the Mariner 10 spacecraft during the period November 3, 1973 to April 14, 1974, comprising approximately 5-2/3 solar rotations and extending in radial distance from the sun from 1 to 0.46 AU. A clearly discernible two-sector pattern of field polarity was observed during the last 3-1/2 months of the period, with the dominant polarity toward the sun below the solar equatorial plane. Two compound high-speed solar wind streams were also present during this period, one in each <span class="hlt">magnetic</span> field sector. Relative fluctuations of the field in magnitude and direction were found to have large time variations, but on <span class="hlt">average</span> the relative magnitude fluctuations were approximately constant over the range of heliocentric distance covered while the relative directional fluctuations showed a slight decrease on <span class="hlt">average</span> with increasing distance. The occurrence rate of directional discontinuities was also found to decrease with increasing radial distance from the sun.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19800011715','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19800011715"><span id="translatedtitle"><span class="hlt">Interplanetary</span> medium data book, supplement, 1975 - 1978</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>King, J. H.</p> <p>1979-01-01</p> <p>Since the issurance of the <span class="hlt">Interplanetary</span> Medium Data Book (NSSDC/WDC-A-R&S 77-04, 1977) which contains plots and listings of hourly <span class="hlt">average</span> <span class="hlt">interplanetary</span> field and plasma parameters covering the period November 27, 1963 through December 30, 1975, additional data are available which fill some 1975 data gaps and which extend the data coverage well into 1978. This supplement contains all the presently available data for the years 1975-1978, <span class="hlt">Interplanetary</span> <span class="hlt">magnetic</span> field (IMF) data are from the IMP 8 triaxial fluxgate magnetometer experiment. Derived plasma parameters are form the IMP 7 and IMP 8 instruments. Some of the early 1975 IMF data are from a HEOS 1 experiment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AnGeo..33..437H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AnGeo..33..437H"><span id="translatedtitle">The dayside magnetopause location during radial <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field periods: Cluster observation and model comparison</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Huang, T.; Wang, H.; Shue, J.-H.; Cai, L.; Pi, G.</p> <p>2015-04-01</p> <p>The present work has investigated the midlatitudinal magnetopause locations under radial <span class="hlt">interplanetary</span> field (RIMF) conditions. Among 262 (256) earthward (sunward) RIMF events from years of 2001 to 2009, Cluster satellites have crossed the magnetopause 22(12) times, with 10 (7) events occurring at midlatitudes. The observed midlatitudinal magnetopause positions are compared with two empirical magnetopause models (Shue et al., 1998; Boardsen et al., 2000) (hereafter referred to as the Shue98 model and the Boardsen00 model). The observation-model differences exhibit local time asymmetry. For earthward RIMF cases, the Shue98 model underestimates the magnetopause positions in the postnoon sector, while it overestimates the magnetopause positions in the dawn and dusk sectors. The Boardsen00 model generally underestimates the magnetopause after 6 MLT (<span class="hlt">magnetic</span> local time), with larger deviations in the postnoon sector as compared to those in the prenoon. For sunward RIMF cases, the selected events are mainly clustered around the dawn and dusk sectors. The comparison with the Shue98 model indicates contractions in the dawn and expansions in the dusk sector, while the comparison with Boardsen00 indicates general expansions, with larger expansions in the later local time sectors. The local time variations in the differences between observations and the Shue98 and the Boardsen00 models indicate that the real magnetopause could be asymmetrically shaped during radial IMF periods, which should be considered by magnetopause models. The observation-model differences in the magnetopause positions (Δ RMP) during RIMF periods correlate well with the solar wind dynamic pressure, with larger Δ RMP for larger Pd. The southern magnetopause expands further outward relative to the model prediction when the dipole tilt angle is more negative (local summer in the Southern Hemisphere). For earthward RIMF cases, the generally good correlations between Δ RMP and the IMF cone angle are consistent with the previous hypothesis (Dušík et al., 2010) that, with more radial IMF, the subsolar magnetopause will expand further outward, owever, this is not the case for the comparison with Boardsen00 during sunward IMF periods, as it shows less dependence on the IMF cone angle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003JGRA..108.1320H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003JGRA..108.1320H"><span id="translatedtitle">A study of the expansion and distortion of the cross section of <span class="hlt">magnetic</span> clouds in the <span class="hlt">interplanetary</span> medium</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hidalgo, M. A.</p> <p>2003-08-01</p> <p>Herein an approach is presented to determine the expansion and distortion of the cross section of <span class="hlt">magnetic</span> clouds (MCs) in their evolution in the <span class="hlt">interplanetary</span> medium. This approach, based on the improvement of our previous elliptical cross-section model for the <span class="hlt">magnetic</span> topology of MCs, gives analytical expressions for ? and ? which incorporate the expansion of the cross section of clouds. Our starting point is the assumption of a spatially uniform jη, the normal component of the plasma current density to the cross section of the cloud. As it is described in the text, this expansion provides a time dependency of the three components of the plasma current density. The main physical consequences of this behavior are discussed. Fittings to eight selected MCs of years 2000 and 2001 with different <span class="hlt">magnetic</span> field profiles are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SpWea..14...56S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SpWea..14...56S"><span id="translatedtitle">Magnetohydrodynamic simulation of <span class="hlt">interplanetary</span> propagation of multiple coronal mass ejections with internal <span class="hlt">magnetic</span> flux rope (SUSANOO-CME)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shiota, D.; Kataoka, R.</p> <p>2016-02-01</p> <p>Coronal mass ejections (CMEs) are the most important drivers of various types of space weather disturbance. Here we report a newly developed magnetohydrodynamic (MHD) simulation of the solar wind, including a series of multiple CMEs with internal spheromak-type <span class="hlt">magnetic</span> fields. First, the polarity of the spheromak <span class="hlt">magnetic</span> field is set as determined automatically according to the Hale-Nicholson law and the chirality law of Bothmer and Schwenn. The MHD simulation is therefore capable of predicting the time profile of the southward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field at the Earth, in relation to the passage of a <span class="hlt">magnetic</span> cloud within a CME. This profile is the most important parameter for space weather forecasts of <span class="hlt">magnetic</span> storms. In order to evaluate the current ability of our simulation, we demonstrate a test case: the propagation and interaction process of multiple CMEs associated with the highly complex active region NOAA 10486 in October to November 2003, and present the result of a simulation of the solar wind parameters at the Earth during the 2003 Halloween storms. We succeeded in reproducing the arrival at the Earth's position of a large amount of southward <span class="hlt">magnetic</span> flux, which is capable of causing an intense <span class="hlt">magnetic</span> storm. We find that the observed complex time profile of the solar wind parameters at the Earth could be reasonably well understood by the interaction of a few specific CMEs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSM33A2155A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSM33A2155A"><span id="translatedtitle">Using ACE Observations of <span class="hlt">Interplanetary</span> Particles and <span class="hlt">Magnetic</span> Fields as Possible Contributors to Variations Observed at Van Allen Probes during Major events in 2013</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Armstrong, T. P.; Manweiler, J. W.; Gerrard, A. J.; Gkioulidou, M.; Lanzerotti, L. J.; Patterson, J. D.</p> <p>2013-12-01</p> <p>Observations from ACE EPAM including energy spectra of protons, helium, and oxygen will be prepared for coordinated use in estimating the direct and indirect access of energetic particles to inner and outer geomagnetic trapping zones. Complete temporal coverage from ACE at 12 seconds, 5 minutes, 17 minutes, hourly and daily cadences will be used to catalog <span class="hlt">interplanetary</span> events arriving at Earth including <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field sector boundaries, <span class="hlt">interplanetary</span> shocks, and <span class="hlt">interplanetary</span> coronal mass ejections, ICMEs. The first 6 months of 2013 have included both highly disturbed times, March 17 and May 22, and extended quiet periods of little or no variations. Among the specific questions that ACE and Van Allen Probes coordinated observations may aid in resolving are: 1. How much, if any, direct capture of <span class="hlt">interplanetary</span> energetic particles occurs and what conditions account for it? 2. How much influence do <span class="hlt">interplanetary</span> field and particle variations have on energization and/or loss of geomagnetically trapped populations? The poster will also present important links and describe methods and important details of access to numerically expressed ACE EPAM and Van Allen Probes RBSPICE observations that can be flexibly and easily accessed via the internet for student and senior researcher use.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/183248','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/183248"><span id="translatedtitle">Magnetopause shape as a bivariate function of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field B{sub z} and solar wind dynamic pressure</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Roelof, E.C.; Sibeck, D.G.</p> <p>1993-12-01</p> <p>The authors present a new method for determining the shape of the magnetopause as a bivariate function of the hourly <span class="hlt">averaged</span> solar wind dynamic pressure (p) and the north-south component of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) B{sub z}. They represent the magnetopause (for X{sub GSE}>{minus}40R{sub E}) as an ellipsoid of revolution in solar-wind-aberrated coordinates and express the (p, B{sub z}) dependence of each of the three ellipsoid parameters as a second-order (6-term) bivariate expansion in lnp and B{sub z}. The authors define 12 overlapping bins in a normalized dimensionless (p,B{sub z}) {open_quotes}control space{close_quotes} and fit an ellipsoid to those magnetopause crossings having (p,B{sub z}) values within each bin. They also calculate the bivariate (lnp, B{sub z}) moments to second order over each bin in control space. They can then calculate the six control-space expansion coefficients for each of the three ellipsoid parameters in configuration space. From these coefficients they can derive useful diagnostics of the magnetopause shape as joint functions of p and B{sub z}: the aspect ratio of the ellipsoid`s minor-to-major axes the flank distance radius of curvature, and flaring angle (at X{sub GSE}=0); and the subsolar distance and radius of curvature. The authors confirm and quantify previous results that during periods of southward B{sub z} the subsolar magnetopause moves inward, while at X{sub GSE}=0 the flank magnetopause moves outward and the flaring angle increases. These changes are most pronounced during periods of low pressure, wherein all have a dependence on B{sub z} that is stronger and functionally different for B{sub z} southward as compared to B{sub z} northward. In contrast, all these changes are much less sensitive to IMF B{sub z} at the highest pressures. 44 refs., 22 figs., 6 tabs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19830030751&hterms=1061&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D%2526%25231061','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19830030751&hterms=1061&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D%2526%25231061"><span id="translatedtitle">Dawn-dusk asymmetry of the tail region of the magnetosphere of Saturn and the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Akasofu, S.-I.; Roederer, M.; Krimigis, S. M.</p> <p>1982-01-01</p> <p>In connection with the findings of the Voyager 1 mission, it appears that the tail lobe of Saturn is very different from that of earth and Jupiter, in that the latter are devoid of energetic particles, and <span class="hlt">magnetic</span> field lines in this region are thought to be open and interconnecting with the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field at large distances in the antisolar direction. The present investigation is concerned with a possible explanation of these observations, taking into account a model of Saturn's magnetosphere. It is shown that the Voyager 1 spacecraft remained in the closed region of the magnetotail during its entire tail traversal and did not have an opportunity to penetrate into the high latitude lobe. It is concluded that Saturn probably has a tail lobe just like earth and Jupiter. However, this tail lobe was not traversed by Voyager.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040171393','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040171393"><span id="translatedtitle">The Fraction of <span class="hlt">Interplanetary</span> Coronal Mass Ejections That Are <span class="hlt">Magnetic</span> Clouds: Evidence for a Solar Cycle Variation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Richardson, I. G.; Cane, H. V.</p> <p>2004-01-01</p> <p>"<span class="hlt">Magnetic</span> clouds" (MCs) are a subset of <span class="hlt">interplanetary</span> coronal mass ejections (ICMEs) characterized by enhanced <span class="hlt">magnetic</span> fields with an organized rotation in direction, and low plasma beta. Though intensely studied, MCs only constitute a fraction of all the ICMEs that are detected in the solar wind. A comprehensive survey of ICMEs in the near- Earth solar wind during the ascending, maximum and early declining phases of solar cycle 23 in 1996 - 2003 shows that the MC fraction varies with the phase of the solar cycle, from approximately 100% (though with low statistics) at solar minimum to approximately 15% at solar maximum. A similar trend is evident in near-Earth observations during solar cycles 20 - 21, while Helios 1/2 spacecraft observations at 0.3 - 1.0 AU show a weaker trend and larger MC fraction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19950048767&hterms=1575&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3D%2526%25231575','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950048767&hterms=1575&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3D%2526%25231575"><span id="translatedtitle">The determination of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field polarities around sector boundaries using E greater than 2 keV electrons</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kahler, S.; Lin, R. P.</p> <p>1994-01-01</p> <p>The determination of the polarities of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> fields (whether the field direction is outward from or inward toward the sun) has been based on a comparison of observed field directions with the nominal Parker spiral angle. These polarities can be mapped back to the solar source field polarities. This technique fails when field directions deviate substantially from the Parker angle or when fields are substantially kinked. We introduce a simple new technique to determine the polarities of <span class="hlt">interplanetary</span> fields using E greater than 2 keV <span class="hlt">interplanetary</span> electrons which stream along field lines away from the sun. Those electrons usually show distinct unidirectional pitch-angle anisotropies either parallel or anti-parallel to the field. Since the electron flow direction is known to be outward from the sun, the anisotropies parallel to the field indicate outward-pointing, positive-polarity fields, and those anti-parallel indicate inward-pointing, negative-polarity fields. We use data from the UC Berkeley electron experiment on the International Sun Earth Explorer 3 (ISSE-3) spacecraft to compare the field polarities deduced from the electron data, Pe (outward or inward), with the polarities inferred from field directions, Pd, around two sector boundaries in 1979. We show examples of large (greater than 100 deg) changes in azimuthal field direction Phi over short (less than 1 hr) time scales, some with and some without reversals in Pe. The latter cases indicate that such large directional changes can occur in unipolar structures. On the other hand, we found an example of a change in Pe during which the rotation in Phi was less than 30 deg, indicating polarity changes in nearly unidirectional structures. The field directions are poor guides to the polarities in these cases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015DPS....4750503L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015DPS....4750503L"><span id="translatedtitle">Impacts of an <span class="hlt">Interplanetary</span> Coronal Mass Ejection and the Crustal <span class="hlt">Magnetic</span> Fields to the Martian hot O corona</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, Yuni; Combi, Michael; Tenishev, Valeriy; Bougher, Stephen</p> <p>2015-11-01</p> <p>An <span class="hlt">interplanetary</span> coronal mass ejection (ICME) is a large amount of mass entrained in the heliospheric <span class="hlt">magnetic</span> field and propagating outward from the Sun into the <span class="hlt">interplanetary</span> medium. Upon arrival at Mars, ICMEs interact with its upper atmosphere and ionosphere, causing important impacts in the planetary environment. In March 2015, a strong solar event was observed and associated with a major ICME. The major ICME events aroused a chain of events on Mars, which were detected by the instruments onboard Mars Atmosphere and Volatile EvolutioN (MAVEN). The consequences in the upper atmosphere are directly related to the important processes that lead to the atmospheric escape. We report here our examinations of the impacts of the March 8th ICME event on the Martian hot O corona by using our 3D framework, which couples the Mars application of the Adaptive Mesh Particle Simulator (M-AMPS), the Mars Global Ionosphere-Thermosphere Model (M-GITM), and the Mars multi-fluid MHD (MF-MHD) model. Also, we present the effects of the crustal <span class="hlt">magnetic</span> fields on the structure of the hot O corona to study the interesting signatures of the crustal <span class="hlt">magnetic</span> fields. Due to the minimal impacts of the ICME deep in the thermosphere and ionosphere, where the maximum production of hot O occurs, our model results showed a stable hot O corona during and after the peak ICME event. However, the structure of the corona was affected by the existence of the crustal <span class="hlt">magnetic</span> fields with a decrease in escape rate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21576620','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21576620"><span id="translatedtitle">PROPAGATION OF SOLAR ENERGETIC PARTICLES IN THREE-DIMENSIONAL <span class="hlt">INTERPLANETARY</span> <span class="hlt">MAGNETIC</span> FIELDS: IN VIEW OF CHARACTERISTICS OF SOURCES</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>He, H.-Q.; Qin, G.; Zhang, M. E-mail: gqin@spaceweather.ac.cn</p> <p>2011-06-20</p> <p>In this paper, a model of solar energetic particle (SEP) propagation in the three-dimensional Parker <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field is calculated numerically. We study the effects of the different aspects of particle sources on the solar surface, which include the source location, coverage of latitude and longitude, and spatial distribution of source particle intensity, on propagation of SEPs with both parallel and perpendicular diffusion. We compute the particle flux and anisotropy profiles at different observation locations in the heliosphere. From our calculations, we find that the observation location relative to the latitudinal and longitudinal coverage of particle source has the strongest effects on particle flux and anisotropy profiles observed by a spacecraft. When a spacecraft is directly connected to the solar sources by the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field lines, the observed particle fluxes are larger than when the spacecraft is not directly connected. This paper focuses on the situations when a spacecraft is not connected to the particle sources on the solar surface. We find that when the <span class="hlt">magnetic</span> footpoint of the spacecraft is farther away from the source, the observed particle flux is smaller and its onset and maximum intensity occur later. When the particle source covers a larger range of latitude and longitude, the observed particle flux is larger and appears earlier. There is east-west azimuthal asymmetry in SEP profiles even when the source distribution is east-west symmetric. However, the detail of particle spatial distribution inside the source does not affect the profile of the SEP flux very much. When the <span class="hlt">magnetic</span> footpoint of the spacecraft is significantly far away from the particle source, the anisotropy of particles in the early stage of an SEP event points toward the Sun, which indicates that the first arriving particles come from outside of the observer through perpendicular diffusion at large radial distances.</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_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" 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_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> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19850044803&hterms=sun+bear&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dsun%2Bbear','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850044803&hterms=sun+bear&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dsun%2Bbear"><span id="translatedtitle"><span class="hlt">Magnetic</span> fields on the sun and the north-south component of transient variations of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field at 1 AU</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tang, F.; Akasofu, S.-I.; Smith, E.; Tsurutani, B.</p> <p>1985-01-01</p> <p>In order to study the relationship between solar <span class="hlt">magnetic</span> fields and the transient variations of the north-south component B(Z) of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) at 1 AU, flares from unusual north-south oriented active regions, large IMF B(Z) events, and large flares with comprehensive flare index higher than 12 were collected. The associated IMF B(Z) changes or the <span class="hlt">magnetic</span> field of the initiating flares are investigated. For those cases where an association between a transient B(Z) variation and an initiating flare is plausible, it is found that, for a given flare field, the orientation of the corresponding transient variation of B(Z) may be in agreement with the flare field, opposite to it, or more often, fluctuating in both magnitude and direction. Conversely, an IMF B(Z) event may originate in a flare field in the same <span class="hlt">magnetic</span> orientation, opposite to it, or in the east-west orientation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19740020146','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19740020146"><span id="translatedtitle"><span class="hlt">Interplanetary</span> shock waves associated with solar flares</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chao, J. K.; Sakurai, K.</p> <p>1974-01-01</p> <p>The interaction of the earth's <span class="hlt">magnetic</span> field with the solar wind is discussed with emphasis on the influence of solar flares. The geomagnetic storms are considerered to be the result of the arrival of shock wave generated by solar flares in <span class="hlt">interplanetary</span> space. Basic processes in the solar atmosphere and <span class="hlt">interplanetary</span> space, and hydromagnetic disturbances associated with the solar flares are discussed along with observational and theoretical problems of <span class="hlt">interplanetary</span> shock waves. The origin of <span class="hlt">interplanetary</span> shock waves is also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20110023418&hterms=CANE&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DCANE','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20110023418&hterms=CANE&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DCANE"><span id="translatedtitle">Galactic Cosmic Ray Intensity Response to <span class="hlt">Interplanetary</span> Coronal Mass Ejections/<span class="hlt">Magnetic</span> Clouds in 1995-2009</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Richardson, I. G.; Cane, H. V.</p> <p>2011-01-01</p> <p>We summarize the response of the galactic cosmic ray (CGR) intensity to the passage of the more than 300 <span class="hlt">interplanetary</span> coronal mass ejections (ICMEs) and their associated shocks that passed the Earth during 1995-2009, a period that encompasses the whole of Solar Cycle 23. In approx.80% of cases, the GCR intensity decreased during the passage of these structures, i.e., a "Forbush decrease" occurred, while in approx.10% there was no significant change. In the remaining cases, the GCR intensity increased. Where there was an intensity decrease, minimum intensity was observed inside the ICME in approx.90% of these events. The observations confirm the role of both post-shock regions and ICMEs in the generation of these decreases, consistent with many previous studies, but contrary to the conclusion of Reames, Kahler, and Tylka (Astrophys. 1. Lett. 700, L199, 2009) who, from examining a subset of ICMEs with flux-rope-like <span class="hlt">magnetic</span> fields (<span class="hlt">magnetic</span> clouds) argued that these are "open structures" that allow free access of particles including GCRs to their interior. In fact, we find that <span class="hlt">magnetic</span> clouds are more likely to participate in the deepest GCR decreases than ICMEs that are not <span class="hlt">magnetic</span> clouds.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JGRA..118.1472L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JGRA..118.1472L"><span id="translatedtitle">Joint responses of geosynchronous <span class="hlt">magnetic</span> field and relativistic electrons to external changes in solar wind dynamic pressure and <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</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.; Dong, Y. X.</p> <p>2013-04-01</p> <p>This paper studied statistically the joint responses of <span class="hlt">magnetic</span> field and relativistic (>0.5 MeV) electrons at geosynchronous orbit to 201 <span class="hlt">interplanetary</span> perturbations during 6 years from 2003 (solar maximum) to 2008 (solar minimum). The statistical results indicate that during geomagnetically quiet times (HSYM > -30 nT, and AE < 200 nT), ~47.3% changes in the geosynchronous <span class="hlt">magnetic</span> field and relativistic electron fluxes are caused by the combined actions of the enhancement of solar wind dynamic pressure (Pd) and the southward turning of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) (ΔPd > 0.4 nPa and IMF Bz < 0 nT), and only ~18.4% changes are due to single dynamic pressure increase (ΔPd > 0.4 nPa, but IMF Bz > 0 nT), and ~34.3% changes are due to single southward turning of IMF (IMF Bz < 0 nT, but |ΔPd| < 0.4 nPa). Although the responses of <span class="hlt">magnetic</span> field and relativistic electrons to the southward turning of IMF are weaker than their responses to the dynamic pressure increase, the southward turning of IMF can cause significant dawn-dusk asymmetric perturbations that the <span class="hlt">magnetic</span> field and relativistic electron fluxes increase on the dawnside (LT ~ 00:00-12:00) but decrease on the duskside (LT ~ 13:00-23:00) during the quiet times. Furthermore, the variation of relativistic electron fluxes is adiabatically controlled by the magnitude and elevation angle changes of <span class="hlt">magnetic</span> field during the single IMF southward turnings. However, the variation of relativistic electron fluxes is independent of the change in <span class="hlt">magnetic</span> field in some magnetospheric compression regions during the solar wind dynamic pressure enhancements (including the single pressure increases and the combined external perturbations), indicating that nonadiabatic dynamic processes of relativistic electrons occur there.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/869326','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/869326"><span id="translatedtitle">High <span class="hlt">average</span> power <span class="hlt">magnetic</span> modulator for metal vapor lasers</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Ball, Don G.; Birx, Daniel L.; Cook, Edward G.; Miller, John L.</p> <p>1994-01-01</p> <p>A three-stage <span class="hlt">magnetic</span> modulator utilizing <span class="hlt">magnetic</span> pulse compression designed to provide a 60 kV pulse to a copper vapor laser at a 4.5 kHz repetition rate is disclosed. This modulator operates at 34 kW input power. The circuit includes a step up auto transformer and utilizes a rod and plate stack construction technique to achieve a high packing factor.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19920059359&hterms=solar+wind+magnetic+field&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsolar%2Bwind%2Bmagnetic%2Bfield','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19920059359&hterms=solar+wind+magnetic+field&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsolar%2Bwind%2Bmagnetic%2Bfield"><span id="translatedtitle"><span class="hlt">Interplanetary</span> <span class="hlt">magnetic</span> field connection to the sun during electron heat flux dropouts in the solar wind</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lin, R. P.; Kahler, S. W.</p> <p>1992-01-01</p> <p>The paper discusses observations of 2- to 8.5-keV electrons, made by measurements aboard the ISEE 3 spacecraft during the periods of heat flux decreases (HFDs) reported by McComas et al. (1989). In at least eight of the total of 25 HFDs observed, strong streaming of electrons that were equal to or greater than 2 keV outward from the sun was recorded. In one HFD, an impulsive solar electron event was observed with an associated type III radio burst, which could be tracked from the sun to about 1 AU. It is concluded that, in many HFDs, the <span class="hlt">interplanetary</span> field is still connected to the sun and that some energy-dependent process may produce HFDs without significantly perturbing electrons of higher energies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMSM23B2306K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMSM23B2306K"><span id="translatedtitle">Geoeffectiveness of <span class="hlt">Interplanetary</span> Coronal Mass Ejections as Drivers of Ground Level <span class="hlt">Magnetic</span> Field Fluctuations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kidd, R.; Wild, J. A.</p> <p>2012-12-01</p> <p>Global geomagnetic indices have proven to be invaluable tools for the investigation of the <span class="hlt">interplanetary</span> drivers of geomagnetic disturbances. Mature global geomagnetic indices, such as Dst, yield multi-decadal time-series of geomagnetic activity levels. The geoeffectiveness of space weather drivers is commonly assessed using these global indices, yet they are not designed to capture the rapid and possibly localised geomagnetic disturbances thought to be responsible for unwanted effects on ground-based technologies (e.g. geomagnetically induced currents in power grids). Using data from the SuperMAG project (a collaboration of organisations and agencies operating over 300 ground-based magnetometers) we have explored indices that capture geomagnetic variations over spatially limited regions and derived from parameters not used in traditional indices (e.g. dB/dt). The geoeffectiveness of ICMEs is investigated, particularly in relation to the disturbances likely to result in geomagnetically induced currents.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19900039383&hterms=COEFFICIENT+ACTIVITY&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DCOEFFICIENT%2BACTIVITY','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19900039383&hterms=COEFFICIENT+ACTIVITY&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DCOEFFICIENT%2BACTIVITY"><span id="translatedtitle"><span class="hlt">Interplanetary</span> Alfven waves and auroral (substorm) activity - IMP 8</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tsurutani, Bruce T.; Gould, Tom; Goldstein, Bruce E.; Gonzalez, Walter D.; Sugiura, Masahisa</p> <p>1990-01-01</p> <p>Almost 1 year of IMP 8 <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field and plasma data (days 1-312, 1979) have been examined to determine the <span class="hlt">interplanetary</span> causes of geomagnetic AE activity. The nature of the <span class="hlt">interplanetary</span> medium (Alfvenic or non-Alfvenic) and the B(s) correlation with AE were examined over 12-hour increments throughout the study. It is found that Alfvenic wave intervals are present over 60 percent of the time, and the southward component of the Alfven waves is well correlated with AE (<span class="hlt">average</span> peak correlation coefficient 0.62), with a median lag of 43 min. From this statistical study, no major differences in the magnetospheric response to Alfvenic and non-Alfvenic intervals were obvious. The high-intensity long-duration continuous AE activity (HILDCAA) events discussed previously by Tsurutani and Gonzales (1987) are demonstrated to be caused by the southward components of the Alfven waves, presumably through the process of <span class="hlt">magnetic</span> reconnection.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015IAUGA..2256637B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015IAUGA..2256637B"><span id="translatedtitle">Solar and <span class="hlt">interplanetary</span> signatures of declining of solar <span class="hlt">magnetic</span> fields: Implications to the next solar cycle 25</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bisoi, Susanta Kumar; Janardhan, P.; Ananthakrishnan, S.; Tokumaru, M.; Fujiki, K.</p> <p>2015-08-01</p> <p>Our detailed study of solar surface <span class="hlt">magnetic</span> fields at high-latitudes, using <span class="hlt">magnetic</span> synoptic magnetograms of NSO/Kitt Peak observatory from 1975-2014, has shown a steady decline of the field strength since mid-1990's until mid-2014, i.e. the solar maximum of cycle 24. We also found that <span class="hlt">magnetic</span> field strength at high-latitudes declines after each solar cycle maximum, and since cycle 24 is already past its peak implies that solar surface <span class="hlt">magnetic</span> fields will be continuing to decline until solar minimum of cycle 24. In addition, <span class="hlt">interplanetary</span> scintillation (IPS) measurements of solar wind micro-turbulence levels, from Solar and Terrestrial Environment Laboratory (STEL), Japan, have also shown a steady decline in sync with the declining surface fields. Even the heliospheric <span class="hlt">magnetic</span> fields (HMF) at 1 AU have been declined much below the previously proposed floor level of HMF of ~4.6 nT. From study of a correlation between the high-latitude surface fields and the HMF at the last four solar minima we found a floor value of HMF of ~3.2 nT. Using the above correlation and the fact that the high-latitude surface fields is expected to decline until the minimum of cycle 24, we estimate the value of the HMF at the minimum of cycle 24 will be 3.8 ± 0.2 nT and the peak sunspot number for solar cycle 25 will be 56±12 suggesting a weak sunspot activity to be continued in cycle 25 too.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19810016474','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19810016474"><span id="translatedtitle"><span class="hlt">Magnetic</span> loop behind an <span class="hlt">interplanetary</span> shock: Voyager, Helios and IMP-8 observations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Burlaga, L.; Sittler, E.; Mariani, F.; Schwenn, R.</p> <p>1981-01-01</p> <p>The shock was followed by a turbulent sheath in which there were large fluctuations in both the strength and direction of the <span class="hlt">magnetic</span> field. This in turn was followed by a region (<span class="hlt">magnetic</span> cloud) in which the <span class="hlt">magnetic</span> field vectors were observed to change by rotating nearly parallel to a plane, consistent with the passage of a <span class="hlt">magnetic</span> loop. This loop extended at least 30 deg in longitude between 1-2 AU, and its radial dimension was approximately 0.5 AU. In the cloud the field strength was high and the density and temperature were relatively low. Thus, the dominant pressure in the cloud was that of the <span class="hlt">magnetic</span> field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19830011396','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19830011396"><span id="translatedtitle">Dynamical evolution of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> fields and flows between 0.3 AU and 8.5 AU: Entrainment</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Burlaga, L. F.; Schwenn, R.; Rosenbauer, H.</p> <p>1983-01-01</p> <p>The radial evolution of <span class="hlt">interplanetary</span> flows and associated <span class="hlt">magnetic</span> fields between 0.3 AU and 8.5 was analyzed using data from Helios 1 and Voyager 1, respectively. During a 70 day interval Voyager 1 observed two streams which appeared to be recurrent and which had little fine structure. The corresponding flows observed by Helios 1 were much more complex, showing numerous small streams, transient flows and shocks as well as a few large corotating streams. It is suggested that in moving to 8 AU the largest corotating streams swept up the slower flows (transient and/or corotating streams) and shocks into a relatively thin region in which they coalesced to form a single large amplitude compression wave. This combined process of sweeping and coalescence is referred to as entrainment. The resulting large amplitude compression wave is different from that formed by the steepening of a corotating stream from a coronal hole, because different flows from distinct sources, with possibly different composition and <span class="hlt">magnetic</span> polarity, are brought together to form a single new structure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/11776989','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/11776989"><span id="translatedtitle">Radiation shielding of astronauts in <span class="hlt">interplanetary</span> flights: the CREAM surveyor to Mars and the <span class="hlt">magnetic</span> lens system for a spaceship.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Spillantini, P; Taccetti, F; Papini, P; Rossi, L; Casolino, M</p> <p>2001-01-01</p> <p>The radiation absorbed by astronauts during <span class="hlt">interplanetary</span> flights is mainly due to cosmic rays of solar origin (SCR). In the most powerful solar flares the dose absorbed in few hours can exceed that cumulated in one year of exposition to the galactic component of cosmic rays (GCR). At energies above the minimum one needed to cross the walls of the spaceship there are extrapolations and guesses, but no data, on the angular distribution of SCR's, an information that is necessary for establishing whatever defence strategy. It was therefore proposed of sending to Mars a measurement device, that should continuously collect data during the travel, and possibly also in the orbit around Mars and on the Mars surface. The device should identify the particle and privilege the completeness in the measurement of its parameters. In fact the high energy electrons travel at speed of the light and could be used in the and future dangerous proton component. Also the much less abundant but individually more dangerous ions should be identified. The device should indeed include a <span class="hlt">magnetic</span> spectrometer and a high granularity range telescope, and a good time of flight measurement. ASI is supporting an assessment study of a possible mission of such a device on board of the 2005 probe to Mars. A parallel technical study is also in progress to define the workable techniques and the possible configurations of a system of <span class="hlt">magnetic</span> lenses for protecting the crew of a spaceship. PMID:11776989</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.3902C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.3902C"><span id="translatedtitle">Maps of <span class="hlt">average</span> ionospheric vorticity ordered by relationship with the open-closed <span class="hlt">magnetic</span> field line boundary</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chisham, Gareth</p> <p>2015-04-01</p> <p>Spatiotemporal variations of ionospheric vorticity are a measure of the dynamical coupling of the magnetosphere to the ionosphere via <span class="hlt">magnetic</span> field-aligned currents (FACs). Indeed, ionospheric vorticity measurements have often been used as proxy measurements for FACs. Previously, we have determined statistical models of ionospheric vorticity using 6 years of ionospheric convection velocity measurements made by the SuperDARN HF radar network in the northern hemisphere ionosphere and shown that the spatial variation of these probability distributions is well organised according to the well-established large-scale FAC structure in the polar ionosphere. However, to date, these statistical models have been parameterised solely by the state of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF), and as such do not account for the range of polar cap sizes that occur for a single IMF state. This leads to a distortion of the shape of the resulting statistical maps that makes features in the statistical variations appear smoother than those in instantaneous/short-time <span class="hlt">averaged</span> measurements. This is because the <span class="hlt">averaging</span> process does not consider the variable size of the polar cap, by which spatial features in the ionospheric vorticity variation are ordered. Using open-closed <span class="hlt">magnetic</span> field line boundary measurements determined from FUV imager data from the IMAGE spacecraft, we investigate the parameterisation of the statistical ionospheric vorticity models with polar cap size in addition to the state of the IMF. The results of this analysis have implications for other statistical models determined in this way, such as those for FACs and ionospheric convection.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015MsT..........2M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015MsT..........2M"><span id="translatedtitle">Statistical Study of <span class="hlt">Interplanetary</span> Coronal Mass Ejections with Strong <span class="hlt">Magnetic</span> Fields</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Murphy, Matthew E.</p> <p></p> <p>Coronal Mass Ejections (CMEs) with strong <span class="hlt">magnetic</span> fields (B ) are typically associated with significant Solar Energetic Particle (SEP) events, high solar wind speed and solar flare events. Successful prediction of the arrival time of a CME at Earth is required to maximize the time available for satellite, infrastructure, and space travel programs to take protective action against the coming flux of high-energy particles. It is known that the <span class="hlt">magnetic</span> field strength of a CME is linked to the strength of a geomagnetic storm on Earth. Unfortunately, the correlations between strong <span class="hlt">magnetic</span> field CMEs from the entire sun (especially from the far side or non-Earth facing side of the sun) to SEP and flare events, solar source regions and other relevant solar variables are not well known. New correlation studies using an artificial intelligence engine (Eureqa) were performed to study CME events with <span class="hlt">magnetic</span> field strength readings over 30 nanoteslas (nT) from January 2010 to October 17, 2014. This thesis presents the results of this study, validates Eureqa to obtain previously published results, and presents previously unknown functional relationships between solar source <span class="hlt">magnetic</span> field data, CME initial speed and the CME <span class="hlt">magnetic</span> field. These new results enable the development of more accurate CME <span class="hlt">magnetic</span> field predictions and should help scientists develop better forecasts thereby helping to prevent damage to humanity's space and Earth assets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998JGR...103.4023R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998JGR...103.4023R"><span id="translatedtitle">A statistical study of the ionospheric convection response to changing <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field conditions using the assimilative mapping of ionospheric electrodynamics technique</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.; Lu, Gang; Clauer, C. R.; Papitashvili, V. O.</p> <p>1998-03-01</p> <p>We examine 65 ionospheric convection changes associated with changes in the Y and Z components of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF). We measure the IMF reorientations (for all but six of the events) at the Wind satellite. For 22 of the events the IMF reorientation is clearly observed by both Wind and IMP 8. Various methods are used to estimate the propagation time of the IMF between the two satellites. We find that using the <span class="hlt">magnetic</span> field before the IMF orientation change gives the smallest error in the expected propagation time. The IMF is then propagated to the magnetopause. The communication time between when the IMF encounters the magnetopause and the start of the convection change is estimated to be 8.4(+/-8.2)min. The resulting change in the ionospheric potential is examined by subtracting a base potential pattern from the changing potential patterns. From these residual patterns, a number of conclusions are made: (1) the location of the change in convection is stationary, implying that the change in convection is broadcast from the cusp region to the rest of the ionosphere in a matter of seconds and that the electric field mapped down the cusp controls the entire dayside ionospheric convection pattern; (2) the shape of the change in the ionospheric convection is dependent on the IMF component that changes, which is indicative of the change in the merging rate on the dayside magnetopause; (3) 62% of the events change linearly form one state to another, while 11% of the events change asymptotically; (4) the change in the ionospheric potential is linearly related to the magnitude of the IMF orientation, with Bz changes having a larger proportionality constant than By changes; (5) the ionospheric convection takes, on <span class="hlt">average</span>, 13 min to completely reconfigure; and (6) some of the ionospheric convection changes occur on a timescale shorter than that of the corresponding IMF reorientation, possibly as a result of thresholding in the dayside merging region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRA..120.4519Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRA..120.4519Z"><span id="translatedtitle">Direct observations of the full Dungey convection cycle in the polar ionosphere for southward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Q.-H.; Lockwood, M.; Foster, J. C.; Zhang, S.-R.; Zhang, B.-C.; McCrea, I. W.; Moen, J.; Lester, M.; Ruohoniemi, J. M.</p> <p>2015-06-01</p> <p>Tracking the formation and full evolution of polar cap ionization patches in the polar ionosphere, we directly observe the full Dungey convection cycle for southward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) conditions. This enables us to study how the Dungey cycle influences the patches' evolution. The patches were initially segmented from the dayside storm enhanced density plume at the equatorward edge of the cusp, by the expansion and contraction of the polar cap boundary due to pulsed dayside magnetopause reconnection, as indicated by in situ Time History of Events and Macroscale Interactions during Substorms (THEMIS) observations. Convection led to the patches entering the polar cap and being transported antisunward, while being continuously monitored by the globally distributed arrays of GPS receivers and Super Dual Auroral Radar Network radars. Changes in convection over time resulted in the patches following a range of trajectories, each of which differed somewhat from the classical twin-cell convection streamlines. Pulsed nightside reconnection, occurring as part of the magnetospheric substorm cycle, modulated the exit of the patches from the polar cap, as confirmed by coordinated observations of the magnetometer at Tromsø and European Incoherent Scatter Tromsø UHF radar. After exiting the polar cap, the patches broke up into a number of plasma blobs and returned sunward in the auroral return flow of the dawn and/or dusk convection cell. The full circulation time was about 3 h.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015P%26SS..117...15L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015P%26SS..117...15L"><span id="translatedtitle">Solar wind interaction effects on the <span class="hlt">magnetic</span> fields around Mars: Consequences for <span class="hlt">interplanetary</span> and crustal field measurements</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Luhmann, J. G.; Ma, Y.-J.; Brain, D. A.; Ulusen, D.; Lillis, R. J.; Halekas, J. S.; Espley, J. R.</p> <p>2015-11-01</p> <p>The first unambiguous detections of the crustal remanent <span class="hlt">magnetic</span> fields of Mars were obtained by Mars Global Surveyor (MGS) during its initial orbits around Mars, which probed altitudes to within ∼110 km of the surface. However, the majority of its measurements were carried out around 400 km altitude, fixed 2 a.m. to 2 p.m. local time, mapping orbit. While the general character and planetary origins of the localized crustal fields were clearly revealed by the mapping survey data, their effects on the solar wind interaction could not be investigated in much detail because of the limited mapping orbit sampling. Previous analyses (Brain et al., 2006) of the field measurements on the dayside nevertheless provided an idea of the extent to which the interaction of the solar wind and planetary fields leads to non-ideal field draping at the mapping altitude. In this study we use numerical simulations of the global solar wind interaction with Mars as an aid to interpreting that observed non-ideal behavior. In addition, motivated by models for different <span class="hlt">interplanetary</span> field orientations, we investigate the effects of induced and reconnected (planetary and external) fields on the Martian field's properties derived at the MGS mapping orbit altitude. The results suggest that inference of the planetary low order moments is compromised by their influence. In particular, the intrinsic dipole contribution may differ from that in the current models because the induced component is so dominant.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SoPh..291..603K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SoPh..291..603K"><span id="translatedtitle">Study of Cosmic Ray Intensity in Relation to the <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field and Geomagnetic Storms for Solar Cycle 23</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kharayat, Hema; Prasad, Lalan; Mathpal, Rajesh; Garia, Suman; Bhatt, Beena</p> <p>2016-02-01</p> <p>We investigate the association of the cosmic-ray intensity (CRI) with the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF, B) and geomagnetic storms (GS) for the period 1997 - 2006 (Solar Cycle 23). To do this, we conducted a Chree analysis by the superposed-epoch method. A transient decrease in CRI is found on the occurrence days of GS, and this decrease shows a similar pattern to that of the disturbance storm-time index (Dst). In addition, we show that the CRI decreases with the increase in IMF. The time lag between the decrease in CRI and increase in IMF is about one day or less. Furthermore, an increase in IMF B is found with the decrease in Dst index. IMF and Dst index are highly anti-correlated to each other, while the sunspot number is not found to be correlated with IMF, Dst index, or CRI for the period studied. The IMF is found to be an effective parameter combination for producing GS and Forbush decrease. We also found two types of decrease in CRI for Solar Cycle 23: i) symmetric and ii) asymmetric decreases. The study of CRI decreases may be useful for studying space-weather effects.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19830051481&hterms=Magnetic+memory&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DMagnetic%2Bmemory','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19830051481&hterms=Magnetic+memory&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DMagnetic%2Bmemory"><span id="translatedtitle">Dynamical evolution of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> fields and flows between 0.3 AU and 8.5 AU - Entrainment</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Burlaga, L. F.; Schwenn, R.; Rosenbauer, H.</p> <p>1983-01-01</p> <p>An analysis is presented of the radial evolution of <span class="hlt">interplanetary</span> flows and associated <span class="hlt">magnetic</span> fields between 0.3 AU and 8.5 AU using data from Helios 1 and B Voyager 1, respectively. The results indicate that in moving to 8 AU the largest corotating streams swept up the slower flows and shocks into a relatively thin region in which they coalesced to form a single large-amplitude compression. As a result of this process, referred to as entrainment, memory of the sources and flow configurations near the sun is lost, while small-scale features are erased as the flows move outward and energy is transferred from small scales to large scales.It is concluded that in the outer solar system the structure of the solar wind may be dominated by large scale pressure waves separated by several AU, while beyond several AU most of the compression waves are no longer driven by streams, and the compression waves expand freely. At large distances (greater than 25 AU) these compression waves will have interacted extensively with one another producing another state of the solar wind, with fewer large-scale nonuniformities and more small-scale nonuniformities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApJ...823L..30Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApJ...823L..30Z"><span id="translatedtitle"><span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field Sector from Solar Wind around Pluto (SWAP) Measurements of Heavy Ion Pickup near Pluto</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zirnstein, E. J.; McComas, D. J.; Elliott, H. A.; Weidner, S.; Valek, P. W.; Bagenal, F.; Stern, S. A.; Ennico, K.; Olkin, C. B.; Weaver, H. A.; Young, L. A.</p> <p>2016-06-01</p> <p>On 2015 July 14, the New Horizons spacecraft flew by the Pluto system. The Solar Wind Around Pluto (SWAP) instrument on board New Horizons, which detects ions in the energy per charge range ∼0.035 to 7.5 keV/q, measured the unique interaction between the solar wind and Pluto's atmosphere. Immediately after the closest approach, SWAP detected a burst of heavy ion counts when the instrument's field of view (FOV) was aligned north and south of the Sun–Pluto line and approximately normal to the solar wind flow direction, suggesting their origin as heavy neutral atoms from Pluto that were ionized and being picked up by the solar wind. The trajectories of heavy pickup ions depend on the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF). New Horizons is not equipped with a magnetometer, and we cannot directly measure the IMF. However, we can utilize SWAP's measurements and instrument FOV during this brief period of time to determine the most likely sector of the IMF that could reproduce SWAP's observations of heavy ion pickup. We find that the IMF was most likely in an outward sector, or retrograde to the planets’ motion, during the Pluto encounter, and that the heavy ions detected by SWAP are more likely {{{CH}}4}+ than {{{{N}}}2}+. This supports the existence of a methane exosphere at Pluto.</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('http://www.osti.gov/scitech/biblio/21448705','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21448705"><span id="translatedtitle">EVOLUTION OF A CORONAL MASS EJECTION AND ITS <span class="hlt">MAGNETIC</span> FIELD IN <span class="hlt">INTERPLANETARY</span> SPACE</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kunkel, V.; Chen, J.</p> <p>2010-06-01</p> <p>This Letter presents the first theoretical study of the dynamics of a coronal mass ejection (CME) observed by STEREO-A/B. The CME was continuously tracked by SECCHI-A, providing position-time data from eruption to 1 AU. The ejecta was intersected by STEREO-B at 1 AU, where the <span class="hlt">magnetic</span> field and plasma parameters were measured. The observed CME trajectory and the evolution of the CME <span class="hlt">magnetic</span> field are modeled using the semianalytic erupting flux-rope model. It is shown that the best-fit theoretical solution is in good agreement-within 1% of the measured CME trajectory in the 1 AU field of view-and is consistent with the in situ <span class="hlt">magnetic</span> field and plasma data at 1 AU.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19890056315&hterms=Luhmann&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DLuhmann','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19890056315&hterms=Luhmann&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DLuhmann"><span id="translatedtitle">Electron heat flux dropouts in the solar wind - Evidence for <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field reconnection?</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mccomas, D. J.; Gosling, J. T.; Phillips, J. L.; Bame, S. J.; Luhmann, J. G.; Smith, E. J.</p> <p>1989-01-01</p> <p>An examination of ISEE-3 data from 1978 reveal 25 electron heat flux dropout events ranging in duration from 20 min to over 11 hours. The heat flux dropouts are found to occur in association with high plasma densities, low plasma velocities, low ion and electron temperatures, and low <span class="hlt">magnetic</span> field magnitudes. It is suggested that the heat flux dropout intervals may indicate that the spacecraft is sampling plasma regimes which are <span class="hlt">magnetically</span> disconnected from the sun and instead are connected to the outer heliosphere at both ends.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5839089','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5839089"><span id="translatedtitle">The <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field B sub y -dependent field-aligned current in the dayside polar cap under quiet conditions</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Yamauchi, M. Kyoto Univ. ); Araki, T. )</p> <p>1989-03-01</p> <p>Spatial distribution and temporal variation of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) B{sub y}-dependent cusp region field-aligned currents (FACs) during quiet periods were studied by use of <span class="hlt">magnetic</span> data observed by Magsat. The analysis was made for 11 events (each event lasts more than one and a half days) when the IMF B{sub y} component was steadily large and B{sub x} was relatively small ({vert bar}B{sub z}{vert bar} < {vert bar}B{sub y}{vert bar}). Results of the analysis of total 62 half-day periods for the IMF B{sub y}-dependent cusp region FAC are summarized as follows: (1) the IMF B{sub y}-dependent cusp region FAC is located at around 86{degree}-87{degree} invariant latitude local noon, which is more poleward than the location of the IMF B{sub z}-dependent cusp region FAC; (2) the current density of this FAC is greater than previous studies ({ge} 4 {mu}A/m{sup 2} for IMF B{sub y} = 6 nT); (3) there are two time scales for the IMF B{sub y}-dependent cusp region FAC to appear: the initial rise of the current is on a short time scale, {approximately} 10 min, and it is followed by a gradual increase on a time scale of several hours to a half day; (4) the seasonal change of this FAC is greater than that of the nightside region 1 or region 2 FACs; (5) the IMF B{sub z}-dependent cusp region FAC is not well observed around the cusp when the IMF B{sub y}-dependent cusp region FAC is intense.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140009617','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140009617"><span id="translatedtitle">Turbulence in a Global Magnetohydrodynamic Simulation of the Earth's Magnetosphere during Northward and Southward <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>El-Alaoui, M.; Richard, R. L.; Ashour-Abdalla, M.; Walker, R. J.; Goldstein, M. L.</p> <p>2012-01-01</p> <p>We report the results of MHD simulations of Earth's magnetosphere for idealized steady solar wind plasma and <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) conditions. The simulations feature purely northward and southward <span class="hlt">magnetic</span> fields and were designed to study turbulence in the magnetotail plasma sheet. We found that the power spectral densities (PSDs) for both northward and southward IMF had the characteristics of turbulent flow. In both cases, the PSDs showed the three scale ranges expected from theory: the energy-containing scale, the inertial range, and the dissipative range. The results were generally consistent with in-situ observations and theoretical predictions. While the two cases studied, northward and southward IMF, had some similar characteristics, there were significant differences as well. For southward IMF, localized reconnection was the main energy source for the turbulence. For northward IMF, remnant reconnection contributed to driving the turbulence. Boundary waves may also have contributed. In both cases, the PSD slopes had spatial distributions in the dissipative range that reflected the pattern of resistive dissipation. For southward IMF there was a trend toward steeper slopes in the dissipative range with distance down the tail. For northward IMF there was a marked dusk-dawn asymmetry with steeper slopes on the dusk side of the tail. The inertial scale PSDs had a dusk-dawn symmetry during the northward IMF interval with steeper slopes on the dawn side. This asymmetry was not found in the distribution of inertial range slopes for southward IMF. The inertial range PSD slopes were clustered around values close to the theoretical expectation for both northward and southward IMF. In the dissipative range, however, the slopes were broadly distributed and the median values were significantly different, consistent with a different distribution of resistivity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002EGSGA..27..577M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002EGSGA..27..577M"><span id="translatedtitle">Ring Current Decay During Northward Turnings of The <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Monreal MacMahon, R.; Llop, C.; Miranda, R.</p> <p></p> <p>The ring current formation and energization is thought to be the main consequence of geomagnetic storms and its strength is characterized by the Dst index which evolu- tion satisfies a simple and well-known differential equation introduced by Burton et al. (1975). Since then, several attempts and approaches have been done to study the evolution of the ring current whether introducing discrete values or continuous func- tions for the decay time involved. In this work, we study the character of the recovery phase of <span class="hlt">magnetic</span> storms in response to well defined northward turnings of the inter- planetary <span class="hlt">magnetic</span> field using our functional form of the decay time of ring current particles introduced previously.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19910040048&hterms=multifractal&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dmultifractal','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19910040048&hterms=multifractal&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dmultifractal"><span id="translatedtitle">Multifractal structure of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field - Voyager 2 observations near 25 AU, 1987-1988</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Burlaga, L. F.</p> <p>1991-01-01</p> <p>Voyager-2 measurements indicate that, for the period day 190, 1987 to day 345, 1988, the large-scale fluctuations of the IMF between 23.3 AU and 27.8 AU have the symmetry properties of a multifractal over scales from 16 hours to 21 days. This suggests the existence of scaling symmetries for the higher moments of the fluctuations of the <span class="hlt">magnetic</span> field strength.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19750043946&hterms=random+fields&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Drandom%2Bfields','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19750043946&hterms=random+fields&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Drandom%2Bfields"><span id="translatedtitle">Simulation of pitch angle diffusion of charged particles in a disordered <span class="hlt">magnetic</span> field. [in <span class="hlt">interplanetary</span> space</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kaiser, T. B.</p> <p>1974-01-01</p> <p>Results are reported for computer simulation experiments in which a statistical ensemble of random <span class="hlt">magnetic</span> field realizations is generated, orbits of charged particles in the random fields are followed, and a pitch-angle diffusion coefficient is derived from the temporal evolution of the orbits. Diffusion coefficients predicted by three nonlinear theories are compared with the derived coefficients for the standard quasilinear theory of velocity diffusion, and the goals of future simulations are outlined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015A%26A...579L...7L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015A%26A...579L...7L"><span id="translatedtitle">Anisotropy of the solar network <span class="hlt">magnetic</span> field around the <span class="hlt">average</span> supergranule</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Langfellner, J.; Gizon, L.; Birch, A. C.</p> <p>2015-07-01</p> <p>Supergranules in the quiet Sun are outlined by a web-like structure of enhanced <span class="hlt">magnetic</span> field strength, the so-called <span class="hlt">magnetic</span> network. We aim to map the <span class="hlt">magnetic</span> network field around the <span class="hlt">average</span> supergranule near disk center. We use observations of the line-of-sight component of the <span class="hlt">magnetic</span> field from the Helioseismic and <span class="hlt">Magnetic</span> Imager (HMI) onboard the Solar Dynamics Observatory (SDO). The <span class="hlt">average</span> supergranule is constructed by coaligning and <span class="hlt">averaging</span> over 3000 individual supergranules. We determine the positions of the supergranules with an image segmentation algorithm that we apply to maps of the horizontal flow divergence measured using time-distance helioseismology. In the center of the <span class="hlt">average</span> supergranule, the <span class="hlt">magnetic</span> (intranetwork) field is weaker by about 2.2 Gauss than the background value (3.5 Gauss), whereas it is enhanced in the surrounding ring of horizontal inflows (by about 0.6 Gauss on <span class="hlt">average</span>). We find that this network field is significantly stronger west (prograde) of the <span class="hlt">average</span> supergranule than in the east (by about 0.3 Gauss). With time-distance helioseismology, we find a similar anisotropy. The observed anisotropy of the <span class="hlt">magnetic</span> field adds to the mysterious dynamical properties of solar supergranulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19900031671&hterms=solar+wind+magnetic+field&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsolar%2Bwind%2Bmagnetic%2Bfield','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19900031671&hterms=solar+wind+magnetic+field&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsolar%2Bwind%2Bmagnetic%2Bfield"><span id="translatedtitle"><span class="hlt">Interplanetary</span> <span class="hlt">magnetic</span> field enhancements - Evidence for solar wind dust trail interactions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Russell, C. T.</p> <p>1990-01-01</p> <p><span class="hlt">Magnetic</span> disturbances related to the passage of the asteroid 2201 Oljato are described. It is pointed out that the process leading to these disturbances must be associated with material in the orbit of Oljato and not the Oljato asteroid itself. Using data from latest space observations, the statistical association of these disturbances with the orbit of 2201 Oljato is updated, and the possible mechanisms for causing the disturbances are discussed. The phenomenon is considered to be associated with comet-like processes in the solar wind.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19910070191&hterms=Luhmann&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DLuhmann','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19910070191&hterms=Luhmann&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DLuhmann"><span id="translatedtitle">Venus ionospheric tail rays - Spatial distributions and <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field control</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ong, M.; Luhmann, J. G.; Russell, C. T.; Strangeway, R. J.; Brace, L. H.</p> <p>1991-01-01</p> <p>The overall properties of Venus ionospheric tail rays (such as density, spatial extent, and distribution) and their relationship to the draped <span class="hlt">magnetic</span> field configuration behind the planet were investigated using measurements obtained by the Pioneer Venus Orbiter Langmuir probe, a magnetometer, and a plasma-wave detector. The results suggest that tail rays are a normal feature of the steady solar wind interaction with Venus and are not generally associated with a central tail plasma sheet. The statistics of the tail rays occurrence point toward the existence of a distributed terminator ionosphere source, consistent with findings of Brace et al. (1990).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19790038772&hterms=Hill+AFB&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DHill%2BAFB','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19790038772&hterms=Hill+AFB&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DHill%2BAFB"><span id="translatedtitle">Occurrence of the lobe plasma at lunar distance. [correlation with <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field data</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hardy, D. A.; Hills, H. K.; Freeman, J. W.</p> <p>1979-01-01</p> <p>Recent analysis has confirmed the existence of the lobe plasma, the extension of the 'boundary layer' and 'plasma mantle' to lunar distances. The observation of the lobe plasma is strongly correlated with the y component of the IMF. Generally, the lobe plasma is observed sporadically for a full day after the moon has entered the tail and a full day before the last magnetopause crossing as it exits the tail. An <span class="hlt">average</span> extent of approximately 8-10 earth radii inward from the magnetopause is inferred; however, the lobe plasma has been seen all across the tail.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19860059674&hterms=Wilson+Cycle&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DWilson%2BCycle','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19860059674&hterms=Wilson+Cycle&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DWilson%2BCycle"><span id="translatedtitle">The <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field during solar cycle 21 ISEE-3/ICE observations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Slavin, J. A.; Jungman, G.; Smith, E. J.</p> <p>1986-01-01</p> <p>Temporal variations in the IMF during solar cycle 21 are investigated using <span class="hlt">magnetic</span> field observations collected by the vector helium magnetometer on the ISEE-3/ICE spacecraft. Analysis of the observations reveal that the IMF magnitude, which had declined to 4.7 nT in 1976, peaked in late 1982 (two years after solar maximum) at 9.0 nT and rapidly decreased during 1983-1984 to an intensity of 6.2 nT in early 1985. The IMF intensities are compared with the auroral AE index; the observed peak in strength during 1981-1983 is related to a 50 percent increase in substorm activity levels. A decrease in Parker spiral angle, revealing the existence of high-speed streams is detected in the declining phase of the solar cycle. Variations in the intensity of the IMF correlate with Mt. Wilson magnetograph measurements of full disk <span class="hlt">magnetic</span> flux. Source regions for the evolution of solar wind and the IMF are proposed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20120016557&hterms=multivariable+model&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dmultivariable%2Bmodel','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20120016557&hterms=multivariable+model&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dmultivariable%2Bmodel"><span id="translatedtitle">Using Statistical Multivariable Models to Understand the Relationship Between <span class="hlt">Interplanetary</span> Coronal Mass Ejecta and <span class="hlt">Magnetic</span> Flux Ropes</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Riley, P.; Richardson, I. G.</p> <p>2012-01-01</p> <p>In-situ measurements of <span class="hlt">interplanetary</span> coronal mass ejections (ICMEs) display a wide range of properties. A distinct subset, "<span class="hlt">magnetic</span> clouds" (MCs), are readily identifiable by a smooth rotation in an enhanced <span class="hlt">magnetic</span> field, together with an unusually low solar wind proton temperature. In this study, we analyze Ulysses spacecraft measurements to systematically investigate five possible explanations for why some ICMEs are observed to be MCs and others are not: i) An observational selection effect; that is, all ICMEs do in fact contain MCs, but the trajectory of the spacecraft through the ICME determines whether the MC is actually encountered; ii) interactions of an erupting flux rope (PR) with itself or between neighboring FRs, which produce complex structures in which the coherent <span class="hlt">magnetic</span> structure has been destroyed; iii) an evolutionary process, such as relaxation to a low plasma-beta state that leads to the formation of an MC; iv) the existence of two (or more) intrinsic initiation mechanisms, some of which produce MCs and some that do not; or v) MCs are just an easily identifiable limit in an otherwise corntinuous spectrum of structures. We apply quantitative statistical models to assess these ideas. In particular, we use the Akaike information criterion (AIC) to rank the candidate models and a Gaussian mixture model (GMM) to uncover any intrinsic clustering of the data. Using a logistic regression, we find that plasma-beta, CME width, and the ratio O(sup 7) / O(sup 6) are the most significant predictor variables for the presence of an MC. Moreover, the propensity for an event to be identified as an MC decreases with heliocentric distance. These results tend to refute ideas ii) and iii). GMM clustering analysis further identifies three distinct groups of ICMEs; two of which match (at the 86% level) with events independently identified as MCs, and a third that matches with non-MCs (68 % overlap), Thus, idea v) is not supported. Choosing between ideas i) and iv) is more challenging, since they may effectively be indistinguishable from one another by a single in-situ spacecraft. We offer some suggestions on how future studies may address this.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19820047466&hterms=correlation+coefficient&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dcorrelation%2Bcoefficient','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19820047466&hterms=correlation+coefficient&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dcorrelation%2Bcoefficient"><span id="translatedtitle">Factors controlling degree of correlation between ISEE 1 and ISEE 3 <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field measurements</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Crooker, N. U.; Siscoe, G. L.; Russell, C. T.; Smith, E. J.</p> <p>1982-01-01</p> <p>Correlation variability between ISEE 1 and 3 IMF measurements is investigated, and factors governing the variability are discussed. About 200 two-hour periods when correlation was good, and 200 when correlation was poor, are examined, and both IMF variance and spacecraft separation distance in the plane perpendicular to the earth-sun line exert substantial control. The scale size of <span class="hlt">magnetic</span> features is larger when variance is high, and abrupt changes in the correlation coefficient from poor to good or good to poor in adjacent two-hour intervals appear to be governed by the sense of change of IMF variance and vice versa. During periods of low variance, good correlations are most likely to occur when the distance between ISEE 1 and 3 perpendicular to the IMF is less than 20 earth radii.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JGRA..11612215D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JGRA..11612215D"><span id="translatedtitle">Solar wind energy input during prolonged, intense northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> fields: A new coupling function</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Du, A. M.; Tsurutani, B. T.; Sun, W.</p> <p>2011-12-01</p> <p>Sudden energy release (ER) events in the midnight sector auroral zone during intense (B > 10 nT), long-duration (T > 3 h), northward (N = Bz > 0 nT) IMF <span class="hlt">magnetic</span> clouds (MCs) during solar cycle 23 (SC23) have been examined in detail. The MCs with northward-then-southward (NS) IMFs were analyzed separately from MCs with southward-then-northward (SN) configurations. It is found that there is a lack of ER/substorms during the N field intervals of NS clouds. In sharp contrast, ER events do occur during the N field portions of SN MCs. From the above two results it is reasonable to conclude that the latter ER events represent residual energy remaining from the preceding S portions of the SN MCs. We derive a new solar wind-magnetosphere coupling function during northward IMFs: ENIMF = ? N-1/12 V7/3 B1/2 + ? V |Dstmin|. The first term on the right-hand side of the equation represents the energy input via viscous interaction, and the second term indicates the residual energy stored in the magnetotail. It is empirically found that the magnetotail/magnetosphere/ionosphere can store energy for a maximum of 4 h before it has dissipated away. This concept is defining one for ER/substorm energy storage. Our scenario indicates that the rate of solar wind energy injection into the magnetotail/magnetosphere/ionosphere for storage determines the potential form of energy release into the magnetosphere/ionosphere. This may be more important to understand solar wind-magnetosphere coupling than the dissipation mechanism itself (in understanding the form of the release). The concept of short-term energy storage is also applied for the solar case. It is argued that it may be necessary to identify the rate of energy input into solar <span class="hlt">magnetic</span> loop systems to be able to predict the occurrence of solar flares.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.4860D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.4860D"><span id="translatedtitle">Solar Wind Energy Input during Prolonged, Intense Northward <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Fields: A New Coupling Function</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Du, A. M.; Tsurutani, B. T.; Sun, W.</p> <p>2012-04-01</p> <p>Sudden energy release (ER) events in the midnight sector at auroral zone latitudes during intense (B > 10 nT), long-duration (T > 3 hr), northward (Bz > 0 nT = N) IMF <span class="hlt">magnetic</span> clouds (MCs) during solar cycle 23 (SC23) have been examined in detail. The MCs with northward-then-southward (NS) IMFs were analyzed separately from MCs with southward-then-northward (SN) configurations. It is found that there is a lack of substorms during the N field intervals of NS clouds. In sharp contrast, ER events do occur during the N field portions of SN MCs. From the above two results it is reasonable to conclude that the latter ER events represent residual energy remaining from the preceding S portions of the SN MCs. We derive a new solar wind-magnetosphere coupling function during northward IMFs: ENIMF = ? N-1/12V 7/3B1/2 + ? V |Dstmin|. The first term on the right-hand side of the equation represents the energy input via "viscous interaction", and the second term indicates the residual energy stored in the magnetotail. It is empirically found that the magnetosphere/magnetotail can store energy for a maximum of ~ 4 hrs before it has dissipated away. This concept is defining one for ER/substorm energy storage. Our scenario indicates that the rate of solar wind energy injection into the magnetosphere/magnetotail determines the form of energy release into the magnetosphere/ionosphere. This may be more important than the dissipation mechanism itself (in understanding the form of the release). The concept of short-term energy storage is applied for the solar case. It is argued that it may be necessary to identify the rate of energy input into solar <span class="hlt">magnetic</span> loop systems to be able to predict the occurrence of solar flares.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22270776','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22270776"><span id="translatedtitle">SOURCE REGIONS OF THE <span class="hlt">INTERPLANETARY</span> <span class="hlt">MAGNETIC</span> FIELD AND VARIABILITY IN HEAVY-ION ELEMENTAL COMPOSITION IN GRADUAL SOLAR ENERGETIC PARTICLE EVENTS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ko, Yuan-Kuen; Wang, Yi-Ming; Tylka, Allan J.; Ng, Chee K.; Dietrich, William F.</p> <p>2013-10-20</p> <p>Gradual solar energetic particle (SEP) events are those in which ions are accelerated to their observed energies by interactions with a shock driven by a fast coronal mass ejection (CME). Previous studies have shown that much of the observed event-to-event variability can be understood in terms of shock speed and evolution in the shock-normal angle. However, an equally important factor, particularly for the elemental composition, is the origin of the suprathermal seed particles upon which the shock acts. To tackle this issue, we (1) use observed solar-wind speed, magnetograms, and the potential-field source-surface model to map the Sun-L1 <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) line back to its source region on the Sun at the time of the SEP observations and (2) then look for a correlation between SEP composition (as measured by Wind and Advanced Composition Explorer at ∼2-30 MeV nucleon{sup –1}) and characteristics of the identified IMF source regions. The study is based on 24 SEP events, identified as a statistically significant increase in ∼20 MeV protons and occurring in 1998 and 2003-2006, when the rate of newly emergent solar <span class="hlt">magnetic</span> flux and CMEs was lower than in solar-maximum years, and the field-line tracing is therefore more likely to be successful. We find that the gradual SEP Fe/O is correlated with the field strength at the IMF source, with the largest enhancements occurring when the footpoint field is strong due to the nearby presence of an active region (AR). In these cases, other elemental ratios show a strong charge-to-mass (q/M) ordering (at least on <span class="hlt">average</span>), similar to that found in impulsive events. Such results lead us to suggest that <span class="hlt">magnetic</span> reconnection in footpoint regions near ARs bias the heavy-ion composition of suprathermal seed ions by processes qualitatively similar to those that produce larger heavy-ion enhancements in impulsive SEP events. To address potential technical concerns about our analysis, we also discuss efforts to exclude impulsive SEP events from our event sample.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1616849T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1616849T"><span id="translatedtitle">Source Regions of the <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field and Variability in Heavy-Ion Elemental Composition in Gradual Solar Energetic Particle Events</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tylka, Allan J.; Ko, Yuan-Kuen; Keong Ng, Chee; Wang, Yi-Ming; Dietrich, William F.</p> <p>2014-05-01</p> <p>Gradual solar energetic particle (SEP) events are those in which ions are accelerated to their observed energies by interactions with a shock driven by a fast coronal mass-ejection (CME). Previous studies have shown that much of the observed event-to-event variability can be understood in terms of shock speed and evolution in the shock-normal angle. But an equally important factor, particularly for the elemental composition, is the origin of the suprathermal seed particles upon which the shock acts. To tackle this issue, we (1) use observed solar-wind speed, magnetograms, and the PFSS model to map the Sun-L1 <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) line back to its source region on the Sun at the time of the SEP observations; and (2) then look for correlation between SEP composition (as measured by Wind and ACE at ~2-30 MeV/nucleon) and characteristics of the identified IMF-source regions. The study is based on 24 SEP events, identified as a statistically-significant increase in ~20 MeV protons and occurring in 1998 and 2003-2006, when the rate of newly-emergent solar <span class="hlt">magnetic</span> flux and CMEs was lower than in solar-maximum years and the field-line tracing is therefore more likely to be successful. We find that the gradual SEP Fe/O is correlated with the field strength at the IMF-source, with the largest enhancements occurring when the footpoint field is strong, due to the nearby presence of an active region. In these cases, other elemental ratios show a strong charge-to-mass (q/M) ordering, at least on <span class="hlt">average</span>, similar to but less pronounced than that found in impulsive events. These results lead us to suggest that <span class="hlt">magnetic</span> reconnection in footpoint regions near active regions bias the heavy-ion composition of suprathermal seed ions by processes qualitatively similar to those that produce larger heavy-ion enhancements in impulsive SEP events.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSH32B..05T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSH32B..05T"><span id="translatedtitle">Source Regions of the <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field and Variability in Heavy-Ion Elemental Composition in Gradual Solar Energetic Particle Events (Invited)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tylka, A. J.; Ko, Y.; Ng, C. K.; Wang, Y.; Dietrich, W. F.</p> <p>2013-12-01</p> <p>Gradual solar energetic particle (SEP) events are those in which ions are accelerated to their observed energies by interactions with a shock driven by a fast coronal mass-ejection (CME). Previous studies have shown that much of the observed event-to-event variability can be understood in terms of shock speed and evolution in the shock-normal angle. But an equally important factor, particularly for the elemental composition, is the origin of the suprathermal seed particles upon which the shock acts. To tackle this issue, we (1) use observed solar-wind speed, magnetograms, and the PFSS model to map the Sun-L1 <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) line back to its source region on the Sun at the time of the SEP observations; and (2) then look for correlation between SEP composition (as measured by Wind and ACE at ~2-30 MeV/nucleon) and characteristics of the identified IMF-source regions. The study is based on 24 SEP events, identified as a statistically-significant increase in ~20 MeV protons and occurring in 1998 and 2003-2006, when the rate of newly-emergent solar <span class="hlt">magnetic</span> flux and CMEs was lower than in solar-maximum years and the field-line tracing is therefore more likely to be successful. We find that the gradual SEP Fe/O is correlated with the field strength at the IMF-source, with the largest enhancements occurring when the footpoint field is strong, due to the nearby presence of an active region. In these cases, other elemental ratios show a strong charge-to-mass (q/M) ordering, at least on <span class="hlt">average</span>, similar to that found in impulsive events. These results lead us to suggest that <span class="hlt">magnetic</span> reconnection in footpoint regions near active regions bias the heavy-ion composition of suprathermal seed ions by processes qualitatively similar to those that produce larger heavy-ion enhancements in impulsive SEP events. To address potential technical concerns about our analysis, we also discuss efforts to exclude impulsive SEP events from our event sample.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ApJ...776...92K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ApJ...776...92K"><span id="translatedtitle">Source Regions of the <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field and Variability in Heavy-ion Elemental Composition in Gradual Solar Energetic Particle Events</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ko, Yuan-Kuen; Tylka, Allan J.; Ng, Chee K.; Wang, Yi-Ming; Dietrich, William F.</p> <p>2013-10-01</p> <p>Gradual solar energetic particle (SEP) events are those in which ions are accelerated to their observed energies by interactions with a shock driven by a fast coronal mass ejection (CME). Previous studies have shown that much of the observed event-to-event variability can be understood in terms of shock speed and evolution in the shock-normal angle. However, an equally important factor, particularly for the elemental composition, is the origin of the suprathermal seed particles upon which the shock acts. To tackle this issue, we (1) use observed solar-wind speed, magnetograms, and the potential-field source-surface model to map the Sun-L1 <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) line back to its source region on the Sun at the time of the SEP observations and (2) then look for a correlation between SEP composition (as measured by Wind and Advanced Composition Explorer at ~2-30 MeV nucleon-1) and characteristics of the identified IMF source regions. The study is based on 24 SEP events, identified as a statistically significant increase in ~20 MeV protons and occurring in 1998 and 2003-2006, when the rate of newly emergent solar <span class="hlt">magnetic</span> flux and CMEs was lower than in solar-maximum years, and the field-line tracing is therefore more likely to be successful. We find that the gradual SEP Fe/O is correlated with the field strength at the IMF source, with the largest enhancements occurring when the footpoint field is strong due to the nearby presence of an active region (AR). In these cases, other elemental ratios show a strong charge-to-mass (q/M) ordering (at least on <span class="hlt">average</span>), similar to that found in impulsive events. Such results lead us to suggest that <span class="hlt">magnetic</span> reconnection in footpoint regions near ARs bias the heavy-ion composition of suprathermal seed ions by processes qualitatively similar to those that produce larger heavy-ion enhancements in impulsive SEP events. To address potential technical concerns about our analysis, we also discuss efforts to exclude impulsive SEP events from our event sample.</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://hdl.handle.net/2060/20140010294','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140010294"><span id="translatedtitle">Source Regions of the <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field and Variability in Heavy-Ion Elemental Composition in Gradual Solar Energetic Particle Events</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ko, Yuan-Kuen; Tylka, Allan J.; Ng, Chee K.; Wang, Yi-Ming; Dietrich, William F.</p> <p>2013-01-01</p> <p>Gradual solar energetic particle (SEP) events are those in which ions are accelerated to their observed energies by interactions with a shock driven by a fast coronal mass-ejection (CME). Previous studies have shown that much of the observed event-to-event variability can be understood in terms of shock speed and evolution in the shock-normal angle. But an equally important factor, particularly for the elemental composition, is the origin of the suprathermal seed particles upon which the shock acts. To tackle this issue, we (1) use observed solar-wind speed, magnetograms, and the PFSS model to map the Sun-L1 <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) line back to its source region on the Sun at the time of the SEP observations; and (2) then look for correlation between SEP composition (as measured by Wind and ACE at approx. 2-30 MeV/nucleon) and characteristics of the identified IMF-source regions. The study is based on 24 SEP events, identified as a statistically-significant increase in approx. 20 MeV protons and occurring in 1998 and 2003-2006, when the rate of newly-emergent solar <span class="hlt">magnetic</span> flux and CMEs was lower than in solar-maximum years and the field-line tracing is therefore more likely to be successful. We find that the gradual SEP Fe/O is correlated with the field strength at the IMF-source, with the largest enhancements occurring when the footpoint field is strong, due to the nearby presence of an active region. In these cases, other elemental ratios show a strong charge-to-mass (q/M) ordering, at least on <span class="hlt">average</span>, similar to that found in impulsive events. These results lead us to suggest that <span class="hlt">magnetic</span> reconnection in footpoint regions near active regions bias the heavy-ion composition of suprathermal seed ions by processes qualitatively similar to those that produce larger heavy-ion enhancements in impulsive SEP events. To address potential technical concerns about our analysis, we also discuss efforts to exclude impulsive SEP events from our event sample.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20040031460&hterms=CANE&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DCANE','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20040031460&hterms=CANE&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DCANE"><span id="translatedtitle">Spatial Relationship of Signatures of <span class="hlt">Interplanetary</span> Coronal Mass Ejections</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Richardson, I. G.; Cane, H. V.; Lepri, S. T.; Zurbuchen, T. H.; Gosling, J. T.</p> <p>2003-01-01</p> <p><span class="hlt">Interplanetary</span> coronal mass ejections (ICMEs) are characterized by a number of signatures. In particular, we examine the relationship between Fe charge states and other signatures during ICMEs in solar cycle 23. Though enhanced Fe charge states characterize many ICMEs, <span class="hlt">average</span> charge states vary from event to event, are more likely to be enhanced in faster or flare-related ICMEs, and do not appear to depend on whether the ICME is a <span class="hlt">magnetic</span> cloud.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19880012611','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19880012611"><span id="translatedtitle"><span class="hlt">Magnetic</span> field hourly <span class="hlt">averages</span> from the Rome-GSFC experiment aboard Helios 1 and Helio 2</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mariani, F.; Ness, N. F.; Bavassano, B.; Bruno, R.; Buccellato, R.; Burlaga, L. F.; Cantarano, S.; Scearce, C. S.; Terenzi, R.; Villante, U.</p> <p>1987-01-01</p> <p>Plots of all the hourly <span class="hlt">averages</span> computed from the solar <span class="hlt">magnetic</span> field measurements obtained during the mission are given separately for Helios 1 and Helios 2. The magnitude and the direction of the <span class="hlt">averaged</span> field are plotted versus the number of solar rotations as seen from Helios, counted from launch.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004cosp...35.3590B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004cosp...35.3590B"><span id="translatedtitle">lower ionosphere cosmic noise absorption responses to the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field behavior in the south atlantic <span class="hlt">magnetic</span> anomaly and sub-auroral regions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brum, C. G. M.; Abdu, M. A.; Batista, I. S.; Santos, P. M. T.; Barros, L. P.</p> <p></p> <p>The <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) plays an important role in the cosmic ray flux modulation that reaches the lower ionosphere, which is one of the main sources of the ionization in these regions. In this work, it is presented data analysis results obtained from riometers operating at 30 MHz over Cachoeira Paulista (located at South Atlantic <span class="hlt">Magnetic</span> Anomaly (SAMA) - connected to an antenna pointed to the zenith direction, 22.50°S; 45.00°W) and the Brazilian Antarctic Station - EACF (connected to an antenna pointed to the zenith and geomagnetic west directions, 62.56°S; 58.39°W) during almost one complete solar cycle (1989-1996). Previous results have shown that there is a strong correlation between the cosmic noise absorption (CNA) behavior and the IMF. Basically, the sub-auroral region presents a decrease in the CNA with the increase of the IMF intensity, while in the SAMA region, for the same IMF conditions, it was registered an increase. Related to the IMF direction, the greater values of CNA are present when the IMF is pointed to the south and to the east for EACF and AMAS regions, respectively. The results of these data analysis are discussed and the galactic cosmic noise absorption is computed by using the geomagnetic activity (geomagnetic field values) to show the relationship between CNA and IMF behavior.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22133988','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22133988"><span id="translatedtitle">INTERVALS OF RADIAL <span class="hlt">INTERPLANETARY</span> <span class="hlt">MAGNETIC</span> FIELDS AT 1 AU, THEIR ASSOCIATION WITH RAREFACTION REGIONS, AND THEIR APPARENT <span class="hlt">MAGNETIC</span> FOOT POINTS AT THE SUN</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Orlove, Steven T.; Smith, Charles W.; Vasquez, Bernard J.; Schwadron, Nathan A.; Skoug, Ruth M.; Zurbuchen, Thomas H.; Zhao Liang E-mail: Charles.Smith@unh.edu E-mail: N.Schwadron@unh.edu E-mail: thomasz@umich.edu</p> <p>2013-09-01</p> <p>We have examined 226 intervals of nearly radial <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field orientations at 1 AU lasting in excess of 6 hr. They are found within rarefaction regions as are the previously reported high-latitude observations. We show that these rarefactions typically do not involve high-speed wind such as that seen by Ulysses at high latitudes during solar minimum. We have examined both the wind speeds and the thermal ion composition before, during and after the rarefaction in an effort to establish the source of the flow that leads to the formation of the rarefaction. We find that the bulk of the measurements, both fast- and slow-wind intervals, possess both wind speeds and thermal ion compositions that suggest they come from typical low-latitude sources that are nominally considered slow-wind sources. In other words, we find relatively little evidence of polar coronal hole sources even when we examine the faster wind ahead of the rarefaction regions. While this is in contrast to high-latitude observations, we argue that this is to be expected of low-latitude observations where polar coronal hole sources are less prevalent. As with the previous high-latitude observations, we contend that the best explanation for these periods of radial <span class="hlt">magnetic</span> field is interchange reconnection between two sources of different wind speed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19900035884&hterms=1087&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3D%2526%25231087','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19900035884&hterms=1087&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3D%2526%25231087"><span id="translatedtitle">Heliocentric distance and temporal dependence of the <span class="hlt">interplanetary</span> density-<span class="hlt">magnetic</span> field magnitude correlation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Roberts, D. A.</p> <p>1990-01-01</p> <p>The Helios, IMP 8, ISEE 3, ad Voyager 2 spacecraft are used to examine the solar cycle and heliocentric distance dependence of the correlation between density n and <span class="hlt">magnetic</span> field magnitude B in the solar wind. Previous work had suggested that this correlation becomes progressively more negative with heliocentric distance out to 9.5 AU. Here it is shown that this evolution is not a solar cycle effect, and that the correlations become even more strongly negative at heliocentric distance larger than 9.5 AU. There is considerable variability in the distributions of the correlations at a given heliocentric distance, but this is not simply related to the solar cycle. Examination of the evolution of correlations between density and speed suggest that most of the structures responsible for evolution in the anticorrelation between n and B are not slow-mode waves, but rather pressure balance structures. The latter consist of both coherent structures such as tangential discontinuities and the more generally pervasive 'pseudosound' which may include the coherent structures as a subset.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19890001307','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19890001307"><span id="translatedtitle"><span class="hlt">Interplanetary</span> medium data book: Supplement 3A, 1977-1985</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Couzens, David A.; King, Joseph H.</p> <p>1986-01-01</p> <p>Supplement 3 of the <span class="hlt">Interplanetary</span> Medium Data Book contains a detailed discussion of a data set compilation of hourly <span class="hlt">averaged</span> <span class="hlt">interplanetary</span> plasma and <span class="hlt">magnetic</span> field parameters. The discussion addresses data sources, systematic and random differences, time shifting of ISEE 3 data, and plasma normalizations. Supplement 3 also contains solar rotation plots of field and plasma parameters. Supplement 3A contains computer-generated listings of selected parameters from the composite data set. These parameters are bulk speed (km/sec), density (per cu cm), temperature (in units of 1000 K) and the IMF parameters: <span class="hlt">average</span> magnitude, latitude and longitude angles of the vector made up of the <span class="hlt">average</span> GSE components, GSM Cartesian components, and the vector standard deviation. The units of field magnitude, components, and standard deviation are gammas, while the units of field direction angles and degrees.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6795502','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6795502"><span id="translatedtitle"><span class="hlt">Interplanetary</span> medium data book: Supplement 3A, 1977-1985</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Couzens, D.A.; King, J.H.</p> <p>1986-04-01</p> <p>Supplement 3 of the <span class="hlt">Interplanetary</span> Medium Data Book contains a detailed discussion of a data set compilation of hourly <span class="hlt">averaged</span> <span class="hlt">interplanetary</span> plasma and <span class="hlt">magnetic</span> field parameters. The discussion addresses data sources, systematic and random differences, time shifting of ISEE 3 data, and plasma normalizations. Supplement 3 also contains solar rotation plots of field and plasma parameters. Supplement 3A contains computer-generated listings of selected parameters from the composite data set. These parameters are bulk speed (km/sec), density (per cu cm), temperature (in units of 1000 K) and the IMF parameters: <span class="hlt">average</span> magnitude, latitude and longitude angles of the vector made up of the <span class="hlt">average</span> GSE components, GSM Cartesian components, and the vector standard deviation. The units of field magnitude, components, and standard deviation are gammas, while the units of field direction angles and degrees.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001JGR...10624505T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001JGR...10624505T"><span id="translatedtitle"><span class="hlt">Interplanetary</span> <span class="hlt">magnetic</span> field <formula alphabet="latin">By and auroral conductance effects on high-latitude ionospheric convection patterns</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tanaka, T.</p> <p>2001-11-01</p> <p>The dependence of the ionospheric electric potential (convection) on the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) and the ionospheric conductivity is investigated to understand the generation of convection patterns in the framework of the solar wind-magnetosphere-ionosphere (S-M-I) coupling scheme and the merging concept. A numerical magnetohydrodynamic (MHD) simulation is adopted for the study of the present problem. To achieve a high resolution in the ionosphere, the MHD calculation employs the finite volume (FV) total-variation diminishing (TVD) scheme with an unstructured grid system. The two-cell convection patterns reproduced from simulation are shown for several cases under the southward IMF condition during the growth-phase interval. In the investigation of these results, special attention is paid to the analysis of mirror symmetry in the convection patterns with respect to the IMF By. On the dayside in the Northern Hemisphere, IMF By- (By+) generates flow deflection on newly opened field lines toward the dusk (dawn) without a severe violation of the mirror symmetry. While the mirror symmetry of the convection pattern is maintained even on the nightside when the ionospheric conductivity is uniform, it is not maintained on the nightside when the ionospheric conductivity is nonuniform. A realistic ionospheric conductivity modifies the convection pattern in the Northern (Southern) Hemisphere so as to emphasize distinctive features seen for IMF By+ (By-) under a uniform conductivity, and the reproduced convection patterns coincide with the observation quite well including fine signatures on the nightside, both for IMF By- and By+. Because of the nonuniform conductivity, cell centers of convection are shifted to the earlier <span class="hlt">magnetic</span> local times, and the antisunward flow in the northern polar cap is nearly aligned with noon-midnight meridian for IMF By-, while the flow in the northern polar cap has a significant inclination from prenoon to premidnight for IMF By+. These convection patterns can be understood by considering the effect due to the Hall current closure of the region-1 field-aligned current. The analysis for the dependence of nightside convection on IMF By and ionospheric conductivity shows that the Harang discontinuity is attributed partially to the structure of magnetospheric driver but mainly to the effect of nonuniform auroral conductivity. As a consequence, it is more adequate to say that convection patterns are more or less caused by the synthesized effect of more than one process rather than a single elementary process. Reproduced convection patterns in this paper show a particular coincidence with satellite observations summarized by adopting the pattern-recognition-based approach.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014APS..DPPNP8095Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014APS..DPPNP8095Z"><span id="translatedtitle">Bounce <span class="hlt">averaged</span> diffusion coefficients in a physics based <span class="hlt">magnetic</span> field geometry from RAM-SCB</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhao, Lei; Yu, Yiqun; Delzanno, Gian Luca; Jordanova, Vania K.</p> <p>2014-10-01</p> <p>In this work we explore wave-particle interaction in the radiation belt. By applying quasilinear theory, we obtain the particle diffusion coefficients in both pitch angle and energy for different configurations of the Earth's <span class="hlt">magnetic</span> field. We consider the Earth's <span class="hlt">magnetic</span> dipole field as a reference, and compare the results against non-dipole field configurations corresponding to quiet and stormy conditions. The latter are obtained with RAM-SCB, a code that models the Earth's ring current and provide a realistic modeling of the Earth's <span class="hlt">magnetic</span> field. The bounce <span class="hlt">averaged</span> electron pitch angle diffusion coefficients are calculated for each <span class="hlt">magnetic</span> field configuration. The equatorial pitch angle, wave frequency and spectral distribution of whistler waves are shown to affect the bounce <span class="hlt">averaged</span> diffusion coefficients. In addition, wave-particle resonance is significantly influenced by the <span class="hlt">magnetic</span> field configuration: in storm conditions, diffusion is strongly reduced for some equatorial pitch angles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006ihy..workE..99B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006ihy..workE..99B"><span id="translatedtitle">Structural and Dynamical Properties of <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Clouds in the Heliosphere and their Interaction with Earth's Magnetosphere (P7)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Badruddin, A.; Singh, Y. P.</p> <p>2006-11-01</p> <p>pht08bdu@rediffmail.com Space-borne and earth-based detectors are monitoring coronal mass ejections (CMEs) launched from the sun into the heliosphere. A subset of CMEs, called <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> clouds (IMCs), shows systematic rotation (northward to southward and vice versa) in their field structures. The IMCs have been identified in the heliospheric plasma and field data. These IMCs, observed at 1 AU, have been observed to show different dynamical properties. Some of them are, (a) isolated structures moving with the ambient solar wind, (b) faster moving IMCs drive a shock/sheath region formed due to compression of the ambient plasma/field ahead of them, and (c) a fraction of IMCs are driven by fast solar wind from coronal holes forming interaction region (IR) between IMCs and high speed solar wind streams (HSS). The interaction of the solar wind and the earth’s magnetosphere is complex and phenomenology of interaction is believed to be very different for solar wind dominated by transient ejecta (e.g. IMCs) compared to solar wind dominated by interaction regions and high speed streams from open field regions of coronal holes. Using different sets of IMCs, we have done a detailed study of their interaction with the magnetosphere and the geoeffectiveness of IMCs and their associated features (shock/sheath, IR and HSS). We have further studied the geoeffectiveness of northward to southward turning and southward to northward turning IMCs along with their associated features. To study the mechanism that produces the geomagnetic disturbances, we have further utilized the heliospheric plasma and field parameters namely, velocity, density, temperature, field strength and its north-south component, during the passage of these structures with different plasma/field properties. Noticeable differences in the geoeffectiveness of IMCs with different structural and dynamical properties have been observed. Correlation analysis between geomagnetic parameters and various heliospheric plasma/field parameters during passage of structures with different properties in done in order to identify the parameters playing important role, and their relative importance, in creating geomagnetic disturbances during their passage.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008JASTP..70..254K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008JASTP..70..254K"><span id="translatedtitle">Time changes of solar activity, <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field and solar wind velocity at the Earth's orbit in different spectral bands</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kuznetsova, Tamara V.; Tsirulnik, Lev B.</p> <p>2008-02-01</p> <p>We present the results of our analysis of the spectra of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) and the solar wind velocity (V) calculated on the basis of measurements near the Earth's orbit for the period 1964-1997, and of the sunspot number W. The major aim is to search for similar features in various frequency bands, with an emphasis on the period of solar (sunspot) cycle and its harmonics, and on so-called "intermittent" oscillations at periods and . We also extract trends from the data to determine long-period changes of IMF and V. A method of non-linear spectral analysis, which we term "the method of global minimum" (MGM) is used. MGM allows self-consistent identification of trends from data and nonstationary sinusoids and estimation of statistical significance of spectral components. The IMF and W spectra both show the main solar cycle at . In addition, the spectrum of the IMF includes (at 99.8% confidence levels) harmonics of this cycle with periods of 151.3 and 136.5 d. We also detect nonstationary sinusoids at in the spectra of IMF and of V and describe their parameters. The detailed description of the 1.3-yr oscillations in the solar wind is of particular interest in that the oscillations are likely to be connected to variations in the rotation rate with the same period near the base of convection zone of the Sun discovered in SOHO data. The 1.3-yr oscillations are not present in the W spectra. Instead, we find oscillations at T=1.014 and 0.950 yr and suggest an explanation of their presence. Relation between the variations in the spectra of W and V is not as evident as between W and the IMF, however, it exists. In particular, harmonics of the 10.8-yr solar cycle (e.g., sinusoid at ) are present in the spectrum of V. Components in the spectra described by high-amplitude sinusoids with in the IMF spectrum and with in the V spectrum make contributions to the long-term trends in these parameters. The trend of V demonstrates a 55% increase in the solar wind velocity for the period 1964-1997. The IMF trend shows a 45% increase of the IMF magnitude for the same time interval; extrapolation of this temporal variation to the past leads to a doubling of the IMF value during the last 100 yr.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19920045478&hterms=earth+events&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dearth%2Bevents','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19920045478&hterms=earth+events&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dearth%2Bevents"><span id="translatedtitle">Prediction of <span class="hlt">magnetic</span> orientation in driver gas associated -Bz events. [in <span class="hlt">interplanetary</span> medium observed at earth when solar source is identified</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hoeksema, J. T.; Zhao, Xuepu</p> <p>1992-01-01</p> <p>The source regions of five strong -Bz events detected at 1 AU for which solar sources were identified by Tang et al. (1989) and Tsurutani et al. (1992) are investigated in order to determine whether the <span class="hlt">magnetic</span> orientation of driver gas in the <span class="hlt">interplanetary</span> medium observed at the earth can be predicted when its solar source is identified. Three -Bz events were traced to flare-associated coronal mass ejections (CMEs), one to an eruptive prominence associated CME, and one to three possible solar sources. The computed <span class="hlt">magnetic</span> orientations at the candidate 'release height' (the height where the front of a CME ceases to accelerate) above the flare sites associated with CMEs show the existence of the expected southward field component. It is concluded that the <span class="hlt">magnetic</span> orientation in flare-associated CME generated driver gas may be predictable.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19740009007','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19740009007"><span id="translatedtitle"><span class="hlt">Average</span> daily variations in the <span class="hlt">magnetic</span> field as observed by ATS-5</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Skillman, T. L.</p> <p>1974-01-01</p> <p>Hourly <span class="hlt">averages</span> of the <span class="hlt">magnetic</span> field components are determined and analyzed using the measurements of the <span class="hlt">magnetic</span> field monitor aboard the ATS-5. The data covering the time period of September 1969 through September 1971 are sorted and analyzed for various Kp values, geomagnetic latitude of the subsolar point, and local time. Local time variations are harmonically analyzed, and amplitudes and phases are given up to the fourth harmonic.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JMMM..394..195S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JMMM..394..195S"><span id="translatedtitle">The effect of stress and incentive <span class="hlt">magnetic</span> field on the <span class="hlt">average</span> volume of <span class="hlt">magnetic</span> Barkhausen jump in iron</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shu, Di; Guo, Lei; Yin, Liang; Chen, Zhaoyang; Chen, Juan; Qi, Xin</p> <p>2015-11-01</p> <p>The <span class="hlt">average</span> volume of <span class="hlt">magnetic</span> Barkhausen jump (AVMBJ) v bar generated by <span class="hlt">magnetic</span> domain wall irreversible displacement under the effect of the incentive <span class="hlt">magnetic</span> field H for ferromagnetic materials and the relationship between irreversible <span class="hlt">magnetic</span> susceptibility χirr and stress σ are adopted in this paper to study the theoretical relationship among AVMBJ v bar(magneto-elasticity noise) and the incentive <span class="hlt">magnetic</span> field H. Then the numerical relationship among AVMBJ v bar, stress σ and the incentive <span class="hlt">magnetic</span> field H is deduced. Utilizing this numerical relationship, the displacement process of <span class="hlt">magnetic</span> domain wall for single crystal is analyzed and the effect of the incentive <span class="hlt">magnetic</span> field H and the stress σ on the AVMBJ v bar (magneto-elasticity noise) is explained from experimental and theoretical perspectives. The saturation velocity of Barkhausen jump characteristic value curve is different when tensile or compressive stress is applied on ferromagnetic materials, because the resistance of <span class="hlt">magnetic</span> domain wall displacement is different. The idea of critical <span class="hlt">magnetic</span> field in the process of <span class="hlt">magnetic</span> domain wall displacement is introduced in this paper, which solves the supersaturated calibration problem of AVMBJ - σ calibration curve.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19970026618','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19970026618"><span id="translatedtitle">Upper Thermosphere Winds and Temperatures in the Geomagnetic Polar Cap: Solar Cycle, Geomagnetic Activity, and <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field Dependencies</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Killeen, T. L.; Won, Y.-I.; Niciejewski, R. J.; Burns, A. G.</p> <p>1995-01-01</p> <p>Ground-based Fabry-Perot interferometers located at Thule, Greenland (76.5 deg. N, 69.0 deg. W, lambda = 86 deg.) and at Sondre Stromfjord, Greenland (67.0 deg. N, 50.9 deg. W, lambda = 74 deg.) have monitored the upper thermospheric (approx. 240-km altitude) neutral wind and temperature over the northern hemisphere geomagnetic polar cap since 1983 and 1985, respectively. The thermospheric observations are obtained by determining the Doppler characteristics of the (OI) 15,867-K (630.0-nm) emission of atomic oxygen. The instruments operate on a routine, automatic, (mostly) untended basis during the winter observing seasons, with data coverage limited only by cloud cover and (occasional) instrument failures. This unique database of geomagnetic polar cap measurements now extends over the complete range of solar activity. We present an analysis of the measurements made between 1985 (near solar minimum) and 1991 (near solar maximum), as part of a long-term study of geomagnetic polar cap thermospheric climatology. The measurements from a total of 902 nights of observations are compared with the predictions of two semiempirical models: the Vector Spherical Harmonic (VSH) model of Killeen et al. (1987) and the Horizontal Wind Model (HWM) of Hedin et al. (1991). The results are also analyzed using calculations of thermospheric momentum forcing terms from the Thermosphere-ionosphere General Circulation Model TGCM) of the National Center for Atmospheric Research (NCAR). The experimental results show that upper thermospheric winds in the geomagnetic polar cap have a fundamental diurnal character, with typical wind speeds of about 200 m/s at solar minimum, rising to up to about 800 m/s at solar maximum, depending on geomagnetic activity level. These winds generally blow in the antisunward direction, but are interrupted by episodes of modified wind velocity and altered direction often associated with changes in the orientation of the <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field (IMF). The central polar cap (greater than approx. 80 <span class="hlt">magnetic</span> latitude) antisunward wind speed is found to be a strong function of both solar and geomagnetic activity. The polar cap temperatures show variations in both solar and geomagnetic activity, with temperatures near 800 K for low K(sub p) and F(sub 10.7) and greater than about 2000 K for high K(sub p) and F(sub 10.7). The observed temperatures are significantly greater than those predicted by the mass spectrometer/incoherent scatter model for high activity conditions. Theoretical analysis based on the NCAR TIGCM indicates that the antisunward upper thermospheric winds, driven by upstream ion drag, basically 'coast' across the polar cap. The relatively small changes in wind velocity and direction within the polar cap are induced by a combination of forcing terms of commensurate magnitude, including the nonlinear advection term, the Coriolis term, and the pressure gradient force term. The polar cap thennospheric thermal balance is dominated by horizontal advection, and adiabatic and thermal conduction terms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSM43B4285Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSM43B4285Z"><span id="translatedtitle">Bounce <span class="hlt">averaged</span> diffusion coefficients in a physics based <span class="hlt">magnetic</span> field geometry from RAM-SCB</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhao, L.; Yu, Y.; Delzanno, G. L.; Jordanova, V.</p> <p>2014-12-01</p> <p>Local acceleration via whistler wave and particle interaction plays an important role in particle dynamics in the radiation belt. In this work we explore wave-particle interaction in different <span class="hlt">magnetic</span> field configurations related to the 17 March, 2013 storm. We consider the Earth's <span class="hlt">magnetic</span> dipole field as a reference, and compare the results against non-dipole field configurations corresponding to quiet and stormy conditions. The latter are obtained with RAM-SCB, a code that models the Earth's ring current and provides a realistic modeling of the Earth's <span class="hlt">magnetic</span> field. By applying quasi-linear theory, the bounce-<span class="hlt">averaged</span> electron pitch angle, energy and mixed term diffusion coefficients are calculated for each <span class="hlt">magnetic</span> field configuration. It is shown that the <span class="hlt">magnetic</span> field can have a significant influence on the diffusion coefficients via the wave-particle resonance condition. In addition, the equatorial pitch angle, wave frequency and spectral distribution of whistler waves also affect the bounce-<span class="hlt">averaged</span> diffusion coefficients in particle energy range from KeV to MeV. Part of the ongoing work will focus on the phase space density evolution based on the Fokker-Planck equation with the bounce-<span class="hlt">averaged</span> diffusion coefficients previously calculated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015STP.....1c..11K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015STP.....1c..11K"><span id="translatedtitle">Effect of geomagnetic activity, solar wind and parameters of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field on regularities in intermittency of Pi2 geomagnetic pulsations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kurazhkovskaya, Nadezhda; Klain, Boris</p> <p>2015-09-01</p> <p>We present the results of investigation of the influence of geomagnetic activity, solar wind and parameters of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) on properties of the intermittency of midlatitude burst series of Pi2 geomagnetic pulsations observed during magnetospheric substorms on the nightside (substorm Pi2) and in the absence of these phenomena (nonsubstorm Pi2). We considered the index α as a main characteristic of intermittency of substorm and nonsubstorm Pi2 pulsations. The index α characterizes the slope of the cumulative distribution function of Pi2 burst amplitudes. The study indicated that the value and dynamics of the index α varies depending on the planetary geomagnetic activity, auroral activity and the intensity of magnetospheric ring currents. In addition, the forms of dependences of the index α; on the density n, velocity V, dynamic pressure Pd of the solar wind and IMF Bx-component are different. The behavior of the index α depending on the module of B, By- and Bz-components is similar. We found some critical values of V, Pd, B, By- and Bz-components, after reaching of which the turbulence of the magnetotail plasma during substorm development is decreased. The revealed patterns of the intermittency of Pi2 pulsations can be used for qualitative assessment of turbulence level in the magnetotail plasma depending on changing <span class="hlt">interplanetary</span> conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMSM11B2290V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMSM11B2290V"><span id="translatedtitle">Sector structure of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field in the second half of the 19th century inferred from ground-based magnetometers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vokhmyanin, M.; Ponyavin, D. I.</p> <p>2012-12-01</p> <p><span class="hlt">Interplanetary</span> <span class="hlt">magnetic</span> field (IMF) polarities can be inferred in the pre-satellite era using Svalgaard-Mansurov effect, according to which different IMF directions lead to different geomagnetic variations at polar stations. Basing on this effect we propose a method to derive a sector structure of the IMF when only ground based data are available. Details of the method and results have been presented in our recent paper: Vokhmyanin, M. V., and D. I. Ponyavin (2012), Inferring <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field polarities from geomagnetic variations, J. Geophys. Res., 117, A06102, doi:10.1029/2011JA017060. Using data from eight stations: Sitka, Sodankyla, Godhavn, Lerwick, Thule, Baker Lake, Vostok and Mirny, we reconstructed sector structure back to 1905. The quality of inferring from 1965 to 2005 ranges between 78% and 90% depending on the used set of stations. Our results show both high success rate and good agreement with the well-known Russell-McPherron and Rosenberg-Coleman effects. In the current study we applied the technique to historical data of Helsinki observatory where digital versions of hourly geomagnetic components are available from 1844 to 1897. Helsinki station stopped operates at the beginning of 20th century. Thus, to create a model describing the local Svalgaard-Mansurov effect we analyzed data from Nurmijarvi station located near the same region. The success rate of reconstruction from 1965 to 2005 is around 82%. So we assume that the IMF polarities obtained for the period 1869-1889 have sufficient quality. Inferred sector structure at this time consists of two sectors typically for all declining phases of solar activity cycle. Catalogue of IMF proxies seem to be important in analyzing structure and dynamics of solar <span class="hlt">magnetic</span> fields in the past.; Left: Bartels diagram of IMF sector structure inferred from Helsinki data. Right: sunspot number indicating solar cycles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SuMi...88..204L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SuMi...88..204L"><span id="translatedtitle">Manipulating spin spatial splitter in a δ-doped semiconductor nanostructure with zero <span class="hlt">average</span> <span class="hlt">magnetic</span> field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Gui-Xiang; Ma, Wen-Yue; Shen, Li-Hua</p> <p>2015-12-01</p> <p>Recently, based on a novel <span class="hlt">magnetic</span> nanostructure with zero <span class="hlt">average</span> <span class="hlt">magnetic</span> field, a spin spatial splitter with a considerable spin-polarized lateral displacement was proposed [Appl. Surf. Sci. 313 (2014) 545]. To further manipulate its spin-polarized behaviour, in this work, we introduce a tunable δ-potential into the device by the atomic layer doping, and calculated its effect on spin-polarized lateral displacement of the electron. Both magnitude and sign of spin polarization are found to be sensitive to the δ-doping. Therefore, such a device can serve as a structurally-controllable spin-polarized source for spintronics applications.</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/2013AGUFMSM33A2168L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSM33A2168L"><span id="translatedtitle">Adiabatic and nonadiabatic responses of the radiation belt relativistic electrons to the external changes in solar wind dynamic pressure and <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</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.</p> <p>2013-12-01</p> <p>By removing the influences of 'magnetopause shadowing' (r0>6.6RE) and geomagnetic activities, we investigated statistically the responses of <span class="hlt">magnetic</span> field and relativistic (>0.5MeV) electrons at geosynchronous orbit to 201 <span class="hlt">interplanetary</span> perturbations during 6 years from 2003 (solar maximum) to 2008 (solar minimum). The statistical results indicate that during geomagnetically quiet times (HSYM ≥-30nT, and AE<200nT), ~47.3% changes in the geosynchronous <span class="hlt">magnetic</span> field and relativistic electron fluxes are caused by the combined actions of the enhancement of solar wind dynamic pressure (Pd) and the southward turning of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) (ΔPd>0.4 nPa, and IMF Bz<0 nT), and only ~18.4% changes are due to single dynamic pressure increase (ΔPd >0.4 nPa, but IMF Bz>0 nT), and ~34.3% changes are due to single southward turning of IMF (IMF Bz<0 nT, but |ΔPd|<0.4 nPa). Although the responses of <span class="hlt">magnetic</span> field and relativistic electrons to the southward turning of IMF are weaker than their responses to the dynamic pressure increase, the southward turning of IMF can cause the dawn-dusk asymmetric perturbations that the <span class="hlt">magnetic</span> field and the relativistic electrons tend to increase on the dawnside (LT~00:00-12:00) but decrease on the duskside (LT~13:00-23:00). Furthermore, the variation of relativistic electron fluxes is adiabatically controlled by the magnitude and elevation angle changes of <span class="hlt">magnetic</span> field during the single IMF southward turnings. However, the variation of relativistic electron fluxes is independent of the change in <span class="hlt">magnetic</span> field in some compression regions during the enhancement of solar wind dynamic pressure (including the single pressure increases and the combined external perturbations), indicating that nonadiabatic dynamic processes of relativistic electrons occur there. Acknowledgments. This work is supported by NSFC (grants 41074119 and 40604018). Liuyuan Li is grateful to the staffs working for the data from GOES 8-12 satellites and OMNI database in CDAWeb.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6416734','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6416734"><span id="translatedtitle">Use of induction linacs with nonlinear <span class="hlt">magnetic</span> drive as high <span class="hlt">average</span> power accelerators</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Birx, D.L.; Cook, E.G.; Hawkins, S.A.; Newton, M.A.; Poor, S.E.; Reginato, L.L.; Schmidt, J.A.; Smith, M.W.</p> <p>1984-08-20</p> <p>The marriage of induction linac technology with Nonlinear <span class="hlt">Magnetic</span> Modulators has produced some unique capabilities. It appears possible to produce electron beams with <span class="hlt">average</span> currents measured in amperes, at gradients exceeding 1 Mev/meter, and with power efficiencies approaching 50%. A 2 MeV, 5 kA electron accelerator is under construction at Lawrence Livermore National Laboratory (LLNL) to allow us to demonstrate some of these concepts. Progress on this project is reported here.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012cosp...39...35A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012cosp...39...35A"><span id="translatedtitle">3-D models of the Forbush decrease and 27-day variation of galactic cosmic rays with three dimensional divergence-free <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alania, Michael; Modzelewska, Renata; Wawrzynczak-Szaban, Anna</p> <p>2012-07-01</p> <p>We develop the three dimensional (3-D) models of the Forbush decrease (Fd) and 27-day variation of the galactic cosmic ray (GCR) intensity with the variable solar wind velocity. In the models is implemented a structure of the three dimensional <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) obtained as a numerical solution of Maxwell's equations with the heliolongitudinal and heliolatitudinal dependencies of the radial component of the solar wind velocity that approximately corresponds to in situ measurements. Based on the Bernoulli principle we consider the possible circumstances leading to the formation of the latitudinal B _{θ} component of the IMF due to violence of the equilibrium between different layers of the variable solar wind streams. We compare 3-D modeling results of the Forbush decrease (Fd) and 27-day variation of the GCR intensity with the observed variation of cosmic ray intensity from world wide network of neutron monitors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930015892','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930015892"><span id="translatedtitle">Anomalous aspects of magnetosheath flow and of the shape and oscillations of the magnetopause during an interval of strongly northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chen, Sheng-Hsien; Kivelson, Margaret G.; Gosling, Jack T.; Walker, Raymond T.; Lazarus, Allan J.</p> <p>1992-01-01</p> <p>On 15 Feb. 1978, the orientation of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) remained steadily northward for more than 12 hours. The ISEE 1 and 2 spacecraft were located near apogee on the dawn side flank of the magnetotail. IMP 8 was almost symmetrically located in the magnetosheath on the dusk flank and IMP 7 was upstream in the solar wind. Using plasma and <span class="hlt">magnetic</span> field data, we show the following: (1) the magnetosheath flow speed on the flanks of the magnetotail steadily exceeded the solar wind speed by 20 percent; (2) surface waves with approximately a 5-min period and very non-sinusoidal waveform were persistently present on the dawn magnetopause and waves of similar period were present in the dusk magnetosheath; and (3) the magnetotail ceased to flare at an antisunward distance of 15 R(sub E). We propose that the acceleration of the magnetosheath flow is achieved by <span class="hlt">magnetic</span> tension in the draped field configuration for northward IMF and that the reduction of tail flaring is consistent with a decreased amount of open <span class="hlt">magnetic</span> flux and a larger standoff distance of the subsolar magnetopause. Results of a three-dimensional magnetohydrodynamic simulation support this phenomenological model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6306067','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6306067"><span id="translatedtitle">Anomalous aspects of magnetosheath flow and of the shape and oscillations of the magnetopause during an interval of strongly northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chen, S.; Kivelson, M.G.; Gosling, J.T.; Walker, R.T.; Lazarus, A.J.</p> <p>1992-09-01</p> <p>On 15 Feb. 1978, the orientation of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) remained steadily northward for more than 12 hours. The ISEE 1 and 2 spacecraft were located near apogee on the dawn side flank of the magnetotail. IMP 8 was almost symmetrically located in the magnetosheath on the dusk flank and IMP 7 was upstream in the solar wind. Using plasma and <span class="hlt">magnetic</span> field data, the authors show the following: (1) the magnetosheath flow speed on the flanks of the magnetotail steadily exceeded the solar wind speed by 20 percent; (2) surface waves with approximately a 5-min period and very non-sinusoidal waveform were persistently present on the dawn magnetopause and waves of similar period were present in the dusk magnetosheath; and (3) the magnetotail ceased to flare at an antisunward distance of 15 R(sub E). They propose that the acceleration of the magnetosheath flow is achieved by <span class="hlt">magnetic</span> tension in the draped field configuration for northward IMF and that the reduction of tail flaring is consistent with a decreased amount of open <span class="hlt">magnetic</span> flux and a larger standoff distance of the subsolar magnetopause. Results of a three-dimensional magnetohydrodynamic simulation support this phenomenological model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70011277','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70011277"><span id="translatedtitle">Statistical <span class="hlt">averaging</span> of marine <span class="hlt">magnetic</span> anomalies and the aging of oceanic crust.</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Blakely, R.J.</p> <p>1983-01-01</p> <p>Visual comparison of Mesozoic and Cenozoic <span class="hlt">magnetic</span> anomalies in the North Pacific suggests that older anomalies contain less short-wavelength information than younger anomalies in this area. To test this observation, <span class="hlt">magnetic</span> profiles from the North Pacific are examined from crust of three ages: 0-2.1, 29.3-33.1, and 64.9-70.3Ma. For each time period, at least nine profiles were analyzed by 1) calculating the power density spectrum of each profile, 2) <span class="hlt">averaging</span> the spectra together, and 3) computing a 'recording filter' for each time period by assuming a hypothetical seafloor model. The model assumes that the top of the source is acoustic basement, the source thickness is 0.5km, and the time scale of geomagnetic reversals is according to Ness et al. (1980). The calculated power density spectra of the three recording filters are complex in shape but show an increase of attenuation of short-wavelength information as the crust ages. These results are interpreted using a multilayer model for marine <span class="hlt">magnetic</span> anomalies in which the upper layer, corresponding to pillow basalt of seismic layer 2A, acts as a source of noise to the <span class="hlt">magnetic</span> anomalies. As the ocean crust ages, this noisy contribution by the pillow basalts becomes less significant to the anomalies. Consequently, <span class="hlt">magnetic</span> sources below layer 2A must be faithful recorders of geomagnetic reversals.-AuthorPacific power density spectrum</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20070023320&hterms=CANE&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DCANE','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20070023320&hterms=CANE&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DCANE"><span id="translatedtitle"><span class="hlt">Interplanetary</span> Coronal Mass Ejections During 1996 - 2007</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Richardson, I. G.; Cane, H. V.</p> <p>2007-01-01</p> <p><span class="hlt">Interplanetary</span> coronal mass ejections, the <span class="hlt">interplanetary</span> counterparts of coronal mass ejections at the Sun, are the major drivers of <span class="hlt">interplanetary</span> shocks in the heliosphere, and are associated with modulations of the galactic cosmic ray intensity, both short term (Forbush decreases caused by the passage of the shock, post-shock sheath, and ICME), and possibly with longer term modulation. Using several in-situ signatures of ICMEs, including plasma temperature, and composition, <span class="hlt">magnetic</span> fields, and cosmic ray modulations, made by near-Earth spacecraft, we have compiled a "comprehensive" list of ICMEs passing the Earth since 1996, encompassing solar cycle 23. We summarize the properties of these ICMEs, such as their occurrence rate, speeds and other parameters, the fraction of ICMEs that are classic <span class="hlt">magnetic</span> clouds, and their association with solar energetic particle events, halo CMEs, <span class="hlt">interplanetary</span> shocks, geomagnetic storms, shocks and cosmic ray decreases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20110007246&hterms=cloud+software&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dcloud%2Bsoftware','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20110007246&hterms=cloud+software&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dcloud%2Bsoftware"><span id="translatedtitle">Erratum to "Solar Sources and Geospace Consequences of <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Clouds Observed During Solar Cycle 23-Paper 1" [J. Atmos. Sol.-Terr. Phys. 70(2-4) (2008) 245-253</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gopalswamy, N.; Akiyama, S.; Yashiro, S.; Michalek, G.; Lepping, R. P.</p> <p>2009-01-01</p> <p>One of the figures (Fig. 4) in "Solar sources and geospace consequences of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> Clouds observed during solar cycle 23 -- Paper 1" by Gopalswamy et al. (2008, JASTP, Vol. 70, Issues 2-4, February 2008, pp. 245-253) is incorrect because of a software error in t he routine that was used to make the plot. The source positions of various <span class="hlt">magnetic</span> cloud (MC) types are therefore not plotted correctly.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014IAUS..300..297W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014IAUS..300..297W"><span id="translatedtitle"><span class="hlt">Interplanetary</span> Disturbances Affecting Space Weather</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wimmer-Schweingruber, Robert F.</p> <p>2014-01-01</p> <p>The Sun somehow accelerates the solar wind, an incessant stream of plasma originating in coronal holes and some, as yet unidentified, regions. Occasionally, coronal, and possibly sub-photospheric structures, conspire to energize a spectacular eruption from the Sun which we call a coronal mass ejection (CME). These can leave the Sun at very high speeds and travel through the <span class="hlt">interplanetary</span> medium, resulting in a large-scale disturbance of the ambient background plasma. These <span class="hlt">interplanetary</span> CMEs (ICMEs) can drive shocks which in turn accelerate particles, but also have a distinct intrinsic <span class="hlt">magnetic</span> structure which is capable of disturbing the Earth's <span class="hlt">magnetic</span> field and causing significant geomagnetic effects. They also affect other planets, so they can and do contribute to space weather throughout the heliosphere. This paper presents a historical review of early space weather studies, a modern-day example, and discusses space weather throughout the heliosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19950047166&hterms=earth+magnetic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dearth%2527s%2Bmagnetic','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950047166&hterms=earth+magnetic&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dearth%2527s%2Bmagnetic"><span id="translatedtitle">The Earth's magnetosphere is 165 R(sub E) long: Self-consistent currents, convection, magnetospheric structure, and processes for northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fedder, J. A.; Lyon, J. G.</p> <p>1995-01-01</p> <p>The subject of this paper is a self-consistent, magnetohydrodynamic numerical realization for the Earth's magnetosphere which is in a quasi-steady dynamic equilibrium for a due northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF). Although a few hours of steady northward IMF are required for this asymptotic state to be set up, it should still be of considerable theoretical interest because it constitutes a 'ground state' for the solar wind-magnetosphere interaction. Moreover, particular features of this ground state magnetosphere should be observable even under less extreme solar wind conditions. Certain characteristics of this magnetosphere, namely, NBZ Birkeland currents, four-cell ionospheric convection, a relatively weak cross-polar potential, and a prominent flow boundary layer, are widely expected. Other characteristics, such as no open tail lobes, no Earth-connected <span class="hlt">magnetic</span> flux beyond 155 R(sub E) downstream, <span class="hlt">magnetic</span> merging in a closed topology at the cusps, and a 'tadpole' shaped magnetospheric boundary, might not be expected. In this paper, we will present the evidence for this unusual but interesting magnetospheric equilibrium. We will also discuss our present understanding of this singular state.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6062150','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6062150"><span id="translatedtitle">Optimal transformation for correcting partial volume <span class="hlt">averaging</span> effects in <span class="hlt">magnetic</span> resonance imaging</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Soltanian-Zadeh, H. Henry Ford Hospital, Detroit, MI ); Windham, J.P. ); Yagle, A.E. )</p> <p>1993-08-01</p> <p>Segmentation of a feature of interest while correcting for partial volume <span class="hlt">averaging</span> effects is a major tool for identification of hidden abnormalities, fast and accurate volume calculation, and three-dimensional visualization in the field of <span class="hlt">magnetic</span> resonance imaging (MRI). The authors present the optimal transformation for simultaneous segmentation of a desired feature and correction of partial volume <span class="hlt">averaging</span> effects, while maximizing the signal-to-noise ratio (SNR) of the desired feature. It is proved that correction of partial volume <span class="hlt">averaging</span> effects requires the removal of the interfering features from the scene. It is also proved that correction of partial volume <span class="hlt">averaging</span> effects can be achieved merely by a linear transformation. It is finally shown that the optimal transformation matrix is easily obtained using the Gram-Schmidt orthogonalization procedure, which is numerically stable. Applications of the technique to MRI simulation, phantom, and brain images are shown. They show that in all cases the desired feature is segmented from the interfering features and partial volume information is visualized in the resulting transformed images.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ExG....47...58A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ExG....47...58A"><span id="translatedtitle">Depth and shape solutions from second moving <span class="hlt">average</span> residual <span class="hlt">magnetic</span> anomalies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Abdelrahman, El-Sayed M.; Essa, Khalid S.; El-Araby, Tarek M.; Abo-Ezz, Eid R.</p> <p>2016-02-01</p> <p>We have developed a simple and fast numerical method to simultaneously determine the depth and shape of a buried structure from second moving <span class="hlt">average</span> residual anomalies obtained from <span class="hlt">magnetic</span> data with filters of successive window lengths. The method is similar to Euler deconvolution, but it solves for depth and shape independently. The method involves using a nonlinear relationship between the depth to the source and the shape factor, and a combination of observations at five points with respect to the coordinate of the source centre with a free parameter (window length). The method is based on computing the standard deviation of the depths determined from all second moving <span class="hlt">average</span> residual anomalies for each value of the shape factor. The standard deviation may generally be considered a criterion for determining the correct depth and shape of the buried structure. When the correct shape factor is used, the standard deviation of the depths is less than the standard deviation using incorrect values of the shape factor. This method can be applied to residuals, as well as the observed <span class="hlt">magnetic</span> data consisting of the combined effect of a residual component due to a purely local structure and a regional component represented by a polynomial of up to fourth-order. The method is applied to synthetic data, with and without random errors, and tested on a field example from Brazil. In all cases, the shape and depth of the buried structures are found in good agreement with the actual ones.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6772193','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6772193"><span id="translatedtitle">The <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field B[sub y] effects on large-scale field-aligned currents near local noon: Contributions from cusp part and noncusp part</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Yamauchi, M.; Lundin, R.; Woch, J. )</p> <p>1993-04-01</p> <p>latitudinals develop a model to account for the effect of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) B[sub y] component on the dayside field-aligned currents (FACs). As part of the model the FACs are divided into a [open quotes]cusp part[close quotes] and a [open quotes]noncusp part[close quotes]. The authors then propose that the cusp part FACs shift in the longitudinal direction while the noncusplike part FACs shift in both longitudinal and latitudinal directions in response to the y component of the IMF. If combined, it is observed that the noncusp part FAC is found poleward of the cusp part FAC system when the y component of the IMF is large. These two FAC systems flow in the same direction. They reinforce one another, creating a strong FAC, termed the DPY-FAC. The model also predicts that the polewardmost part of the DPY-FAC flows on closed field lines, even in regions conventionally occupied by the polar cap. Results of the model are successfully compared with particle and <span class="hlt">magnetic</span> field data from Viking missions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6584334','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6584334"><span id="translatedtitle">Anomalous aspects of magnetosheath flow and of the shape and oscillations of the magnetopause during an interval of strongly northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chen, Shenghsien; Kivelson, M.G.; Walker, R.J. ); Gosling, J.T. ); Lazarus, A.J. )</p> <p>1993-04-01</p> <p>The authors address the question of the flow of the magnetosheath, and its coupling to the magnetopause, in particular along the flanks of the magnetotail. There was a greater than 12 hour period on February 15, 1978, when the orientation of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field remained northward. Several satellites observed this occurance. The ISEE 1 and 2 satellites were on the dawnside edge of the magnetotail. IMP 8 was on the duskside edge of the magnetosheath almost symmetric from the ISEE satellites. IMP 7 was at an upsteam location in the solar wind. The authors use plasma and <span class="hlt">magnetic</span> field measurement data to propose a model which they then support with three-dimensional magnetohydrodynamic simulations. They observe that the flow speed of the magnetosheath on the edges of the magnetotail exceeds the solar wind speed by roughly 20%. Plasma surface wave with roughly 5 minute periods were observed in the magnetopause and magnetosphere. Flaring of the magnetotail ceased at an antisunward distance of roughly 15R[sub E].</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhyE...71...39S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhyE...71...39S"><span id="translatedtitle">A structurally-controllable spin filter in a δ-doped <span class="hlt">magnetically</span> modulated semiconductor nanostructure with zero <span class="hlt">average</span> <span class="hlt">magnetic</span> field</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shen, Li-Hua; Ma, Wen-Yue; Zhang, Gui-Lian; Yang, Shi-Peng</p> <p>2015-07-01</p> <p>We report on a theoretical investigation of spin-polarized transport in a δ-doped <span class="hlt">magnetically</span> modulated semiconductor nanostructure, which can be experimentally realized by depositing a ferromagnetic stripe on the top of a semiconductor heterostructure and by using the atomic layer doping technique such as molecular beam epitaxy (MBE). It is shown that although such a nanostructure has a zero <span class="hlt">average</span> <span class="hlt">magnetic</span> filed, a sizable spin polarization exists due to the Zeeman splitting mechanism. It is also shown that the degree of spin polarization varies sensitively with the weight and/or position of the δ-doping. Therefore, one can conveniently tailor the behaviour of the spin-polarized electron by tuning the δ -doping, and such a device can be employed as a controllable spin filter for spintronics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19950053481&hterms=swimming&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dswimming','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950053481&hterms=swimming&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dswimming"><span id="translatedtitle">Penetration of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field B(sub y) magnetosheath plasma into the magnetosphere: Implications for the predominant magnetopause merging site</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Newell, Patrick T.; Sibeck, David G.; Meng, Ching-I</p> <p>1995-01-01</p> <p>Magnetosheath plasma peertated into the magnetospere creating the particle cusp, and similarly the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) B(sub y) component penetrates the magnetopause. We reexamine the phenomenology of such penetration to investigate implications for the magnetopause merging site. Three models are popular: (1) the 'antiparallel' model, in which merging occurs where the local <span class="hlt">magnetic</span> shear is largest (usually high <span class="hlt">magnetic</span> latitude); (2) a tilted merging line passing through the subsolar point but extending to very high latitudes; or (3) a tilted merging line passing through the subsolar point in which most merging occurs within a few Earth radii of the equatorial plane and local noon (subsolar merging). It is difficult to distinguish between the first two models, but the third implies some very different predictions. We show that properties of the particle cusp imply that plasma injection into the magnetosphere occurs most often at high <span class="hlt">magnetic</span> latitudes. In particular, we note the following: (1) The altitude of the merging site inferred from midaltitude cusp ion pitch angle dispersion is typically 8-12 R(sub E). (2) The highest ion energy observable when moving poleward through the cusp drops long before the bulk of the cusp plasma is reached, implying that ions are swimming upstream against the sheath flow shortly after merging. (3) Low-energy ions are less able to enter the winter cusp than the summer cusp. (4) The local time behavior of the cusp as a function of B(sub y) and B(sub z) corroborates predictions of the high-latitude merging models. We also reconsider the penetration of the IMF B(sub y) component onto closed dayside field lines. Our approach, in which closed field lines ove to fill in flux voids created by asymmetric magnetopause flux erosion, shows that strich subsolar merging cannot account for the observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19870017315&hterms=Giotto&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DGiotto','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19870017315&hterms=Giotto&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DGiotto"><span id="translatedtitle">Macroscopic perturbations of the <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field (IMF) by P/Halley as seen by the Giotto magnetometer</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Raeder, J.; Neubauer, F. M.; Ness, N.; Burlaga, L. F.</p> <p>1986-01-01</p> <p>Giotto <span class="hlt">magnetic</span> field data were used to analyze the macroscopic field structure in the vicinity of P/Halley. During the Giotto flyby at comet P/Halley the IMF showed a quite stable away polarity. Draping of <span class="hlt">magnetic</span> field lines is clearly observed along the outbound leg of the trajectory. Inside the <span class="hlt">magnetic</span> pile-up region the field reverses its polarity several times. A symmetry of oppositely <span class="hlt">magnetized</span> sheets with respect to the nucleus is found and explained in terms of convected IMF features.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19950058919&hterms=empirical+formula&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dempirical%2Bformula','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950058919&hterms=empirical+formula&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dempirical%2Bformula"><span id="translatedtitle">Three-dimensional position and shape of the bow shock and their variation with Alfvenic, sonic and magnetosonic Mach numbers and <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field orientation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Peredo, M.; Slavin, J. A.; Mazur, E.; Curtis, S. A.</p> <p>1995-01-01</p> <p>A large set of bow shock crossings (i.e., 1392) observed by 17 spacecraft has been used to explore the three-dimensional shape and location of the Earth's bow shock and its dependence on solar wind and <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) conditions. This study investigates deviations from gas dynamic flow models associated with the <span class="hlt">magnetic</span> terms in the magnetohydrodynamic (MHD) equations. Empirical models predicting the statistical position and shape of the bow shock for arbitrary values of the solar wind pressure, IMF, and Alfvenic Mach number (M(sub A)) have been derived. The resulting data set has been used to fit three-dimensional bow shock surfaces and to explore the variations in these surfaces with sonic (M(sub S)), Alfvenic (M(sub A)) and magnetosonic (M(sub MS)) Mach numbers. Analysis reveals that among the three Mach numbers, M(sub A) provides the best ordering of the least square bow shock curves. The subsolar shock is observed to move Earthward while the flanks flare outward in response to decreasing M(sub A); the net change represents a 6-10% effect. Variations due to changes in the IMF orientation were investigated by rotating the crossings into geocentric <span class="hlt">interplanetary</span> medium coordinates. Past studies have suggested that the north-south extent of the bow shock surface exceeds the east-west dimension due to asymmetries in the fast mode Mach cone. This study confirms such a north-south versus east-west asymmetry and quantifies its variation with M(sub S), M(sub A), M(sub MS), and IMF orientation. A 2-7% effect is measured, with the asymmetry being more pronounced at low Mach numbers. Combining the bow shock models with the magnetopause model of Roelof and Sibeck (1993), variations in the magnetosheath thickness at different local times are explored. The ratio of the bow shock size to the magnetopause size at the subpolar point is found to be 1.46; at dawn and dusk, the ratios are found to be 1.89 and 1.93, respectively. The subsolar magnetosheath thickness is used to derive the polytropic index gamma according to the empirical relation of Spreiter et al. (1966). The resulting gamma = 2.3 suggests the empirical formula is inadequate to describe the MHD interaction between the solar wind and the magnetosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011hst..prop12800V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011hst..prop12800V"><span id="translatedtitle">Velocity measurement of the <span class="hlt">interplanetary</span> hydrogen</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vincent, Frederic</p> <p>2011-10-01</p> <p>We are proposing to use HST/STIS over a single orbit to make Lyman-alpha observations of the <span class="hlt">interplanetary</span> hydrogen during the March-April period of this year {2012}. This special request is driven by a recent reanalysis of HST data {Vincent et al. 2011, published after the last call for proposals}.The heliospheric interface results from the interaction of the solar wind and the interstellar medium {ISM}. Within the heliosphere, the <span class="hlt">interplanetary</span> hydrogen {IPH} flows at an <span class="hlt">average</span> speed of about 23 km/sec, carrying the signature of the ISM and the heliospheric interface. The IPH has been observed for decades through the backscattering of solar Lyman-alpha photons and solar cycle 23 provided the first partial temporal map of the IPH velocity. It is now well established that the IPH velocity depends on solar activity. Moreover some analyses suggested that it may be also affected by the obliquity of the interstellar <span class="hlt">magnetic</span> field, yielding a change of 1-2 km/sec.However a combination of the uncertainty of some measurements {e.g. GHRS} and the clustering of others near points on the cycle make it difficult to identify an unambiguous trend. Only one limited set is able to show a cycle dependence, but these represent an annual <span class="hlt">average</span> and do not match the existing models. The best approach to address these issues is a new set of yearly spectroscopic measurements for at least a half solar cycle. Since we are currently just leaving a solar maximum, it is essential to start immediately in order to have an adequate baseline for temporal measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19820012231','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19820012231"><span id="translatedtitle"><span class="hlt">Magnetic</span> field measurements at Jupiter by Voyagers 1 and 2: Daily plots of 48 second <span class="hlt">averages</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lepping, R. P.; Silverstein, M. J.; Ness, N. F.</p> <p>1981-01-01</p> <p>A series of 24 hour summary plots of the <span class="hlt">magnetic</span> field, in 48-s <span class="hlt">average</span> form, measured in the vicinity of Jupiter by the magnetometers onboard Voyagers 1 and 2 are presented. The Voyager 1 data cover the period from 27 February 1979 (day = 58) to 23 March (day = 82) inclusive, and the Voyager 2 data cover the period from 2 July 1979 (day = 183) to 14 August (day = 226) inclusive. Closest approach to the planet occurred on days 64 (AT 1205 UT) and 190 (AT 2230 UT) for Voyagers 1 and 2, respectively. Also included are: a description of the characteristics of the magnetometers, a brief description of the near-planet trajectories of the two spacecraft, a listing of the bow shock and magnetopause crossing times, and a bibliography containing Voyager-Jupiter related papers and reports.</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://hdl.handle.net/2060/20140009615','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140009615"><span id="translatedtitle">The First in situ Observation of Kelvin-Helmholtz Waves at High-Latitude Magnetopause during Strongly Dawnward <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field Conditions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hwang, K.-J.; Goldstein, M. L.; Kuznetsova, M. M.; Wang, Y.; Vinas, A. F.; Sibeck, D. G.</p> <p>2012-01-01</p> <p>We report the first in situ observation of high-latitude magnetopause (near the northern duskward cusp) Kelvin-Helmholtz waves (KHW) by Cluster on January 12, 2003, under strongly dawnward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) conditions. The fluctuations unstable to Kelvin-Helmholtz instability (KHI) are found to propagate mostly tailward, i.e., along the direction almost 90 deg. to both the magnetosheath and geomagnetic fields, which lowers the threshold of the KHI. The <span class="hlt">magnetic</span> configuration across the boundary layer near the northern duskward cusp region during dawnward IMF is similar to that in the low-latitude boundary layer under northward IMF, in that (1) both magnetosheath and magnetospheric fields across the local boundary layer constitute the lowest <span class="hlt">magnetic</span> shear and (2) the tailward propagation of the KHW is perpendicular to both fields. Approximately 3-hour-long periods of the KHW during dawnward IMF are followed by the rapid expansion of the dayside magnetosphere associated with the passage of an IMF discontinuity that characterizes an abrupt change in IMF cone angle, Phi = acos (B(sub x) / absolute value of Beta), from approx. 90 to approx. 10. Cluster, which was on its outbound trajectory, continued observing the boundary waves at the northern evening-side magnetopause during sunward IMF conditions following the passage of the IMF discontinuity. By comparing the signatures of boundary fluctuations before and after the IMF discontinuity, we report that the frequencies of the most unstable KH modes increased after the discontinuity passed. This result demonstrates that differences in IMF orientations (especially in f) are associated with the properties of KHW at the high-latitude magnetopause due to variations in thickness of the boundary layer, and/or width of the KH-unstable band on the surface of the dayside magnetopause.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUSMSH23B..02O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUSMSH23B..02O"><span id="translatedtitle">Update from the BU-CME Group: Accurate Prediction of CME Deflection and <span class="hlt">Magnetic</span> reconnection in the interior of <span class="hlt">interplanetary</span> CMEs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Opher, M.; Kay, C.; Fermo, R. L.; Drake, J. F.; Evans, R. M.</p> <p>2013-05-01</p> <p>The accurate prediction of the path of coronal mass ejections (CMEs) plays an important role in space weather forecasting, and knowing the source location of the CME does not always suffice. During solar minimum, for example, polar coronal holes (CHs) can deflect high latitude CMEs toward the ecliptic plane and when CHs extend to lower latitudes deflections in other directions can occur. To predict whether a CME will impact Earth the effects of the solar background on the CME's trajectory must be taken into account. Here we develop a model (Kay et al. 2013), called ForeCAT (Forecasting a CME's Altered Trajectory), of CME deflection close to the Sun where <span class="hlt">magnetic</span> forces dominate. Given the background solar wind conditions, the launch site of the CME, and the properties of the CME (such as its mass and size), ForeCAT predicts the deflection of the CME as well as the full trajectory as the CME propagates away from the Sun. For a <span class="hlt">magnetic</span> background where the CME is launched from an active region located in between a CH and streamer region the strong <span class="hlt">magnetic</span> gradients cause a deflection of 39.0o in latitude and 21.9o in longitude. Varying the CME's input parameters within observed ranges leads to deflections predominantly between 36.2o and 44.5o in latitude and between 19.5o and 27.9 in longitude. For all cases, the majority of the deflection occurs before the CME reaches a radial distance of 3 R⊙. Recent in situ observations of <span class="hlt">interplanetary</span> mass ejections (ICMEs) found signatures of reconnection exhausts in their interior or trailing edge. This result suggests that the internal <span class="hlt">magnetic</span> field reconnects with itself. To this end, we propose an approach (Fermo et al. 2013) borrowed from the fusion plasma community. Taylor (1974) showed that the lowest energy state corresponds to one in which \\grad × B = λ B. Variations from this state will result in the <span class="hlt">magnetic</span> field trying to re-orient itself into the Taylor state solution, subject to the constraints that the toroidal flux and <span class="hlt">magnetic</span> helicity are invariant. In tokamaks, the result is a sawtooth crash. In an ICME, if we likewise treat the flux rope as a toroidal flux tube, any variation from the Taylor state will result in reconnection within the interior of the flux tube, in accord with the observations by Gosling et al. (2007). We present MHD and PIC simulations that shows that indeed this is the case and discuss the implications for ICMEs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19780065152&hterms=solar+wind+magnetic+field&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dsolar%2Bwind%2Bmagnetic%2Bfield','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19780065152&hterms=solar+wind+magnetic+field&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dsolar%2Bwind%2Bmagnetic%2Bfield"><span id="translatedtitle">The 3-dimensional radio mapping experiment /SBH/ on ISEE-C. [<span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field structure for solar wind flow studies using type 3 bursts</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Knoll, R.; Epstein, G.; Hoang, S.; Huntzinger, G.; Steinberg, J. L.; Fainberg, J.; Grena, F.; Stone, R. G.; Mosier, S. R.</p> <p>1978-01-01</p> <p>The SBH experiment on ISEE-C will provide maps of the large scale structure of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field from ten solar radii altitude to the earth orbit, in and out of the ecliptic. The SBH instrument will track type III solar radio bursts at 24 frequencies in the range 30 kHz-2 MHz thus providing the positions of 24 points along the line of force which guides the electrons producing the radio radiation. The antennas are two dipoles: one (90 m long) in the spin plane, the other (15 m long) along the spin axis. The receiver was designed for high sensitivity (0.3 microV in 3 kHz BW), high intermodulation rejection (80 dB/1 microV input for order 2 products), large dynamic range (70 dB), high selectivity (-30-dB response 6.5 kHz away from the center frequency of 10.7 MHz for the 3 kHz BW channels), and high reliability (expected orbital life: 3 years).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19860041563&hterms=magnetic+control+satellite&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dmagnetic%2Bcontrol%2Bsatellite','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19860041563&hterms=magnetic+control+satellite&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dmagnetic%2Bcontrol%2Bsatellite"><span id="translatedtitle">A theoretical and empirical study of the response of the high latitude thermosphere to the sense of the 'Y' component of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rees, D.; Fuller-Rowell, T. J.; Gordon, R.; Smith, M. F.; Maynard, N. C.; Heppner, J. P.; Spencer, N. W.; Wharton, L.</p> <p>1986-01-01</p> <p>Patterns of magnetospheric energetic plasma precipitation as a function of the Y component of the <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field (IMF) are studied. The development of a three-dimensional, time-dependent global thermospheric model using a polar conversion electric field with a dependence on the Y component of the IMF to evaluate thermospheric wind circulation is examined. Thermospheric wind data from the ISEE-3 satellite, Dynamics Explorer-2 satellite, and a ground-based Fabry-Perot interferometer in Kiruna, Sweden, collected on December 1, 2, 6, 25, 1981 and February 12, 13, 1982 are described. The observed data and simulations of polar thermospheric winds are compared. In the Northern Hemisphere a strong antisunward ion flow on the dawn side of the geomagnetic polar cap is observed when the BY is positive, and the flow is detected on the dusk side when the BY is negative. It is concluded that the strength and direction of the IMF directly control the transfer of solar wind momentum and energy to the high latitude thermosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19910052371&hterms=CANE&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DCANE','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19910052371&hterms=CANE&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DCANE"><span id="translatedtitle">Prompt arrival of solar energetic particles from far eastern events - The role of large-scale <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field structure</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Richardson, I. G.; Cane, H. V.; Von Rosenvinge, T. T.</p> <p>1991-01-01</p> <p>Intensity-time profiles of solar energetic particle enhancements generally show an asymmetry with respect to the heliolongitude of the associated solar event. Particles arrive promptly from events to the west of an observer because of good <span class="hlt">magnetic</span> connection, whereas particle enhancements from poorly connected eastern source regions usually show much slower onsets. However, some 15 percent of eastern events do show prompt onsets. Two prompt particle enhancements associated with eastern solar events are studied using data from the Goddard Space Flight Center instruments on the ISEE 3 and IMP 8 spacecraft. In both events the prompt particle onset was observed when the spacecraft were in a postshock plasma region, apparently within a <span class="hlt">magnetic</span> bottle. It is suggested that the <span class="hlt">magnetic</span> bottle extended back to the sun and served as a channel for fast particle propagation to the spacecraft. Particles accelerated at an expanding coronal shock initiated by the eastern event could be injected onto field lines in the foot of the bottle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19950057064&hterms=solar+wind+magnetic+field&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsolar%2Bwind%2Bmagnetic%2Bfield','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950057064&hterms=solar+wind+magnetic+field&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsolar%2Bwind%2Bmagnetic%2Bfield"><span id="translatedtitle">Cusp/cleft auroral activity in relation to solar wind dynamic pressure, <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field B(sub z) and B(sub y)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sandholt, P. E.; Farrugia, C. J.; Burlaga, L. F.; Holtet, J. A.; Moen, J.; Lybekk, B.; Jacobsen, B.; Opsvik, D.; Egeland, A.; Lepping, R.</p> <p>1994-01-01</p> <p>Continuous optical observations of cusp/cleft auroral activities within approximately equal to 09-15 MLT and 70-76 deg <span class="hlt">magnetic</span> latitude are studied in relation to changes in solar wind dynamic pressure and <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) variability. The observed latitudinal movements of the cusp/cleft aurora in response to IMF B(sub z) changes may be explained as an effect of a variable <span class="hlt">magnetic</span> field intensity in the outer dayside magnetosphere associated with the changing intensity of region 1 field-aligned currents and associated closure currents. Ground <span class="hlt">magnetic</span> signatures related to such currents were observed in the present case (January 10, 1993). Strong, isolated enhancements in solar wind dynamic pressure (Delta p/p is greater than or equal to 0.5) gave rise to equatorward shifts of the cusp/cleft aurora, characteristic auroral transients, and distinct ground <span class="hlt">magnetic</span> signatures of enhanced convection at cleft latitudes. A sequence of auroral events of approximately equal to 5-10 min recurrence time, moving eastward along the poleward boundary of the persistent cusp/cleft aurora in the approximately equal to 10-14 MLT sector, during negative IMF B(sub z) and B(sub y) conditions, were found to be correlated with brief pulses in solar wind dynamic pressure (0.1 is less than Delta p/p is less than 0.5). Simultaneous photometer observations from Ny Alesund, Svalbard, and Danmarkshavn, Greenland, show that the events often appeared on the prenoon side (approximately equal to 10-12 MLT), before moving into the postnoon sector in the case we study here, when IMF B(sub y) is less than 0. In other cases, similar auroral event sequences have been observed to move westward in the prenoon sector, during intervals of positive B(sub y). Thus a strong prenoon/postnoon asymmetry of event occurence and motion pattern related to the IMF B(sub y) polarity is observed. We find that this category of auroral event sequence is stimulated bursts of electron precipitation that originate from magnetosheath plasma that has accessed that dayside magnetosphere in the noon or near-noon sector, possibly at high latitudes, partly governed by the IMF orientation as well as by solar wind dynamic pressure pulses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19930039184&hterms=wave+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dwave%2Benergy','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19930039184&hterms=wave+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dwave%2Benergy"><span id="translatedtitle">Wave properties near the subsolar magnetopause - Pc 3-4 energy coupling for northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Song, P.; Russell, C. T.; Strangeway, R. J.; Wygant, J. R.; Cattell, C. A.; Fitzenreiter, R. J.; Anderson, R. R.</p> <p>1993-01-01</p> <p>Strong slow mode waves in the Pc 3-4 frequency range are found in the magnetosheath close to the magnetopause. We have studied these waves at one of the ISEE subsolar magnetopause crossings using the <span class="hlt">magnetic</span> field, electric field, and plasma measurements. We use the pressure balance at the magnetopause to calibrate the Fast Plasma Experiment data versus the magnetometer data. When we perform such a calibration and renormalization, we find that the slow mode structures are not in pressure balance and small scale fluctuations in the total pressure still remain in the Pc 3-4 range. Energy in the total pressure fluctuations can be transmitted through the magnetopause by boundary motions. The Poynting flux calculated from the electric and <span class="hlt">magnetic</span> field measurements suggests that a net Poynting flux is transmitted into the magnetopause. The two independent measurements show a similar energy transmission coefficient. The transmitted energy flux is about 18 percent of the <span class="hlt">magnetic</span> energy flux of the waves in the magnetosheath. Part of this transmitted energy is lost in the sheath transition layer before it enters the closed field line region. The waves reaching the boundary layer decay rapidly. Little wave power is transmitted into the magnetosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.9519L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.9519L"><span id="translatedtitle">Influence of <span class="hlt">interplanetary</span> solar wind sector polarity on the ionosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>liu, jing</p> <p>2014-05-01</p> <p>Knowledge of solar sector polarity effects on the ionosphere may provide some clues in understanding of the ionospheric day-to-day variability. A solar-terrestrial connection ranging from solar sector boundary (SB) crossings, geomagnetic disturbance and ionospheric perturbations has been demonstrated. The increases in <span class="hlt">interplanetary</span> solar wind speed within three days are seen after SB crossings, while the decreases in solar wind dynamic pressure and <span class="hlt">magnetic</span> field intensity immediately after SB crossings are confirmed by the superposed epoch analysis results. Furthermore, the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) Bz component turns from northward to southward in March equinox and June solstice as the Earth passes from a solar sector of outward to inward directed <span class="hlt">magnetic</span> fields, whereas the reverse situation occurs for the transition from toward to away sectors. The F2 region critical frequency (foF2) covering about four solar cycles and total electron content (TEC) during 1998-2011 are utilized to extract the related information, revealing that they are not modified significantly and vary within the range of 15% on <span class="hlt">average</span>. The responses of the ionospheric TEC to SB crossings exhibit complex temporal and spatial variations and have strong dependencies on season, latitude, and solar cycle. This effect is more appreciable in equinoctial months than in solstitial months, which is mainly caused by larger southward Bz components in equinox. In September equinox, latitudinal profile of relative variations of foF2 at noon is featured by depressions at high latitudes and enhancements in low-equatorial latitudes during IMF away sectors. The negative phase of foF2 is delayed at solar minimum relative to it during other parts of solar cycle, which might be associated with the difference in longevity of major <span class="hlt">interplanetary</span> solar wind drivers perturbing the Earth's environment in different phases of solar cycle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19870027662&hterms=solar+wind+magnetic+field&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsolar%2Bwind%2Bmagnetic%2Bfield','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19870027662&hterms=solar+wind+magnetic+field&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dsolar%2Bwind%2Bmagnetic%2Bfield"><span id="translatedtitle">An MHD simulation of the effects of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field By component on the interaction of the solar wind with the earth's magnetosphere during southward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ogino, T.; Walker, R. J.; Ashour-Abdalla, M.; Dawson, J. M.</p> <p>1986-01-01</p> <p>The interaction between the solar wind and the earth's magnetosphere has been studied by using a time-dependent three-dimensional MHD model in which the IMF pointed in several directions between dawnward and southward. When the IMF is dawnward, the dayside cusp and the tail lobes shift toward the morningside in the northern magnetosphere. The plasma sheet rotates toward the north on the dawnside of the tail and toward the south on the duskside. For an increasing southward IMF component, the plasma sheet becomes thinner and subsequently wavy because of patchy or localized tail reconnection. At the same time, the tail field-aligned currents have a filamentary layered structure. When projected onto the northern polar cap, the filamentary field-aligned currents are located in the same area as the region 1 currents, with a pattern similar to that associated with auroral surges. <span class="hlt">Magnetic</span> reconnection also occurs on the dayside magnetopause for southward IMF.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19880059341&hterms=average+wind+speeds&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Daverage%2Bwind%2Bspeeds','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19880059341&hterms=average+wind+speeds&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Daverage%2Bwind%2Bspeeds"><span id="translatedtitle">The <span class="hlt">average</span> configuration of the induced Venus magnetotail</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mccomas, D. J.; Spence, H. E.; Russell, C. T.</p> <p>1987-01-01</p> <p>The interaction of the solar-wind flow with Venus is discussed as well as the morphology of <span class="hlt">magnetic</span>-field-line draping in the Venus magnetotail. Emphasis is placed on the importance of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field X-component in controlling the configuration of field draping in this induced magnetotail. The <span class="hlt">average</span> <span class="hlt">magnetic</span> configuration of this magnetotail is studied. A connection is made between the derived consistent plasma flow speed and density and the observational energy/charge range and sensitivity of the Pioneer Venus Orbiter plasma analyzer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.P34B..05J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.P34B..05J"><span id="translatedtitle">Mercury's Time-<span class="hlt">Averaged</span> and Induced <span class="hlt">Magnetic</span> Fields from MESSENGER Observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Johnson, C. L.; Winslow, R. M.; Anderson, B. J.; Purucker, M. E.; Korth, H.; Al Asad, M. M.; Slavin, J. A.; Baker, D. N.; Hauck, S. A.; Phillips, R. J.; Zuber, M. T.; Solomon, S. C.</p> <p>2012-12-01</p> <p>Observations from MESSENGER's Magnetometer (MAG) have allowed the construction of a baseline, time-<span class="hlt">averaged</span> model for Mercury's magnetosphere. The model, constructed with the approximation that the magnetospheric shape can be represented as a paraboloid, includes two external (magnetopause and magnetotail) current systems and an internal (dipole) field. We take advantage of the geometry of the orbital MAG data to constrain all but one of the model parameters, and their ranges, directly from the observations. These parameters are then used as a priori constraints in the magnetospheric model, and the remaining parameter, the dipole moment, is estimated from a grid search. The model provides an excellent fit to the MAG observations, with a root-mean-square misfit of less than 20 nT globally. The mean distance from the planetary dipole origin to the magnetopause subsolar point, RSS, is 1.45 RM (where RM = 2440 km) and the mean planetary dipole moment is 190 nT- RM3. Temporal variations in the global-scale <span class="hlt">magnetic</span> fields result from changes in solar wind ram pressure, Pram, at Mercury that arise from the planet's 88-day eccentric orbit around the Sun and from transient, rapid changes in solar wind conditions. For a constant planetary dipole moment, RSS varies as Pram-1/6. However, magnetopause crossings obtained from several Mercury years of MESSENGER observations indicate that RSS is proportional to Pram-1/a where a is greater than 6, suggesting induction in Mercury's highly conducting metallic interior. We obtain an effective dipole moment that varies by up to ˜15% about its mean value. We further investigate the periodic 88-day induction signature and use the paraboloid model to describe the spatial structure in the inducing magnetopause field, together with estimates for the outer radius of Mercury's liquid core and possible overlying solid iron sulfide layer, to calculate induced core fields. The baseline magnetospheric model is adapted to include the 88-day periodic induction signature, and residuals to this time-varying global model from <span class="hlt">magnetically</span> quiet orbits are then used to investigate structure at higher degree and order in the internal and external fields.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20060036252&hterms=balogh&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAuthor-Name%26N%3D0%26No%3D10%26Ntt%3Dbalogh','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20060036252&hterms=balogh&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAuthor-Name%26N%3D0%26No%3D10%26Ntt%3Dbalogh"><span id="translatedtitle">Ulysses OUt-of-ecleptic Observations of <span class="hlt">Interplanetary</span> Shocks</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Burton, M. E.; Smith, E. J.; Balogh, A.; Forsyth, R. J.; Bame, S. J.; Goldstein, B. E.</p> <p>1996-01-01</p> <p><span class="hlt">Interplanetary</span> shocks observed at the Ulysses spacecraft as it traveled from the ecliptic plane to the southern solar pole have been identified and analyzed using both <span class="hlt">magnetic</span> field and plasma measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22408061','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22408061"><span id="translatedtitle">Orbit-<span class="hlt">averaged</span> quantities, the classical Hellmann-Feynman theorem, and the <span class="hlt">magnetic</span> flux enclosed by gyro-motion</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Perkins, R. J. Bellan, P. M.</p> <p>2015-02-15</p> <p>Action integrals are often used to <span class="hlt">average</span> a system over fast oscillations and obtain reduced dynamics. It is not surprising, then, that action integrals play a central role in the Hellmann-Feynman theorem of classical mechanics, which furnishes the values of certain quantities <span class="hlt">averaged</span> over one period of rapid oscillation. This paper revisits the classical Hellmann-Feynman theorem, rederiving it in connection to an analogous theorem involving the time-<span class="hlt">averaged</span> evolution of canonical coordinates. We then apply a modified version of the Hellmann-Feynman theorem to obtain a new result: the <span class="hlt">magnetic</span> flux enclosed by one period of gyro-motion of a charged particle in a non-uniform <span class="hlt">magnetic</span> field. These results further demonstrate the utility of the action integral in regards to obtaining orbit-<span class="hlt">averaged</span> quantities and the usefulness of this formalism in characterizing charged particle motion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSH52A..06T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSH52A..06T"><span id="translatedtitle">On the Estimate of Frequency Break and Spectral Index at Ion Scales for <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field Fluctuations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Telloni, D.; Bruno, R.; Trenchi, L.</p> <p>2014-12-01</p> <p>We exploited radial alignments between MESSENGER and WIND spacecraft to study: 1) the radial dependence of the spectral break located at the border between fluid and kinetic regimes; 2) the dependence, if any, of the spectral slope, around the frequency break, on the type of wind, either fast or slow.We found that this spectral break moves to lower and lower frequencies as heliocentric distance increases, following a power-law dependence. Moreover, we found evidence that a cyclotron-resonant dissipation mechanism must participate into the spectral energy cascade together with other possible kinetic noncyclotron-resonant mechanisms.On the other hand, the spectral slope shows a large variability between -3.75 and -1.75 with an <span class="hlt">average</span> value around -2.8 and a robust tendency for this parameter to be steeper within the trailing edge of high speed streams and to be flatter within the subsequent slower wind, following a gradual transition between these two states. The value of the spectral index seems to depend firmly on the power associated to the fluctuations within the inertial range, higher the power steeper the slope. Research partially supported by the Agenzia Spaziale Italiana, contract ASI/INAF I/013/12/0 and by the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 313038/STORM</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19750017288','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19750017288"><span id="translatedtitle"><span class="hlt">Interplanetary</span> field and plasma during initial phase of geomagnetic storms</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Patel, V. L.; Wiskerchen, M. J.</p> <p>1975-01-01</p> <p>Twenty-three geomagnetic storm events during 1966 to 1970 were studied by using simultaneous <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field and plasma parameters. Explorer 33 and 35 field and plasma data were analyzed on large-scale (hourly) and small-scale (3 min.) during the time interval coincident with the initial phase of the geomagnetic storms. The solar-ecliptic Bz component turns southward at the end of the initial phase, thus triggering the main phase decrease in Dst geomagnetic field. The By component also shows large fluctuations along with Bz. When there are no clear changes in the Bz component, the By shows abrupt changes at the main phase onset. On the small-scale, behavior of the <span class="hlt">magnetic</span> field and electric field were studied in detail for the three events; it is found that the field fluctuations in By, Bz and Ey and Ez are present in the initial phase. In the large-scale, the behavior field remains quiet because the small-scale variations are <span class="hlt">averaged</span> out. It appears that large as well as small time scale fluctuations in the <span class="hlt">interplanetary</span> field and plasma help to alter the internal electromagnetic state of the magnetosphere so that a ring current could causing a geomagnetic storm decrease.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012cosp...39.1247M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012cosp...39.1247M"><span id="translatedtitle">High Amplitude Events in relation to <span class="hlt">Interplanetary</span> disturbances</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mishra, Rajesh Kumar; Agarwal Mishra, Rekha</p> <p>2012-07-01</p> <p>The Sun emits the variable solar wind which interacts with the very local interstellar medium to form the heliosphere. Hence variations in solar activity strongly influence <span class="hlt">interplanetary</span> space, from the Sun's surface out to the edge of the heliosphere. Superimposed on the solar wind are mass ejections from the Sun and/or its corona which, disturb the <span class="hlt">interplanetary</span> medium - hence the name "<span class="hlt">interplanetary</span> disturbances". <span class="hlt">Interplanetary</span> disturbances are the sources of large-scale particle acceleration, of disturbances in the Earth's magnetosphere, of modulations of galactic cosmic rays in short, they are the prime focus for space weather studies. The investigation deals with the study of cosmic ray intensity, solar wind plasma and <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field parameters variation due to <span class="hlt">interplanetary</span> disturbances (<span class="hlt">magnetic</span> clouds) during an unusual class of days i.e. high amplitude anisotropic wave train events. The high amplitude anisotropic wave train events in cosmic ray intensity has been identified using the data of ground based Goose Bay neutron monitor and studied during the period 1981-94. Even though, the occurrence of high amplitude anisotropic wave trains does not depend on the onset of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> clouds. But the possibility of occurrence of these events cannot be overlooked during the periods of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> cloud events. It is observed that solar wind velocity remains higher (> 300) than normal and <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field B remains lower than normal on the onset of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> cloud during the passage of these events. It is also noted from the superposed epoch analysis of cosmic ray intensity and geomagnetic activity for high amplitude anisotropic wave train events during the onset of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> clouds that the increase in cosmic ray intensity and decrease in geomagnetic activity start not at the onset of <span class="hlt">magnetic</span> clouds but after few days. The north south component of IMF (Bz), IMF (B), proton density (N), proton temperature (T) and latitude angle reaches to their maximum, whereas solar wind velocity (V) and longitude angle reaches to their minimum on the day of <span class="hlt">magnetic</span> cloud event during the passage of high amplitude anisotropic wave trains. The cosmic ray intensity and Dst index both are found to decrease with the increase of solar wind velocity and reaches to their minimum on the days of high-speed solar wind streams during HAEs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.1509M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.1509M"><span id="translatedtitle">Comparisons between in situ measurements of the <span class="hlt">magnetic</span> shadowing of high energy ions at Mars and hybrid model simulations, using contemporary particle and field measurements to define the upstream <span class="hlt">interplanetary</span> conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McKenna-Lawlor, S.; Kallio, E.; Alho, M.; Jarvinen, R.; Afonin, V.</p> <p>2012-04-01</p> <p>Energetic particle data recorded by the SLED instrument aboard Phobos-2 while in circular orbit about Mars in March, 1989 showed the presence of <span class="hlt">magnetic</span> shadowing. A 3-D, self consistent, hybrid model (HYB-Mars) supplemented by test particle simulations was developed to study the response of the Martian plasma environment to solar disturbances and to interpret, in particular, the SLED observations. The <span class="hlt">magnetic</span> and electric fields, as well as the properties of high energy ions, present at Mars under conditions of extreme solar disturbance can be derived from HYB-Mars. Our initial study [McKenna-Lawlor et al., EPS 2011, in press] showed that the HYB-Mars model predicted an already well-documented plasma phenomenon at the planet, namely 'sw-flow shadowing (identified in the measurements of the ASPERA (plasma) experiment aboard Phobos-2). HYB further, importantly, predicted the occurrence of <span class="hlt">magnetic</span> shadowing which is qualitatively similar to that recorded by SLED. The simulations in addition suggested that the configuration of a <span class="hlt">magnetic</span> shadow depends on the pertaining solar wind density and velocity, and on the magnitude and direction of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field. The present work presents a more detailed study where plasma and <span class="hlt">magnetic</span> field inputs to the HYB model come from measurements made aboard Phobos-2 contemporaneously with the SLED observations. In this way it is possible to realistically match the upstream <span class="hlt">interplanetary</span> conditions with the configuration of the <span class="hlt">magnetic</span> shadow recorded at various energies in the SLED data. One-to-one comparisons between the SLED observations and simulated high energy H+ fluxes will be presented in this context and similarities and differences between the observations and simulations discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhFl...27i3101M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhFl...27i3101M"><span id="translatedtitle">The <span class="hlt">average</span> stress in a suspension of cube-shaped <span class="hlt">magnetic</span> particles subject to shear and <span class="hlt">magnetic</span> fields</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mallavajula, Rajesh K.; Archer, Lynden A.; Koch, Donald L.</p> <p>2015-09-01</p> <p>The effect of a homogeneous <span class="hlt">magnetic</span> field (H) on the bulk stress in a dilute suspension of weakly Brownian, <span class="hlt">magnetic</span> cubes suspended in a Newtonian fluid subjected to a linear shear flow is studied. The stresslet on each cube is anisotropic and depends on its orientation. Application of a <span class="hlt">magnetic</span> field results in anisotropy in the orientation distribution. The steady-state orientation distribution is derived as a function of the angle between the directions of the <span class="hlt">magnetic</span> field and the fluid vorticity vector and the ratio of the <span class="hlt">magnetic</span> torque to the viscous torque. Knowledge of the distribution function is used to derive a general expression for the bulk stress in a general linear flow field and a <span class="hlt">magnetic</span> field. Specific numerical results are obtained for the intrinsic viscosity in a simple shear flow when the <span class="hlt">magnetic</span> field is either parallel or perpendicular to the vorticity. When the <span class="hlt">magnetic</span> field is perpendicular to vorticity, we find that the intrinsic viscosity increases at first with increasing shear rate passes through a maximum and then shear thins. The intrinsic viscosity can vary from 3.25 to 5.5 in response to changes in the relative strengths of the shear and <span class="hlt">magnetic</span> fields. The maximum value of 5.5 is obtained when the <span class="hlt">magnetic</span> moment of the cube, which is assumed to be parallel to the normal of one of the faces, lies in the flow gradient plane at an angle of π/4 from the flow direction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015Ap%26SS.356....7C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015Ap%26SS.356....7C"><span id="translatedtitle">Short-term periodicities in <span class="hlt">interplanetary</span>, geomagnetic and solar phenomena during solar cycle 24</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chowdhury, Partha; Choudhary, D. P.; Gosain, S.; Moon, Y.-J.</p> <p>2015-03-01</p> <p>In this paper we study the quasi-periodic variations of sunspot area/number, 10.7 cm solar radio flux, <span class="hlt">Average</span> Photospheric <span class="hlt">Magnetic</span> Flux, <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field ( B z ) and the geomagnetic activity index A p during the ascending phase of the current solar cycle 24. We use both Lomb-Scargle periodogram and wavelet analysis technique and find evidence for a multitude of quasi-periodic oscillations in all the data sets. In high frequency range (10 days to 100 days), both methods yield similar significance periodicities around 20-35 days and 45-60 days in all data sets. In the case of intermediate range, the significant periods were around 100-130 days, 140-170 days and 180-240 days The Morlet wavelet power spectrum shows that all of the above-mentioned periods are intermittent in nature. We find that the well-known "Rieger period" of (150-160 days) and near Rieger periods (130-190 days) were significant in both solar, <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field and geomagnetic activity data sets during cycle 24. The geomagnetic activity is the result of the solar wind-magnetosphere interaction. Thus the variations in the detected periodicity in variety of solar, <span class="hlt">interplanetary</span> and geomagnetic indices could be helpful to improve our knowledge of the inter-relationship between various processes in the Sun-Earth-Heliosphere system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRA..120.4503K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRA..120.4503K"><span id="translatedtitle">Modular model for Mercury's magnetospheric <span class="hlt">magnetic</span> field confined within the <span class="hlt">average</span> observed magnetopause</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Korth, Haje; Tsyganenko, Nikolai A.; Johnson, Catherine L.; Philpott, Lydia C.; Anderson, Brian J.; Al Asad, Manar M.; Solomon, Sean C.; McNutt, Ralph L.</p> <p>2015-06-01</p> <p>Accurate knowledge of Mercury's magnetospheric <span class="hlt">magnetic</span> field is required to understand the sources of the planet's internal field. We present the first model of Mercury's magnetospheric <span class="hlt">magnetic</span> field confined within a magnetopause shape derived from Magnetometer observations by the MErcury Surface, Space ENvironment, GEochemistry, and Ranging spacecraft. The field of internal origin is approximated by a dipole of magnitude 190 nT RM3, where RM is Mercury's radius, offset northward by 479 km along the spin axis. External field sources include currents flowing on the magnetopause boundary and in the cross-tail current sheet. The cross-tail current is described by a disk-shaped current near the planet and a sheet current at larger (≳ 5 RM) antisunward distances. The tail currents are constrained by minimizing the root-mean-square (RMS) residual between the model and the <span class="hlt">magnetic</span> field observed within the magnetosphere. The magnetopause current contributions are derived by shielding the field of each module external to the magnetopause by minimizing the RMS normal component of the <span class="hlt">magnetic</span> field at the magnetopause. The new model yields improvements over the previously developed paraboloid model in regions that are close to the magnetopause and the nightside <span class="hlt">magnetic</span> equatorial plane. <span class="hlt">Magnetic</span> field residuals remain that are distributed systematically over large areas and vary monotonically with <span class="hlt">magnetic</span> activity. Further advances in empirical descriptions of Mercury's magnetospheric external field will need to account for the dependence of the tail and magnetopause currents on <span class="hlt">magnetic</span> activity and additional sources within the magnetosphere associated with Birkeland currents and plasma distributions near the dayside magnetopause.</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/2008GMS...181...99T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008GMS...181...99T"><span id="translatedtitle"><span class="hlt">Interplanetary</span> causes of middle latitude ionospheric disturbances</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tsurutani, Bruce T.; Echer, Ezequiel; Guarnieri, Fernando L.; Verkhoglyadova, Olga P.</p> <p></p> <p>The solar and <span class="hlt">interplanetary</span> causes of major middle latitude ionospheric disturbances are reviewed. Solar flare photons can cause abrupt (within ˜5 min), 30% increases in ionospheric total electron content, a feature that can last for tens of minutes to hours, depending on the altitude of concern. Fast <span class="hlt">interplanetary</span> coronal mass ejection sheath fields and <span class="hlt">magnetic</span> clouds can cause intense <span class="hlt">magnetic</span> storms if the field in either region is intensely southward for several hours or more. If the field conditions in both regions are southward, "double storms" will occur. Multiple <span class="hlt">interplanetary</span> fast forward shocks "pump up" the sheath <span class="hlt">magnetic</span> field, leading to conditions that can lead to superstorms. <span class="hlt">Magnetic</span> storm auroral precipitation and Joule heating cause pressure waves that propagate from subauroral latitudes to middle and equatorial latitudes. Shocks can create middle latitude dayside auroras as well as trigger nightside subauroral supersubstorms. Solar wind ram pressure increases after fast shocks can lead to the formation of new radiation belts under proper conditions. Prompt penetration electric fields can cause a dayside ionospheric superfountain, leading to plasma transport from the equatorial region to middle latitudes. The large amplitude Alfvén waves present in solar wind high-speed streams cause sporadic <span class="hlt">magnetic</span> reconnection, plasma injections, and electromagnetic chorus wave generation. Energetic electrons interacting with chorus (and PC5) waves are accelerated to hundreds of keV up to MeV energies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993SoPh..143..345U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993SoPh..143..345U"><span id="translatedtitle"><span class="hlt">Interplanetary</span> <span class="hlt">magnetic</span> field structure and solar wind parameters as inferred from solar <span class="hlt">magnetic</span> field observations and by using a numerical 2-D MHD model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Usmanov, A. V.</p> <p>1993-02-01</p> <p>A numerical, self-consistent MHD simulation is used to determine the parameters of the solar corona and the solar wind. Observations of the large-scale <span class="hlt">magnetic</span> field at the sun are used to find the boundary conditions for the <span class="hlt">magnetic</span> field. The planar model used for the solar wind flow consists of two regions. Region I, covering the distance from the solar surface to 10 solar radii, is the region of transonic flow. Region II extends from 10 solar radii to the earth's orbit, and is the region of supersonic, super-Alfvenic flow. Region I is treated as a mixed initial-boundary value problem. For region II, solar rotation is taken into consideration, so that the interaction between fast and slow solar wind streams is treated self-consistently. The calculated solar wind velocity, radial <span class="hlt">magnetic</span> field, and number density are compared with space-based observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19720005195','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19720005195"><span id="translatedtitle"><span class="hlt">Magnetic</span> field measurements by Pioneer 6. 1: Hourly <span class="hlt">averages</span> of the field elements from 17 December 1965 to 5 September 1967 (Bartels solar rotation 1811 to 1834)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ness, N. F.; Ottens, F. W.</p> <p>1971-01-01</p> <p><span class="hlt">Magnetic</span> field data obtained on Pioneer 6 flights are presented in graph form as hourly <span class="hlt">averages</span>. The spacecraft and <span class="hlt">magnetic</span> field detector are described. The standard data analysis procedures are also given.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19720027242&hterms=Yoshida&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DYoshida','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19720027242&hterms=Yoshida&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DYoshida"><span id="translatedtitle">Cosmic-ray variations and the <span class="hlt">interplanetary</span> sector structures.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Yoshida, S.; Akasofu, S.; Ogita, N.</p> <p>1971-01-01</p> <p>Fifteen passages of <span class="hlt">interplanetary</span> sector structures that occurred between December 1967 and June 1968 are examined. A spherical harmonic analysis of cosmic ray intensity is performed to obtain cosmic ray intensity variations as a function of asymptotic latitude, longitude, and universal time. A clear north-south asymmetry of cosmic ray intensity, which depends on the sign of the <span class="hlt">interplanetary</span> sector <span class="hlt">magnetic</span> fields, is revealed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19740008403','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19740008403"><span id="translatedtitle">Observations of interactions between <span class="hlt">interplanetary</span> and geomagnetic fields</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Burch, J. L.</p> <p>1973-01-01</p> <p>Magnetospheric effects associated with variations of the north-south component of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field are examined in light of recent recent experimental and theoretical results. Although the occurrence of magnetospheric substorms is statistically related to periods of southward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field, the details of the interaction are not understood. In particular, attempts to separate effects resulting directly from the interaction between the <span class="hlt">interplanetary</span> and geomagnetic fields from those associated with substorms have produced conflicting results. The transfer of <span class="hlt">magnetic</span> flux from the dayside to the nightside magnetosphere is evidenced by equatorward motion of the polar cusp and increases of the <span class="hlt">magnetic</span> energy density in the lobes of the geomagnetic tail. The formation of a macroscopic X-type neutral line at tail distances less than 35 R sub E appears to be a substorm phenomenon.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26437746','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26437746"><span id="translatedtitle">The role of size polydispersity in <span class="hlt">magnetic</span> fluid hyperthermia: <span class="hlt">average</span> vs. local infra/over-heating effects.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Munoz-Menendez, Cristina; Conde-Leboran, Ivan; Baldomir, Daniel; Chubykalo-Fesenko, Oksana; Serantes, David</p> <p>2015-11-01</p> <p>An efficient and safe hyperthermia cancer treatment requires the accurate control of the heating performance of <span class="hlt">magnetic</span> nanoparticles, which is directly related to their size. However, in any particle system the existence of some size polydispersity is experimentally unavoidable, which results in a different local heating output and consequently a different hyperthermia performance depending on the size of each particle. With the aim to shed some light on this significant issue, we have used a Monte Carlo technique to study the role of size polydispersity in heat dissipation at both the local (single particle) and global (macroscopic <span class="hlt">average</span>) levels. We have systematically varied size polydispersity, temperature and interparticle dipolar interaction conditions, and evaluated local heating as a function of these parameters. Our results provide a simple guide on how to choose, for a given polydispersity degree, the more adequate <span class="hlt">average</span> particle size so that the local variation in the released heat is kept within some limits that correspond to safety boundaries for the <span class="hlt">average</span>-system hyperthermia performance. All together we believe that our results may help in the design of more effective <span class="hlt">magnetic</span> hyperthermia applications. PMID:26437746</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19960021484&hterms=statistical+analysis&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dstatistical%2Banalysis','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19960021484&hterms=statistical+analysis&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dstatistical%2Banalysis"><span id="translatedtitle">Statistical analysis of <span class="hlt">interplanetary</span> shock waves observed during a complete solar activity cycle</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Khalisi, E.; Schwenn, R.</p> <p>1995-01-01</p> <p>During the Helios mission a total of 391 fast forward non-corotating <span class="hlt">interplanetary</span> shock waves was identified. For most of the 12 years between 1974 and 1986 unique shock detection was possible for more than 80 % of the time. The occurrence rate (in shocks per day) varied from 0.02 at activity minimum in 1976 to 0.17 in 1979 and 0.22 in 1982 with a significant drop to 0.13 in 1980, i.e. right at activity maximum. The <span class="hlt">average</span> properties of all events as functions of solar distance. phase in the solar cycle, heliographic and -<span class="hlt">magnetic</span> latitude and others are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhDT........37L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhDT........37L"><span id="translatedtitle"><span class="hlt">Interplanetary</span> Field Enhancements: The Interaction between Solar Wind and <span class="hlt">Interplanetary</span> Dusty Plasma Released by <span class="hlt">Interplanetary</span> Collisions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lai, Hairong</p> <p></p> <p><span class="hlt">Interplanetary</span> field enhancements (IFEs) are unique large-scale structures in the solar wind. During IFEs, the <span class="hlt">magnetic</span>-field strength is significantly enhanced with little perturbation in the solar-wind plasma. Early studies showed that IFEs move at nearly the solar-wind speed and some IFEs detected at 0.72AU by Pioneer Venus Orbiter (PVO) are associated with material co-orbiting with asteroid Oljato. To explain the observed IFE features, we develop and test an IFE formation hypothesis: IFEs result from interactions between the solar wind and clouds of nanoscale charged dust particles released in <span class="hlt">interplanetary</span> collisions. This hypothesis predicts that the <span class="hlt">magnetic</span> field drapes and the solar wind slows down in the upstream. Meanwhile the observed IFE occurrence rate should be comparable with the detectable <span class="hlt">interplanetary</span> collision rate. Based on this hypothesis, we can use the IFE occurrence to determine the spatial distribution and temporal variation of <span class="hlt">interplanetary</span> objects which produce IFEs. To test the hypothesis, we perform a systematic survey of IFEs in the <span class="hlt">magnetic</span>-field data from many spacecraft. Our datasets cover from 1970s to present and from inner than 0.3AU to outer than 5 AU. In total, more than 470 IFEs are identified and their occurrences show clustering features in both space and time. We use multi-spacecraft simultaneous observations to reconstruct the <span class="hlt">magnetic</span>-field geometry and find that the <span class="hlt">magnetic</span> field drapes in the upstream region. The results of a superposed epoch study show that the solar wind slows down in the upstream and there is a plasma depletion region near the IFE centers. In addition, the solar-wind slowdown and plasma depletion feature are more significant in larger IFEs. The mass contained in IFEs can be estimated by balancing the solar-wind pressure force exerted on the IFEs against the solar gravity. The solar-wind slowdown resultant from the estimated mass is consistent with the result in superposed epoch study. The <span class="hlt">interplanetary</span> collision rate is estimated based on the flux model of Ceplecha [1992] and collision model of Grun [et al., 1985]. A debris distribution model of Fujiwara [et al., 1977] is modified to estimate the mass carried by nanoscale dust particles. The integrated collision rate inside a detectable volume, which is a truncated cone starting from 0.2AU, is used to compare with the observed IFE rate. At 1AU, we find that in the same mass range, the two rates are comparable. Inside 1AU, both rates increase slowly as the heliocentric distance increases. We reanalyze the PVO observations and confirm the association between IFEs and co-orbiting material of asteroid 2201 Oljato. An analogous study is performed at 1AU and we find that material co-orbiting with asteroid 138175 produces many IFEs there. We then compare the earlier PVO observations with the present Venus Express (VEX) observation and find that the IFE production rate of the material co-orbiting with Oljato has decreased in the past three decades. A comparison between earlier IMP 8 observations and current observations shows a similar decrease in the rate of IFEs associated with asteroid 138175. Such a rate decrease can be explained by the gravitational scattering of co-orbiting material accompanying both asteroids, as they make occasional close passes of the Earth and Venus. Simulations show that due to the gravitational perturbations from the Earth and Venus, gaps can be formed in the otherwise continuous debris trails in periods of decades [Connors et al.,2014a]. The importance of this IFE study is discussed in this thesis. We now have a better understanding of a previous mysterious phenomenon, sufficient to use the IFE occurrence to identify small <span class="hlt">interplanetary</span> objects. Material of tens of meters across co-orbiting with near-Earth objects is too small to detect by traditional survey methods, but still can cause great property and civilian damage once it enters the Earth's atmosphere. In addition, due to gravitational perturbations, the co-orbiting material can be spread along and across the orbits of their parent bodies, which otherwise might be considered to have been well determined and safe. With our new small-object-identification technique, we can obtain the spatial distribution of the potentially hazardous material and develop a planetary defense stratagem.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19830025541','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19830025541"><span id="translatedtitle">Electron heating at <span class="hlt">interplanetary</span> shocks</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Feldman, W. C.; Asbridge, J. R.; Bame, S. J.; Gosling, J. T.; Zwickl, R. D.</p> <p>1982-01-01</p> <p>Data for 41 forward <span class="hlt">interplanetary</span> shocks show that the ratio of downstream to upstream electron temperatures, T/sub e/(d/u) is variable in the range between 1.0 (isothermal) and 3.0. On <span class="hlt">average</span>, (T/sub e/(d/u) = 1.5 with a standard deviation, sigma e = 0.5. This ratio is less than the <span class="hlt">average</span> ratio of proton temperatures across the same shocks, (T/sub p/(d/u)) = 3.3 with sigma p = 2.5 as well as the <span class="hlt">average</span> ratio of electron temperatures across the Earth's bow shock. Individual samples of T/sub e/(d/u) and T/sub p/(d/u) appear to be weakly correlated with the number density ratio. However the amounts of electron and proton heating are well correlated with each other as well as with the bulk velocity difference across each shock. The stronger shocks appear to heat the protons relatively more efficiently than they heat the electrons.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1082462','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1082462"><span id="translatedtitle">Determination of the <span class="hlt">Average</span> Aromatic Cluster Size of Fossil Fuels by Solid-State NMR at High <span class="hlt">Magnetic</span> Field</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Mao, Kanmi; Kennedy, Gordon J.; Althaus, Stacey M.; Pruski, Marek</p> <p>2013-01-07</p> <p>We show that the <span class="hlt">average</span> aromatic cluster size in complex carbonaceous materials can be accurately determined using fast magic-angle spinning (MAS) NMR at a high <span class="hlt">magnetic</span> field. To accurately quantify the nonprotonated aromatic carbon, we edited the 13C spectra using the recently reported MAS-synchronized spin–echo, which alleviated the problem of rotational recoupling of 1H-13C dipolar interactions associated with traditional dipolar dephasing experiments. The dependability of this approach was demonstrated on selected Argonne Premium coal standards, for which full sets of basic structural parameters were determined with high accuracy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050070873','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050070873"><span id="translatedtitle">The "Approximate 150 Day Quasi-Periodicity" in <span class="hlt">Interplanetary</span> and Solar Phenomena During Cycle 23</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Richardson, I. G.; Cane, H. V.</p> <p>2004-01-01</p> <p>A"quasi-periodicity" of approx. 150 days in various solar and <span class="hlt">interplanetary</span> phenomena has been reported in earlier solar cycles. We suggest that variations in the occurrence of solar energetic particle events, <span class="hlt">inter-planetary</span> coronal mass ejections, and geomagnetic storm sudden commenceents during solar cycle 23 show evidence of this quasi-periodicity, which is also present in the sunspot number, in particular in the northern solar hemisphere. It is not, however, prominent in the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field strength.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JASS...32..181P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JASS...32..181P"><span id="translatedtitle">Storm Sudden Commencements Without <span class="hlt">Interplanetary</span> Shocks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Park, Wooyeon; Lee, Jeongwoo; Yi, Yu; Ssessanga, Nicholas; Oh, Suyeon</p> <p>2015-09-01</p> <p>Storm sudden commencements (SSCs) occur due to a rapid compression of the Earth's <span class="hlt">magnetic</span> field. This is generally believed to be caused by <span class="hlt">interplanetary</span> (IP) shocks, but with exceptions. In this paper we explore possible causes of SSCs other than IP shocks through a statistical study of geomagnetic storms using SYM-H data provided by the World Data Center for Geomagnetism ? Kyoto and by applying a superposed epoch analysis to simultaneous solar wind parameters obtained with the Advanced Composition Explorer (ACE) satellite. We select a total of 274 geomagnetic storms with minimum SYM-H of less than ?30nT during 1998-2008 and regard them as SSCs if SYM-H increases by more than 10 nT over 10 minutes. Under this criterion, we found 103 geomagnetic storms with both SSC and IP shocks and 28 storms with SSC not associated with IP shocks. Storms in the former group share the property that the strength of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF), proton density and proton velocity increase together with SYM-H, implying the action of IP shocks. During the storms in the latter group, only the proton density rises with SYM-H. We find that the density increase is associated with either high speed streams (HSSs) or <span class="hlt">interplanetary</span> coronal mass ejections (ICMEs), and suggest that HSSs and ICMEs may be alternative contributors to SSCs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010cosp...38.2146S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010cosp...38.2146S"><span id="translatedtitle">Effect of the solar wind and <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field parameter variations to the enhancement and dynamics of auroral electrojet during superstrong <span class="hlt">magnetic</span> storms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Solovyev, Stepan; Boroev, Roman; Moiseyev, Alexey; Du, Aimin; Yumoto, Kiyohumi</p> <p></p> <p>According to the global ground geomagnetic observations in the six meridian chains and analysis of satellite measurements the auroral elektrojet features at various conditions in the solar wind (SW) and the IMF: during a sharp rise of dynamic pressure up to 15-60 nPa and variations in the intensity and sign of the IMF Bz-component to -40 --50 nT. The data obtained during super strong <span class="hlt">magnetic</span> storms of October 29-30, 2003, November 20-21, 2003, November 07-08, 2004 and November 09-10, 2004 (Dst = -300 --400 nT) are analysed. The following scientific results are obtained: • It is shown that a sharp increase of the SW dynamic pressure (Pd) and the excitation of a sudden impulse (SC) during IMF Bz negative (Bz<0) leads to a simultaneous (with accuracy 1-3 min) increase of DP2 current system and the intensity of the western elec-trojet (Jw) in a broad sector of longitudes and expansion of Jw to the pole up to the polar cap latitudes with the velocity of VN = 1-3 km/s. • It is found that during the sharp rise of Pd up to 60 nPa for IMF Bz positive (Bz>0) 35 nT is the amplification of eastward magnetopause currents and DP2 current system are observed. Strengthening and dynamics of the westward electrojet is not observed. • We find that during periods of intensity growth of negative values of IMF Bz to -50 nT within a few hours there is a shift of the centers of auroral electrojet to the equator up to latitudes about 10-20 degrees along the meridian with a speed of 1-4 km/s with a simultaneous amplifications of Jw repeated in 1-2 hours with a duration of 1-2 hours at latitudes from low to auroral latitudes and with a possible extension to electrojets up to the polar cap latitudes and the abrupt extension of the subsequent Jw electrojets localization region by azimuth. • It is shown that after the electrojet displacement to the equator during southward direc-tion of IMF Bz and enhancement of the SW electric field the IMF Bz turning to the north accompanied by the poleward expansion of Jw electrojet at a speed of 1 km/s in a wide range of longitudes is observed. • It is found that the electrojet expansion to the pole during superstorms often occurs up to the polar cap latitudes due to the extension of the precipitating particles and increased ionospheric conductivity region from the low and auroral latitudes, but not due to the movement of localized westward electrojet along the meridian, as is the case in the substorm. The report discusses the possible causes of the dynamics of auroral electrojets under different geophysical conditions. This work was supported by the Presidium of the Russian Academy of Sciences (program 16, part 3), by the RFBR grant No.09-05-98546 and also supported by the SB RAS project No.69.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSH22B...5K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSH22B...5K"><span id="translatedtitle"><span class="hlt">Interplanetary</span> Shocks Observed by the DSCOVR Spacecraft</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Koval, A.; Wilson, L. B., III; Szabo, A.; Kasper, J. C.; Stevens, M.; Case, A.; Biesecker, D.</p> <p>2015-12-01</p> <p>We are examining <span class="hlt">magnetic</span> field fluctuations in and around <span class="hlt">interplanetary</span> shocks observed by the DSCOVR spacecraft. The DSCOVR spacecraft, launched in February 2015 and currently in an orbit about L1, provides very high cadence measurements of the <span class="hlt">magnetic</span> field (50 Hz) and ion velocity distribution functions (1 Hz). Observations suggest the fluctuations near the shock ramps are whistler precursors. The properties of both the precursor waves and the shock ramp structure are compared to the shock geometry and strength. The observations are compared with the observations by the Wind spacecraft, also in an orbit about L1.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRA..121...42L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRA..121...42L"><span id="translatedtitle">A new approach to identify <span class="hlt">interplanetary</span> Alfvén waves and to obtain their frequency properties</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, H.; Wang, C.; Chao, J. K.; Hsieh, W. C.</p> <p>2016-01-01</p> <p>Conventional diagnosis of <span class="hlt">interplanetary</span> Alfvén waves requires an accurately determined de Hoffmann-Teller (HT) frame or background <span class="hlt">magnetic</span> field. For simplicity, the <span class="hlt">averaged</span> HT frame and the mean value of the <span class="hlt">magnetic</span> field are often used in the literature. However, HT frame can change quite fast in high-speed solar wind streams, and it is not always appropriate to take the <span class="hlt">average</span> value of the <span class="hlt">magnetic</span> field to be the background state. In order to reduce the uncertainty introduced by determining HT frame and background <span class="hlt">magnetic</span> field, we propose a new approach for identifying large-amplitude <span class="hlt">interplanetary</span> Alfvén waves. This new approach is independent of HT frame and of background <span class="hlt">magnetic</span> field. Instead of the original data sets, the band-pass filtered signals of plasma velocity and <span class="hlt">magnetic</span> field observations are used to check the Walén relation. The robustness of this technique is verified by applying to simulated pure Alfvén waves with two separate frequencies and contaminated by pink colored noises in a varying solar wind stream. Furthermore, in our approach, more properties of Alfvén waves in frequency domain can be obtained, which have been rarely discussed before. Our analysis technique is applied to two intervals of solar wind high-speed streams, and it is shown that large-amplitude Alfvén waves near 1 AU are frequently found during these two intervals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/399362','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/399362"><span id="translatedtitle">A pure permanent <span class="hlt">magnet</span>-two plane focusing-tapered wiggler for a high <span class="hlt">average</span> power FEL</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Fortgang, C.M.</p> <p>1996-11-01</p> <p>A high-<span class="hlt">average</span> power FEL is under construction at Los Alamos. The FEL will have aspects of both an oscillator and a SASE (self-amplified spontaneous emission) device. That is, a high-gain and high- extraction efficiency wiggler will be used with a very low-Q optical resonator. FEL simulations reveal that a tapered wiggler with two- plane focusing is required to obtain desired performance. The wiggler is comprised of a I meter long untapered section followed by a 1 meter tapered section. The taper is achieved with the <span class="hlt">magnetic</span> gap and not the wiggler period which is constant at 2 cm. The gap is tapered from 5.9 mm to 8.8 mm. The, gap, rather than the period, is tapered to avoid vignetting of the 16 {mu}m optical beam. Two-plane focusing is necessary to maintain high current density and thus high gain through out the 2 meter long wiggler. Several <span class="hlt">magnetic</span> designs have been considered for the wiggler. The leading candidate approach is a pure permanent wiggler with pole faces that are cut to roughly approximate the classical parabolic pole face design. Focusing is provided by the sextupole component of the wiggler <span class="hlt">magnetic</span> field and is often called ``natural`` or ``betatron`` focusing. Details of the design will be presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1981aiaa.confT....D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1981aiaa.confT....D"><span id="translatedtitle"><span class="hlt">Interplanetary</span> trajectory optimization</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Damario, L. A.; Stanford, R. H.; Byrnes, D. V.</p> <p>1981-08-01</p> <p>A procedure for minimizing total impulsive Delta-V for constrained multiple-flyby trajectories, which was originally developed for application to satellite tours, has been modified for application to <span class="hlt">interplanetary</span> trajectories. The modification includes adding to the cost function the Delta-V required to escape from a parking orbit about the launch planet and the Delta-V required for insertion into orbit about the arrival planet. The hyperbolic excess velocity vector with respect to the launch planet and the launch date have been added to the set of independent variables for the optimization. Each trajectory originates at departure from the parking orbit rather than at a fixed position in space, as is the case for the satellite tour application. The multi-conic trajectory propagation techniques and the Newton optimization algorithm of the original method have been retained. Examples of the application of this new method are given for several types of Galileo <span class="hlt">interplanetary</span> trajectory options, including Mars powered flyby, broken plane, VEGA, and Delta VEGA trajectories.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140006630','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140006630"><span id="translatedtitle">Whistler Waves Associated with Weak <span class="hlt">Interplanetary</span> Shocks</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Velez, J. C. Ramirez; Blanco-Cano, X.; Aguilar-Rodriguez, E.; Russell, C. T.; Kajdic, P.; Jian,, L. K.; Luhmann, J. G.</p> <p>2012-01-01</p> <p>We analyze the properties of 98 weak <span class="hlt">interplanetary</span> shocks measured by the dual STEREO spacecraft over approximately 3 years during the past solar minimum. We study the occurrence of whistler waves associated with these shocks, which on <span class="hlt">average</span> are high beta shocks (0.2 < Beta < 10). We have compared the waves properties upstream and downstream of the shocks. In the upstream region the waves are mainly circularly polarized, and in most of the cases (approx. 75%) they propagate almost parallel to the ambient <span class="hlt">magnetic</span> field (<30 deg.). In contrast, the propagation angle with respect to the shock normal varies in a broad range of values (20 deg. to 90 deg.), suggesting that they are not phase standing. We find that the whistler waves can extend up to 100,000 km in the upstream region but in most cases (88%) are contained in a distance within 30,000 km from the shock. This corresponds to a larger region with upstream whistlers associated with IP shocks than previously reported in the literature. The maximum amplitudes of the waves are observed next to the shock interface, and they decrease as the distance to the shock increases. In most cases the wave propagation direction becomes more aligned with the <span class="hlt">magnetic</span> field as the distance to the shock increases. These two facts suggest that most of the waves in the upstream region are Landau damping as they move away from the shock. From the analysis we also conclude that it is likely that the generation mechanism of the upstream whistler waves is taking place at the shock interface. In the downstream region, the waves are irregularly polarized, and the fluctuations are very compressive; that is, the compressive component of the wave clearly dominates over the transverse one. The majority of waves in the downstream region (95%) propagate at oblique angles with respect to the ambient <span class="hlt">magnetic</span> field (>60 deg.). The wave propagation with respect to the shock-normal direction has no preferred direction and varies similarly to the upstream case. It is possible that downstream fluctuations are generated by ion relaxation as suggested in previous hybrid simulation shocks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19780046167&hterms=free+radial&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dfree%2Bradial','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19780046167&hterms=free+radial&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dfree%2Bradial"><span id="translatedtitle">The <span class="hlt">interplanetary</span> scattering mean free path from 1 to 3 x 1000 MV. [for solar protons and electrons</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zwickl, R. D.; Webber, W. R.</p> <p>1978-01-01</p> <p>The paper reports a statistical study of published intensity-time profiles of proton and electron solar particle events from 1967 to 1974. The purpose of the study was to examine systematically the temporal and rigidity dependence of the <span class="hlt">interplanetary</span> scattering mean free path from approximately 1000 to 3000 MV. The observed t-max, the time from release of particles at the sun to the time of maximum flux at the spacecraft, were interpreted in terms of a propagation model to obtain the <span class="hlt">average</span> radial scattering mean-free path. This path (1) appears to be species independent when it is derived from proton and electron solar particle events, (2) varies less than a factor of 2 from solar maximum to solar minimum, and (3) is nearly rigidity independent below approximately 500 MV. The path values obtained at low rigidities are inconsistent with path values derived theoretically from the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field fluctuations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRA..121.1294C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRA..121.1294C"><span id="translatedtitle"><span class="hlt">Average</span> field-aligned current configuration parameterized by solar wind conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Carter, J. A.; Milan, S. E.; Coxon, J. C.; Walach, M.-T.; Anderson, B. J.</p> <p>2016-02-01</p> <p>We present the first large-scale comparison of the spatial distribution of field-aligned currents as measured by the Active Magnetosphere and Planetary Electrodynamics Response Experiment, with the location and brightness of the <span class="hlt">average</span> auroral oval, determined from the Imager for Magnetopause-to-Aurora Global Exploration far ultraviolet instrument. These distributions are compared under the same <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field magnitude and clock angle conditions. The field-aligned currents and auroral oval drop to lower latitudes, as the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field becomes both increasingly stronger in magnitude and increasingly southward. We find that the region 2 currents are more closely aligned with the distribution of auroral UV emission, whether that be in the discrete auroral zone about dusk or in the postmidnight diffuse aurora sector. The lack of coincidence between the region 1 field-aligned currents with the auroral oval in the dusk sector is contrary to expectation.</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://hdl.handle.net/2060/19720004688','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19720004688"><span id="translatedtitle"><span class="hlt">Magnetic</span> field measurements by Pioneer 7. 1: Hourly <span class="hlt">averages</span> of the field elements from 17 August 1966 to 29 October 1967 (Bartel's Solar Rotation 1820 to 1836)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ness, N. F.; Ottens, F. W.</p> <p>1971-01-01</p> <p>The <span class="hlt">magnetic</span> observations of Pioneer 7, located in the aftward portion of the disturbed solar plasma caused by interaction with the geomagnetic field, are summarized in graphical form. Hourly <span class="hlt">averages</span> of the <span class="hlt">magnetic</span> field elements for Bartel's solar rotation number are shown for each month from August 1966 to October 1967.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012PhDT.......113C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012PhDT.......113C"><span id="translatedtitle">Autonomous <span class="hlt">interplanetary</span> constellation design</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chow, Cornelius Channing, II</p> <p></p> <p>According to NASA's integrated space technology roadmaps, space-based infrastructures are envisioned as necessary ingredients to a sustained effort in continuing space exploration. Whether it be for extra-terrestrial habitats, roving/cargo vehicles, or space tourism, autonomous space networks will provide a vital communications lifeline for both future robotic and human missions alike. Projecting that the Moon will be a bustling hub of activity within a few decades, a near-term opportunity for in-situ infrastructure development is within reach. This dissertation addresses the anticipated need for in-space infrastructure by investigating a general design methodology for autonomous <span class="hlt">interplanetary</span> constellations; to illustrate the theory, this manuscript presents results from an application to the Earth-Moon neighborhood. The constellation design methodology is formulated as an optimization problem, involving a trajectory design step followed by a spacecraft placement sequence. Modeling the dynamics as a restricted 3-body problem, the investigated design space consists of families of periodic orbits which play host to the constellations, punctuated by arrangements of spacecraft autonomously guided by a navigation strategy called LiAISON (Linked Autonomous <span class="hlt">Interplanetary</span> Satellite Orbit Navigation). Instead of more traditional exhaustive search methods, a numerical continuation approach is implemented to map the admissible configuration space. In particular, Keller's pseudo-arclength technique is used to follow folding/bifurcating solution manifolds, which are otherwise inaccessible with other parameter continuation schemes. A succinct characterization of the underlying structure of the local, as well as global, extrema is thus achievable with little a priori intuition of the solution space. Furthermore, the proposed design methodology offers benefits in computation speed plus the ability to handle mildly stochastic systems. An application of the constellation design methodology to the restricted Earth-Moon system, reveals optimal pairwise configurations for various L1, L2, and L5 (halo, axial, and vertical) periodic orbit families. Navigation accuracies, ranging from O (10+/-1) meters in position space, are obtained for the optimal Earth-Moon constellations, given measurement noise on the order of 1 meter.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5619090','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5619090"><span id="translatedtitle">Laser-fusion rocket for <span class="hlt">interplanetary</span> propulsion</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hyde, R.A.</p> <p>1983-09-27</p> <p>A rocket powered by fusion microexplosions is well suited for quick <span class="hlt">interplanetary</span> travel. Fusion pellets are sequentially injected into a <span class="hlt">magnetic</span> thrust chamber. There, focused energy from a fusion Driver is used to implode and ignite them. Upon exploding, the plasma debris expands into the surrounding <span class="hlt">magnetic</span> field and is redirected by it, producing thrust. This paper discusses the desired features and operation of the fusion pellet, its Driver, and <span class="hlt">magnetic</span> thrust chamber. A rocket design is presented which uses slightly tritium-enriched deuterium as the fusion fuel, a high temperature KrF laser as the Driver, and a thrust chamber consisting of a single superconducting current loop protected from the pellet by a radiation shield. This rocket can be operated with a power-to-mass ratio of 110 W gm/sup -1/, which permits missions ranging from occasional 9 day VIP service to Mars, to routine 1 year, 1500 ton, Plutonian cargo runs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20060037420&hterms=solar+activity&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dsolar%2Bactivity','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20060037420&hterms=solar+activity&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dsolar%2Bactivity"><span id="translatedtitle">The Solar and <span class="hlt">Interplanetary</span> Causes of Geomagnetic Activity and Quiet</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gonzalez, W. D.; Tsurutani, B. T.; Tang, F.</p> <p>1995-01-01</p> <p>This presentation will show that the three distinct phases of <span class="hlt">magnetic</span> storms (initial, main, recovery) can each have considerably different characteristics during solar minimum and solar maximum. Illustrated will be the <span class="hlt">interplanetary</span> causes of these differences; and, that a year during the descending phase of the solar cycle had significantly greater auroral activity than a year of solar maximum.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120009632','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120009632"><span id="translatedtitle">Search Coil vs. Fluxgate Magnetometer Measurements at <span class="hlt">Interplanetary</span> Shocks</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wilson, L.B., III</p> <p>2012-01-01</p> <p>We present <span class="hlt">magnetic</span> field observations at <span class="hlt">interplanetary</span> shocks comparing two different sample rates showing significantly different results. Fluxgate magnetometer measurements show relatively laminar supercritical shock transitions at roughly 11 samples/s. Search coil magnetometer measurements at 1875 samples/s, however, show large amplitude (dB/B as large as 2) fluctuations that are not resolved by the fluxgate magnetometer. We show that these fluctuations, identified as whistler mode waves, would produce a significant perturbation to the shock transition region changing the interpretation from laminar to turbulent. Thus, previous observations of supercritical <span class="hlt">interplanetary</span> shocks classified as laminar may have been under sampled.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19850026502','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850026502"><span id="translatedtitle">Determination of the pitch-angle distribution and transverse anisotropy of <span class="hlt">interplanetary</span> particles</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ng, C. K.</p> <p>1985-01-01</p> <p>A method to determine the directional differential intensity (d.d.i.), expressed in terms of spherical harmonics, from sectored particle data, concurrent <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) and solar wind velocity is presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRA..120.2616Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRA..120.2616Z"><span id="translatedtitle">Bounce- and MLT-<span class="hlt">averaged</span> diffusion coefficients in a physics-based <span class="hlt">magnetic</span> field geometry obtained from RAM-SCB for 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>Zhao, Lei; Yu, Yiqun; Delzanno, Gian Luca; Jordanova, Vania K.</p> <p>2015-04-01</p> <p>Local acceleration via whistler wave and particle interaction plays a significant role in particle dynamics in the radiation belt. In this work we explore gyroresonant wave-particle interaction and quasi-linear diffusion in different <span class="hlt">magnetic</span> field configurations related to the 17 March 2013 storm. We consider the Earth's <span class="hlt">magnetic</span> dipole field as a reference and compare the results against nondipole field configurations corresponding to quiet and stormy conditions. The latter are obtained with the ring current-atmosphere interactions model with a self-consistent <span class="hlt">magnetic</span> field (RAM-SCB), a code that models the Earth's ring current and provides a realistic modeling of the Earth's <span class="hlt">magnetic</span> field. By applying quasi-linear theory, the bounce- and <span class="hlt">Magnetic</span> Local Time (MLT)-<span class="hlt">averaged</span> electron pitch angle, mixed-term, and energy diffusion coefficients are calculated for each <span class="hlt">magnetic</span> field configuration. For radiation belt (˜1 MeV) and ring current (˜100 keV) electrons, it is shown that at some MLTs the bounce-<span class="hlt">averaged</span> diffusion coefficients become rather insensitive to the details of the <span class="hlt">magnetic</span> field configuration, while at other MLTs storm conditions can expand the range of equatorial pitch angles where gyroresonant diffusion occurs and significantly enhance the diffusion rates. When MLT <span class="hlt">average</span> is performed at drift shell L=4.25 (a good approximation to drift <span class="hlt">average</span>), the diffusion coefficients become quite independent of the <span class="hlt">magnetic</span> field configuration for relativistic electrons, while the opposite is true for lower energy electrons. These results suggest that, at least for the 17 March 2013 storm and for L≲4.25, the commonly adopted dipole approximation of the Earth's <span class="hlt">magnetic</span> field can be safely used for radiation belt electrons, while a realistic modeling of the <span class="hlt">magnetic</span> field configuration is necessary to describe adequately the diffusion rates of ring current electrons.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19830025554','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19830025554"><span id="translatedtitle">Plasma properties of driver gas following <span class="hlt">interplanetary</span> shocks observed by ISEE-3</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zwickl, R. D.; Ashbridge, J. R.; Bame, S. J.; Feldman, W. C.; Gosling, J. T.; Smith, E. J.</p> <p>1982-01-01</p> <p>Plasma fluid parameters calculated from solar wind and <span class="hlt">magnetic</span> field data obtained on ISEE 3 were studied. The characteristic properties of driver gas following <span class="hlt">interplanetary</span> shocks was determined. Of 54 shocks observed from August 1978 to February 1980, nine contained a well defined driver gas that was clearly identifiable by a discontinuous decrease in the <span class="hlt">average</span> proton temperature across a tangential discontinuity. While helium enhancements were present in all of nine of these events, only about half of them contained simultaneous changes in the two quantities. Often the He/H ratio changed over a period of minutes. Simultaneous with the drop in proton temperature the helium and electron temperature decreased abruptly. In some cases the proton temperature depression was accompanied by a moderate increase in <span class="hlt">magnetic</span> field magnitude with an unusually low variance and by an increase in the ratio of parallel to perpendicular temperature. The drive gas usually displayed a bidirectional flow of suprathermal solar wind electrons at higher energies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRA..120.7307K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRA..120.7307K"><span id="translatedtitle">Estimation of <span class="hlt">interplanetary</span> electric field conditions for historical geomagnetic storms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kumar, Sandeep; Veenadhari, B.; Tulasi Ram, S.; Selvakumaran, R.; Mukherjee, Shyamoli; Singh, Rajesh; Kadam, B. D.</p> <p>2015-09-01</p> <p>Ground <span class="hlt">magnetic</span> measurements provide a unique database in understanding space weather. The continuous geomagnetic records from Colaba-Alibag observatories in India contain historically longest and continuous observations from 1847 to present date. Some of the super intense geomagnetic storms that occurred prior to 1900 have been revisited and investigated in order to understand the probable <span class="hlt">interplanetary</span> conditions associated with intense storms. Following Burton et al. (1975), an empirical relationship is derived for estimation of <span class="hlt">interplanetary</span> electric field (IEFy) from the variations of Dst index and ΔH at Colaba-Alibag observatories. The estimated IEFy values using Dst and ΔHABG variations agree well with the observed IEFy, calculated using Advanced Composition Explorer (ACE) satellite observations for intense geomagnetic storms in solar cycle 23. This study will provide the uniqueness of each event and provide important insights into possible <span class="hlt">interplanetary</span> conditions for intense geomagnetic storms and probable frequency of their occurrence.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20070023318&hterms=CANE&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DCANE','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20070023318&hterms=CANE&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DCANE"><span id="translatedtitle">A Survey of <span class="hlt">Interplanetary</span> Coronal Mass Ejections During 1996 - 2007</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Richardson, Ian; Cane, Hilary</p> <p>2007-01-01</p> <p><span class="hlt">Interplanetary</span> coronal mass ejections, the <span class="hlt">interplanetary</span> counterparts of coronal mass ejections at the Sun, are the major drivers of <span class="hlt">interplanetary</span> shocks in the heliosphere, and are associated with modulations of the galactic cosmic ray intensity, both short term (Forbush decreases caused by the passage of the shock, post-shock sheath, and ICME) and possibly with longer term modulation. Using several in-situ signatures of ICMEs, including plasma temperature, and composition, <span class="hlt">magnetic</span> fields, and cosmic ray modulations, made by near-Earth spacecraft, we have compiled a "comprehensive" list of ICMEs passing the Earth since 1996, encompassing solar cycle 23. We summarize the properties of these ICMEs, such as their occurrence rate, speeds, association with solar energetic particle events, shocks and cosmic ray decreases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760017031','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760017031"><span id="translatedtitle">Proceedings of the Symposium on the Study of the Sun and <span class="hlt">Interplanetary</span> Medium in Three Dimensions. [space mission planning and <span class="hlt">interplanetary</span> trajectories by NASA and ESA to better observe the sun and solar system</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fisk, L. A. (Editor); Axford, W. I. (Editor)</p> <p>1976-01-01</p> <p>A series of papers are presented from a symposium attended by over 200 European and American scientists to examine the importance of exploring the <span class="hlt">interplanetary</span> medium and the sun by out-of-the-ecliptic space missions. The likely scientific returns of these missions in the areas of solar, <span class="hlt">interplanetary</span>, and cosmic ray physics is examined. Theoretical models of the solar wind and its interaction with <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> fields are given.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19990053118&hterms=MCP&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DMCP','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19990053118&hterms=MCP&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DMCP"><span id="translatedtitle"><span class="hlt">Interplanetary</span> Microlaser Transponders</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Degnan, John J.</p> <p>1999-01-01</p> <p>The feasibility of an asynchronous (i.e. independently firing) <span class="hlt">interplanetary</span> laser transponder, capable of ranging between Earth and Mars and using the automated SLR2000 Satellite Laser Ranging (SLR) system as an Earth base station, has been suggested. Since that time, we have received a small amount of discretionary funding to further explore the transponder concept and to develop and test an engineering breadboard. Candidate operational scenarios for acquiring and tracking the opposite laser terminal over <span class="hlt">interplanetary</span> distances have been developed, and breadboard engineering parameters were chosen to reflect the requirements of an Earth-Mars link Laboratory tests have been devised to simulate the Earth- Mars link between two independent SLR2000 transceivers and to demonstrate the transfer of range and time in single photon mode. The present paper reviews the concept of the asynchronous microlaser transponder, the transponder breadboard design, an operational scenario recently developed for an asteroid rendezvous, and the laboratory test setup. The optical head of the transponder breadboard fits within a cylinder roughly 15 cm in diameter and 32 cm in length and is mounted in a commercial two axis gimbal driven by two computer-controlled stepper motors which allows the receiver optical axis to be centered on a simulated Earth image. The optical head is built around a small optical bench which supports a 14.7 cm diameter refractive telescope, a prototype 2 kHz SLR2000 microlaser transmitter, a quadrant microchannel plate photomultiplier (MCP/PMT), a CCD array camera, spatial and spectral filters, assorted lenses and mirrors, and protective covers and sun shields. The microlaser is end-pumped by a fiber-coupled diode laser array. An annular mirror is employed as a passive transmit/receive (T/R) switch in an aperture-sharing arrangement wherein the transmitted beam passes through the central hole and illuminates only the central 2.5 cm of the common telescope (adequate to achieve a 10 arcsecond full laser beam divergence) while the receiver uses the remainder of the 14.7 cm aperture. Additional electronic instrumentation includes the diode pump array and associated heat sink and current drivers, rubidium frequency standard, timing distribution module, range gate generator, a recently developed all-digital correlation range receiver, and system computer. Acquisition of the opposite transponder terminal requires a search within a three-dimensional volume determined by the initial pointing uncertainty and a maximum 500 microsecond uncertainty in the laser time of fire at the opposite terminal for totally uncorrelated Earth and spacecraft clocks. The angular search is aided by a sensitive CCD array capable of imaging the Earth, Moon, and surrounding stars within the nominal + 0.5 degree cone of uncertainty associated with the initial pointing of a spacecraft body or microwave communications dish.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20070016645&hterms=CANE&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DCANE','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20070016645&hterms=CANE&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DCANE"><span id="translatedtitle"><span class="hlt">Interplanetary</span> Shocks and "Suprathermal" Flare Particles</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cane, H. V.; Richardson, I. G.; vonRosenvinge, T. T.</p> <p>2006-01-01</p> <p>We use ion-composition data from ACE/ULEIS, low energy electrons from ACE/EPAM, high energy protons from SoHO/ERNE, radio data from Wind/WAVES, and solar wind data from ACE/SWEPAM and ACE/MAG to investigate the solar and <span class="hlt">interplanetary</span> circumstances near the times of passage of near-Earth shocks. We are particularly interested in claims that local acceleration by some <span class="hlt">interplanetary</span> shocks produces Fe/O > 0.3 ('Fe-rich' shocks). The choice of the specific interval used to calculate the Fe/O ratio is extremely important because shock-accelerated particles can be masked by particles from flare events, related or unrelated to the shock, that have Fe/O > 0.3. We conclude that shock- accelerated populations have Fe/0<0.3. We illustrate 5 events which have been reported to be Fe-rich and for which Fe/O increases with energy in the 0.5-2 MeV/nuc range. We find that in each case there are direct flare particles included in the <span class="hlt">averaging</span> time interval. We also demonstrate that the Fe/O ratio increases as a result of the <span class="hlt">averaging</span> time interval being too large.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1200613','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1200613"><span id="translatedtitle">Bounce- and MLT-<span class="hlt">averaged</span> diffusion coefficients in a physics-based <span class="hlt">magnetic</span> field geometry obtained from RAM-SCB for the March 17 2013 storm</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Zhao, Lei; Yu, Yiqun; Delzanno, Gian Luca; Jordanova, Vania K.</p> <p>2015-04-01</p> <p>Local acceleration via whistler wave and particle interaction plays a significant role in particle dynamics in the radiation belt. In this work we explore gyro-resonant wave-particle interaction and quasi-linear diffusion in different <span class="hlt">magnetic</span> field configurations related to the March 17 2013 storm. We consider the Earth's <span class="hlt">magnetic</span> dipole field as a reference and compare the results against non-dipole field configurations corresponding to quiet and stormy conditions. The latter are obtained with the ring current-atmosphere interactions model with a self-consistent <span class="hlt">magnetic</span> field RAM-SCB, a code that models the Earth's ring current and provides a realistic modeling of the Earth's <span class="hlt">magnetic</span> field. By applying quasi-linear theory, the bounce- and MLT-<span class="hlt">averaged</span> electron pitch angle, mixed term, and energy diffusion coefficients are calculated for each <span class="hlt">magnetic</span> field configuration. For radiation belt (~1 MeV) and ring current (~100 keV) electrons, it is shown that at some MLTs the bounce-<span class="hlt">averaged</span> diffusion coefficients become rather insensitive to the details of the <span class="hlt">magnetic</span> field configuration, while at other MLTs storm conditions can expand the range of equatorial pitch angles where gyro-resonant diffusion occurs and significantly enhance the diffusion rates. When MLT <span class="hlt">average</span> is performed at drift shell L = 4.25 (a good approximation to drift <span class="hlt">average</span>), the diffusion coefficients become quite independent of the <span class="hlt">magnetic</span> field configuration for relativistic electrons, while the opposite is true for lower energy electrons. These results suggest that, at least for the March 17 2013 storm and for L ≲ 4.25, the commonly adopted dipole approximation of the Earth's <span class="hlt">magnetic</span> field can be safely used for radiation belt electrons, while a realistic modeling of the <span class="hlt">magnetic</span> field configuration is necessary to describe adequately the diffusion rates of ring current electrons.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/pages/biblio/1200613-bounce-mlt-averaged-diffusion-coefficients-physics-based-magnetic-field-geometry-obtained-from-ram-scb-march-storm','SCIGOV-DOEP'); return false;" href="http://www.osti.gov/pages/biblio/1200613-bounce-mlt-averaged-diffusion-coefficients-physics-based-magnetic-field-geometry-obtained-from-ram-scb-march-storm"><span id="translatedtitle">Bounce- and MLT-<span class="hlt">averaged</span> diffusion coefficients in a physics-based <span class="hlt">magnetic</span> field geometry obtained from RAM-SCB for the March 17 2013 storm</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGESBeta</a></p> <p>Zhao, Lei; Yu, Yiqun; Delzanno, Gian Luca; Jordanova, Vania K.</p> <p>2015-04-01</p> <p>Local acceleration via whistler wave and particle interaction plays a significant role in particle dynamics in the radiation belt. In this work we explore gyro-resonant wave-particle interaction and quasi-linear diffusion in different <span class="hlt">magnetic</span> field configurations related to the March 17 2013 storm. We consider the Earth's <span class="hlt">magnetic</span> dipole field as a reference and compare the results against non-dipole field configurations corresponding to quiet and stormy conditions. The latter are obtained with the ring current-atmosphere interactions model with a self-consistent <span class="hlt">magnetic</span> field RAM-SCB, a code that models the Earth's ring current and provides a realistic modeling of the Earth's <span class="hlt">magnetic</span> field.more » By applying quasi-linear theory, the bounce- and MLT-<span class="hlt">averaged</span> electron pitch angle, mixed term, and energy diffusion coefficients are calculated for each <span class="hlt">magnetic</span> field configuration. For radiation belt (~1 MeV) and ring current (~100 keV) electrons, it is shown that at some MLTs the bounce-<span class="hlt">averaged</span> diffusion coefficients become rather insensitive to the details of the <span class="hlt">magnetic</span> field configuration, while at other MLTs storm conditions can expand the range of equatorial pitch angles where gyro-resonant diffusion occurs and significantly enhance the diffusion rates. When MLT <span class="hlt">average</span> is performed at drift shell L = 4.25 (a good approximation to drift <span class="hlt">average</span>), the diffusion coefficients become quite independent of the <span class="hlt">magnetic</span> field configuration for relativistic electrons, while the opposite is true for lower energy electrons. These results suggest that, at least for the March 17 2013 storm and for L ≲ 4.25, the commonly adopted dipole approximation of the Earth's <span class="hlt">magnetic</span> field can be safely used for radiation belt electrons, while a realistic modeling of the <span class="hlt">magnetic</span> field configuration is necessary to describe adequately the diffusion rates of ring current electrons.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1200613','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1200613"><span id="translatedtitle">Bounce- and MLT-<span class="hlt">averaged</span> diffusion coefficients in a physics-based <span class="hlt">magnetic</span> field geometry obtained from RAM-SCB for the March 17 2013 storm</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Zhao, Lei; Yu, Yiqun; Delzanno, Gian Luca; Jordanova, Vania K.</p> <p>2015-04-01</p> <p>Local acceleration via whistler wave and particle interaction plays a significant role in particle dynamics in the radiation belt. In this work we explore gyro-resonant wave-particle interaction and quasi-linear diffusion in different <span class="hlt">magnetic</span> field configurations related to the March 17 2013 storm. We consider the Earth's <span class="hlt">magnetic</span> dipole field as a reference and compare the results against non-dipole field configurations corresponding to quiet and stormy conditions. The latter are obtained with the ring current-atmosphere interactions model with a self-consistent <span class="hlt">magnetic</span> field RAM-SCB, a code that models the Earth's ring current and provides a realistic modeling of the Earth's <span class="hlt">magnetic</span> field. By applying quasi-linear theory, the bounce- and MLT-<span class="hlt">averaged</span> electron pitch angle, mixed term, and energy diffusion coefficients are calculated for each <span class="hlt">magnetic</span> field configuration. For radiation belt (~1 MeV) and ring current (~100 keV) electrons, it is shown that at some MLTs the bounce-<span class="hlt">averaged</span> diffusion coefficients become rather insensitive to the details of the <span class="hlt">magnetic</span> field configuration, while at other MLTs storm conditions can expand the range of equatorial pitch angles where gyro-resonant diffusion occurs and significantly enhance the diffusion rates. When MLT <span class="hlt">average</span> is performed at drift shell L = 4.25 (a good approximation to drift <span class="hlt">average</span>), the diffusion coefficients become quite independent of the <span class="hlt">magnetic</span> field configuration for relativistic electrons, while the opposite is true for lower energy electrons. These results suggest that, at least for the March 17 2013 storm and for L ? 4.25, the commonly adopted dipole approximation of the Earth's <span class="hlt">magnetic</span> field can be safely used for radiation belt electrons, while a realistic modeling of the <span class="hlt">magnetic</span> field configuration is necessary to describe adequately the diffusion rates of ring current electrons.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002EGSGA..27.3758V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002EGSGA..27.3758V"><span id="translatedtitle">Heliospheric Consecuences of Solar Activity In Several <span class="hlt">Interplanetary</span> Phenomena</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Valdés-Galicia, J. F.; Mendoza, B.; Lara, A.; Maravilla, D.</p> <p></p> <p>We have done an analysis of several phenomena related to solar activity such as the total <span class="hlt">magnetic</span> flux, coronal hole area and sunspots, investigated its long trend evolu- tion over several solar cycles and its possible relationships with <span class="hlt">interplanetary</span> shocks, sudden storm commencements at earth and cosmic ray variations. Our results stress the physical connection between the solar <span class="hlt">magnetic</span> flux emergence and the interplan- etary medium dynamics, in particular the importance of coronal hole evolution in the structuring of the heliosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4765993','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4765993"><span id="translatedtitle">Phase Error Correction in Time-<span class="hlt">Averaged</span> 3D Phase Contrast <span class="hlt">Magnetic</span> Resonance Imaging of the Cerebral Vasculature</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>MacDonald, M. Ethan; Forkert, Nils D.; Pike, G. Bruce; Frayne, Richard</p> <p>2016-01-01</p> <p>Purpose Volume flow rate (VFR) measurements based on phase contrast (PC)-<span class="hlt">magnetic</span> resonance (MR) imaging datasets have spatially varying bias due to eddy current induced phase errors. The purpose of this study was to assess the impact of phase errors in time <span class="hlt">averaged</span> PC-MR imaging of the cerebral vasculature and explore the effects of three common correction schemes (local bias correction (LBC), local polynomial correction (LPC), and whole brain polynomial correction (WBPC)). Methods Measurements of the eddy current induced phase error from a static phantom were first obtained. In thirty healthy human subjects, the methods were then assessed in background tissue to determine if local phase offsets could be removed. Finally, the techniques were used to correct VFR measurements in cerebral vessels and compared statistically. Results In the phantom, phase error was measured to be <2.1 ml/s per pixel and the bias was reduced with the correction schemes. In background tissue, the bias was significantly reduced, by 65.6% (LBC), 58.4% (LPC) and 47.7% (WBPC) (p < 0.001 across all schemes). Correction did not lead to significantly different VFR measurements in the vessels (p = 0.997). In the vessel measurements, the three correction schemes led to flow measurement differences of -0.04 ± 0.05 ml/s, 0.09 ± 0.16 ml/s, and -0.02 ± 0.06 ml/s. Although there was an improvement in background measurements with correction, there was no statistical difference between the three correction schemes (p = 0.242 in background and p = 0.738 in vessels). Conclusions While eddy current induced phase errors can vary between hardware and sequence configurations, our results showed that the impact is small in a typical brain PC-MR protocol and does not have a significant effect on VFR measurements in cerebral vessels. PMID:26910600</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19930049293&hterms=lazarus&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dlazarus','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19930049293&hterms=lazarus&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dlazarus"><span id="translatedtitle">Anomalous aspects of magnetosheath flow and of the shape and oscillations of the magnetopause during an interval of strongly northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chen, Sheng-Hsien; Kivelson, Margaret G.; Gosling, Jack T.; Walker, Raymond J.; Lazarus, Allan J.</p> <p>1993-01-01</p> <p>On February 15, 1978, the orientation of the IMF remained steadily northward for more than 12 hours. Using plasma and <span class="hlt">magnetic</span> field data from ISEE 1 and 2, IMP 8, and IMP 7, we show that (1) the magnetosheath flow speed on the flanks of the magnetotail steadily exceeded the solar wind speed by 20 percent, (2) surface waves of about 5-min period and very nonsinusoidal waveform were persistently present on the dawn magnetopause and waves of similar period were present in the dusk magnetosheath, and (3) the magnetotail ceased to flare at an antisunward distance of 15 earth radii. We propose that the acceleration of the magnetosheath flow is achieved by <span class="hlt">magnetic</span> tension in the draped field configuration for northward IMP; the reduction of tail flaring is consistent with a decreased amount of open <span class="hlt">magnetic</span> flux and a larger standoff distance of the subsolar magnetopause. Results of a 3D MHD simulation support this phenomenological model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120009629','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120009629"><span id="translatedtitle">Electromagnetic Whistler Precursors at Supercritical <span class="hlt">Interplanetary</span> Shocks</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wilson, L. B., III</p> <p>2012-01-01</p> <p>We present observations of electromagnetic precursor waves, identified as whistler mode waves, at supercritical <span class="hlt">interplanetary</span> shocks using the Wind search coil magnetometer. The precursors propagate obliquely with respect to the local <span class="hlt">magnetic</span> field, shock normal vector, solar wind velocity, and they are not phase standing structures. All are right-hand polarized with respect to the <span class="hlt">magnetic</span> field (spacecraft frame), and all but one are right-hand polarized with respect to the shock normal vector in the normal incidence frame. Particle distributions show signatures of specularly reflected gyrating ions, which may be a source of free energy for the observed modes. In one event, we simultaneously observe perpendicular ion heating and parallel electron acceleration, consistent with wave heating/acceleration due to these waves.</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://ntrs.nasa.gov/search.jsp?R=19870034276&hterms=perovskite+solar&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dperovskite%252C%2Bsolar','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19870034276&hterms=perovskite+solar&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dperovskite%252C%2Bsolar"><span id="translatedtitle">Refractory minerals in <span class="hlt">interplanetary</span> dust</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Christoffersen, Roy; Buseck, Peter R.</p> <p>1986-01-01</p> <p>A newly studied <span class="hlt">interplanetary</span> dust particle contains a unique set of minerals that closely resembles assemblages in the refractory, calcium- and aluminum-rich inclusions in carbonaceous chondrite meteorites. The set of minerals includes diopside, magnesium-aluminum spinel, anorthite, perovskite, and fassaite. Only fassaite has previously been identified in <span class="hlt">interplanetary</span> dust particles. Diopside and spinel occur in complex symplectic intergrowths that may have formed by a reaction between condensed melilite and the solar nebula gas. The particle represents a new link between <span class="hlt">interplanetary</span> dust particles and carbonaceous chondrites; however, the compositions of its two most abundant refractory phases, diopside and spinel, differ in detail from corresponding minerals in calcium- and aluminum-rich inclusions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19810012468','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19810012468"><span id="translatedtitle">Fine-scale characteristics of <span class="hlt">interplanetary</span> sector</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Behannon, K. W.; Neubauer, F. M.; Barnstoff, H.</p> <p>1980-01-01</p> <p>The structure of the <span class="hlt">interplanetary</span> sector boundaries observed by Helios 1 within sector transition regions was studied. Such regions consist of intermediate (nonspiral) <span class="hlt">average</span> field orientations in some cases, as well as a number of large angle directional discontinuities (DD's) on the fine scale (time scales 1 hour). Such DD's are found to be more similar to tangential than rotational discontinuities, to be oriented on <span class="hlt">average</span> more nearly perpendicular than parallel to the ecliptic plane to be accompanied usually by a large dip ( 80%) in B and, with a most probable thickness of 3 x 10 to the 4th power km, significantly thicker previously studied. It is hypothesized that the observed structures represent multiple traversals of the global heliospheric current sheet due to local fluctuations in the position of the sheet. There is evidence that such fluctuations are sometimes produced by wavelike motions or surface corrugations of scale length 0.05 - 0.1 AU superimposed on the large scale structure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000PhDT.......278C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000PhDT.......278C"><span id="translatedtitle">Adaptive <span class="hlt">interplanetary</span> orbit determination</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Crain, Timothy Price</p> <p></p> <p>This work documents the development of a real-time <span class="hlt">interplanetary</span> orbit determination monitoring algorithm for detecting and identifying changes in the spacecraft dynamic and measurement environments. The algorithm may either be utilized in a stand-alone fashion as a spacecraft monitor and hypothesis tester by navigators or may serve as a component in an autonomous adaptive orbit determination architecture. In either application, the monitoring algorithm serves to identify the orbit determination filter parameters to be modified by an offline process to restore the operational model accuracy when the spacecraft environment changes unexpectedly. The monitoring algorithm utilizes a hierarchical mixture-of-experts to regulate a multilevel bank organization of extended Kalman filters. Banks of filters operate on the hierarchy top-level and are composed of filters with configurations representative of a specific environment change called a macromode. Fine differences, or micromodes, within the macromodes are represented by individual filter configurations. Regulation is provided by two levels of single-layer neural networks called gating networks. A single top-level gating network regulates the weighting among macromodes and each bank uses a gating network to regulate member filters internally. Experiments are conducted on the Mars Pathfinder cruise trajectory environment using range and Doppler data from the Deep Space Network. The experiments investigate the ability of the hierarchical mixture-of-experts to identify three environment macromodes: (1) unmodeled impulsive maneuvers, (2) changes in the solar radiation pressure dynamics, and (3) changes in the measurement noise strength. Two methods of initializing the gating networks are examined in each experiment. One method gives the neurons associated with all filters equivalent synaptic weight. The other method places greater weight on the operational filter initially believed to model the spacecraft environment. The results will show that the equal synaptic weight initialization method is superior to the one favoring the operational filter and that processing range and Doppler data together is superior to processing Doppler data alone. When processing range and Doppler with an equally initialized hierarchy, all three macromodes are definitively identified by the top-level gating network weights. Additionally, in the case of multiple successive macromode changes, the hierarchy is generally able to recover from one macromode and identify a change to another macromode.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21300682','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21300682"><span id="translatedtitle">THREE-DIMENSIONAL FEATURES OF THE OUTER HELIOSPHERE DUE TO COUPLING BETWEEN THE INTERSTELLAR AND <span class="hlt">INTERPLANETARY</span> <span class="hlt">MAGNETIC</span> FIELDS. III. THE EFFECTS OF SOLAR ROTATION AND ACTIVITY CYCLE</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Pogorelov, Nikolai V.; Borovikov, Sergey N.; Zank, Gary P.; Ogino, Tatsuki E-mail: snb0003@uah.edu E-mail: ogino@stelab.nagoya-u.ac.jp</p> <p>2009-05-10</p> <p>We investigate the effects of the 11 year solar cycle and 25 day rotation period of the Sun on the interaction of the solar wind (SW) with the local interstellar medium (LISM). Our models take into account the partially ionized character of the LISM and include momentum and energy transfer between the ionized and neutral components. We assume that the interstellar <span class="hlt">magnetic</span> field vector belongs to the hydrogen deflection plane as discovered in the SOHO SWAN experiment. This plane is inclined at an angle of about 60 deg. toward the ecliptic plane of the Sun, as suggested in recent publications relating the local interstellar cloud properties to the radio emission observed by Voyager 1. It is assumed that the latitudinal extent of the boundary between the slow and fast SW regions, as well as the angle between the Sun's rotation and <span class="hlt">magnetic</span>-dipole axes, are periodic functions of time, while the polarity of the interstellar <span class="hlt">magnetic</span> field changes sign every 11 years at the solar maximum. The global variation of the SW-LISM interaction pattern, the excursions of the termination shock and the heliopause, and parameter distributions in certain directions are investigated. The analysis of the behavior of the wavy heliospheric current sheet in the supersonic SW region shows the importance of neutral atoms on its dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19970021679','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19970021679"><span id="translatedtitle">Latitudinal Dependence of the Radial IMF Component - <span class="hlt">Interplanetary</span> Imprint</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Suess, S. T.; Smith, E. J.; Phillips, J.; Goldstein, B. E.; Nerney, S.</p> <p>1996-01-01</p> <p>Ulysses measurements have confirmed that there is no significant gradient with respect to heliomagnetic latitude in the radial component, B(sub r,), of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field. There are two processes responsible for this observation. In the corona, the plasma beta is much less than 1, except directly above streamers, so both longitudinal and latitudinal (meridional) gradients in field strength will relax, due to the transverse <span class="hlt">magnetic</span> pressure gradient force, as the solar wind carries <span class="hlt">magnetic</span> flux away from the Sun. This happens so quickly that the field is essentially uniform by 5 solar radius. Beyond 10 solar radius, beta is greater than 1 and it is possible for a meridional thermal pressure gradient to redistribute <span class="hlt">magnetic</span> flux - an effect apparently absent in Ulysses and earlier ICE and <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Physics (IMP) data. We discuss this second effect here, showing that its absence is mainly due to the perpendicular part of the anisotropic thermal pressure gradient in the <span class="hlt">interplanetary</span> medium being too small to drive significant meridional transport between the Sun and approx. 4 AU. This is done using a linear analytic estimate of meridional transport. The first effect was discussed in an earlier paper.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19720000603','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19720000603"><span id="translatedtitle"><span class="hlt">Interplanetary</span> Trajectories, Encke Method (ITEM)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Whitlock, F. H.; Wolfe, H.; Lefton, L.; Levine, N.</p> <p>1972-01-01</p> <p>Modified program has been developed using improved variation of Encke method which avoids accumulation of round-off errors and avoids numerical ambiguities arising from near-circular orbits of low inclination. Variety of <span class="hlt">interplanetary</span> trajectory problems can be computed with maximum accuracy and efficiency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19850024742&hterms=Cummings&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAuthor-Name%26N%3D0%26No%3D30%26Ntt%3DCummings%252C%2BF','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850024742&hterms=Cummings&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAuthor-Name%26N%3D0%26No%3D30%26Ntt%3DCummings%252C%2BF"><span id="translatedtitle">Differential measurement of cosmic-ray gradient with respect to <span class="hlt">interplanetary</span> current sheet</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Christon, S. P.; Cummings, A. C.; Stone, E. C.; Behannon, K. W.; Burlaga, L. F.</p> <p>1985-01-01</p> <p>Simultaneous <span class="hlt">magnetic</span> field and charged particle measurements from the Voyager pacecraft at heliographic latitude separations from 10 deg to 21 deg are used to determine the latitude gradient of the galactic cosmic ray flux with respect to the <span class="hlt">interplanetary</span> current sheet. By comparing the ratio of cosmic ray flux at Voyager 1 to that at Voyager 2 during periods when both spacecraft are first north and then south of the <span class="hlt">interplanetary</span> current sheet, we find an estimate of the latitudinal gradient with respect to the current sheet of approximately -0.15 + or- 0.05%/deg under restricted <span class="hlt">interplanetary</span> conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19850026534','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850026534"><span id="translatedtitle">Differential measurement of cosmic-ray gradient with respect to <span class="hlt">interplanetary</span> current sheet</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Christon, S. P.; Cummings, A. C.; Stone, E. C.; Behannon, K. W.; Burlaga, L. F.</p> <p>1985-01-01</p> <p>Simultaneous <span class="hlt">magnetic</span> field and charged particle measurements from the Voyager spacecraft at heliographic latitude separations from 10 deg. to 21 deg. are used to determine the latitude gradient of the galactic cosmic ray flux with respect to the <span class="hlt">interplanetary</span> current sheet. By comparing the ratio of cosmic ray flux at Voyager 1 to that a Voyager 2 during periods when both spacecraft are first nort and then south of the <span class="hlt">interplanetary</span> current sheet, we find an estimate of the latitudinal gradient with respect to the current sheet of approximately -0.15 + or 0.05% deg under restricted <span class="hlt">interplanetary</span> conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20110015529&hterms=CANE&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DCANE','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20110015529&hterms=CANE&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DCANE"><span id="translatedtitle"><span class="hlt">Interplanetary</span> Circumstances of Quasi-Perpendicular <span class="hlt">Interplanetary</span> Shocks in 1996-2005</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Richardson, I. G.; Cane, H. V.</p> <p>2010-01-01</p> <p>The angle (theta(sub Bn)) between the normal to an <span class="hlt">interplanetary</span> shock front and the upstream <span class="hlt">magnetic</span> field direction, though often thought of as a property "of the shock," is also determined by the configuration of the <span class="hlt">magnetic</span> field immediately upstream of the shock. We investigate the <span class="hlt">interplanetary</span> circumstances of 105 near-Earth quasi-perpendicular shocks during 1996-2005 identified by theta(sub Bn) greater than or equal to 80 degrees and/or by evidence of shock drift particle acceleration. Around 87% of these shocks were driven by <span class="hlt">interplanetary</span> coronal mass ejections (ICMEs); the remainder were probably the forward shocks of corotating interaction regions. For around half of the shocks, the upstream field was approximately perpendicular to the radial direction, either east-west or west-east or highly inclined to the ecliptic. Such field directions will give quasi-perpendicular configurations for radially propagating shocks. Around 30% of the shocks were propagating through, or closely followed, ICMEs at the time of observation. Another quarter were propagating through the heliospheric plasma sheet (HPS), and a further quarter occurred in slow solar wind that did not have characteristics of the HPS. Around 11% were observed in high-speed streams, and 7% in the sheaths following other shocks. The fraction of shocks found in high-speed streams is around a third of that expected based on the fraction of the time when such streams were observed at Earth. Quasi-perpendicular shocks are found traveling through ICMEs around 2-3 times more frequently than expected. In addition, shocks propagating through ICMEs are more likely to have larger values of theta(sub Bn) than shocks outside ICMEs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22270672','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22270672"><span id="translatedtitle">USING COORDINATED OBSERVATIONS IN POLARIZED WHITE LIGHT AND FARADAY ROTATION TO PROBE THE SPATIAL POSITION AND <span class="hlt">MAGNETIC</span> FIELD OF AN <span class="hlt">INTERPLANETARY</span> SHEATH</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Xiong, Ming; Feng, Xueshang; Liu, Ying D.; Davies, Jackie A.; Harrison, Richard A.; Owens, Mathew J.; Davis, Chris J.</p> <p>2013-11-01</p> <p>Coronal mass ejections (CMEs) can be continuously tracked through a large portion of the inner heliosphere by direct imaging in visible and radio wavebands. White light (WL) signatures of solar wind transients, such as CMEs, result from Thomson scattering of sunlight by free electrons and therefore depend on both viewing geometry and electron density. The Faraday rotation (FR) of radio waves from extragalactic pulsars and quasars, which arises due to the presence of such solar wind features, depends on the line-of-sight <span class="hlt">magnetic</span> field component B{sub ∥} and the electron density. To understand coordinated WL and FR observations of CMEs, we perform forward magnetohydrodynamic modeling of an Earth-directed shock and synthesize the signatures that would be remotely sensed at a number of widely distributed vantage points in the inner heliosphere. Removal of the background solar wind contribution reveals the shock-associated enhancements in WL and FR. While the efficiency of Thomson scattering depends on scattering angle, WL radiance I decreases with heliocentric distance r roughly according to the expression I∝r {sup –3}. The sheath region downstream of the Earth-directed shock is well viewed from the L4 and L5 Lagrangian points, demonstrating the benefits of these points in terms of space weather forecasting. The spatial position of the main scattering site r{sub sheath} and the mass of plasma at that position M{sub sheath} can be inferred from the polarization of the shock-associated enhancement in WL radiance. From the FR measurements, the local B{sub ∥sheath} at r{sub sheath} can then be estimated. Simultaneous observations in polarized WL and FR can not only be used to detect CMEs, but also to diagnose their plasma and <span class="hlt">magnetic</span> field properties.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22270645','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22270645"><span id="translatedtitle">MAGNETOHYDRODYNAMIC SIMULATIONS OF <span class="hlt">INTERPLANETARY</span> CORONAL MASS EJECTIONS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lionello, Roberto; Downs, Cooper; Linker, Jon A.; Török, Tibor; Riley, Pete; Mikić, Zoran E-mail: cdowns@predsci.com E-mail: tibor@predsci.com E-mail: mikic@predsci.com</p> <p>2013-11-01</p> <p>We describe a new MHD model for the propagation of <span class="hlt">interplanetary</span> coronal mass ejections (ICMEs) in the solar wind. Accurately following the propagation of ICMEs is important for determining space weather conditions. Our model solves the MHD equations in spherical coordinates from a lower boundary above the critical point to Earth and beyond. On this spherical surface, we prescribe the <span class="hlt">magnetic</span> field, velocity, density, and temperature calculated typically directly from a coronal MHD model as time-dependent boundary conditions. However, any model that can provide such quantities either in the inertial or rotating frame of the Sun is suitable. We present two validations of the technique employed in our new model and a more realistic simulation of the propagation of an ICME from the Sun to Earth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19760053294&hterms=lazarus&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dlazarus','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19760053294&hterms=lazarus&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dlazarus"><span id="translatedtitle">Suprathermal protons in the <span class="hlt">interplanetary</span> solar wind</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Goodrich, C. C.; Lazarus, A. J.</p> <p>1976-01-01</p> <p>Using the Mariner 5 solar wind plasma and <span class="hlt">magnetic</span> field data, we present observations of field-aligned suprathermal proton velocity distributions having pronounced high-energy shoulders. These observations, similar to the interpenetrating stream observations of Feldman et al. (1974), are clear evidence that such proton distributions are <span class="hlt">interplanetary</span> rather than bow shock associated phenomena. Large Alfven speed is found to be a requirement for the occurrence of suprathermal proton distribution; further, we find the proportion of particles in the shoulder to be limited by the magnitude of the Alfven speed. It is suggested that this last result could indicate that the proton thermal anisotropy is limited at times by wave-particle interactions</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003EAEJA....10268D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA....10268D"><span id="translatedtitle">The Orbital Distributions of <span class="hlt">Interplanetary</span> Dust Revised</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dikarev, V. V.; Gruen, E.; Landgraf, M.; Jehn, R.; Baggaley, W. J.; Galligan, D.; Grant, J.</p> <p>2003-04-01</p> <p>The distribution of orbits of <span class="hlt">interplanetary</span> dust particles is revised. Infrared observations of the zodiacal cloud by the COBE DIRBE instrument, flux measurements by the dust detectors on board Galileo and Ulysses spacecraft, meteor orbit database acquired by the AMOR radar and the crater size distributions on lunar rock samples retrieved by the Apollo missions are fused into a single model. The main results are: the inclination distribution is unexpectedly wide, suggesting dominance of cometary particles in the flux on Earth; the <span class="hlt">average</span> impact speed of meteoroids onto the lunar rocks is two times higher than it was previously thought; asteroidal dust was not necessary in explaining all the observations, however, there is ambiguity in interpreting the observations at low ecliptic latitudes where a fraction of dust particles may originate from asteroids.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19850026461','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850026461"><span id="translatedtitle">Particle acceleration due to shocks in the <span class="hlt">interplanetary</span> field: High time resolution data and simulation results</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kessel, R. L.; Armstrong, T. P.; Nuber, R.; Bandle, J.</p> <p>1985-01-01</p> <p>Data were examined from two experiments aboard the Explorer 50 (IMP 8) spacecraft. The Johns Hopkins University/Applied Lab Charged Particle Measurement Experiment (CPME) provides 10.12 second resolution ion and electron count rates as well as 5.5 minute or longer <span class="hlt">averages</span> of the same, with data sampled in the ecliptic plane. The high time resolution of the data allows for an explicit, point by point, merging of the <span class="hlt">magnetic</span> field and particle data and thus a close examination of the pre- and post-shock conditions and particle fluxes associated with large angle oblique shocks in the <span class="hlt">interplanetary</span> field. A computer simulation has been developed wherein sample particle trajectories, taken from observed fluxes, are allowed to interact with a planar shock either forward or backward in time. One event, the 1974 Day 312 shock, is examined in detail.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003TrGeo...1..689B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003TrGeo...1..689B"><span id="translatedtitle"><span class="hlt">Interplanetary</span> Dust Particles</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bradley, J. P.</p> <p>2003-12-01</p> <p>One of the fundamental goals of the study of meteorites is to understand how the solar system and planetary systems around other stars formed. It is known that the solar system formed from pre-existing (presolar) interstellar dust grains and gas. The grains originally formed in the circumstellar outflows of other stars. They were modified to various degrees, ranging from negligible modification to complete destruction and reformation during their ˜108 yr lifetimes in the interstellar medium (ISM) (Seab, 1987; Mathis, 1993). Finally, they were incorporated into the solar system. Submicrometer-sized silicates and carbonaceous material are believed to be the most common grains in the ISM ( Mathis, 1993; Sandford, 1996), but it is not known how much of this presolar particulate matter was incorporated into the solar system, to what extent it has survived, and how it might be distinguished from solar system grains. In order to better understand the process of solar system formation, it is important to identify and analyze these solid grains. Since all of the alteration processes that modified solids in the solar nebula presumably had strong radial gradients, the logical place to find presolar grains is in small primitive bodies like comets and asteroids that have undergone little, if any, parent-body alteration.Trace quantities of refractory presolar grains (e.g., SiC and Al2O3) survive in the matrices of the most primitive carbon-rich chondritic meteorites (Anders and Zinner, 1993; Bernatowicz and Zinner, 1996; Bernatowicz and Walker, 1997; Hoppe and Zinner, 2000; see Chapter 1.02). Chondritic meteorites are believed to be from the asteroid belt, a narrow region between 2.5 and 3.5 astronomical units (AU) that marks the transition from the terrestrial planets to the giant gas-rich planets. The spectral properties of the asteroids suggest a gradation in properties with some inner and main belt C and S asteroids (the source region of most meteorites and polar micrometeorites) containing layer silicates indicative of parent-body aqueous alteration and the more distant anhydrous P and D asteroids exhibiting no evidence of (aqueous) alteration (Gradie and Tedesco, 1982). This gradation in spectral properties presumably extends several hundred AU out to the Kuiper belt, the source region of most short-period comets, where the distinction between comets and outer asteroids may simply be one of the orbital parameters ( Luu, 1993; Brownlee, 1994; Jessberger et al., 2001). The mineralogy and petrography of meteorites provides direct confirmation of aqueous alteration, melting, fractionation, and thermal metamorphism among the inner asteroids ( Zolensky and McSween, 1988; Farinella et al., 1993; Brearley and Jones, 1998). Because the most common grains in the ISM (silicates and carbonaceous matter) are not as refractory as those found in meteorites, it is unlikely that they have survived in significant quantities in meteorites. Despite a prolonged search, not a single presolar silicate grain has yet been identified in any meteorite.<span class="hlt">Interplanetary</span> dust particles (IDPs) are the smallest and most fine-grained meteoritic objects available for laboratory investigation (Figure 1). In contrast to meteorites, IDPs are derived from a broad range of dust-producing bodies extending from the inner main belt of the asteroids to the Kuiper belt (Flynn, 1996, 1990; Dermott et al., 1994; Liou et al., 1996). After release from their asteroidal or cometary parent bodies the orbits of IDPs evolve by Poynting-Robertson (PR) drag (the combined influence of light pressure and radiation drag) ( Dermott et al., 2001). Irrespective of the location of their parent bodies nearly all IDPs under the influence of PR drag can eventually reach Earth-crossing orbits. IDPs are collected in the stratosphere at 20-25 km altitude using NASA ER2 aircraft ( Sandford, 1987; Warren and Zolensky, 1994). Laboratory measurements of implanted rare gases, solar flare tracks ( Figure 2), and isotope abundances have confirmed that the collected particles are indeed extraterrestrial and that, prior to atmospheric entry, they spent 104-105 yr as small particles orbiting the Sun (Rajan et al., 1977; Hudson et al., 1981; Bradley et al., 1984a; McKeegan et al., 1985; Messenger, 2000). (21K)Figure 1. (a)-(c) Secondary electron images. (a) Anhydrous CP IDP. (b) Hydrated CS IDP (RB12A44). (c) Single-mineral forsterite grain with adhering chondritic material. (d) Optical micrograph (transmitted light) of giant cluster IDP (U220GCA) in silicone oil on ER2 collection flag. (14K)Figure 2. Darkfield transmission electron micrographs. (a) Solar-wind sputtered rim on exterior surface plus implanted solar flare tracks in chondritic IDP U220A19 (from Bradley and Brownlee, 1986). (b) Solar flare tracks in a forsterite crystal in chondritic IDP U220B11 (from Bradley et al., 1984a). The track densities in both IDPs are ˜1010-1011 cm2 corresponding to an orbital exposure age of ˜104yr. During atmospheric entry most IDPs are frictionally heated to within 100 °C of their peak heating temperature for ˜1 s and, to a first-order approximation, the smallest particles are the least strongly heated. Although some IDPs may experience thermal pulses in excess of 1,000 °C for up to 10 s (depending on particle size, mass, entry angle, and speed) (Love and Brownlee, 1991, 1996), the presence of solar flare tracks in an IDP establishes that it was not heated above ˜650 °C ( Bradley et al., 1984a). Since IDPs decelerate from cosmic velocities at altitudes >90 km, where the maximum aerodynamic ram pressure is a factor of ˜103 less than that exerted on conventional meteorites, extremely fragile meteoritic materials that cannot survive as large objects can survive as small IDPs (Figure 1(a)) ( Brownlee, 1994). Such fragile materials are suspected to be among the most primitive objects and potentially the most informative regarding early solar system and presolar processes. (Conventional meteorites penetrate deep into the atmosphere such that only relatively well-indurated rocks can survive.) Collected IDPs are briefly exposed to the terrestrial environment but since their residence time in the stratosphere is short (˜2 weeks), they are not subjected to longer-term weathering that affects the surfaces of most meteorites (Flynn, 1994a).This chapter examines the compositions, mineralogy, sources, and geochemical significance of IDPs. Additional reading can be found in reviews by Fraundorf (1981), Brownlee (1985), Sandford (1987), Bradley et al. (1988), Jessberger et al. (2001), Rietmeijer (1998), and the book edited by Zolensky et al. (1994). Despite their micrometer-scale dimensions and nanogram masses it is now possible, primarily as a result of advances in small particle handling techniques and analytical instrumentation, to examine IDPs at close to atomic-scale resolution. The most widely used instruments for IDP studies are presently the analytical electron microscope, synchrotron facilities, and the ion microprobe. These laboratory analytical techniques are providing fundamental insights about IDP origins, mechanisms of formation, and grain processing phenomena that were important in the early solar system and presolar environments. At the same time, laboratory data from IDPs are being compared with astronomical data from dust in comets, circumstellar disks, and the ISM. The direct comparison of grains in the laboratory with grains in astronomical environments defines the new discipline of "astromineralogy" ( Jaeger et al., 1998; Bradley et al., 1999a, b; Molster et al., 2001; Keller et al., 2001; Flynn et al., 2002). ,</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014IAUS..300..397B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014IAUS..300..397B"><span id="translatedtitle">24 synoptic maps 1974-1982 (ascending phase of cycle XXI) of 323 prominence <span class="hlt">average</span> <span class="hlt">magnetic</span> fields measured by the Hanle effect</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bommier, Véronique</p> <p>2014-01-01</p> <p>The poster was made of 323 <span class="hlt">average</span> prominence <span class="hlt">magnetic</span> fields reported on 24 synoptic maps. The paper first resumes the methods for the field derivation, and the different results of the whole program of these second generation Hanle effect observations. From their conclusions, it was possible to derive a unique field vector for each of the 323 prominences. The maps put in evidence a large scale structure of the prominence <span class="hlt">magnetic</span> field, probably distorted by the differential rotation, which leads to a systematically small angle (on the order of 30°) between the field vector and the prominence long axis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ApJ...772....2P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ApJ...772....2P"><span id="translatedtitle">Three-dimensional Features of the Outer Heliosphere due to Coupling between the Interstellar and <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Fields. IV. Solar Cycle Model Based on Ulysses Observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pogorelov, N. V.; Suess, S. T.; Borovikov, S. N.; Ebert, R. W.; McComas, D. J.; Zank, G. P.</p> <p>2013-07-01</p> <p>The solar cycle has a profound influence on the solar wind (SW) interaction with the local interstellar medium (LISM) on more than one timescales. Also, there are substantial differences in individual solar cycle lengths and SW behavior within them. The presence of a slow SW belt, with a variable latitudinal extent changing within each solar cycle from rather small angles to 90°, separated from the fast wind that originates at coronal holes substantially affects plasma in the inner heliosheath (IHS)—the SW region between the termination shock (TS) and the heliopause (HP). The solar cycle may be the reason why the complicated flow structure is observed in the IHS by Voyager 1. In this paper, we show that a substantial decrease in the SW ram pressure observed by Ulysses between the TS crossings by Voyager 1 and 2 contributes significantly to the difference in the heliocentric distances at which these crossings occurred. The Ulysses spacecraft is the source of valuable information about the three-dimensional and time-dependent properties of the SW. Its unique fast latitudinal scans of the SW regions make it possible to create a solar cycle model based on the spacecraft in situ measurements. On the basis of our analysis of the Ulysses data over the entire life of the mission, we generated time-dependent boundary conditions at 10 AU from the Sun and applied our MHD-neutral model to perform a numerical simulation of the SW-LISM interaction. We analyzed the global variations in the interaction pattern, the excursions of the TS and the HP, and the details of the plasma and <span class="hlt">magnetic</span> field distributions in the IHS. Numerical results are compared with Voyager data as functions of time in the spacecraft frame. We discuss solar cycle effects which may be reasons for the recent decrease in the TS particles (ions accelerated to anomalous cosmic-ray energies) flux observed by Voyager 1.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22140113','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22140113"><span id="translatedtitle">THREE-DIMENSIONAL FEATURES OF THE OUTER HELIOSPHERE DUE TO COUPLING BETWEEN THE INTERSTELLAR AND <span class="hlt">INTERPLANETARY</span> <span class="hlt">MAGNETIC</span> FIELDS. IV. SOLAR CYCLE MODEL BASED ON ULYSSES OBSERVATIONS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Pogorelov, N. V.; Zank, G. P.; Suess, S. T.; Borovikov, S. N.; Ebert, R. W.; McComas, D. J.</p> <p>2013-07-20</p> <p>The solar cycle has a profound influence on the solar wind (SW) interaction with the local interstellar medium (LISM) on more than one timescales. Also, there are substantial differences in individual solar cycle lengths and SW behavior within them. The presence of a slow SW belt, with a variable latitudinal extent changing within each solar cycle from rather small angles to 90 Degree-Sign , separated from the fast wind that originates at coronal holes substantially affects plasma in the inner heliosheath (IHS)-the SW region between the termination shock (TS) and the heliopause (HP). The solar cycle may be the reason why the complicated flow structure is observed in the IHS by Voyager 1. In this paper, we show that a substantial decrease in the SW ram pressure observed by Ulysses between the TS crossings by Voyager 1 and 2 contributes significantly to the difference in the heliocentric distances at which these crossings occurred. The Ulysses spacecraft is the source of valuable information about the three-dimensional and time-dependent properties of the SW. Its unique fast latitudinal scans of the SW regions make it possible to create a solar cycle model based on the spacecraft in situ measurements. On the basis of our analysis of the Ulysses data over the entire life of the mission, we generated time-dependent boundary conditions at 10 AU from the Sun and applied our MHD-neutral model to perform a numerical simulation of the SW-LISM interaction. We analyzed the global variations in the interaction pattern, the excursions of the TS and the HP, and the details of the plasma and <span class="hlt">magnetic</span> field distributions in the IHS. Numerical results are compared with Voyager data as functions of time in the spacecraft frame. We discuss solar cycle effects which may be reasons for the recent decrease in the TS particles (ions accelerated to anomalous cosmic-ray energies) flux observed by Voyager 1.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013LatJP..50...68A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013LatJP..50...68A"><span id="translatedtitle">Low-Amplitude Anisotropic Wave Train Events during Passage of <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Clouds / Mazas Amplitūdas Anizotropiju Viļņu Parādību Secība Starpplanētu Magnētisko Mākoņu Rašanās Laikā</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Agarwal, R.; Mishra, R. K.</p> <p>2013-04-01</p> <p>The work presents a continuation in the series related to the long-term space observations made by ground-based neutron monitoring stations. The cosmic ray intensity variation is considered as affected by <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> clouds during low-amplitude anisotropic wave train (LAAWT) events. It was observed that the solar wind velocity is higher than normal (> 300 km/s) while the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) strength is lower than normal on the arrival of <span class="hlt">magnetic</span> cloud during LAAWT events. The proton density is found to remain significantly low at high solar-wind velocity, which was expected. The north/south component of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field turns southward one day before the arrival of cloud and remains in this direction after that. The cosmic ray intensity is found to increase with the solar wind velocity. It is noteworthy that the cosmic ray intensity significantly increases before and 90 h after the arrival of such a cloud, and decreases gradually after its passage. The north/south component of IMF (Bz) is found to significantly correlate with latitude angle (Ө) and disturbance storm time index Dst, whereas the geomagnetic activity index (Ap) significantly anti-correlates with these parameters, decreasing with (Ө) and Dst increasing on the arrival of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> cloud during LAAWT events. Raksts ir turpinājums darbu sērijai par dažādām parādībām kosmosā, kas balstītas uz novērojumiem un datiem, iegūtiem dažādos laika periodos pasaules neitronu monitoringa stacijās (Deep River, Tokija, Maskava, u.c.). Rakstā apskatītās kosmisko staru intensitātes izmaiņas tiek pamatotas ar starpplanētu magnētisko mākoņu parādīšanos. Tiek parādītas saules vēja, magnētiskā lauka spēka, vētru pertubāciju indeksa un citu parametru atkarība no magnētisko mākoņu parādīšanās. Tiek atzīmēts, ka kosmisko staru intensitāte strauji pieaug pirms mākoņu parādīšanās un 90 stundu laikā pēc tiem, un pakāpeniski samazinās pēc to aiziešanas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20070017872','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20070017872"><span id="translatedtitle">Quaternion <span class="hlt">Averaging</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Markley, F. Landis; Cheng, Yang; Crassidis, John L.; Oshman, Yaakov</p> <p>2007-01-01</p> <p>Many applications require an algorithm that <span class="hlt">averages</span> quaternions in an optimal manner. For example, when combining the quaternion outputs of multiple star trackers having this output capability, it is desirable to properly <span class="hlt">average</span> the quaternions without recomputing the attitude from the the raw star tracker data. Other applications requiring some sort of optimal quaternion <span class="hlt">averaging</span> include particle filtering and multiple-model adaptive estimation, where weighted quaternions are used to determine the quaternion estimate. For spacecraft attitude estimation applications, derives an optimal <span class="hlt">averaging</span> scheme to compute the <span class="hlt">average</span> of a set of weighted attitude matrices using the singular value decomposition method. Focusing on a 4-dimensional quaternion Gaussian distribution on the unit hypersphere, provides an approach to computing the <span class="hlt">average</span> quaternion by minimizing a quaternion cost function that is equivalent to the attitude matrix cost function Motivated by and extending its results, this Note derives an algorithm that deterniines an optimal <span class="hlt">average</span> quaternion from a set of scalar- or matrix-weighted quaternions. Rirthermore, a sufficient condition for the uniqueness of the <span class="hlt">average</span> quaternion, and the equivalence of the mininiization problem, stated herein, to maximum likelihood estimation, are shown.</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://ntrs.nasa.gov/search.jsp?R=19940016180&hterms=1076&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3D%2526%25231076','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19940016180&hterms=1076&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3D%2526%25231076"><span id="translatedtitle">Helium in <span class="hlt">interplanetary</span> dust particles</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nier, A. O.; Schlutter, D. J.</p> <p>1993-01-01</p> <p>Helium and neon were extracted from fragments of individual stratosphere-collected <span class="hlt">interplanetary</span> dust particles (IDP's) by subjecting them to increasing temperature by applying short-duration pulses of power in increasing amounts to the ovens containing the fragments. The experiment was designed to see whether differences in release temperatures could be observed which might provide clues as to the asteroidal or cometary origin of the particles. Variations were observed which show promise for elucidating the problem.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010cosp...38.1924W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010cosp...38.1924W"><span id="translatedtitle">Imaging <span class="hlt">Interplanetary</span> CMEs at Radio Frequency From Solar Polar Orbit</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, Ji; Sun, Weiying; Zheng, Jianhua; Zhang, Cheng; Wang, Chi; Wang, C. B.; Wang, S.</p> <p></p> <p>Coronal mass ejections (CMEs) are violent discharges of plasma and <span class="hlt">magnetic</span> fields from the Sun's corona. They have come to be recognized as the major driver of physical conditions in the Sun-Earth system. Consequently, the detection of CMEs is important for un-derstanding and ultimately predicting space weather conditions. The Solar Polar Orbit Radio Telescope (SPORT) is a proposed mission to observe the propagation of <span class="hlt">interplanetary</span> CMEs from solar polar orbit. The main payload (radio telescope) on board SPORT will be an in-terferometric imaging radiometer working at the meter wavelength band, which will follow the propagation of <span class="hlt">interplanetary</span> CMEs from a distance of a few solar radii to near 1 AU from solar polar orbit. The SPORT spacecraft will also be equipped with a set of optical and in situ measurement instruments such as a EUV solar telescope, a solar wind plasma experiment, a solar wind ion composition instrument, an energetic particle detector, a wave detector, a mag-netometer and an <span class="hlt">interplanetary</span> radio burst tracker. In this paper, we first describe the current shortage of <span class="hlt">interplanetary</span> CME observations. Next, the scientific motivation and objectives of SPORT are introduced. We discuss the basic specifications of the main radio telescope of SPORT with reference to the radio emission mechanisms and the radio frequency band to be observed. Finally, we discuss the key technologies of the SPORT mission, including the con-ceptual design of the main telescope, the image retrieval algorithm and the solar polar orbit injection. Other payloads and their respective observation objectives are also briefly discussed. Key words: <span class="hlt">Interplanetary</span> CMEs; Interferometric imaging; Solar polar orbit; Radiometer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013IAUS..294..487L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013IAUS..294..487L"><span id="translatedtitle">Observations of <span class="hlt">interplanetary</span> scintillation in China</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Li-Jia; Peng, Bo</p> <p>2013-07-01</p> <p>The Sun affects the Earth in multiple ways. In particular, the material in <span class="hlt">interplanetary</span> space comes from coronal expansion in the form of solar wind, which is the primary source of the <span class="hlt">interplanetary</span> medium. Ground-based <span class="hlt">Interplanetary</span> Scintillation (IPS) observations are an important and effective method for measuring solar wind speed and the structures of small diameter radio sources. In this paper we will discuss the IPS observations in China.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AIPC.1670c0015K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AIPC.1670c0015K"><span id="translatedtitle">The dynamics of solar plasma events and their <span class="hlt">interplanetary</span> consequences</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kaushik, Subhash Chandra; Sharma, Giriraj</p> <p>2015-07-01</p> <p>In the present study we have analyzed the <span class="hlt">interplanetary</span> plasma / field parameter, which have initiated the complex nature intense and highly geo-effective events in the magnetosphere. It is believed that Solar wind velocity V. <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) B and Bz are the crucial drivers of these activities. However, sometimes strong geomagnetic disturbance is associated with the interaction between slow and fast solar wind streams originating from coronal holes leads to create co-rotating plasma interaction region (CIR). Thus the dynamics of the magnetospheric plasma configuration is the reflection of measured solar wind and <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) conditions. While the magnetospheric plasma anomalies are generally represented by geomagnetic storms and sudden ionosphere disturbance (SIDs). The study considers 220 geomagnetic storms associated with disturbance storm time (Dst) decrease of more than -50 nT to -300 nT, observed during solar cycle 23 and the ascending phase of solar cycle 24. These have been analyzed and studied statistically. The spacecraft data acquired by space satellites and those provided by World Data Center (WDC) - A and geomagnetic stations data from WDC- C, Kyoto are utilized in the study. It is observed that the yearly occurrences of geomagnetic storm are strongly correlated with sunspot cycle, however we have not found any significant correlation between the maximum and minimum phase of solar cycle. It is also inferred from the results that solar cycle-23 was remarkable for occurrence of intense geomagnetic storms during its descending phase.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050180487','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050180487"><span id="translatedtitle">Propagation of <span class="hlt">Interplanetary</span> Disturbances in the Outer Heliosphere</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wang, Chi</p> <p>2005-01-01</p> <p>Contents include the following: 1. We have developed a one-dimensional, spherically symmetric, multi-fluid MHD model that includes solar wind protons and electrons, pickup ions, and interstellar neutral hydrogen. This model advances the existing solar wind models for the outer heliosphere in two important ways: one is that it distinguishes solar wind protons from pickup ions, and the other is that it allows for energy transfer from pickup ions to the solar wind protons. Model results compare favorably with the Voyager 2 observations. 2. 2. Solar wind slowdown and interstellar neutral density. The solar wind in the outer heliosphere is fundamentally different from that in the inner heliosphere since the effects of interstellar neutrals become significant. 3. ICME propagation from the inner to outer heliosphere. Large coronal mass ejections (CMEs) have major effects on the structure of the solar wind and the heliosphere. The plasma and <span class="hlt">magnetic</span> field can be compressed ahead of <span class="hlt">interplanetary</span> CMEs. 4. During the current solar cycle (Cycle 23), several major CMEs associated with solar flares produced large transient shocks which were observed by widely-separated spacecraft such as Wind at Earth and Voyager 2 beyond 60 AU. Using data from these spacecraft, we use the multi-fluid model to investigate shock propagation and interaction in the heliosphere. Specifically, we studied the Bastille Day 2000, April 2001 and Halloween 2003 events. 5. Statistical properties of the solar wind in the outer heliosphere. In a collaboration with L.F. Burlaga of GSFC, it is shown that the basic statistical properties of the solar wind in the outer heliosphere can be well produced by our model. We studied the large-scale heliospheric <span class="hlt">magnetic</span> field strength fluctuations as a function of distance from the Sun during the declining phase of a solar cycle, using our numerical model with observations made at 1 AU during 1995 as input. 6. Radial heliospheric <span class="hlt">magnetic</span> field events. The heliospheric <span class="hlt">magnetic</span> field (HMF) direction, on <span class="hlt">average</span>, conforms well to the Parker spiral.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19930054555&hterms=balogh&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAuthor-Name%26N%3D0%26No%3D80%26Ntt%3Dbalogh','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19930054555&hterms=balogh&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAuthor-Name%26N%3D0%26No%3D80%26Ntt%3Dbalogh"><span id="translatedtitle">Ulysses - <span class="hlt">Interplanetary</span> shocks between 1 and 4 AU</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Burton, M. E.; Smith, E. J.; Goldstein, B. E.; Balogh, A.; Forsyth, R. J.; Bame, S. J.</p> <p>1992-01-01</p> <p>The complex solar events of March 1991 are evident as a large increase in the rate of occurrence of <span class="hlt">interplanetary</span> shocks. Using Ulysses <span class="hlt">magnetic</span> field and plasma measurements, 32 forward shocks and 7 reverse shocks have been identified in the 280 day interval from October 26, 1990 to August 1, 1991. The March events alone have produced 9 shocks, several in association with coronal mass ejections. The shocks have been identified and analyzed to find theta(BN), the speeds in the upstream solar wind, the Mach number, and the inertial speeds along the radial and <span class="hlt">magnetic</span> field directions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.9149K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.9149K"><span id="translatedtitle">Particle Acceleration at <span class="hlt">Interplanetary</span> Discontinuities</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kucharek, Harald; Farrugia, Charles; Popecki, Mark; Klecker, Berndt; Simunac, Kristin; Galvin, Antoinette</p> <p>2014-05-01</p> <p><span class="hlt">Interplanetary</span> discontinuities, long-duration Alfvenic fluctuations and transient structures such as shocks, stream interfaces (SIs), and coronal mass ejections (CME's) are considered to be prime candidates for accelerating particles in space and are therefore also responsible for producing the suprathermal particle population. The spectral slope of the phase space density of of the suprathermal particle population has been reported to cluster around v-5 but may vary significantly over longer time periods [1]. It is unclear, however, how such as slope is generated and how these <span class="hlt">interplanetary</span> structures contribute. In a statistical study for the years 2007-2009 we investigate shocks, SIs (alone or combined) as well as CME's with respect to ion acceleration efficiency and the formation of suprathermal tails in the particle distribution. This depends on solar wind plasma conditions (for example, the presence of Alfvenic fluctuations) and on the acceleration process, the shock geometry, and on the intensity of the source population. Pickup helium (He+) is an excellent tracer for <span class="hlt">interplanetary</span> discontinuities. It is abundant at these plasma discontinuities because it is preferentially accelerated compared to solar wind ions (including He+2). This study shows that all of these discontinuities produce a suprathermal population with varying number density and spectral slope. Depending on the discontinuity/structure type, the solar wind plasma conditions, the data accumulation time, and the location within the discontinuity, the slopes of the suprathermal tails are shown to vary between v-3 and v-7. This large range is most likely due to the fact that the plasma at these discontinuities has not yet reached stationary state conditions. This conjecture can be confirmed by measurements and simulated particle distributions. [1] Gloeckler et al., : AIP Conf. Proc. 1436, 136 (2012); doi: 10.1063/1.4723601</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002cosp...34E.347E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002cosp...34E.347E"><span id="translatedtitle"><span class="hlt">Interplanetary</span> shocks and sudden impulses in solar maximum (2000) and solar minimum (1995-1996)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Echer, E.; Gonzalez, W.; dal Lago, A.; Vieira, L.; Guarnieri, F.; Prestes, A.; Gonzalez, A.; Schuch, N.</p> <p></p> <p>In this work a study is presented on the correlation between fast forward <span class="hlt">interplanetary</span> shock parameters and sudden impulse (SI) amplitude in the H-component of the geomagnetic field, for periods of maximum (2000) and minimum (1995-1996) solar activity. Solar wind temperature, density and speed, and total <span class="hlt">magnetic</span> field, as well static (thermal and <span class="hlt">magnetic</span>) and dynamic pressures, were calculated in the upstream and downstream sides of the shock. The variation of the solar wind parameters and pressures was then correlated with SI amplitude. For the solar wind pressures, the difference between upstream and downstream square root values was taken, because in the balance pressure expression, the solar wind pressures are equal to the geomagnetic <span class="hlt">magnetic</span> field pressure, that is proportional to the square <span class="hlt">magnetic</span> field (and squared SI amplitude). The solar wind speed have showed good correlations with sudden impulse, with correlation coefficients higher than 0.70 both in solar maximum and solar minimum, whereas the solar wind density presented a poor correlation. The better correlated parameter with SI was the square root dynamic pressure variation, showing a higher correlation in solar maximum ( r = 0.82) than in solar minimum (r = 0.77). The correlations of SI with square root thermal and <span class="hlt">magnetic</span> pressure was lower than with the dynamic pressure, but they also present a good correlation, with r > 0.70 both in solar maximum and minimum. Multiple correlation anaylsis of SI in terms of the three pressure terms resulted in that 78% and 85% of the variance in SI at solar maximum and minimum, respectively, are explained by the three pressure variations. <span class="hlt">Average</span> sudden impulse amplitude was 25 nT in solar maximum and 20.9 nT in solar minimum, while square root dynamic pressure variation is 1.2 nPa1/2 at solar maximum and 0.9 nPa1/2 at solar minimum. Thus on <span class="hlt">average</span>, fast forward <span class="hlt">interplanetary</span> shocks are 33% stronger (in therms of squared root dynamic pressure variation) in solar maximum than in solar minimum, and the magnetospheric SI response had an amplitude 20% higher in solar maximum than in solar minimum.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19740034379&hterms=1091&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3D%2526%25231091','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19740034379&hterms=1091&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3D%2526%25231091"><span id="translatedtitle"><span class="hlt">Interplanetary</span> Lyman-beta emissions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Paresce, F.</p> <p>1973-01-01</p> <p>Derivation of the intensity of the diffuse hydrogen Lyman-beta glow at 1025 A which is due to resonance scattering of the solar H I 1025 A line by interstellar and <span class="hlt">interplanetary</span> hydrogen. Two sources of neutral hydrogen are considered: the local interstellar medium interacting with the solar system, and the dust deionization of the H(+) component of the solar wind. It is shown that if the dust geometrical factor is less than or equal to five quintillionths per cm, observations of backscattered Lyman-beta radiation will provide a unique determination of the density and temperature of the local interstellar medium.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19880052777&hterms=Luhmann&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DLuhmann','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19880052777&hterms=Luhmann&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DLuhmann"><span id="translatedtitle">Solar and <span class="hlt">interplanetary</span> control of the location of the Venus bow shock</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Russell, C. T.; Chou, E.; Luhmann, J. G.; Gazis, P.; Brace, L. H.; Hoegy, W. R.</p> <p>1988-01-01</p> <p>The Venus bow shock location has been measured at nearly 2000 shock crossings, and its dependence on solar EUV, solar wind conditions, and the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field determined. The shock position at the terminator varies from about 2.14 Venus radii at solar minimum to 2.40 Venus radii at solar maximum. The location of the shock varies little with solar wind dynamic pressure but strongly with solar wind Mach number. The shock is farthest from Venus on the side of the planet in which newly created ions gyrate away from the ionosphere. When the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field is perpendicular to the flow, the cross section of the shock is quite elliptical. This effect appears to be due to the anisotropic propagation of the fast magnetosonic wave. When the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field is aligned with the flow, the bow shock cross section is circular and only weakly sensitive to changing EUV flux.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19990010034&hterms=earth+magnetic&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dearth%2527s%2Bmagnetic','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19990010034&hterms=earth+magnetic&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dearth%2527s%2Bmagnetic"><span id="translatedtitle">Performance of a Bounce-<span class="hlt">Averaged</span> Global Model of Super-Thermal Electron Transport in the Earth's <span class="hlt">Magnetic</span> Field</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>McGuire, Tim</p> <p>1998-01-01</p> <p>In this paper, we report the results of our recent research on the application of a multiprocessor Cray T916 supercomputer in modeling super-thermal electron transport in the earth's <span class="hlt">magnetic</span> field. In general, this mathematical model requires numerical solution of a system of partial differential equations. The code we use for this model is moderately vectorized. By using Amdahl's Law for vector processors, it can be verified that the code is about 60% vectorized on a Cray computer. Speedup factors on the order of 2.5 were obtained compared to the unvectorized code. In the following sections, we discuss the methodology of improving the code. In addition to our goal of optimizing the code for solution on the Cray computer, we had the goal of scalability in mind. Scalability combines the concepts of portabilty with near-linear speedup. Specifically, a scalable program is one whose performance is portable across many different architectures with differing numbers of processors for many different problem sizes. Though we have access to a Cray at this time, the goal was to also have code which would run well on a variety of architectures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25574595','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25574595"><span id="translatedtitle">Noise reduction of nuclear <span class="hlt">magnetic</span> resonance (NMR) transversal data using improved wavelet transform and exponentially weighted moving <span class="hlt">average</span> (EWMA).</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ge, Xinmin; Fan, Yiren; Li, Jiangtao; Wang, Yang; Deng, Shaogui</p> <p>2015-02-01</p> <p>NMR logging and core NMR signals acts as an effective way of pore structure evaluation and fluid discrimination, but it is greatly contaminated by noise for samples with low <span class="hlt">magnetic</span> resonance intensity. Transversal relaxation time (T(2)) spectrum obtained by inversion of decay signals intrigued by Carr-Purcell-Meiboom-Gill (CPMG) sequence may deviate from the truth if the signal-to-noise ratio (SNR) is imperfect. A method of combing the improved wavelet thresholding with the EWMA is proposed for noise reduction of decay data. The wavelet basis function and decomposition level are optimized in consideration of information entropy and white noise estimation firstly. Then a hybrid threshold function is developed to avoid drawbacks of hard and soft threshold functions. To achieve the best thresholding values of different levels, a nonlinear objective function based on SNR and mean square error (MSE) is constructed, transforming the problem to a task of finding optimal solutions. Particle swarm optimization (PSO) is used to ensure the stability and global convergence. EWMA is carried out to eliminate unwanted peaks and sawtooths of the wavelet denoised signal. With validations of numerical simulations and experiments, it is demonstrated that the proposed approach can reduce the noise of T(2) decay data perfectly. PMID:25574595</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19830066648&hterms=Lab+973&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DLab%2B973','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19830066648&hterms=Lab+973&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DLab%2B973"><span id="translatedtitle"><span class="hlt">Average</span> configuration of the distant (less than 220-earth-radii) magnetotail - Initial ISEE-3 <span class="hlt">magnetic</span> field results</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Slavin, J. A.; Tsurutani, B. T.; Smith, E. J.; Jones, D. E.; Sibeck, D. G.</p> <p>1983-01-01</p> <p><span class="hlt">Magnetic</span> field measurements from the first two passes of the ISEE-3 GEOTAIL Mission have been used to study the structure of the trans-lunar tail. Good agreement was found between the ISEE-3 magnetopause crossings and the Explorer 33, 35 model of Howe and Binsack (1972). Neutral sheet location was well ordered by the hinged current sheet models based upon near earth measurements. Between X = -20 and -120 earth radii the radius of the tail increases by about 30 percent while the lobe field strength decreases by approximately 60 percent. Beyond X = -100 to -1200 earth radii the tail diameter and lobe field magnitude become nearly constant at terminal values of approximately 60 earth radii and 9 nT, respectively. The distance at which the tail was observed to cease flaring, 100-120 earth radii, is in close agreement with the predictions of the analytic tail model of Coroniti and Kennel (1972). Overall, the findings of this study suggest that the magnetotail retains much of its near earth structure out to X = -220 earth radii.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JMagR.251...71G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JMagR.251...71G"><span id="translatedtitle">Noise reduction of nuclear <span class="hlt">magnetic</span> resonance (NMR) transversal data using improved wavelet transform and exponentially weighted moving <span class="hlt">average</span> (EWMA)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ge, Xinmin; Fan, Yiren; Li, Jiangtao; Wang, Yang; Deng, Shaogui</p> <p>2015-02-01</p> <p>NMR logging and core NMR signals acts as an effective way of pore structure evaluation and fluid discrimination, but it is greatly contaminated by noise for samples with low <span class="hlt">magnetic</span> resonance intensity. Transversal relaxation time (T2) spectrum obtained by inversion of decay signals intrigued by Carr-Purcell-Meiboom-Gill (CPMG) sequence may deviate from the truth if the signal-to-noise ratio (SNR) is imperfect. A method of combing the improved wavelet thresholding with the EWMA is proposed for noise reduction of decay data. The wavelet basis function and decomposition level are optimized in consideration of information entropy and white noise estimation firstly. Then a hybrid threshold function is developed to avoid drawbacks of hard and soft threshold functions. To achieve the best thresholding values of different levels, a nonlinear objective function based on SNR and mean square error (MSE) is constructed, transforming the problem to a task of finding optimal solutions. Particle swarm optimization (PSO) is used to ensure the stability and global convergence. EWMA is carried out to eliminate unwanted peaks and sawtooths of the wavelet denoised signal. With validations of numerical simulations and experiments, it is demonstrated that the proposed approach can reduce the noise of T2 decay data perfectly.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRA..121.1062B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRA..121.1062B"><span id="translatedtitle">STEREO database of <span class="hlt">interplanetary</span> Langmuir electric waveforms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Briand, C.; Henri, P.; Génot, V.; Lormant, N.; Dufourg, N.; Cecconi, B.; Nguyen, Q. N.; Goetz, K.</p> <p>2016-02-01</p> <p>This paper describes a database of electric waveforms that is available at the Centre de Données de la Physique des Plasmas (CDPP, http://cdpp.eu/). This database is specifically dedicated to waveforms of Langmuir/Z-mode waves. These waves occur in numerous kinetic processes involving electrons in space plasmas. Statistical analysis from a large data set of such waves is then of interest, e.g., to study the relaxation of high-velocity electron beams generated at <span class="hlt">interplanetary</span> shock fronts, in current sheets and <span class="hlt">magnetic</span> reconnection region, the transfer of energy between high and low frequencies, the generation of electromagnetic waves. The Langmuir waveforms were recorded by the Time Domain Sampler (TDS) of the WAVES radio instrument on board the STEREO mission. In this paper, we detail the criteria used to identify the Langmuir/Z-mode waves among the whole set of waveforms of the STEREO spacecraft. A database covering the November 2006 to August 2014 period is provided. It includes electric waveforms expressed in the normalized frame (B,B × Vsw,B × (B × Vsw)) with B and Vsw the local <span class="hlt">magnetic</span> field and solar wind velocity vectors, and the local <span class="hlt">magnetic</span> field in the variance frame, in an interval of ±1.5 min around the time of the Langmuir event. Quicklooks are also provided that display the three components of the electric waveforms together with the spectrum of E∥, together with the magnitude and components of the <span class="hlt">magnetic</span> field in the 3 min interval, in the variance frame. Finally, the distribution of the Langmuir/Z-mode waves peak amplitude is also analyzed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EP%26S...67...11I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EP%26S...67...11I"><span id="translatedtitle">A new leveling method without the direct use of crossover data and its application in marine <span class="hlt">magnetic</span> surveys: weighted spatial <span class="hlt">averaging</span> and temporal filtering</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ishihara, Takemi</p> <p>2015-12-01</p> <p>The author has developed a new leveling method for use with <span class="hlt">magnetic</span> survey data, which consists of adjusting each measurement using the weighted spatial <span class="hlt">average</span> of its neighboring data and subsequent temporal filtering. There are two key parameters in the method: the `weight distance' represents the characteristic distance of the weight function and the `filtering width' represents the full width of the Gaussian filtering function on the time series. This new method was applied to three examples of actual marine survey data. Leveling using optimum values of these two parameters for each example was found to significantly reduce the standard deviations of crossover differences by one third to one fifth of the values before leveling. The obtained time series of correction values for each example had a good correlation with the <span class="hlt">magnetic</span> observatory data obtained relatively close to the survey areas, thus validating this new leveling method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19960021314&hterms=helicity&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dhelicity','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19960021314&hterms=helicity&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dhelicity"><span id="translatedtitle"><span class="hlt">Magnetic</span> clouds, helicity conservation, and intrinsic scale flux ropes</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kumar, A.; Rust, D. M.</p> <p>1995-01-01</p> <p>An intrinsic-scale flux-rope model for <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> clouds, incorporating conservation of <span class="hlt">magnetic</span> helicity, flux and mass is found to adequately explain clouds' <span class="hlt">average</span> thermodynamic and <span class="hlt">magnetic</span> properties. In spite their continuous expansion as they balloon into <span class="hlt">interplanetary</span> space, <span class="hlt">magnetic</span> clouds maintain high temperatures. This is shown to be due to <span class="hlt">magnetic</span> energy dissipation. The temperature of an expanding cloud is shown to pass through a maximum above its starting temperature if the initial plasma beta in the cloud is less than 2/3. Excess <span class="hlt">magnetic</span> pressure inside the cloud is not an important driver of the expansion as it is almost balanced by the tension in the helical field lines. It is conservation of <span class="hlt">magnetic</span> helicity and flux that requires that clouds expand radially as they move away from the Sun. Comparison with published data shows good agreement between measured cloud properties and theory. Parameters determined from theoretical fits to the data, when extended back to the Sun, are consistent with the origin of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> clouds in solar filament eruptions. A possible extension of the heating mechanism discussed here to heating of the solar corona is discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19850012177&hterms=modulated+structures&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dmodulated%2Bstructures','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850012177&hterms=modulated+structures&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dmodulated%2Bstructures"><span id="translatedtitle">Dependence of the High Latitude Middle Atmosphere Ionization on Structures in <span class="hlt">Interplanetary</span> Space</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bremer, J.; Lauter, E. A.</p> <p>1984-01-01</p> <p>The precipitation of high energetic electrons during and after strong geomagnetic storms into heights below 100 km in middle and subauroral latitudes is markedly modulated by the structure of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF). Under relative quiet conditions the D-region ionization caused by high energetic particle precipitation (energies greater than 20 to 50 keV) depends on changes of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field and also on the velocity of the solar wind. To test this assumption, the influence of the IMF-sector boundary crossings on ionospheric absorption data of high and middle latitudes by the superposed-epoch method was investigated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19760050070&hterms=traditional+media&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dtraditional%2Bmedia','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19760050070&hterms=traditional+media&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dtraditional%2Bmedia"><span id="translatedtitle">A quasi-linear kinetic equation for cosmic rays in the <span class="hlt">interplanetary</span> medium</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Luhmann, J. G.</p> <p>1976-01-01</p> <p>A kinetic equation for <span class="hlt">interplanetary</span> cosmic rays is set up with the aid of weak-plasma-turbulence theory for an idealized radially symmetric model of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field. As a starting point, this treatment invokes the Vlasov equation instead of the traditional Fokker-Planck equation. Quasi-linear theory is applied to obtain a momentum diffusion equation for the heliocentric frame of reference which describes the interaction of cosmic rays with convecting <span class="hlt">magnetic</span> irregularities in the solar-wind plasma. Under restricted conditions, the well-known equation of solar modulation can be obtained from this kinetic equation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19770051690&hterms=average+wind+speeds&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Daverage%2Bwind%2Bspeeds','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19770051690&hterms=average+wind+speeds&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Daverage%2Bwind%2Bspeeds"><span id="translatedtitle">On the high correlation between long-term <span class="hlt">averages</span> of solar wind speed and geomagnetic activity</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Crooker, N. U.; Feynman, J.; Gosling, J. T.</p> <p>1977-01-01</p> <p>Six-month and yearly <span class="hlt">averages</span> of solar-wind speed from 1962 to 1975 are shown to be highly correlated with geomagnetic activity as measured by <span class="hlt">averages</span> of the Ap index. On the same time scale the correlation between the southward component of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field and geomagnetic activity is poor. Previous studies with hourly <span class="hlt">averages</span> gave opposite results. The better correlation with the southward component on an hourly time scale is explained by its large variation compared with the relatively constant solar-wind speed. However, on a yearly time scale the magnitude of the variations in both parameters are about the same. This problem can be solved by invoking an energy transfer mechanism which is proportional to the first power of the southward component and a higher power of the solar-wind speed.</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://ntrs.nasa.gov/search.jsp?R=19930053283&hterms=EAST-WEST+ASYMMETRY&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DEAST-WEST%2BASYMMETRY','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19930053283&hterms=EAST-WEST+ASYMMETRY&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DEAST-WEST%2BASYMMETRY"><span id="translatedtitle">The interaction of a <span class="hlt">magnetic</span> cloud with the Earth - Ionospheric convection in the Northern and Southern Hemispheres for a wide range of quasi-steady <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field conditions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Freeman, M. P.; Farrugia, C. J.; Burlaga, L. F.; Hairston, M. R.; Greenspan, M. E.; Ruohoniemi, J. M.; Lepping, R. P.</p> <p>1993-01-01</p> <p>Observations are presented of the ionospheric convection in cross sections of the polar cap and auroral zone as part of the study of the interaction of the Earth's magnetosphere with the <span class="hlt">magnetic</span> cloud of January 13-15, 1988. For strongly northward IMF, the convection in the Southern Hemisphere is characterized by a two-cell convection pattern comfined to high latitudes with sunward flow over the pole. The strength of the flows is comparable to that later seen under southward IMF. Superimposed on this convection pattern there are clear dawn-dusk asymmetries associated with a one-cell convection component whose sense depends on the polarity of the <span class="hlt">magnetic</span> cloud's large east-west <span class="hlt">magnetic</span> field component. When the cloud's <span class="hlt">magnetic</span> field turns southward, the convection is characterized by a two-cell pattern extending to lower latitude with antisunward flow over the pole. There is no evident interhemispheric difference in the structure and strength of the convection. Superimposed dawn-dusk asymmetries in the flow patterns are observed which are only in part attributable to the east-west component of the <span class="hlt">magnetic</span> field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002JKAS...35..151O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002JKAS...35..151O"><span id="translatedtitle">Classification of the <span class="hlt">Interplanetary</span> Shocks by Shock Drivers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Oh, Su Yeon; Yi, Yu; Nah, Ja-Kyung; Cho, Kyung-Seok</p> <p>2002-09-01</p> <p>From the data of solar wind observation by ACE spacecraft orbiting the Earth-Sun Lagrangian point, we selected 48 forward <span class="hlt">interplanetary</span> shocks(IPSs) occurred in 2000, maximum solar activity period. Examining the profiles of solar wind parameters, the IPSs are classified by their shock drivers. The significant shock drivers are the <span class="hlt">interplanetary</span> coronal mass ejection(ICME) and the high speed stream(HSS). The IPSs driven by the ICMEs are classified into shocks driven by <span class="hlt">magnetic</span> clouds and by ejectas based on the existence of <span class="hlt">magnetic</span> flux rope structure and <span class="hlt">magnetic</span> field strength. Some IPSs could be formed as the blast wave by the smaller energy and shorter duration of shock drivers such as type II radio burst. Out of selected 48 forward IPSs, 56.2% of the IPSs are driven by ICME, 16.7% by HSS, and 16.7% of the shocks are classified into blast-wave type shocks. However, the shock drivers of remaining 10% of the IPSs are unidentified. The classification of the IPSs by their driver is a first step toward investigating the critical magnitudes of the IPS drivers commencing the <span class="hlt">magnetic</span> storms in each class.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ApJ...803...96S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ApJ...803...96S"><span id="translatedtitle">First Taste of Hot Channel in <span class="hlt">Interplanetary</span> Space</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Song, H. Q.; Zhang, J.; Chen, Y.; Cheng, X.; Li, G.; Wang, Y. M.</p> <p>2015-04-01</p> <p>A hot channel (HC) is a high temperature (˜10 MK) structure in the inner corona first revealed by the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory. Eruptions of HCs are often associated with flares and coronal mass ejections (CMEs). Results of previous studies have suggested that an HC is a good proxy for a <span class="hlt">magnetic</span> flux rope (MFR) in the inner corona as well as another well known MFR candidate, the prominence-cavity structure, which has a normal coronal temperature (˜1-2 MK). In this paper, we report a high temperature structure (HTS, ˜1.5 MK) contained in an <span class="hlt">interplanetary</span> CME induced by an HC eruption. According to the observations of bidirectional electrons, high temperature and density, strong <span class="hlt">magnetic</span> field, and its association with the shock, sheath, and plasma pile-up region, we suggest that the HTS is the <span class="hlt">interplanetary</span> counterpart of the HC. The scale of the measured HTS is around 14 R ⊙ , and it maintained a much higher temperature than the background solar wind even at 1 AU. It is significantly different from the typical <span class="hlt">magnetic</span> clouds, which usually have a much lower temperature. Our study suggests that the existence of a corotating interaction region ahead of the HC formed a <span class="hlt">magnetic</span> container to inhibit expansion of the HC and cool it down to a low temperature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19920041922&hterms=1609&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D%2526%25231609','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19920041922&hterms=1609&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D%2526%25231609"><span id="translatedtitle">Location of the radio emitting regions of <span class="hlt">interplanetary</span> shocks</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lengyel-Frey, D.</p> <p>1992-01-01</p> <p>Twenty <span class="hlt">interplanetary</span> type II radio bursts are analyzed to determine the location of the type II source region relative to the <span class="hlt">interplanetary</span> shock. The first determination of a density-distance relationship (density model) appropriate for <span class="hlt">interplanetary</span> type II source regions is reported. To determine source location, densities in type II source regions, derived from observed type II emission frequencies, are compared to ambient solar wind densities to determine whether source regions are in the ambient, upstream solar wind or in the compressed plasma behind the shock. Densities in the ambient solar wind upstream of each shock are computed by using a simple model to extrapolate solar wind plasma densities measured at 1 AU back to the shock front. Densities in the type II source regions are found to be enhanced relative to densities in the ambient solar wind by a factor which is close to the <span class="hlt">average</span> shock density compression ratio. The simplest interpretation of this result is that the source is located in the compressed plasma within or behind the shock. Although it is possible that the emission is produced in enhanced density regions of the upstream solar wind, it is argued that the weight of evidence favors the compressed postshock plasma as the source site.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110012255','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110012255"><span id="translatedtitle">CFDP for <span class="hlt">Interplanetary</span> Overlay Network</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Burleigh, Scott C.</p> <p>2011-01-01</p> <p>The CCSDS (Consultative Committee for Space Data Systems) File Delivery Protocol for <span class="hlt">Interplanetary</span> Overlay Network (CFDP-ION) is an implementation of CFDP that uses IO' s DTN (delay tolerant networking) implementation as its UT (unit-data transfer) layer. Because the DTN protocols effect automatic, reliable transmission via multiple relays, CFDP-ION need only satisfy the requirements for Class 1 ("unacknowledged") CFDP. This keeps the implementation small, but without loss of capability. This innovation minimizes processing resources by using zero-copy objects for file data transmission. It runs without modification in VxWorks, Linux, Solaris, and OS/X. As such, this innovation can be used without modification in both flight and ground systems. Integration with DTN enables the CFDP implementation itself to be very simple; therefore, very small. Use of ION infrastructure minimizes consumption of storage and processing resources while maximizing safety.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6141713','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6141713"><span id="translatedtitle">Infrared emission from <span class="hlt">interplanetary</span> dust</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Temi, P.; De Bernardis, P.; Masi, S.; Moreno, G.; Salama, A.</p> <p>1989-02-01</p> <p>Standard models of the <span class="hlt">interplanetary</span> dust emission fail to account satisfactorily for IR observations. A new model of the dust, based on very simple assumptions on the grain structure (spherical and homogeneous) and chemical composition (astronomical silicates, graphite, blackbodies) is developed. Updated values of the refractive indexes have been included in the analysis. The predictions of the model (absolute values of the fluxes, spectral shape, elongation dependence of the emission) have then been compared with all the available IR observations performed by the ARGO (balloon-borne experiment by University of Rome), AFGL and Zodiacal Infrared Project (ZIP) (rocket experiments by Air Force Geophysics Laboratory, Bedford, Mass.), and IRAS satellite. Good agreement is found when homogeneous data sets from single experiments (e.g., ZIP and ARGO) are considered separately. 19 references.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1989ApJ...337..528T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1989ApJ...337..528T"><span id="translatedtitle">Infrared emission from <span class="hlt">interplanetary</span> dust</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Temi, P.; de Bernardis, P.; Masi, S.; Moreno, G.; Salama, A.</p> <p>1989-02-01</p> <p>Standard models of the <span class="hlt">interplanetary</span> dust emission fail to account satisfactorily for IR observations. A new model of the dust, based on very simple assumptions on the grain structure (spherical and homogeneous) and chemical composition (astronomical silicates, graphite, blackbodies) is developed. Updated values of the refractive indexes have been included in the analysis. The predictions of the model (absolute values of the fluxes, spectral shape, elongation dependence of the emission) have then been compared with all the available IR observations performed by the ARGO (balloon-borne experiment by University of Rome), AFGL and Zodiacal Infrared Project (ZIP) (rocket experiments by Air Force Geophysics Laboratory, Bedford, Mass.), and IRAS satellite. Good agreement is found when homogeneous data sets from single experiments (e.g., ZIP and ARGO) are considered separately.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1985ASSL..119..117S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1985ASSL..119..117S"><span id="translatedtitle">The LDEF <span class="hlt">Interplanetary</span> Dust Experiment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Singer, S. F.; Stanley, J. E.; Kassel, P.</p> <p></p> <p>The Long Duration Exposure Facility was launched for the first time on April 6, 1984 by the NASA space shuttle Challenger. An array of solid-state detectors record the arrival time and approximate direction of an impacting particle. Two levels of detector sensitivity provide an indication of particle energy and mass. The orbit of the particle cannot be obtained, except statistically. To study the fate and origin of IP (<span class="hlt">interplanetary</span>) dust, the authors measure various kinds of time variations. Among the most interesting is the secular variations, i.e., the flux in various meteor streams, as a function of the passage of a comet. One of the challenging problems will be to distinguish IP dust from man-made space debris.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSM31D4226O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSM31D4226O"><span id="translatedtitle">Impact Angle Control of <span class="hlt">Interplanetary</span> Shock Geoeffectiveness</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Oliveira, D.; Raeder, J.</p> <p>2014-12-01</p> <p>We use OpenGGCM global MHD simulations to study the nightside magnetospheric/ magnetotail/ ionospheric responses to <span class="hlt">interplanetary</span> (IP) fast foward shocks. Three cases are presented in this study: two inclined oblique shocks, hereafter IOS-1 and IOS-2, where the latter has a Mach number twice stronger than the former. Both shocks have impact angles of 30o in relation to the Sun-Earth line. Lastly, we choose a frontal perpendicular shock, FPS, whose shock normal is along th Sun-Earth line, with the same Mach number as IOS-1. We find that, in the IOS-1 case, due to the north-south asymmetry, the magnetotail is deflected southward, leading to a mild compression. The geomagnetic activity observed in the nightside ionosphere is then weak. On the other hand, in the head-on case, the FPS compresses the magnetotail on both sides symmetrically. This compression triggers a substorm allowing a larger amount of stored energy in the magnetotail to be released to the nightside ionosphere, resulting in a larger geomagnetic activity there. By comparing IOS-2 and FPS, we find that, despite the IOS-2 having a larger Mach number, the FPS leads to larger geomagnetic responses in the ionosphere nightside. As a result, we conclude that IP shocks with similar upstream conditions, such as <span class="hlt">magnetic</span> field, speed, density, and even Mach number, can be differently geoeffective, depending on their shock normal orientation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JGRA..119.8188O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JGRA..119.8188O"><span id="translatedtitle">Impact angle control of <span class="hlt">interplanetary</span> shock geoeffectiveness</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Oliveira, D. M.; Raeder, J.</p> <p>2014-10-01</p> <p>We use Open Geospace General Circulation Model global MHD simulations to study the nightside magnetospheric, magnetotail, and ionospheric responses to <span class="hlt">interplanetary</span> (IP) fast forward shocks. Three cases are presented in this study: two inclined oblique shocks, hereafter IOS-1 and IOS-2, where the latter has a Mach number twice stronger than the former. Both shocks have impact angles of 30° in relation to the Sun-Earth line. Lastly, we choose a frontal perpendicular shock, FPS, whose shock normal is along the Sun-Earth line, with the same Mach number as IOS-1. We find that, in the IOS-1 case, due to the north-south asymmetry, the magnetotail is deflected southward, leading to a mild compression. The geomagnetic activity observed in the nightside ionosphere is then weak. On the other hand, in the head-on case, the FPS compresses the magnetotail from both sides symmetrically. This compression triggers a substorm allowing a larger amount of stored energy in the magnetotail to be released to the nightside ionosphere, resulting in stronger geomagnetic activity. By comparing IOS-2 and FPS, we find that, despite the IOS-2 having a larger Mach number, the FPS leads to a larger geomagnetic response in the nightside ionosphere. As a result, we conclude that IP shocks with similar upstream conditions, such as <span class="hlt">magnetic</span> field, speed, density, and Mach number, can have different geoeffectiveness, depending on their shock normal orientation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012cosp...39.1998T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012cosp...39.1998T"><span id="translatedtitle">Shielding Structures for <span class="hlt">Interplanetary</span> Human Mission</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tracino, Emanuele; Lobascio, Cesare</p> <p>2012-07-01</p> <p>Since the end of Apollo missions, human spaceflight has been limited to the Low Earth Orbit (LEO), inside the protective <span class="hlt">magnetic</span> field of the Earth, because astronauts are, to the largest degree, protected from the harsh radiation environment of the <span class="hlt">interplanetary</span> space. However, this situation will change when space exploration missions beyond LEO will become the real challenge of the human exploration program. The feasibility of these missions in the solar system is thus strongly connected to the capability to mitigate the radiation-induced biological effects on the crew during the journey and the permanence on the intended planet surface. Inside the International Space Station (ISS), the volumes in which the crew spends most of the time, namely the crew quarters are the only parts that implement dedicated additional radiation shielding made of polyethylene tiles designed for mitigating SPE effects. Furthermore, specific radiation shielding materials are often added to the described configuration to shield crew quarters or the entire habitat example of these materials are polyethylene, liquid hydrogen, etc. but, increasing the size of the exploration vehicles to bring humans beyond LEO, and without the magnetosphere protection, such approach is unsustainable because the mass involved is a huge limiting factor with the actual launcher engine technology. Moreover, shielding against GCR with materials that have a low probability of nuclear interactions and in parallel a high ionizing energy loss is not always the best solution. In particular there is the risk to increase the LET of ions arriving at the spacecraft shell, increasing their Radio-Biological Effectiveness. Besides, the production of secondary nuclei by projectile and target fragmentation is an important issue when performing an engineering assessment of materials to be used for radiation shielding. The goal of this work is to analyze different shielding solutions to increase as much as possible the radiation shielding power of the <span class="hlt">interplanetary</span> habitat structures, like the spacecraft shell, minimizing the amount of mass used. From the radiation protection point of view the spacecraft shell is an interesting spacecraft system because it surrounds almost homogeneously all the habitat and it is typically composed by the Micrometeorites and Debris Protection Systems (MDPS), the Multilayer Insulation (MLI) for thermal control purposes, and the primary structure that offers the pressure containment functionality. Nevertheless, the spacecraft internal outfitting is important to evaluate the different shielded areas in the habitat. Using Geant4 Monte Carlo simulations toolkit through GRAS (Geant4 Radiation Analysis for Space) tool, different spacecraft structures will be analyzed for their shielding behavior in terms of fluxes, dose reduction and radiation quality, and for their implementation in a real pressurized module. Effects on astronauts and electronic equipments will be also assessed with respect to the standard aluminum structures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ApJ...813...85L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ApJ...813...85L"><span id="translatedtitle">Energetic Particle Pressure at <span class="hlt">Interplanetary</span> Shocks: STEREO-A Observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lario, D.; Decker, R. B.; Roelof, E. C.; Viñas, A.-F.</p> <p>2015-11-01</p> <p>We study periods of elevated energetic particle intensities observed by STEREO-A when the partial pressure exerted by energetic (≥83 keV) protons (PEP) is larger than the pressure exerted by the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (PB). In the majority of cases, these periods are associated with the passage of <span class="hlt">interplanetary</span> shocks. Periods when PEP exceeds PB by more than one order of magnitude are observed in the upstream region of fast <span class="hlt">interplanetary</span> shocks where depressed <span class="hlt">magnetic</span> field regions coincide with increases of energetic particle intensities. When solar wind parameters are available, PEP also exceeds the pressure exerted by the solar wind thermal population (PTH). Prolonged periods (>12 hr) with both PEP > PB and PEP > PTH may also occur when energetic particles accelerated by an approaching shock encounter a region well upstream of the shock characterized by low <span class="hlt">magnetic</span> field magnitude and tenuous solar wind density. Quasi-exponential increases of the sum PSUM = PB + PTH + PEP are observed in the immediate upstream region of the shocks regardless of individual changes in PEP, PB, and PTH, indicating a coupling between PEP and the pressure of the background medium characterized by PB and PTH. The quasi-exponential increase of PSUM implies a radial gradient ∂PSUM/∂r > 0 that is quasi-stationary in the shock frame and results in an outward force applied to the plasma upstream of the shock. This force can be maintained by the mobile energetic particles streaming upstream of the shocks that, in the most intense events, drive electric currents able to generate diamagnetic cavities and depressed solar wind density regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoRL..43.1810J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoRL..43.1810J"><span id="translatedtitle">The auroral ionosphere TEC response to an <span class="hlt">interplanetary</span> shock</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jin, Yaqi; Zhou, Xiaoyan; Moen, Jøran I.; Hairston, Marc</p> <p>2016-03-01</p> <p>This letter investigates the global total electron content (TEC) response in the auroral ionosphere to an <span class="hlt">interplanetary</span> shock on 8 March 2012, using GPS TEC data from three pierce point chains. One is a longitudinal chain along ~65° <span class="hlt">magnetic</span> latitude (MLAT) from ~19 <span class="hlt">magnetic</span> local time (MLT) through dayside to 03 MLT clockwise; one meridional chain is around 14 MLT from 88° to 59° MLAT; and the third one is a chain along ~75° MLAT from ~14 to 00 MLT clockwise. The first chain clearly presents a TEC signal propagation away from ~14 MLT, indicating the shock impact location. Such a propagation is well consistent with the diffuse shock aurora propagation, and the impact location is well predicted by the shock normal direction calculated using the Geotail solar wind and <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field data. The meridional chain reveals a very fast TEC signal equatorward expansion at ~45 km/s, which is the manifestation of the shock impact and further compression near the subsolar magnetopause. While TEC along the high-latitude chain varies randomly, lacking any pattern, it is consistent with the discrete aurora dynamics along the poleward boundary of the auroral oval. These findings strongly support the shock aurora mechanisms of adiabatic compression and field-aligned current establishment or enhancement, suggest that due to the same mechanisms a shock-generated TEC variation is a "duplication" of the shock aurora from the global picture to the auroral forms and their dynamics, and open the door for the TEC to be an important tool to understand the solar wind and geospace coupling. These results, for the first time, reveal the prompt, intense, and global ionospheric TEC response to the <span class="hlt">interplanetary</span> fast-forward shock.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.6435P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.6435P"><span id="translatedtitle">Cause of the exceptionally high AE <span class="hlt">average</span> for 2003</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Prestes, A.</p> <p>2012-04-01</p> <p>In this work we focus on the year of 2003 when the AE index was extremely high (AE=341nT, with peak intensity more than 2200nT), this value is almost 100 nT higher when compared with others years of the cycle 23. <span class="hlt">Interplanetary</span> <span class="hlt">magnetic</span> field (IMF) and plasma data are compared with geomagnetic AE and Dst indices to determine the causes of exceptionally high AE <span class="hlt">average</span> value. Analyzing the solar wind parameters we found that the annual <span class="hlt">average</span> speed value was extremely high, approximately 542 km/s (peak value ~1074 km/s). These values were due to recurrent high-speed solar streams from large coronal holes, which stretch to the solar equator, and low-latitude coronal holes, which exist for many solar rotations. AE was found to increase with increasing solar wind speed and decrease when solar wind speed decrease. The cause of the high AE activity during 2003 is the presence of the high-speed corotating streams that contain large-amplitude Alfvén waves throughout the streams, which resulted in a large number of HILDCAAs events. When plasma and field of solar wind impinge on Earth's magnetosphere, the southward field turnings associated with the wave fluctuations cause <span class="hlt">magnetic</span> reconnection and consequential high levels of AE activity and very long recovery phases on Dst, sometimes lasting until the next stream arrives.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19770018265','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19770018265"><span id="translatedtitle"><span class="hlt">Interplanetary</span> Physics Laboratory (IPL): A concept for an <span class="hlt">interplanetary</span> mission in the mid-eighties</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Burlaga, L. F.; Ogilvie, K. W.; Feldman, W.</p> <p>1977-01-01</p> <p>A concept for a near-earth <span class="hlt">interplanetary</span> mission in the mid-eighties is described. The proposed objectives would be to determine the composition of the <span class="hlt">interplanetary</span> constituents and its dependence on source-conditions and to investigate energy and momentum transfer processes in the <span class="hlt">interplanetary</span> medium. Such a mission would accomplish three secondary objectives: (1) provide a baseline for deep space missions, (2) investigate variations of the solar wind with solar activity, and (3) provide input functions for magnetospheric studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19740023204','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19740023204"><span id="translatedtitle">Post-shock spikes: A new feature of proton and alpha enhancements associated with an <span class="hlt">interplanetary</span> shock wave</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gloeckler, G.; Ipavich, F. M.; Fan, C. Y.; Hovestadt, D.</p> <p>1974-01-01</p> <p>Abrupt and prolonged enhancements in the intensities of 100 to approximately 2000 keV nucleon protons and alpha particles observed in <span class="hlt">interplanetary</span> space are interpreted as particle populations confined between an <span class="hlt">interplanetary</span> shock front and a <span class="hlt">magnetic</span> field discontinuity. Prominent intensity spikes observed only below approximately 400 keV per charge for both protons and alpha particles several hours behind the shock front suggest that some fraction of the confined particles is accelerated by an energy per charge dependent process.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19900020833','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19900020833"><span id="translatedtitle"><span class="hlt">Interplanetary</span> medium data book, supplement 4, 1985-1988</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>King, Joseph H.</p> <p>1989-01-01</p> <p>An extension is presented of the series of <span class="hlt">Interplanetary</span> Medium Data Books and supplements which have been issued by the National Space Science Data Center since 1977. This volume contains solar wind <span class="hlt">magnetic</span> field (IMF) and plasma data from the IMP 8 spacecraft for 1985 to 1988, and 1985 IMF data from the Czechoslovakian Soviet Prognoz 10 spacecraft. The normalization of the MIT plasma density and temperature, which has been discussed at length in previous volumes, is implemented as before, using the same normalization constants for 1985 to 1988 data as for the earlier data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1989imds.book.1985K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1989imds.book.1985K"><span id="translatedtitle"><span class="hlt">Interplanetary</span> medium data book, supplement 4, 1985-1988</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>King, Joseph H.</p> <p>1989-09-01</p> <p>An extension is presented of the series of <span class="hlt">Interplanetary</span> Medium Data Books and supplements which have been issued by the National Space Science Data Center since 1977. This volume contains solar wind <span class="hlt">magnetic</span> field (IMF) and plasma data from the IMP 8 spacecraft for 1985 to 1988, and 1985 IMF data from the Czechoslovakian Soviet Prognoz 10 spacecraft. The normalization of the MIT plasma density and temperature, which has been discussed at length in previous volumes, is implemented as before, using the same normalization constants for 1985 to 1988 data as for the earlier data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/75631','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/75631"><span id="translatedtitle">Observations of an intermediate shock in <span class="hlt">interplanetary</span> space</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chao, J.K.; Lyu, L.H.; Wu, B.H.; Lazarus, A.J.; Chang, T.S.; Lepping, R.P.</p> <p>1993-10-01</p> <p>The authors report the observation of an intermediate shock in <span class="hlt">interplanetary</span> space by the Voyager I spacecraft on May 1, 1980. The spacecraft was at a distance of approximately 9 AU from the sun. The observational properties support the magnetohydrodynamic properties for such an intermediate shock. Simulations give profiles of the plasma velocity, density, temperature, and <span class="hlt">magnetic</span> fields, for both the pre- and post-shock plasma which are in agreement with observations. This is the first reported observation of such shocks, whose possible observation has been questioned in the literature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19840004976','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19840004976"><span id="translatedtitle">Spectral analysis of magnetohydrodynamic fluctuations near <span class="hlt">interplanetary</span> schocks</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Vinas, A. F.; Goldstein, M. L.; Acuna, M. H.</p> <p>1983-01-01</p> <p>Evidence for two types of relatively large amplitude MHD waves upstream and downstream of quasi-parallel forward and reverse <span class="hlt">interplanetary</span> shocks is presented. The first mode is an Alfven wave with frequencies (in the spacecraft frame) in the range of 0.025 to 0.07 Hz. This is a left-hand polarized mode and propagates within a few degrees of the ambient <span class="hlt">magnetic</span> field. The second is a fast MHD mode with frequencies in the range of 0.025 to 0.17 Hz, right-hand polarization and propagating along the <span class="hlt">magnetic</span> field. These waves are detected principally in association with quasi-parallel shock. The Alfven waves are found to have plasma rest frame frequencies in the range of 1.1 to 6.3 mHz with wavelengths in the order of 4.8 x 10 to the 8th power to 2.7 x 10 to the 9th power cm. Similarly, the fast MHD modes have rest frame frequencies in the range 1.6 to 26 mHz with typical wavelengths about 2.19 x 10 to the 8th power cm. The <span class="hlt">magnetic</span> field power spectrum in the vicinity of these <span class="hlt">interplanetary</span> shocks is much steeper than f to the -s/3 at high frequencies. The observed spectra have a high frequency dependence of f to the -2/5 to f to the -4.</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('http://hdl.handle.net/2060/19850025738','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19850025738"><span id="translatedtitle">On the possibility of the determining the <span class="hlt">average</span> mass composition near 10 to the 14th power eV through the solar <span class="hlt">magnetic</span> field</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lloyd-Evans, J.</p> <p>1985-01-01</p> <p>The discovery of primary ultrahigh energy (UHE) gamma-rays has spawned plans for a new generation of air shower experiments with unprecedented directional resolution. Such accuracy permits observation of a cosmic ray shadow due to the solar disc. Particle trajectory simulations through models of the large scale solar <span class="hlt">magnetic</span> field were performed. The shadow is apparent above 10 to the 15th power eV for all cosmic ray charges /Z/ 26; at lower energies, trajectories close to the Sun are bent sufficiently for this shadow to be lost. The onset of the shadow is rigidity dependent, and occurs at an energy per nucleus of approx. Z x 10 to the 13th power eV. The possibility of determining the <span class="hlt">average</span> mass composition near 10 to the 14th power eV from 1 year's observation at a mountain altitude array is investigated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/11537855','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/11537855"><span id="translatedtitle">Volatiles in <span class="hlt">interplanetary</span> dust particles: a review.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gibson, E K</p> <p>1992-03-25</p> <p>The paper presents a review of the volatiles found within <span class="hlt">interplanetary</span> dust particles. These particles have been shown to represent primitive material from early in the solar system's formation and also may contain records of stellar processes. The organogenic elements (i.e., H, C, N, O, and S) are among the most abundant elements in our solar system, and their abundances, distributions, and isotopic compositions in early solar system materials permit workers to better understand the processes operating early in the evolutionary history of solar system materials. <span class="hlt">Interplanetary</span> dust particles have a range of elemental compositions, but generally they have been shown to be similar to carbonaceous chondrites, the solar photosphere, Comet Halley's chondritic cores, and matrix materials of chondritic chondrites. Recovery and analysis of <span class="hlt">interplanetary</span> dust particles have opened new opportunities for analysis of primitive materials, although <span class="hlt">interplanetary</span> dust particles represent major challenges to the analyst because of their small size. PMID:11537855</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20060029807&hterms=internet&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dinternet','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20060029807&hterms=internet&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dinternet"><span id="translatedtitle">Operating CFDP in the <span class="hlt">Interplanetary</span> Internet</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Burleigh, S.</p> <p>2002-01-01</p> <p>This paper examines the design elements of CCSDS File Delivery Protocol and <span class="hlt">Interplanetary</span> Internet technologies that will simplify their integration and discusses the resulting new capabilities, such as efficient transmission of large files via multiple relay satellites operating in parallel.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100042593','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100042593"><span id="translatedtitle">TPS Ablator Technologies for <span class="hlt">Interplanetary</span> Spacecraft</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Curry, Donald M.</p> <p>2004-01-01</p> <p>This slide presentation reviews the status of Thermal Protection System (TPS) Ablator technologies and the preparation for use in <span class="hlt">interplanetary</span> spacecraft. NASA does not have adequate TPS ablatives and sufficient selection for planned missions. It includes a comparison of shuttle and <span class="hlt">interplanetary</span> TPS requirements, the status of mainline TPS charring ablator materials, a summary of JSC SBIR accomplishments in developing advanced charring ablators and the benefits of SBIR Ablator/fabrication technology.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993PhDT........53L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993PhDT........53L"><span id="translatedtitle">The source of <span class="hlt">interplanetary</span> dust</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Love, Stanley Glen</p> <p>1993-01-01</p> <p><span class="hlt">Interplanetary</span> dust particles can provide a wealth of information about the history and environment of the solar system. Unfortunately, it has not yet been clear whether their parent objects were primarily asteroidal or cometary. This situation seriously limits the applicability of the information gained form dust studies. I present here five experiments intended to reveal the source of <span class="hlt">interplanetary</span> dust. First, I examine the IRAS asteroidal dust bands to find the fraction of the zodiacal dust contributed by single asteroid sources. The bands studied here contain approximately 1% of the zodiacal emission, insufficient to assign parent objects to most of the material. Gravitational focussing effects may boost the dust band contribution in terrestrial IDP collections to as high as 15%. The second and third experiments address micrometeoroid collisions, which appear to forbid delivery of particles larger than about 10-5 g from the asteroid belt to the Earth, in turn implying a cometary or near-Earth source for large dust motes. I test the assumed meteoroid of realistic porous materials. The result is that the previous collisional model is essentially correct. The verified break in the slope of the meteoroid mass distribution is consistent with collisional removal of greater than 10-5 g particles on a timescale similar to their Poynting-Robertson orbit decay lifetimes, if most originate in the asteroid belt. The fourth and fifth experiments turn to atmospheric entry heating effects as velocity diagnostic to separate fast cometary particles from slower asteroidal ones. I develop a new, physically realistic numerical simulation of particle entry. This model provides general results on particle origins, but is most useful when coupled with accurate measurements (based on the release of solar wind implant helium) of the peak entry temperatures of individual particles. It is found that most particles enter at low speeds. The few high-temperature particles imply a cometary fraction near 20%. Taking these results together, and considering previous work such as the meteoroid velocity distribution, I find an asteroid:comet dust ratio of approximately 4:1.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19950049162&hterms=balogh&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAuthor-Name%26N%3D0%26No%3D80%26Ntt%3Dbalogh','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950049162&hterms=balogh&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAuthor-Name%26N%3D0%26No%3D80%26Ntt%3Dbalogh"><span id="translatedtitle">The evolution of the <span class="hlt">interplanetary</span> sector structure in 1992</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Balogh, A.; Erdos, G.; Forsyth, R. J.; Smith, E. J.</p> <p>1993-01-01</p> <p>The unique vantage point of the Ulysses spacecraft throughout 1992 and the beginning of 1993, at a close to constant heliocentric distance of about 5 AU and a slowly varying heliographic latitude from 5 deg to 30 deg south is used to describe and discuss the evolution of the sector structure of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field during the declining phase of the solar cycle. From the end of 1990 to the beginning of 1992 the sector structure changed from a four sector to a two sector structure, but remained constant in solar longitude. From about June-July 1992, the structure, matching the evolution in the computed coronal <span class="hlt">magnetic</span> fields, drifted eastwards, with a recurrence period of about 28 days. This result may indicate a slower rotation rate for the dipolar component of the solar <span class="hlt">magnetic</span> field which becomes dominant about this time in the solar cycle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005HvaOB..29..251B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005HvaOB..29..251B"><span id="translatedtitle">Geoeffective and Climate-Influencing Solar and <span class="hlt">Interplanetary</span> Conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Baranyi, T.; Ludmány, A.</p> <p></p> <p>Several connections have been detected and demonstrated between solar <span class="hlt">magnetic</span> conditions and climatic responses which hint at a highly complicated mechanism of sun-climate relations through plasma streams. The present contribution overviews our results about the possible factors of this mechanism. The main factor is the negative value of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> B_z component which exhibits a fairly complex behaviour. Its strength is influenced by the solar dipole cycle, the nature of ejected plasma (CME or fast stream), the <span class="hlt">magnetic</span> topology of the CME and the position of the Earth (Rosenberg-Coleman and Russell-McPherron effects). The persistence of the negative B_z is also effective. The impacts of these features can be pointed out in the climatic responses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19730002072&hterms=Electrical+conductivity&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DElectrical%2Bconductivity','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19730002072&hterms=Electrical+conductivity&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DElectrical%2Bconductivity"><span id="translatedtitle"><span class="hlt">Interplanetary</span> double-shock ensembles with anomalous electrical conductivity</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Dryer, M.</p> <p>1972-01-01</p> <p>Similarity theory is applied to the case of constant velocity, piston-driven, shock waves. This family of solutions, incorporating the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field for the case of infinite electric conductivity, represents one class of experimentally observed, flare-generated shock waves. This paper discusses the theoretical extension to flows with finite conductivity (presumably caused by unspecified modes of wave-particle interactions). Solutions, including reverse shocks, are found for a wide range of <span class="hlt">magnetic</span> Reynolds numbers from one to infinity. Consideration of a zero and nonzero ambient flowing solar wind (together with removal of <span class="hlt">magnetic</span> considerations) enables the recovery of earlier similarity solutions as well as numerical simulations. A limited comparison with observations suggests that flare energetics can be reasonably estimated once the shock velocity, ambient solar wind velocity and density, and ambient azimuthal Alfven Mach number are known.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20060036609&hterms=balogh&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAuthor-Name%26N%3D0%26No%3D20%26Ntt%3Dbalogh','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20060036609&hterms=balogh&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAuthor-Name%26N%3D0%26No%3D20%26Ntt%3Dbalogh"><span id="translatedtitle">(abstract) An Extensive Search for <span class="hlt">Interplanetary</span> Slow-mode Shocks: Ulysses</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sakurai, R.; Ho, C. M.; Tsurutani, B. T.; Goldstein, B. E.; Balogh, A.</p> <p>1996-01-01</p> <p>Ulysses has accumulated five years of <span class="hlt">interplanetary</span> solar wind plasma and IMF measurements. These data cover from 1 to approximately 5 AU and all the heliographic latitudes. Based on these data, we perform an extensive search for the slow-mode shocks. We find a considerable number of discontinuities that have large <span class="hlt">magnetic</span> field magnitude changes and also large field normal components.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005SpWea...3.3001D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005SpWea...3.3001D"><span id="translatedtitle"><span class="hlt">Interplanetary</span> sources of space weather disturbances in 1997 to 2000</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dmitriev, A. V.; Crosby, N. B.; Chao, J.-K.</p> <p>2005-03-01</p> <p>Seventy-five disturbed intervals from 1997 through 2000 were analyzed and selected on the basis of space weather effect occurrences such as significant compression of the dayside magnetosphere, strong <span class="hlt">magnetic</span> storms, ionospheric perturbations, relativistic electron enhancements, and increases in the rate of data failures and radiation doses on board the Mir station. Solar wind disturbances were considered as the main factor influencing the Earth's magnetosphere. We distinguished four geoeffective <span class="hlt">interplanetary</span> (IP) phenomena: <span class="hlt">interplanetary</span> coronal mass ejections (ICME), <span class="hlt">interplanetary</span> forward shocks with compressed region (IS), fast solar wind streams from coronal holes (CH), and corotating interaction regions (CIR) between the CH and relatively slow ambient solar wind. Each selected interval was studied and classified under the IP phenomena that it was a direct consequence of. It was found that IP phenomena ``containing'' ISs, ICMEs, and CIRs were mostly responsible for geosynchronous magnetopause crossings, strong geomagnetic storms, and intensification of geomagnetically induced currents. The fast solar wind streams from coronal holes controlled mainly geosynchronous relativistic electron enhancements. The rate of data failures and variations of the radiation dose on board the Mir station were related to both IS-ICME and CIR-CH phenomena. Such a relationship was interpreted in terms of (1) decrease of cutoff threshold for solar energetic particles due to the magnetospheric compression and/or ring current intensification on the main phase of geomagnetic storms and (2) intensive relativistic electron precipitation from the outer radiation belt and its contribution to the radiation conditions at low altitudes during recovery phase of recurrent <span class="hlt">magnetic</span> storms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19900060054&hterms=dao&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Ddao','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19900060054&hterms=dao&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Ddao"><span id="translatedtitle">New <span class="hlt">interplanetary</span> proton fluence model</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Feynman, Joan; Armstrong, T. P.; Dao-Gibner, L.; Silverman, S.</p> <p>1990-01-01</p> <p>A new predictive engineering model for the <span class="hlt">interplanetary</span> fluence of protons with above 10 MeV and above 30 MeV is described. The data set used is a combination of observations made from the earth's surface and from above the atmosphere between 1956 and 1963 and observations made from spacecraft in the vicinity of earth between 1963 and 1985. The data cover a time period three times as long as the period used in earlier models. With the use of this data set the distinction between 'ordinary proton events' and 'anomalously large events' made in earlier work disappears. This permitted the use of statistical analysis methods developed for 'ordinary events' on the entire data set. The greater than 10 MeV fluences at 1 AU calculated with the new model are about twice those expected on the basis of models now in use. At energies above 30 MeV, the old and new models agree. In contrast to earlier models, the results do not depend critically on the fluence from any one event and are independent of sunspot number. Mission probability curves derived from the fluence distribution are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EPSC...10..146L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EPSC...10..146L"><span id="translatedtitle">Mars' "Magnetospheric" Response to <span class="hlt">Interplanetary</span> Field Orientation: Inferences from Models for MAVEN Investigation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Luhmann, J. G.; Dong, C.; Ma, Y.-J.; Curry, S. M.; Alvarez, K.; Hara, T.; Halekas, J.; Brain, D. A.; Bougher, S.; Espley, J.</p> <p>2015-10-01</p> <p>Planetary space weather at Mars has attracted much interest, but the focus is usually on the response to solar activity and its related disturbances in the solar wind. While this aspect is important and may be key to understanding Mars' atmosphere evolution, an additional consideration is based on the sensitivity of Earth's magnetospheric solar wind interaction to southward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> fields. The study described here investigates whether Mars has its own specific <span class="hlt">interplanetary</span> field orientation sensitivities that might be identified in the MAVEN data analyses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6261170','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6261170"><span id="translatedtitle">In situ observations of coronal mass ejections in <span class="hlt">interplanetary</span> space</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gosling, J.T.</p> <p>1991-01-01</p> <p>Coronal mass ejections, CMEs, in the solar wind at 1 AU generally have distinct plasma and field signatures by which they can be distinguished from the ordinary solar wind. These include one or more of the following: helium abundance enhancements, ion and electron temperature depressions, unusual ionization states, strong <span class="hlt">magnetic</span> fields, low plasma beta, low <span class="hlt">magnetic</span> field variance, coherent field rotations, counterstreaming (along the field) energetic protons, and counterstreaming suprathermal electrons. The most reliable of these appears to be counterstreaming electrons, which indicates that CMEs at 1 AU typically are closed field structures either rooted at both ends in the Sun or entirely disconnected from it as plasmoids. About 1/3 of all CMEs have sufficiently high speeds to produce transient <span class="hlt">interplanetary</span> shock disturbances at 1 AU; the remainder simply ride along with the solar wind. The frequency of occurrence of CMEs in the ecliptic plane, as distinguished by the counterstreaming electron signature, varies roughly in phase and amplitude with the 11-yr solar activity cycle. Near solar maximum they account for {approximately} 15% of all solar wind measurements, while near solar minimum they account for less than 1% of all the measurements. All but one of the 37 largest geomagnetic storms near the last solar maximum were associated with Earth-passage of <span class="hlt">interplanetary</span> disturbances driven by fast CMEs; that is, CMEs are the prime link between solar and geomagnetic activity. However, more than half of all earthward directed CMEs are relatively ineffective in a geomagnetic sense. 19 refs., 6 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003ICRC....6.3655P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003ICRC....6.3655P"><span id="translatedtitle">Solar and <span class="hlt">Interplanetary</span> Disturbances Causing Moderate Geomagnetic Storms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pratap Yadav, Mahendra; Kumar, Santosh</p> <p>2003-07-01</p> <p>The effect of solar and <span class="hlt">interplanetary</span> disturbances on geomagnetospheric conditions leading to one hundred twenty one moderate geomagnetic storms (MGSs) with planetary index, Ap ≥ 20 and horizontal component of earth's <span class="hlt">magnetic</span> field, H ≤ 250γ have been investigated using solar geophysical data (SGD), solar wind plasma (SWP) and <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) data during the period 1978-99. It is observed statistically that 64%, 36%, MGSs have occurred during maximum and minimum phase of solar cycle 21st and 22nd respectively. Further, it is observed that Hα, X-ray solar flares and active prominences and disapp earing filaments (APDFs) have occurred within lower helio latitude region associated with larger number of MGSs. No significant correlation between the intensity of GMSs and importance of Hα, X-ray solar flares have been observed. Maximum number of MGSs are associated with solar flares of lower importance of solar flare faint (SF). The lower importance in association with some specific characteristics i.e. location, region, duration of occurrence of event may also cause MGSs. The correlation coefficient between MGSs and sunspot numbers (SSNs) using Karl Pearson method, has been obtained 0.37 during 1978-99.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSM31D4230P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSM31D4230P"><span id="translatedtitle">On the high correlation between storm sudden commencements and <span class="hlt">interplanetary</span> shocks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Park, W.; Lee, J.; Oh, S.; Yi, Y.</p> <p>2014-12-01</p> <p>Storm Sudden Commencements (SSCs) occur due to sudden compression of <span class="hlt">magnetic</span> field and current enhancement in the magnetopause, which is generally believed to be caused by <span class="hlt">interplanetary</span> shock. However, neither all geomagnetic storms exhibit the SSC nor all SSCs are accompanied by <span class="hlt">interplanetary</span> shocks. In this study, we search for geomagnetic storms without SSC using the SYM-H index data which is provided by the World Data Center for Geomagnetism Kyoto (WDC Geomag, Kyoto) during the period of 1998-2010. We also investigate the physical conditions such as density and velocity of protons, IMF Bz and total field strength provided by Advanced Composition Explorer (ACE) satellite. Finally, we classify the geomagnetic storms into two groups depending on whether or not accompanied by SSC and then further classify them based on their association with <span class="hlt">interplanetary</span> shocks. Physical characteristics of the storms in each group will briefly be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19820051678&hterms=Fredricks&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DFredricks','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19820051678&hterms=Fredricks&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DFredricks"><span id="translatedtitle">Plasma wave levels and IMF orientations preceding observations of <span class="hlt">interplanetary</span> shocks by ISEE-3</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Greenstadt, E. W.; Scarf, F. L.; Fredricks, R. W.; Kennel, C. F.; Smith, E. J.</p> <p>1982-01-01</p> <p>Some <span class="hlt">interplanetary</span> shocks detected by ISEE-3 are preceded by many hours of strongly enhanced plasma wave noise at a few kHz, while others have essentially no wave precursors above background. It has been shown that these extremes correspond to quasi-parallel and quasi-perpendicular shocks, respectively, based on the instantaneous orientation angle of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) to the shock normal at the time the shocks cross the spacecraft. It is shown that precursor wave noise level is correlated with field orientation and an extrapolated instantaneous orientation angle throughout the preshock observation interval for two contrasting active and quiet cases, and that intermediate, variable noise levels correspond to intermediate, variable IMF orientations. It is inferred that foreshocks are an intrinsic part of the structure of quasiparallel <span class="hlt">interplanetary</span> shocks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20060044310&hterms=proton&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dproton','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20060044310&hterms=proton&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dproton"><span id="translatedtitle">A study of spacecraft charging due to exposure to <span class="hlt">interplanetary</span> protons</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Green, Nelson W.; Frederickson, A. Robb</p> <p>2005-01-01</p> <p>The <span class="hlt">interplanetary</span> space environment is composed mostly of plasma from the solar wind and high energy protons from solar events such as coronal mass ejections. Satellites orbiting Earth are shielded to some degree from these events by the Earth's <span class="hlt">magnetic</span> field but spacecraft traveling between planets are exposed to these solar protons directly. A major concern for spacecraft is internal electrostatic discharge (IESD), a form of spacecraft charging. The majority of research regarding IESD has been concerned with the electrons in the space environment around the Earth and at Jupiter; little research has been done on the charging of spacecraft in <span class="hlt">interplanetary</span> space due to solar event protons. This paper reviews the work done so far on IESD due to protons and provides a possible example of an anomaly due to a proton induced discharge in <span class="hlt">interplanetary</span> space on the Galileo spacecraft.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20100026445&hterms=Media&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DMedia','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20100026445&hterms=Media&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DMedia"><span id="translatedtitle">Propagation and Evolution of CMEs in the <span class="hlt">Interplanetary</span> Medium: Analysis of Remote Sensing and In situ Observations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Figueroa-Vinas, Adolfo; Nieves-Chinchilla, Teresa; Vourlidas, Angelos; Gomez-Herrero, Raul; Malandraki, Olga; Szabo, Adam; Dresing, Nina; Davila, Joseph M.</p> <p>2010-01-01</p> <p>EUV disk imagers and white light coronagraphs have provided for many years information on the early formation and evolution of corona) mass ejections (CMEs). More recently, the novel heliospheric imaging instruments aboard the STEREO mission are providing crucial remote sensing information on the <span class="hlt">interplanetary</span> evolution of these events while in situ instruments complete the overall characterization of the <span class="hlt">interplanetary</span> CMEs. In this work, we present an analysis of CMEs from the Sun to the <span class="hlt">interplanetary</span> medium using combined data from THE SOHO, STEREO, WIND, and ACE spacecraft. The events were selected to cover the widest possible spectrum of different ambient solar wind, <span class="hlt">magnetic</span> field configurations, plasma parameters, etc. to allow uncovering those aspects that are important in understanding the propagation and evolution mechanisms of CMEs in the <span class="hlt">interplanetary</span> medium.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19890058805&hterms=Luhmann&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DLuhmann','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19890058805&hterms=Luhmann&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DLuhmann"><span id="translatedtitle">A search for the solar roots of the most disturbed <span class="hlt">interplanetary</span> field intervals of solar cycle 21</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Luhmann, J. G.; Russell, C. T.; Barnes, A.</p> <p>1989-01-01</p> <p>During the course of the Pioneer Venus Orbiter mission, fairly continuous <span class="hlt">interplanetary</span> plasma and <span class="hlt">magnetic</span> field data were obtained which span the interval from prior to the last solar maximum to the current solar minimum recovery. Within this nearly complete solar cycle interval, several periods of exceptional disturbance of the <span class="hlt">interplanetary</span> field stand out. The available solar data have been examined to determine what features, if any, distinguish these periods. Neither flare nor coronal mass ejection reports show particularly unusual behavior. However, these periods appear to occur in conjunction with marked changes in the <span class="hlt">interplanetary</span> sector structure. This suggests that heliospheric current sheet reconfiguration is an indicator of the level of <span class="hlt">interplanetary</span> disturbance distinct from the more traditional solar activity data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20110013494&hterms=Butterfly&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DButterfly','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20110013494&hterms=Butterfly&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DButterfly"><span id="translatedtitle"><span class="hlt">Interplanetary</span> Shocks Lacking Type 2 Radio Bursts</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gopalswamy, N.; Xie, H.; Maekela, P.; Akiyama, S.; Yashiro, S.; Kaiser, M. L.; Howard, R. A.; Bougeret, J.-L.</p> <p>2010-01-01</p> <p>We report on the radio-emission characteristics of 222 <span class="hlt">interplanetary</span> (IP) shocks detected by spacecraft at Sun-Earth L1 during solar cycle 23 (1996 to 2006, inclusive). A surprisingly large fraction of the IP shocks (approximately 34%) was radio quiet (RQ; i.e., the shocks lacked type II radio bursts). We examined the properties of coronal mass ejections (CMEs) and soft X-ray flares associated with such RQ shocks and compared them with those of the radio-loud (RL) shocks. The CMEs associated with the RQ shocks were generally slow (<span class="hlt">average</span> speed approximately 535 km/s) and only approximately 40% of the CMEs were halos. The corresponding numbers for CMEs associated with RL shocks were 1237 km/s and 72%, respectively. Thus, the CME kinetic energy seems to be the deciding factor in the radio-emission properties of shocks. The lower kinetic energy of CMEs associated with RQ shocks is also suggested by the lower peak soft X-ray flux of the associated flares (C3.4 versus M4.7 for RL shocks). CMEs associated with RQ CMEs were generally accelerating within the coronagraph field of view (<span class="hlt">average</span> acceleration approximately +6.8 m/s (exp 2)), while those associated with RL shocks were decelerating (<span class="hlt">average</span> acceleration approximately 3.5 m/s (exp 2)). This suggests that many of the RQ shocks formed at large distances from the Sun, typically beyond 10 Rs, consistent with the absence of metric and decameter-hectometric (DH) type II radio bursts. A small fraction of RL shocks had type II radio emission solely in the kilometric (km) wavelength domain. Interestingly, the kinematics of the CMEs associated with the km type II bursts is similar to those of RQ shocks, except that the former are slightly more energetic. Comparison of the shock Mach numbers at 1 AU shows that the RQ shocks are mostly subcritical, suggesting that they were not efficient in accelerating electrons. The Mach number values also indicate that most of these are quasi-perpendicular shocks. The radio-quietness is predominant in the rise phase and decreases through the maximum and declining phases of solar cycle 23. About 18% of the IP shocks do not have discernible ejecta behind them. These shocks are due to CMEs moving at large angles from the Sun-Earth line and hence are not blast waves. The solar sources of the shock-driving CMEs follow the sunspot butterfly diagram, consistent with the higher-energy requirement for driving shocks.</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://www.osti.gov/scitech/biblio/21394456','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21394456"><span id="translatedtitle"><span class="hlt">INTERPLANETARY</span> SHOCKS LACKING TYPE II RADIO BURSTS</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gopalswamy, N.; Kaiser, M. L.; Xie, H.; Maekelae, P.; Akiyama, S.; Yashiro, S.; Howard, R. A.; Bougeret, J.-L.</p> <p>2010-02-20</p> <p>We report on the radio-emission characteristics of 222 <span class="hlt">interplanetary</span> (IP) shocks detected by spacecraft at Sun-Earth L1 during solar cycle 23 (1996 to 2006, inclusive). A surprisingly large fraction of the IP shocks ({approx}34%) was radio quiet (RQ; i.e., the shocks lacked type II radio bursts). We examined the properties of coronal mass ejections (CMEs) and soft X-ray flares associated with such RQ shocks and compared them with those of the radio-loud (RL) shocks. The CMEs associated with the RQ shocks were generally slow (<span class="hlt">average</span> speed {approx}535 km s{sup -1}) and only {approx}40% of the CMEs were halos. The corresponding numbers for CMEs associated with RL shocks were 1237 km s{sup -1} and 72%, respectively. Thus, the CME kinetic energy seems to be the deciding factor in the radio-emission properties of shocks. The lower kinetic energy of CMEs associated with RQ shocks is also suggested by the lower peak soft X-ray flux of the associated flares (C3.4 versus M4.7 for RL shocks). CMEs associated with RQ CMEs were generally accelerating within the coronagraph field of view (<span class="hlt">average</span> acceleration {approx}+6.8 m s{sup -2}), while those associated with RL shocks were decelerating (<span class="hlt">average</span> acceleration {approx}-3.5 m s{sup -2}). This suggests that many of the RQ shocks formed at large distances from the Sun, typically beyond 10 Rs, consistent with the absence of metric and decameter-hectometric (DH) type II radio bursts. A small fraction of RL shocks had type II radio emission solely in the kilometric (km) wavelength domain. Interestingly, the kinematics of the CMEs associated with the km type II bursts is similar to those of RQ shocks, except that the former are slightly more energetic. Comparison of the shock Mach numbers at 1 AU shows that the RQ shocks are mostly subcritical, suggesting that they were not efficient in accelerating electrons. The Mach number values also indicate that most of these are quasi-perpendicular shocks. The radio-quietness is predominant in the rise phase and decreases through the maximum and declining phases of solar cycle 23. About 18% of the IP shocks do not have discernible ejecta behind them. These shocks are due to CMEs moving at large angles from the Sun-Earth line and hence are not blast waves. The solar sources of the shock-driving CMEs follow the sunspot butterfly diagram, consistent with the higher-energy requirement for driving shocks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/175772','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/175772"><span id="translatedtitle">Cross-tail <span class="hlt">magnetic</span> flux ropes as observed by the GEOTAIL spacecraft</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Leppintg, R.P.; Fairfield, D.H.</p> <p>1995-05-15</p> <p>Ten transient <span class="hlt">magnetic</span> structures in Earth`s magnetotail, as observed in GEOTAIL measurements, selected for early 1993 [at({minus}) X{sub GSM}=90-130 R{sub E}], are shown to have helical <span class="hlt">magnetic</span> field configurations similar to those of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> clouds at 1 AU but smaller in size by a factor of {approx} 700. Such structures are shown to be well approximated by a comprehensive <span class="hlt">magnetic</span> force-free flux-rope model. For this limited set of 10 events the rope axes and the <span class="hlt">average</span> diameter of these structures is {approx} 15 R{sub E}. 18 refs., 2 figs., 1 tab.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19950056921&hterms=GSM&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DGSM','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950056921&hterms=GSM&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DGSM"><span id="translatedtitle">Cross-tail <span class="hlt">magnetic</span> flux ropes as observed by the GEOTAIL spacecraft</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lepping, R. P.; Fairfield, D. H.; Jones, J.; Frank, L. A.; Paterson, W. R.; Kokubun, S.; Yamamoto, T.</p> <p>1995-01-01</p> <p>Ten transient <span class="hlt">magnetic</span> structures in Earth's magnetotail, as observed in GEOTAIL measurements, selected for early 1993 (at (-) X(sub GSM) = 90 - 130 Earth radii), are shown to have helical <span class="hlt">magnetic</span> field configurations similar to those of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> clouds at 1 AU but smaller in size by a factor of approximately = 700. Such structures are shown to be well approximated by a comprehensive <span class="hlt">magnetic</span> force-free flux-rope model. For this limited set of 10 events the rope axes are seen to be typically aligned with the Y(sub GSM) axis and the <span class="hlt">average</span> diameter of these structures is approximately = 15 Earth radii.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SoPh..284....5Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SoPh..284....5Y"><span id="translatedtitle">Post-Eruption Arcades and <span class="hlt">Interplanetary</span> Coronal Mass Ejections</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yashiro, S.; Gopalswamy, N.; Mäkelä, P.; Akiyama, S.</p> <p>2013-05-01</p> <p>We compare the temporal and spatial properties of posteruption arcades (PEAs) associated with coronal mass ejections (CMEs) at the Sun that end up as <span class="hlt">magnetic</span> cloud (MC) and non-MC events in the solar wind. We investigate the length, width, area, tilt angle, and formation time of the PEAs associated with 22 MC and 29 non-MC events and we find no difference between the two populations. According to current ideas on the relation between flares and CMEs, the PEA is formed together with the CME flux-rope structure by <span class="hlt">magnetic</span> reconnection. Our results indicate that at the Sun flux ropes form during CMEs in association with both MC and non-MC events; however, for non-MC events the flux-rope structure is not observed in the <span class="hlt">interplanetary</span> space because of the geometry of the observation, i.e. the location of the spacecraft when the structure passes through it.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012APS..DPPUP8049I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012APS..DPPUP8049I"><span id="translatedtitle">Measurements of line-<span class="hlt">averaged</span> electron density of pulsed plasmas using a He-Ne laser interferometer in a <span class="hlt">magnetized</span> coaxial plasma gun device</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Iwamoto, D.; Sakuma, I.; Kitagawa, Y.; Kikuchi, Y.; Fukumoto, N.; Nagata, M.</p> <p>2012-10-01</p> <p>In next step of fusion devices such as ITER, lifetime of plasma-facing materials (PFMs) is strongly affected by transient heat and particle loads during type I edge localized modes (ELMs) and disruption. To clarify damage characteristics of the PFMs, transient heat and particle loads have been simulated by using a plasma gun device. We have performed simulation experiments by using a <span class="hlt">magnetized</span> coaxial plasma gun (MCPG) device at University of Hyogo. The line-<span class="hlt">averaged</span> electron density measured by a He-Ne interferometer is 2x10^21 m-3 in a drift tube. The plasma velocity measured by a time of flight technique and ion Doppler spectrometer was 70 km/s, corresponding to the ion energy of 100 eV for helium. Thus, the ion flux density is 1.4x10^26 m-2s-1. On the other hand, the MCPG is connected to a target chamber for material irradiation experiments. It is important to measure plasma parameters in front of target materials in the target chamber. In particular, a vapor cloud layer in front of the target material produced by the pulsed plasma irradiation has to be characterized in order to understand surface damage of PFMs under ELM-like plasma bombardment. In the conference, preliminary results of application of the He-Ne laser interferometer for the above experiment will be shown.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19750038526&hterms=Gas+propagation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DGas%2Bpropagation','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19750038526&hterms=Gas+propagation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DGas%2Bpropagation"><span id="translatedtitle">Propagation of solar disturbances in <span class="hlt">interplanetary</span> space</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wu, S. T.; Han, S. M.; Dryer, M.</p> <p>1974-01-01</p> <p>Time-dependent solutions of a one-fluid model of the <span class="hlt">interplanetary</span> medium are investigated. This set of unsteady hydrodynamic equations has been written in conservation form in order to apply the Lax-Wendroff method for the solution of this problem. The initial condition is specified by a pulse at 1 solar radius. The equilibrium condition is chosen to be the steady solution of a quiet solar wind. The specified solar disturbances in this calculation are allowed to be both sub- and supersonic by the present theoretical formulation. The results are presented in terms of density, velocity, and temperature profiles of the <span class="hlt">interplanetary</span> gas flow at heliocentric distances up to about 10 AU at any particular time. The trajectories of disturbances for various initial pulses are shown. Some 1972 solar-flare observational data are compared with these theoretical calculations. From these calculations, the effects on the <span class="hlt">interplanetary</span> environment, due to the propagation of solar disturbances, can be determined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20000011205&hterms=against+thought+unique&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dagainst%2Bthought%2Bunique','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20000011205&hterms=against+thought+unique&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dagainst%2Bthought%2Bunique"><span id="translatedtitle">"Driverless" Shocks in the <span class="hlt">Interplanetary</span> Medium</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gopalswamy, N.; Kaiser, M. L.; Lara, A.</p> <p>1999-01-01</p> <p>Many <span class="hlt">interplanetary</span> shocks have been detected without an obvious driver behind them. These shocks have been thought to be either blast waves from solar flares or shocks due to sudden increase in solar wind speed caused by interactions between large scale open and closed field lines of the Sun. We investigated this problem using a set of <span class="hlt">interplanetary</span> shock detected {\\it in situ} by the Wind space craft and tracing their solar origins using low frequency radio data obtained by the Wind/WAVES experiment. For each of these "driverless shocks" we could find a unique coronal mass ejections (CME) event observed by the SOHO (Solar and Heliospheric Observatory) coronagraphs. We also found that these CMEs were ejected at large angles from the Sun-Earth line. It appears that the "driverless shocks" are actually driver shocks, but the drivers were not intercepted by the spacecraft. We conclude that the <span class="hlt">interplanetary</span> shocks are much more extended than the driving CMEs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100011347','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100011347"><span id="translatedtitle">International Launch Vehicle Selection for <span class="hlt">Interplanetary</span> Travel</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ferrone, Kristine; Nguyen, Lori T.</p> <p>2010-01-01</p> <p>In developing a mission strategy for <span class="hlt">interplanetary</span> travel, the first step is to consider launch capabilities which provide the basis for fundamental parameters of the mission. This investigation focuses on the numerous launch vehicles of various characteristics available and in development internationally with respect to upmass, launch site, payload shroud size, fuel type, cost, and launch frequency. This presentation will describe launch vehicles available and in development worldwide, then carefully detail a selection process for choosing appropriate vehicles for <span class="hlt">interplanetary</span> missions focusing on international collaboration, risk management, and minimization of cost. The vehicles that fit the established criteria will be discussed in detail with emphasis on the specifications and limitations related to <span class="hlt">interplanetary</span> travel. The final menu of options will include recommendations for overall mission design and strategy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5915564','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5915564"><span id="translatedtitle"><span class="hlt">Interplanetary</span> energetic ions and polar radio wave absorption</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Armstrong, T.P.; Laird, C.M. ); Venkatesan, D. ); Krishnaswamy, S.; Rosenberg, T.J. )</p> <p>1989-04-01</p> <p>This is a study of the ionization input of <span class="hlt">interplanetary</span> (including solar flare) energetic protons and alpha particles into the south polar ionosphere over the interval 1982-1985. It is well known that <span class="hlt">interplanetary</span> ions have full and prompt access to the polar ionosphere. The incremental ionization produced at 20-120 km. altitudes causes enhanced radio wave absorption which is observed by riometers operated by the University of Maryland, at South Pole, Antarctica. The authors compute the expected absorption from the vertical structure of the ionization deposited by these energetic particles and compare the computed values with the observations. The contribution of the alpha particles is found to be quite small as a percentage of the absorption except at the peak of the day 35, 1983, event, when their contribution to the absorption is about 0.6 dB out of a total of 3.4 dB. The dominant contribution to absorption at 30 MHz usually arises from protons below 10 MeV, specifically in the 2- to 4-MeV interval. They have propagated the observed fluxes and energy spectra of protons and alpha particles through a seasonally adjusted slab model of the polar atmosphere. The atmospheric ionization resulting from the slowing and stopping of protons and alpha particles is used to estimate an equilibrium vertical ionization profile which is then convolved with an absorption efficiency profile to yield a calculated absorption. There is good agreement between the computed and observed absorption when the daily <span class="hlt">averaged</span> absorption is above 0.1 dB; this shows that the <span class="hlt">interplanetary</span> ions are the dominant contributors on those days.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002APS..APRN17049C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002APS..APRN17049C"><span id="translatedtitle">The <span class="hlt">Interplanetary</span> GRB Network in 2002</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cline, T. L.; Barthelmy, S. D.; Hurley, K. C.; Anfimov, D.; Mitrofanov, I.; Golenetskii, S.; Mazets, E.; Crew, G.; Ricker, G.; Frontera, F.; Montanari, E.; Guidorzi, C.; Feroci, M.</p> <p>2002-04-01</p> <p>The <span class="hlt">Interplanetary</span> GRB Network (IPN) has been recently enhanced with the successful addition of the Mars Odyssey mission. This compensates for the loss in 2001 of the asteroid mission NEAR, reconstituting a fully long-baseline <span class="hlt">interplanetary</span> triangle with Ulysses, also in deep space, and with GGS-Wind, BeppoSAX and HETE-2, near the Earth. The operation of the renewed IPN has been demonstrated with the detection of many SGR and solar events in recent months, and with an appropriate detection rate of GRBs. The observations to date and the afterglow detections that the IPN has enabled will be outlined, and the future performance will be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20150008672&hterms=navigation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dnavigation','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20150008672&hterms=navigation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dnavigation"><span id="translatedtitle">Mars Science Laboratory <span class="hlt">Interplanetary</span> Navigation Performance</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Martin-Mur, Tomas J.; Kruizinga, Gerhard; Wong, Mau</p> <p>2013-01-01</p> <p>The Mars Science Laboratory spacecraft, carrying the Curiosity rover to Mars, hit the top of the Martian atmosphere just 200 meters from where it had been predicted more than six days earlier, and 2.6 million kilometers away. This un-expected level of accuracy was achieved by a combination of factors including: spacecraft performance, tracking data processing, dynamical modeling choices, and navigation filter setup. This paper will describe our best understanding of what were the factors that contributed to this excellent <span class="hlt">interplanetary</span> trajectory prediction performance. The accurate <span class="hlt">interplanetary</span> navigation contributed to the very precise landing performance, and to the overall success of the mission.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19870039705&hterms=drift+diffusion&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Ddrift%2Bor%2Bdiffusion','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19870039705&hterms=drift+diffusion&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Ddrift%2Bor%2Bdiffusion"><span id="translatedtitle">Modeling of ion acceleration through drift and diffusion at <span class="hlt">interplanetary</span> shocks</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Decker, R. B.; Vlahos, L.</p> <p>1986-01-01</p> <p>A test particle simulation designed to model ion acceleration through drift and diffusion at <span class="hlt">interplanetary</span> shocks is described. The technique consists of integrating along exact particle orbits in a system where the angle between the shock normal and mean upstream <span class="hlt">magnetic</span> field, the level of <span class="hlt">magnetic</span> fluctuations, and the energy of injected particles can assume a range of values. The technique makes it possible to study time-dependent shock acceleration under conditions not amenable to analytical techniques. To illustrate the capability of the numerical model, proton acceleration was considered under conditions appropriate for <span class="hlt">interplanetary</span> shocks at 1 AU, including large-amplitude transverse <span class="hlt">magnetic</span> fluctuations derived from power spectra of both ambient and shock-associated MHD waves.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015Ge%26Ae..55..926G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015Ge%26Ae..55..926G"><span id="translatedtitle">Features of the behavior of some magnetohydrodynamic structures in the <span class="hlt">interplanetary</span> space</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Grib, S. A.; Leora, S. N.</p> <p>2015-12-01</p> <p>Constant pressure structures moving together with a solar wind flux are described based on magnetohydrodynamic representations. The action of <span class="hlt">magnetic</span> hole type structures on the bow shock wave before the Earth's magnetosphere is thus considered. In the presence of a rotational discontinuity in the <span class="hlt">magnetic</span> cloud, it is shown that the decomposition of an arbitrary discontinuity generates a plateau with an increase in the density of charged particles and a decrease in the intensity of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field, which is repeatedly observed on spacecrafts. The plateau coincides with the properties of the <span class="hlt">magnetic</span> hole to a large extent but is of another origin (in fact, local).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRA..120.6101W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRA..120.6101W"><span id="translatedtitle"><span class="hlt">Interplanetary</span> coronal mass ejections from MESSENGER orbital observations at Mercury</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Winslow, Reka M.; Lugaz, Noé; Philpott, Lydia C.; Schwadron, Nathan A.; Farrugia, Charles J.; Anderson, Brian J.; Smith, Charles W.</p> <p>2015-08-01</p> <p>We use observations from the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft, in orbit around Mercury, to investigate <span class="hlt">interplanetary</span> coronal mass ejections (ICMEs) near 0.3 AU. MESSENGER is the first spacecraft since Helios 1 and 2 in the 1980s to make in situ measurements of the <span class="hlt">interplanetary</span> medium at heliocentric distances < 0.5 AU. As such, it presents a unique opportunity for observing the innermost heliosphere. It also allows for observations of ICMEs well within 1 AU to study their evolution as they expand and propagate outward, interacting with the solar wind. We catalog ICME events observed by the MESSENGER Magnetometer between 2011 and 2014 and present statistical analyses of ICME properties at Mercury. In addition, using existing data sets of ICMEs at 1 AU, we investigate key ICME property changes from Mercury to 1 AU. We find good agreement with previous studies for the <span class="hlt">magnetic</span> field strength dependence on distance, and we also find evidence that ICME deceleration continues past the orbit of Mercury. This paper describes the database of ICMEs from MESSENGER orbital observations around Mercury, which is publicly available through the supporting information (Table S1) associated with this manuscript and the Virtual Energetic Particle Observatory. Our ICME database will prove particularly useful for multipoint spacecraft studies of recent ICMEs, as well as for model validation of ICME properties.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19960021296&hterms=global+goes+local&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D20%26Ntt%3Dglobal%2Bgoes%2Blocal','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19960021296&hterms=global+goes+local&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DTitle%26N%3D0%26No%3D20%26Ntt%3Dglobal%2Bgoes%2Blocal"><span id="translatedtitle">Local and global scattering properties of the <span class="hlt">interplanetary</span> medium obtained from Solar Energetic Particles (SEPs)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wibberenz, G.; Hatzky, R.; Bieber, J. W.</p> <p>1995-01-01</p> <p>Solar energetic particles can be used as probes for the turbulence level in the <span class="hlt">interplanetary</span> medium. It is of general interest to compare the LOCAL scattering properties near an observer with GLOBAL properties which characterize the <span class="hlt">average</span> scattering along the <span class="hlt">magnetic</span> field. We discuss various methods by which the scattering conditions can be determined: (1) overall fits of observed particle intensities and anisotropies to a transport model; (2) evaluation of the steady-state pitch angle distribution; and (3) suitably normalized angular distributions during the intensity maximum of a particle event. Energetic particle data from HELIOS 1/2 are analyzed, and the mean free paths obtained with the different methods are compared with each other. As a result one can state: (1) for a number of solar particle events the radial mean free path is essentially constant between the Sun and Helios; and (2) large variations in the degree of scattering exist from one event to the other. These results indicate the existence of 'regimes' where the amount of particle scattering is relatively constant over extended regions in radius and azimuth, but with marked differences from one regime to the other.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995sowi.conf...40W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995sowi.conf...40W"><span id="translatedtitle">Local and global scattering properties of the <span class="hlt">interplanetary</span> medium obtained from Solar Energetic Particles (SEPs)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wibberenz, G.; Hatzky, R.; Bieber, J. W.</p> <p>1995-06-01</p> <p>Solar energetic particles can be used as probes for the turbulence level in the <span class="hlt">interplanetary</span> medium. It is of general interest to compare the LOCAL scattering properties near an observer with GLOBAL properties which characterize the <span class="hlt">average</span> scattering along the <span class="hlt">magnetic</span> field. We discuss various methods by which the scattering conditions can be determined: (1) overall fits of observed particle intensities and anisotropies to a transport model; (2) evaluation of the steady-state pitch angle distribution; and (3) suitably normalized angular distributions during the intensity maximum of a particle event. Energetic particle data from HELIOS 1/2 are analyzed, and the mean free paths obtained with the different methods are compared with each other. As a result one can state: (1) for a number of solar particle events the radial mean free path is essentially constant between the Sun and Helios; and (2) large variations in the degree of scattering exist from one event to the other. These results indicate the existence of 'regimes' where the amount of particle scattering is relatively constant over extended regions in radius and azimuth, but with marked differences from one regime to the other.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRA..120.4112K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRA..120.4112K"><span id="translatedtitle">Properties and drivers of fast <span class="hlt">interplanetary</span> shocks near the orbit of the Earth (1995-2013)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kilpua, E. K. J.; Lumme, E.; Andreeova, K.; Isavnin, A.; Koskinen, H. E. J.</p> <p>2015-06-01</p> <p>We present a comprehensive statistical analysis spanning over a solar cycle of the properties and drivers of traveling fast forward and fast reverse <span class="hlt">interplanetary</span> shocks. We combine statistics of 679 shocks between 1995 and 2013 identified from the near-Earth (Wind and ACE) and STEREO-A observations. We find that fast forward shocks dominate over fast reverse shocks in all solar cycle phases except during solar minimum. Nearly all fast reverse shocks are driven by slow-fast stream interaction regions (SIRs), while coronal mass ejections (CMEs) are the principal drivers of fast forward shocks in all phases except at solar minimum. The occurrence rate and median speeds of CME-driven fast forward shocks follow the sunspot cycle, while SIR-associated shocks do not show such correspondence. The strength of the shock (characterized by the magnetosonic Mach number and by the upstream to downstream <span class="hlt">magnetic</span> field and density ratio) shows relatively little variations over solar cycle. However, the shocks were slightly stronger during the ascending phase of a relatively weak solar cycle 24 than during the previous ascending phase. The CME- and SIR-driven fast forward shocks and fast reverse shocks have distinct upstream solar wind conditions, which reflect to their relative strengths. We found that CME-driven shocks are on <span class="hlt">average</span> stronger and faster, and they show broader distributions of shock parameters than the shocks driven by SIRs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19800012928','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19800012928"><span id="translatedtitle"><span class="hlt">Interplanetary</span> monitoring platform engineering history and achievements</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Butler, P. M.</p> <p>1980-01-01</p> <p>In the fall of 1979, last of ten <span class="hlt">Interplanetary</span> Monitoring Platform Satellite (IMP) missions ended a ten year series of flights dedicated to obtaining new knowledge of the radiation effects in outer space and of solar phenomena during a period of maximum solar flare activity. The technological achievements and scientific accomplishments from the IMP program are described.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19870039702&hterms=CANE&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DCANE','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19870039702&hterms=CANE&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DCANE"><span id="translatedtitle"><span class="hlt">Interplanetary</span> shocks preceded by solar filament eruptions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cane, H. V.; Kahler, S. W.; Sheeley, N. R., Jr.</p> <p>1986-01-01</p> <p>The solar and <span class="hlt">interplanetary</span> characteristics of six <span class="hlt">interplanetary</span> shock and energetic particle events associated with the eruptions of solar filaments lying outside active regions are discussed. The events are characterized by the familiar double-ribbon H-alpha brightenings observed with large flares, but only very weak soft X-ray and microwave bursts. Both impulsive phases and metric type II bursts are absent in all six events. The energetic particles observed near the earth appear to be accelerated predominantly in the <span class="hlt">interplanetary</span> shocks. The <span class="hlt">interplanetary</span> shock speeds are lower and the longitudinal extents considerably less than those of flare-associated shocks. Three of the events were associated with unusual enhancements of singly-ionized helium in the solar wind following the shocks. These enhancements appear to be direct detections of the cool filament material expelled from the corona. It is suggested that these events are part of a spectrum of solar eruptive events which include both weaker events and the large flares. Despite their unimpressive and unreported solar signatures, the quiescent filament eruptions can result in substantial space and geophysical disturbances.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730006137','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730006137"><span id="translatedtitle">The <span class="hlt">interplanetary</span> pioneers. Volume 1: Summary</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Corliss, W. R.</p> <p>1972-01-01</p> <p>The Pioneer Space Probe Project is explained to document the events which occurred during the project. The subjects discussed are: (1) origin and history of <span class="hlt">interplanetary</span> Pioneer program, (2) Pioneer system development and design, (3) Pioneer flight operations, and (4) Pioneer scientific results. Line drawings, circuit diagrams, illustrations, and photographs are included to augment the written material.</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/2012LPICo1679.4146W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012LPICo1679.4146W"><span id="translatedtitle">Hummingbird: Dramatically Reducing <span class="hlt">Interplanetary</span> Mission Cost</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wertz, J. R.; Van Allen, R. E.; Sarzi-Amade, N.; Shao, A.; Taylor, C.</p> <p>2012-06-01</p> <p>The Hummingbird <span class="hlt">interplanetary</span> spacecraft has an available delta V of 2 to 4 km/sec and a recurring cost of 2 to 3 million, depending on the payload and configuration. The baseline telescope has a resolution of 30 cm at a distance of 100 km.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19810058178&hterms=electric+current&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3D%2528electric%2Bcurrent%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19810058178&hterms=electric+current&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3D%2528electric%2Bcurrent%2529"><span id="translatedtitle">An electrodynamic model of electric currents and <span class="hlt">magnetic</span> fields in the dayside ionosphere of Venus</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cloutier, P. A.; Tascione, T. F.; Danieli, R. E., Jr.</p> <p>1981-01-01</p> <p>The electric current configuration induced in the ionosphere of Venus by the interaction of the solar wind has been calculated in previous papers (Cloutier and Daniell, 1973; Daniell and Cloutier, 1977; Cloutier and Daniell, 1979) for <span class="hlt">average</span> steady-state solar wind conditions and <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field. This model is generalized to include the effects of (1) plasma depletion and <span class="hlt">magnetic</span> field enhancement near the ionopause, (2) velocity-shear-induced MHD instabilities of the Kelvin-Helmholtz type within the ionosphere, and (3) variations in solar wind parameters and <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field. It is shown that the <span class="hlt">magnetic</span> field configuration resulting from the model varies in response to changes in solar wind and <span class="hlt">interplanetary</span> field conditions, and that these variations produce <span class="hlt">magnetic</span> field profiles in excellent agreement with those seen by the Pioneer-Venus Orbiter. The formation of flux-ropes by the Kelving-Helmholtz instability is shown to be a natural consequence of the model, with the spatial distribution and size of the flux-ropes determined by the <span class="hlt">magnetic</span> Reynolds number.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19740038948&hterms=source+types&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsource%2Btypes','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19740038948&hterms=source+types&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsource%2Btypes"><span id="translatedtitle">Motion of the sources for type II and type IV radio bursts and flare-associated <span class="hlt">interplanetary</span> disturbances</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sakurai, K.; Chao, J. K.</p> <p>1974-01-01</p> <p>Shock waves are indirectly observed as the source of type II radio bursts, whereas <span class="hlt">magnetic</span> bottles are identified as the source of moving metric type IV radio bursts. The difference between the expansion speeds of these waves and bottles is examined during their generation and propagation near the flare regions. It is shown that, although generated in the explosive phase of flares, the bottles behave quite differently from the waves and that the bottles are generally much slower than the waves. It has been suggested that the waves are related to flare-associated <span class="hlt">interplanetary</span> disturbances which produce SSC geomagnetic storms. These disturbances may, therefore, be identified as <span class="hlt">interplanetary</span> shock waves. The relationship among <span class="hlt">magnetic</span> bottles, shock waves near the sun, and flare-associated disturbances in <span class="hlt">interplanetary</span> space is briefly discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19790059028&hterms=Wind+Energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DWind%2BEnergy','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19790059028&hterms=Wind+Energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DWind%2BEnergy"><span id="translatedtitle">Relationship between the growth of the ring current and the <span class="hlt">interplanetary</span> quantity. [solar wind energy-magnetospheric coupling parameter correlation with substorm AE index</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Akasofu, S.-I.</p> <p>1979-01-01</p> <p>Akasofu (1979) has reported that the <span class="hlt">interplanetary</span> parameter epsilon correlates reasonably well with the magnetospheric substorm index AE; in the first approximation, epsilon represents the solar wind coupled to the magnetosphere. The correlation between the <span class="hlt">interplanetary</span> parameter, the auroral electrojet index and the ring current index is examined for three <span class="hlt">magnetic</span> storms. It is shown that when the <span class="hlt">interplanetary</span> parameter exceeds the amount that can be dissipated by the ionosphere in terms of the Joule heat production, the excess energy is absorbed by the ring current belt, producing an abnormal growth of the ring current index.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760012956','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760012956"><span id="translatedtitle">On the acceleration of energetic particles in the <span class="hlt">interplanetary</span> medium</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fisk, L. A.</p> <p>1976-01-01</p> <p>Fermi scattering and transit time damping are two possible mechanisms for accelerating low energy protons (approximately 1 Mev) in co-rotating particle streams. Solutions to the equations which govern particle behavior in such streams are presented. It was found that acceleration by Fermi scattering requires a scattering mean-free path more than an order of magnitude smaller than the nominal value for low energy particles of 0.1 AU. Transit time damping of only the observed low level of magnitude fluctuations in the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field appears to yield the required acceleration rate. Measurements of the direction of the anisotropy in the particle streams could help in deciding which mechanism is operative. In the case of Fermi scattering the anisotropy must be in the heliocentric radial direction, whereas for transit time damping a significant azimuthal anisotropy could be present.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19930049649&hterms=pantellini&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dpantellini','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19930049649&hterms=pantellini&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dpantellini"><span id="translatedtitle"><span class="hlt">Interplanetary</span> fast shock diagnosis with the radio receiver on Ulysses</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hoang, S.; Pantellini, F.; Harvey, C. C.; Lacombe, C.; Mangeney, A.; Meuer-Vernet, N.; Perche, C.; Steinberg, J.-L.; Lengyel-Frey, D.; Macdowall, R. J.</p> <p>1992-01-01</p> <p>The radio receiver on Ulysses records the quasi-thermal noise which allows a determination of the density and temperature of the cold (core) electrons of the solar wind. Seven <span class="hlt">interplanetary</span> fast forward or reverse shocks are identified from the density and temperature profiles, together with the <span class="hlt">magnetic</span> field profile from the Magnetometer experiment. Upstream of the three strongest shocks, bursts of nonthermal waves are observed at the electron plasma frequency f(peu). The more perpendicular the shock, the longer the time interval during which these upstream bursts are observed. For one of the strongest shocks we also observe two kinds of upstream electromagnetic radiation: radiation at 2 f(peu), and radiation at the downstream electron plasma frequency, which propagates into the less dense upstream regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20070026139&hterms=environmental+analysis&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Denvironmental%2Banalysis','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20070026139&hterms=environmental+analysis&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Denvironmental%2Banalysis"><span id="translatedtitle">Planetary and <span class="hlt">Interplanetary</span> Environmental Models for Radiation Analysis</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>DeAngelis, G.; Cucinotta, F. A.</p> <p>2005-01-01</p> <p>The essence of environmental modeling is presented as suited for radiation analysis purposes. The variables of fundamental importance for radiation environmental assessment are discussed. The characterization is performed by dividing modeling into three areas, namely the <span class="hlt">interplanetary</span> medium, the circumplanetary environment, and the planetary or satellite surface. In the first area, the galactic cosmic rays (GCR) and their modulation by the heliospheric <span class="hlt">magnetic</span> field as well as and solar particle events (SPE) are considered, in the second area the magnetospheres are taken into account, and in the third area the effect of the planetary environment is also considered. Planetary surfaces and atmospheres are modeled based on results from the most recent targeted spacecraft. The results are coupled with suited visualization techniques and radiation transport models in support of trade studies of health risks for future exploration missions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=EL-1994-00334&hterms=FAS&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DFAS','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=EL-1994-00334&hterms=FAS&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DFAS"><span id="translatedtitle">LDEF (Prelaunch), AO201 : <span class="hlt">Interplanetary</span> Dust Experiment, Tray G10</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1984-01-01</p> <p>The prelaunch photograph shows the Inter planetary Dust Experiment (IDE) in a three (3) inch deep corner tray. The IDE is an active exper iment and is located on the earth facing end of the LDEF in the G10 location. AO201 - The <span class="hlt">Interplanetary</span> Dust Experiment (IDE) is an active experiment consisting of impact detectors, detector frames, a solar sensor and the necessary mounting hardware. The eighty (80) detectors, metal-oxide-silicon (MOS) capacitor-type impact sensors, bonded into anodized alumi num frames, are attached to the aluminum mounting plate with non-<span class="hlt">magnetic</span> stainless steel fas teners. A solar sensor, four (4) silicon solar cells in series mounted on an aluminum baseplate, is shown in the approximate center of the IDE mounting plate. The different colors seen on the detectors are the reflections of LDEF technicians and the surrounding clean room work area.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3377503','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3377503"><span id="translatedtitle">Cancer Screening with Digital Mammography for Women at <span class="hlt">Average</span> Risk for Breast Cancer, <span class="hlt">Magnetic</span> Resonance Imaging (MRI) for Women at High Risk</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>2010-01-01</p> <p>Executive Summary Objective The purpose of this review is to determine the effectiveness of 2 separate modalities, digital mammography (DM) and <span class="hlt">magnetic</span> resonance imaging (MRI), relative to film mammography (FM), in the screening of women asymptomatic for breast cancer. A third analysis assesses the effectiveness and safety of the combination of MRI plus mammography (MRI plus FM) in screening of women at high risk. An economic analysis was also conducted. Research Questions How does the sensitivity and specificity of DM compare to FM? How does the sensitivity and specificity of MRI compare to FM? How do the recall rates compare among these screening modalities, and what effect might this have on radiation exposure? What are the risks associated with radiation exposure? How does the sensitivity and specificity of the combination of MRI plus FM compare to either MRI or FM alone? What are the economic considerations? Clinical Need The effectiveness of FM with respect to breast cancer mortality in the screening of asymptomatic <span class="hlt">average</span>- risk women over the age of 50 has been established. However, based on a Medical Advisory Secretariat review completed in March 2006, screening is not recommended for women between the ages of 40 and 49 years. Guidelines published by the Canadian Task Force on Preventive Care recommend mammography screening every 1 to 2 years for women aged 50 years and over, hence, the inclusion of such women in organized breast cancer screening programs. In addition to the uncertainty of the effectiveness of mammography screening from the age of 40 years, there is concern over the risks associated with mammographic screening for the 10 years between the ages of 40 and 49 years. The lack of effectiveness of mammography screening starting at the age of 40 years (with respect to breast cancer mortality) is based on the assumption that the ability to detect cancer decreases with increased breast tissue density. As breast density is highest in the premenopausal years (approximately 23% of postmenopausal and 53% of premenopausal women having at least 50% of the breast occupied by high density), mammography screening is not promoted in Canada nor in many other countries for women under the age of 50 at <span class="hlt">average</span> risk for breast cancer. It is important to note, however, that screening of premenopausal women (i.e., younger than 50 years of age) at high risk for breast cancer by virtue of a family history of cancer or a known genetic predisposition (e.g., having tested positive for the breast cancer genes BRCA1 and/or BRCA2) is appropriate. Thus, this review will assess the effectiveness of breast cancer screening with modalities other than film mammography, specifically DM and MRI, for both pre/perimenopausal and postmenopausal age groups. International estimates of the epidemiology of breast cancer show that the incidence of breast cancer is increasing for all ages combined whereas mortality is decreasing, though at a slower rate. The observed decreases in mortality rates may be attributable to screening, in addition to advances in breast cancer therapy over time. Decreases in mortality attributable to screening may be a result of the earlier detection and treatment of invasive cancers, in addition to the increased detection of ductal carcinoma in situ (DCIS), of which certain subpathologies are less lethal. Evidence from the Surveillance, Epidemiology and End Results (better known as SEER) cancer registry in the United States, indicates that the age-adjusted incidence of DCIS has increased almost 10-fold over a 20 year period, from 2.7 to 25 per 100,000. There is a 4-fold lower incidence of breast cancer in the 40 to 49 year age group than in the 50 to 69 year age group (approximately 140 per 100,000 versus 500 per 100,000 women, respectively). The sensitivity of FM is also lower among younger women (approximately 75%) than for women aged over 50 years (approximately 85%). Specificity is approximately 80% for younger women versus 90% for women over 50 years. The increased density of breast tissue in younger women is likely responsible for the decreased accuracy of FM. Treatment options for breast cancer vary with the stage of disease (based on tumor size, involvement of surrounding tissue, and number of affected axillary lymph nodes) and its pathology, and may include a combination of surgery, chemotherapy and/or radiotherapy. Surgery is the first-line intervention for biopsy-confirmed tumors. The subsequent use of radiation, chemotherapy or hormonal treatments is dependent on the histopathologic characteristics of the tumor and the type of surgery. There is controversy regarding the optimal treatment of DCIS, which is considered a noninvasive tumour. Women at high risk for breast cancer are defined as genetic carriers of the more commonly known breast cancer genes (BRCA1, BRCA2 TP53), first degree relatives of carriers, women with varying degrees of high risk family histories, and/or women with greater than 20% lifetime risk for breast cancer based on existing risk models. Genetic carriers for this disease, primarily women with BRCA1 or BRCA2 mutations, have a lifetime probability of approximately 85% of developing breast cancer. Preventive options for these women include surgical interventions such as prophylactic mastectomy and/or oophorectomy, i.e., removal of the breasts and/or ovaries. Therefore, it is important to evaluate the benefits and risks of different screening modalities, to identify additional options for these women. This Medical Advisory Secretariat review is the second of 2 parts on breast cancer screening, and concentrates on the evaluation of both DM and MRI relative to FM, the standard of care. Part I of this review (March 2006) addressed the effectiveness of screening mammography in 40 to 49 year old <span class="hlt">average</span>-risk women. The overall objective of the present review is to determine the optimal screening modality based on the evidence. Evidence Review Strategy The Medical Advisory Secretariat followed its standard procedures and searched the following electronic databases: Ovid MEDLINE, EMBASE, Ovid MEDLINE In-Process & Other Non-Indexed Citations, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews and The International Network of Agencies for Health Technology Assessment database. The subject headings and keywords searched included breast cancer, breast neoplasms, mass screening, digital mammography, <span class="hlt">magnetic</span> resonance imaging. The detailed search strategies can be viewed in Appendix 1. Included in this review are articles specific to screening and do not include evidence on diagnostic mammography. The search was further restricted to English-language articles published between January 1996 and April 2006. Excluded were case reports, comments, editorials, nonsystematic reviews, and letters. Digital Mammography: In total, 224 articles specific to DM screening were identified. These were examined against the inclusion/exclusion criteria described below, resulting in the selection and review of 5 health technology assessments (HTAs) (plus 1 update) and 4 articles specific to screening with DM. <span class="hlt">Magnetic</span> Resonance Imaging: In total, 193 articles specific to MRI were identified. These were examined against the inclusion/exclusion criteria described below, resulting in the selection and review of 2 HTAs and 7 articles specific to screening with MRI. The evaluation of the addition of FM to MRI in the screening of women at high risk for breast cancer was also conducted within the context of standard search procedures of the Medical Advisory Secretariat. as outlined above. The subject headings and keywords searched included the concepts of breast cancer, <span class="hlt">magnetic</span> resonance imaging, mass screening, and high risk/predisposition to breast cancer. The search was further restricted to English-language articles published between September 2007 and January 15, 2010. Case reports, comments, editorials, nonsystematic reviews, and letters were not excluded. MRI plus mammography: In total, 243 articles specific to MRI plus FM screening were identified. These were examined against the inclusion/exclusion criteria described below, resulting in the selection and review of 2 previous HTAs, and 1 systematic review of 11 paired design studies. Inclusion Criteria English-language articles, and English or French-language HTAs published from January 1996 to April 2006, inclusive. Articles specific to screening of women with no personal history of breast cancer. Studies in which DM or MRI were compared with FM, and where the specific outcomes of interest were reported. Randomized controlled trials (RCTs) or paired studies only for assessment of DM. Prospective, paired studies only for assessment of MRI. Exclusion Criteria Studies in which outcomes were not specific to those of interest in this report. Studies in which women had been previously diagnosed with breast cancer. Studies in which the intervention (DM or MRI) was not compared with FM. Studies assessing DM with a sample size of less than 500. Intervention Digital mammography. <span class="hlt">Magnetic</span> resonance imaging. Comparator Screening with film mammography. Outcomes of Interest Breast cancer mortality (although no studies were found with such long follow-up). Sensitivity. Specificity. Recall rates. Summary of Findings Digital Mammography There is moderate quality evidence that DM is significantly more sensitive than FM in the screening of asymptomatic women aged less than 50 years, those who are premenopausal or perimenopausal, and those with heterogeneously or extremely dense breast tissue (regardless of age). It is not known what effect these differences in sensitivity will have on the more important effectiveness outcome measure of breast cancer mortality, as there was no evidence of such an assessment. Other factors have been set out to promote DM, for example, issues of recall rates and reading and examination times. Our analysis did not show that recall rates were necessarily improved in DM, though examination times were lower than for FM. Other factors including storage and retrieval of screens were not the subject of this analysis. <span class="hlt">Magnetic</span> Resonance Imaging There is moderate quality evidence that the sensitivity of MRI is significantly higher than that of FM in the screening of women at high risk for breast cancer based on genetic or familial factors, regardless of age. Radiation Risk Review Cancer Care Ontario conducted a review of the evidence on radiation risk in screening with mammography women at high risk for breast cancer. From this review of recent literature and risk assessment that considered the potential impact of screening mammography in cohorts of women who start screening at an earlier age or who are at increased risk of developing breast cancer due to genetic susceptibility, the following conclusions can be drawn: For women over 50 years of age, the benefits of mammography greatly outweigh the risk of radiation-induced breast cancer irrespective of the level of a woman’s inherent breast cancer risk. Annual mammography for women aged 30 – 39 years who carry a breast cancer susceptibility gene or who have a strong family breast cancer history (defined as a first degree relative diagnosed in their thirties) has a favourable benefit:risk ratio. Mammography is estimated to detect 16 to 18 breast cancer cases for every one induced by radiation (Table 1). Initiation of screening at age 35 for this same group would increase the benefit:risk ratio to an even more favourable level of 34-50 cases detected for each one potentially induced. Mammography for women under 30 years of age has an unfavourable benefit:risk ratio due to the challenges of detecting cancer in younger breasts, the aggressiveness of cancers at this age, the potential for radiation susceptibility at younger ages and a greater cumulative radiation exposure. Mammography when used in combination with MRI for women who carry a strong breast cancer susceptibility (e.g., BRCA1/2 carriers), which if begun at age 35 and continued for 35 years, may confer greatly improved benefit:risk ratios which were estimated to be about 220 to one. While there is considerable uncertainty in the risk of radiation-induced breast cancer, the risk expressed in published studies is almost certainly conservative as the radiation dose absorbed by women receiving mammography recently has been substantially reduced by newer technology. A CCO update of the mammography radiation risk literature for 2008 and 2009 gave rise to one article by Barrington de Gonzales et al. published in 2009 (Barrington de Gonzales et al., 2009, JNCI, vol. 101: 205-209). This article focuses on estimating the risk of radiation-induced breast cancer for mammographic screening of young women at high risk for breast cancer (with BRCA gene mutations). Based on an assumption of a 15% to 25% or less reduction in mortality from mammography in these high risk women, the authors conclude that such a reduction is not substantially greater than the risk of radiation-induced breast cancer mortality when screening before the age of 34 years. That is, there would be no net benefit from annual mammographic screening of BRCA mutation carriers at ages 25-29 years; the net benefit would be zero or small if screening occurs in 30-34 year olds, and there would be some net benefit at age 35 years or older. The Addition of Mammography to <span class="hlt">Magnetic</span> Resonance Imaging The effects of the addition of FM to MRI screening of high risk women was also assessed, with inclusion and exclusion criteria as follows: Inclusion Criteria English-language articles and English or French-language HTAs published from September 2007 to January 15, 2010. Articles specific to screening of women at high risk for breast cancer, regardless of the definition of high risk. Studies in which accuracy data for the combination of MRI plus FM are available to be compared to that of MRI and FM alone. RCTs or prospective, paired studies only. Studies in which women were previously diagnosed with breast cancer were also included. Exclusion Criteria Studies in which outcomes were not specific to those of interest in this report. Studies in which there was insufficient data on the accuracy of MRI plus FM. Intervention Both MRI and FM. Comparators Screening with MRI alone and FM alone. Outcomes of Interest Sensitivity. Specificity. Summary of Findings <span class="hlt">Magnetic</span> Resonance Imaging Plus Mammography Moderate GRADE Level Evidence that the sensitivity of MRI plus mammography is significantly higher than that of MRI or FM alone, although the specificity remains either unchanged or decreases in the screening of women at high risk for breast cancer based on genetic/familial factors, regardless of age. These studies include women at high risk defined as BRCA1/2 or TP53 carriers, first degree relatives of carriers, women with varying degrees of high risk family histories, and/or >20% lifetime risk based on existing risk models. This definition of high risk accounts for approximately 2% of the female adult population in Ontario. PMID:23074406</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/787785','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/787785"><span id="translatedtitle">Toroidal Plasma Thruster for <span class="hlt">Interplanetary</span> and Interstellar Space Flights</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>N.N. Gorelenkov; L.E. Zakharov; and M.V. Gorelenkova</p> <p>2001-07-11</p> <p>This work involves a conceptual assessment for using the toroidal fusion reactor for deep space <span class="hlt">interplanetary</span> and interstellar missions. Toroidal thermonuclear fusion reactors, such as tokamaks and stellarators, are unique for space propulsion, allowing for a design with the <span class="hlt">magnetic</span> configuration localized inside toroidal <span class="hlt">magnetic</span> field coils. Plasma energetic ions, including charged fusion products, can escape such a closed configuration at certain conditions, a result of the vertical drift in toroidal rippled <span class="hlt">magnetic</span> field. Escaping particles can be used for direct propulsion (since toroidal drift is directed one way vertically) or to create and heat externally confined plasma, so that the latter can be used for propulsion. Deuterium-tritium fusion neutrons with an energy of 14.1 MeV also can be used for direct propulsion. A special design allows neutrons to escape the shield and the blanket of the tokamak. This provides a direct (partial) conversion of the fusion energy into the directed motion of the propellant. In contrast to other fusion concepts proposed for space propulsion, this concept utilizes the natural drift motion of charged particles out of the closed <span class="hlt">magnetic</span> field configuration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003AsBio...3...75P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003AsBio...3...75P"><span id="translatedtitle">Fullerenes and <span class="hlt">Interplanetary</span> Dust at the Permian-Triassic Boundary</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Poreda, Robert J.; Becker, Luann</p> <p>2003-01-01</p> <p>We recently presented new evidence that an impact occurred ~250 million years ago at the Permian-Triassic boundary (PTB), triggering the most severe mass extinction in the history of life on Earth. We used a new extraterrestrial tracer, fullerene, a third carbon carrier of noble gases besides diamond and graphite. By exploiting the unique properties of this molecule to trap noble gases inside of its caged structure (helium, neon, argon), the origin of the fullerenes can be determined. Here, we present new evidence for fullerenes with extraterrestrial noble gases in the PTB at Graphite Peak, Antarctica, similar to PTB fullerenes from Meishan, China and Sasayama, Japan. In addition, we isolated a 3He-rich <span class="hlt">magnetic</span> carrier phase in three fractions from the Graphite Peak section. The noble gases in this <span class="hlt">magnetic</span> fraction were similar to zero-age deep-sea <span class="hlt">interplanetary</span> dust particles (IDPs) and some <span class="hlt">magnetic</span> grains isolated from the Cretaceous-Tertiary boundary. The helium and neon isotopic compositions for both the bulk Graphite Peak sediments and an isolated <span class="hlt">magnetic</span> fraction from the bulk material are consistent with solar-type gases measured in zero-age deep-sea sediments and point to a common source, namely, the flux of IDPs to the Earth's surface. In this instance, the IDP noble gas signature for the bulk sediment can be uniquely decoupled from fullerene, demonstrating that two separate tracers are present (direct flux of IDPs for 3He vs. giant impact for fullerene).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19740061138&hterms=streaming&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dstreaming','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19740061138&hterms=streaming&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dstreaming"><span id="translatedtitle">Cosmic-ray streaming perpendicular to the mean <span class="hlt">magnetic</span> field</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Forman, M. A.; Jokipii, J. R.; Owens, A. J.</p> <p>1974-01-01</p> <p>Starting from a quasi-linear approximation for the ensemble-<span class="hlt">averaged</span> particle distribution function in a random <span class="hlt">magnetic</span> field, the complete diffusion tensor is derived. This is done by assuming a simple form for the ensemble-<span class="hlt">averaged</span> distribution function, explicitly retaining all components of the streaming flux. This derivation obtains the antisymmetric terms in a natural manner. The necessary dropping of higher-order terms gives a criterion for the lower-energy limit of validity of the perpendicular and antisymmetric diffusion coefficients. The limit for the assumed distribution function is about 0.8 GV rigidity in the <span class="hlt">interplanetary</span> field near 1 AU.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/17841865','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/17841865"><span id="translatedtitle">Radio emission from the heliopause triggered by an <span class="hlt">interplanetary</span> shock.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gurnett, D A; Kurth, W S; Allendorf, S C; Poynter, R L</p> <p>1993-10-01</p> <p>A strong heliospheric radio emission event has been detected by Voyagers 1 and 2 in the frequency range of 2 to 3 kilohertz. This event started in July 1992 and is believed to have been generated at or near the heliopause by an <span class="hlt">interplanetary</span> shock that originated during a period of intense solar activity in late May and early June 1991. This shock produced large plasma disturbances and decreases in cosmic ray intensity at Earth, Pioneers 10 and 11, and Voyagers 1 and 2. The <span class="hlt">average</span> propagation speed estimated from these effects is 600 to 800 kilometers per second. After correction for the expected decrease in the shock speed in the outer heliosphere, the distance to the heliopause is estimated to be between 116 and 177 astronomical units. PMID:17841865</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19930022495&hterms=balogh&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAuthor-Name%26N%3D0%26No%3D80%26Ntt%3Dbalogh','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19930022495&hterms=balogh&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAuthor-Name%26N%3D0%26No%3D80%26Ntt%3Dbalogh"><span id="translatedtitle">Plasma wave phenomena observed at <span class="hlt">interplanetary</span> shocks by the Ulysses URAP experiment</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lengyel-Frey, D.; Macdowall, R. J.; Stone, R. G.; Hoang, S.; Pantellini, F.; Canu, P.; Cornilleau-Wehrlin, N.; Balogh, A.; Forsyth, R.</p> <p>1992-01-01</p> <p>Results of a study of 24 <span class="hlt">interplanetary</span> shocks observed by the Unified Radio and Plasma Wave Experiment (URAP) on the Ulysses spacecraft are presented. These shocks, observed between approximately 1 and 4 AU, display a variety of wave phenomena similar to those detected in earlier studies of shocks near 1 AU. The correspondence of the observed low frequency <span class="hlt">magnetic</span> and electric field waves with the parallel index of refraction for whistler waves was investigated. Observed B/E ratios are found to be typically about a factor of 0.7 times the computed index of refraction, supporting the whistler interpretation of these waves, but also implying a prevalent electrostatic wave component which may be due to whistlers propagating at an angle to the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field. A statistical correlation of the amplitudes of the various types of waves with shock and solar wind properties is presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19880003642','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19880003642"><span id="translatedtitle">The VISTA spacecraft: Advantages of ICF (Inertial Confinement Fusion) for <span class="hlt">interplanetary</span> fusions propulsion applications</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Orth, Charles D.; Klein, Gail; Sercel, Joel; Hoffman, Nate; Murray, Kathy; Chang-Diaz, Franklin</p> <p>1987-01-01</p> <p>Inertial Confinement Fusion (ICF) is an attractive engine power source for <span class="hlt">interplanetary</span> manned spacecraft, especially for near-term missions requiring minimum flight duration, because ICF has inherent high power-to-mass ratios and high specific impulses. We have developed a new vehicle concept called VISTA that uses ICF and is capable of round-trip manned missions to Mars in 100 days using A.D. 2020 technology. We describe VISTA's engine operation, discuss associated plasma issues, and describe the advantages of DT fuel for near-term applications. Although ICF is potentially superior to non-fusion technologies for near-term <span class="hlt">interplanetary</span> transport, the performance capabilities of VISTA cannot be meaningfully compared with those of <span class="hlt">magnetic</span>-fusion systems because of the lack of a comparable study of the <span class="hlt">magnetic</span>-fusion systems. We urge that such a study be conducted.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6112845','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6112845"><span id="translatedtitle">The VISTA spacecraft: Advantages of ICF (Inertial Confinement Fusion) for <span class="hlt">interplanetary</span> fusion propulsion applications</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Orth, C.D.; Klein, G.; Sercel, J.; Hoffman, N.; Murray, K.; Chang-Diaz, F.</p> <p>1987-10-02</p> <p>Inertial Confinement Fusion (ICF) is an attractive engine power source for <span class="hlt">interplanetary</span> manned spacecraft, especially for near-term missions requiring minimum flight duration, because ICF has inherent high power-to-mass ratios and high specific impulses. We have developed a new vehicle concept called VISTA that uses ICF and is capable of round-trip manned missions to Mars in 100 days using A.D. 2020 technology. We describe VISTA's engine operation, discuss associated plasma issues, and describe the advantages of DT fuel for near-term applications. Although ICF is potentially superior to non-fusion technologies for near-term <span class="hlt">interplanetary</span> transport, the performance capabilities of VISTA cannot be meaningfully compared with those of <span class="hlt">magnetic</span>-fusion systems because of the lack of a comparable study of the <span class="hlt">magnetic</span>-fusion systems. We urge that such a study be conducted.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120015887','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120015887"><span id="translatedtitle">Coronal Mass Ejections Near the Sun and in the <span class="hlt">Interplanetary</span> Medium</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gopalswamy, Nat</p> <p>2012-01-01</p> <p>Coronal mass ejections (CMEs) are the most energetic phenomenon in the heliosphere. During solar eruptions, the released energy flows out from the Sun in the form of <span class="hlt">magnetized</span> plasma and electromagnetic radiation. The electromagnetic radiation suddenly increases the ionization content of the ionosphere, thus impacting communication and navigation systems. The plasma clouds can drive shocks that accelerate charged particles to very high energies in the <span class="hlt">interplanetary</span> space, which pose radiation hazard to astronauts and space systems. The plasma clouds also arrive at Earth in about two days and impact Earth's magnetosphere, producing geomagnetic storms. The <span class="hlt">magnetic</span> storms result in a number of effects including induced currents that can disrupt power grids, railroads, and underground pipelines. This lecture presents an overview of the origin, propagation, and geospace consequences of CMEs and their <span class="hlt">interplanetary</span> counterparts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMSM41A2008L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMSM41A2008L"><span id="translatedtitle">Heating of Plasmas in the Near-Earth Magnetotail by the Impact of an <span class="hlt">Interplanetary</span> Shock</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lee, E.; Parks, G. K.; Wilber, M.; Lin, N.; Kim, K.; Lee, D.; SEON, J.; Jin, H.</p> <p>2011-12-01</p> <p>It has been reported that radiation belt particles are rapidly energized by the impact of an <span class="hlt">interplanetary</span> shock. In this study we report the observations by Cluster spacecraft that strong heating of plasmas occurs in the near-Earth magnetotail at ~-17 RE when an <span class="hlt">interplanetary</span> shock impacts Earth's magnetosphere. On 24 August 2005 an <span class="hlt">interplanetary</span> shock impacted Earth's magnetosphere and induced a storm sudden commencement (SSC) and <span class="hlt">magnetic</span> storm. After the SSC both the density and temperature of plasmas in the near-Earth magnetotail significantly increased. The increases are more clearly seen in electrons than ions. Also, the particle fluxes of ions and electrons with E > ~30 keV increased more than an order of magnitude after the SSC. For ions significant flux enhancement was observed up to ~92.2 keV. On the other hand, for electrons the enhancement was observed up to ~127.5 keV. These results suggest that the heating is more efficient on electrons than ions. We will discuss about the physical mechanism responsible for the heating of plasmas in the magnetotail due to the impact of an <span class="hlt">interplanetary</span> shock.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AN....336..749B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AN....336..749B"><span id="translatedtitle"><span class="hlt">Interplanetary</span> GPS using pulsar signals</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Becker, W.; Bernhardt, M. G.; Jessner, A.</p> <p>2015-11-01</p> <p>An external reference system suitable for deep space navigation can be defined by fast spinning and strongly <span class="hlt">magnetized</span> neutron stars, called pulsars. Their beamed periodic signals have timing stabilities comparable to atomic clocks and provide characteristic temporal signatures that can be used as natural navigation beacons, quite similar to the use of GPS satellites for navigation on Earth. By comparing pulse arrival times measured on-board a spacecraft with predicted pulse arrivals at a reference location, the spacecraft position can be determined autonomously and with high accuracy everywhere in the solar system and beyond. The unique properties of pulsars make clear already today that such a navigation system will have its application in future astronautics. In this paper we describe the basic principle of spacecraft navigation using pulsars and report on the current development status of this novel technology.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040171195','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040171195"><span id="translatedtitle">Identification of <span class="hlt">Interplanetary</span> Coronal Mass Ejections at 1 AU Using Multiple Solar Wind Plasma Composition Anomalies</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Richardson, I. G.; Cane, H. V.</p> <p>2004-01-01</p> <p>We investigate the use of multiple simultaneous solar wind plasma compositional anomalies, relative to the composition of the ambient solar wind, for identifying <span class="hlt">interplanetary</span> coronal mass ejection (ICME) plasma. We first summarize the characteristics of several solar wind plasma composition signatures (O(+7)/O(+6), Mg/O, Ne/O, Fe charge states, He/p) observed by the ACE and WIND spacecraft within the ICMEs during 1996 - 2002 identsed by Cane and Richardson. We then develop a set of simple criteria that may be used to identify such compositional anomalies, and hence potential ICMEs. To distinguish these anomalies from the normal variations seen in ambient solar wind composition, which depend on the wind speed, we compare observed compositional signatures with those 'expected' in ambient solar wind with the same solar wind speed. This method identifies anomalies more effectively than the use of fixed thresholds. The occurrence rates of individual composition anomalies within ICMEs range from approx. 70% for enhanced iron and oxygen charge states to approx. 30% for enhanced He/p (> 0.06) and Ne/O, and are generally higher in <span class="hlt">magnetic</span> clouds than other ICMEs. Intervals of multiple anomalies are usually associated with ICMEs, and provide a basis for the identification of the majority of ICMEs. We estimate that Cane and Richardson, who did not refer to composition data, probably identitied approx. 90% of the ICMEs present. However, around 10% of their ICMEs have weak compositional anomalies, suggesting that the presence of such signatures does not provide a necessary requirement for an ICME. We note a remarkably similar correlation between the Mg/O and O(7)/O(6) ratios in hourly-<span class="hlt">averaged</span> data both within ICMEs and the ambient solar wind. This 'universal' relationship suggests that a similar process (such as minor ion heating by waves inside coronal <span class="hlt">magnetic</span> field loops) produces the first-ionization potential bias and ion freezing-in temperatures in the source regions of both ICMEs and the ambient solar wind.</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('http://www.osti.gov/scitech/biblio/5508711','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5508711"><span id="translatedtitle">Tin in a chondritic <span class="hlt">interplanetary</span> dust particle</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Rietmeijer, F.J.M. )</p> <p>1989-03-01</p> <p>Submicron platey Sn-rich grains are present in chondritic porous <span class="hlt">interplanetary</span> dust particle (IDP) W7029 A and it is the second occurrence of a tin mineral in a stratospheric micrometeorite. Selected Area Electron Diffraction data for the Sn-rich grains match with Sn{sub 2}O{sub 3} and Sn{sub 3}O{sub 4}. The oxide(s) may have formed in the solar nebula when tin metal catalytically supported reduction of CO or during flash heating on atmospheric entry of the IDP. The presence of tin is consistent with enrichments for other volatile trace elements in chondritic IDPs and may signal an emerging trend toward nonchondritic volatile element abundances in chondritic IDPs. The observation confirms small-scale mineralogical heterogeneity in fine-grained chondritic porous <span class="hlt">interplanetary</span> dust. 27 refs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992ChJSS..12...57X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992ChJSS..12...57X"><span id="translatedtitle">Raman spectra of seven <span class="hlt">interplanetary</span> dust particles</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xu, Yin-Lin; Yu, Min; Fan, Chang-Yun</p> <p>1992-01-01</p> <p>The Raman shift spectra of seven <span class="hlt">interplanetary</span> dust particles, U2034(F10), U2034(F8), U2022(B1), W7074 18, W7074 C15, W7074 C3 and W7074 A7, were measured with a Spex-1403 Raman spectrograph. The exciting radiations were the 488 nm and 514 nm line of a 5W argon ion laser. All seven spectra exhibit the 1350 and 1600 Delta/cm arbon bands, implying that the <span class="hlt">Interplanetary</span> dust particles were coated with hydrocarbon and incompletely crystallized carbon, the part of which may be the residue of hydrocarbon contents in the particles after water loss by the heating during their entry into the earth's atmosphere. A weak band structure in the 520-610/cm range could be caused by cyclosilicates, and a weak band at 2900/cm is tentatively identified as due to hydrocarbon molecules.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19890056998&hterms=Tin&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DTin','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19890056998&hterms=Tin&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DTin"><span id="translatedtitle">Tin in a chondritic <span class="hlt">interplanetary</span> dust particle</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rietmeijer, Frans J. M.</p> <p>1989-01-01</p> <p>Submicron platey Sn-rich grains are present in chondritic porous <span class="hlt">interplanetary</span> dust particle (IDP) W7029 A and it is the second occurrence of a tin mineral in a stratospheric micrometeorite. Selected Area Electron Diffraction data for the Sn-rich grains match with Sn2O3 and Sn3O4. The oxide(s) may have formed in the solar nebula when tin metal catalytically supported reduction of CO or during flash heating on atmospheric entry of the IDP. The presence of tin is consistent with enrichments for other volatile trace elements in chondritic IDPs and may signal an emerging trend toward nonchondritic volatile element abundances in chondritic IDPs. The observation confirms small-scale mineralogical heterogeneity in fine-grained chondritic porous <span class="hlt">interplanetary</span> dust.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1989ommd.proc..191S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1989ommd.proc..191S"><span id="translatedtitle">Earth orbital operations supporting manned <span class="hlt">interplanetary</span> missions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sherwood, Brent; Buddington, Patricia A.; Whittaker, William L.</p> <p></p> <p>The orbital operations required to accumulate, assemble, test, verify, maintain, and launch complex manned space systems on <span class="hlt">interplanetary</span> missions from earth orbit are as vital as the flight hardware itself. Vast numbers of orbital crew are neither necessary nor desirable for accomplishing the required tasks. A suite of robotic techniques under human supervisory control, relying on sensors, software and manipulators either currently emergent or already applied in terrestrial settings, can make the job tractable. The mission vehicle becomes largely self-assembling, using its own rigid aerobrake as a work platform. The Space Station, having been used as a laboratory testbed and to house an assembly crew of four, is not dominated by the process. A feasible development schedule, if begun soon, could emplace orbital support technologies for exploration missions in time for a 2004 first <span class="hlt">interplanetary</span> launch.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19780032247&hterms=bispectral+index&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dbispectral%2Bindex','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19780032247&hterms=bispectral+index&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dbispectral%2Bindex"><span id="translatedtitle">Bispectral analysis of meter wavelength <span class="hlt">interplanetary</span> scintillation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Armstrong, J. W.</p> <p>1977-01-01</p> <p>The bispectrum of <span class="hlt">interplanetary</span> scintillation is investigated. Rice-squared and lognormal point-source intensity probability density functions are used to derive model bispectra as functionals of the intensity autocovariance. Simultaneous observations of the source CTA 21 at 270, 340, and 470 MHz are analyzed to produce scintillation indices, skewness parameters, and bispectra, which are compared with the models for the cases of weak, intermediate, and strong scattering. The results obtained for CTA 21 are shown to rule out lognormal statistics for <span class="hlt">interplanetary</span> scintillation over the frequency range from 340 to 470 MHz. It is found that the observed bispectra correspond well with the predictions of the Rice-squared model for weak and intermediate scattering, but are systematically different from model bispectra computed by assuming a point source in the case of strong scattering.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19900043523&hterms=Theory+Activity&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DTheory%2BActivity','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19900043523&hterms=Theory+Activity&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DTheory%2BActivity"><span id="translatedtitle">Do <span class="hlt">interplanetary</span> Alfven waves cause auroral activity?</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Roberts, D. Aaron; Goldstein, Melvyn L.</p> <p>1990-01-01</p> <p>A recent theory holds that high-intensity, long-duration, continuous auroral activity (HILDCAA) is caused by <span class="hlt">interplanetary</span> Alfven waves propagating outward from the sun. A survey of Alfvenic intervals in over a year of ISEE 3 data shows that while Alfvenic intervals often accompany HILDCAAs, the reverse is often not true. There are many Alfvenic intervals during which auroral activity (measured by high values of the AE index) is very low, as well as times of high auroral activity that are not highly Alfvenic. This analysis supports the common conclusion that large AE values are associated with a southward <span class="hlt">interplanetary</span> field of sufficient strength and duration. This field configuration is independent of the presence of Alfven waves (whether solar generated or not) and is expected to occur at random intervals in the large-amplitude stochastic fluctuations in the solar wind.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014cosp...40E1986M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014cosp...40E1986M"><span id="translatedtitle">Dusty Plasma Effects in the <span class="hlt">Interplanetary</span> Medium?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mann, Ingrid; Issautier, Karine; Meyer-Vernet, Nicole; Le Chat, Gaétan; Czechowski, Andrzej; Zaslavsky, Arnaud; Zouganelis, Yannis; Belheouane, Soraya</p> <p></p> <p>Cosmic dust particles exist in a variety of compositions and sizes in the <span class="hlt">interplanetary</span> medium. There is little direct information on the composition, but those <span class="hlt">interplanetary</span> dust particles that are collected in the upper Earth’s atmosphere and can be studied in the laboratory typically have an irregular, sometimes porous structure on scales <100 nm. They contain magnesium-rich silicates and silicon carbide, iron-nickel and iron-sulfur compounds, calcium- and aluminum oxides, and chemical compounds that contain a large mass fraction of carbon (e.g. carbonaceous species). A fraction of the dust originates from comets, but because of their bulk material temperature of about 280 K near 1 AU, most icy compounds have disappeared. The dust particles are embedded in the solar wind, a hot plasma with at 1 AU kinetic temperatures around 100 000 K and flow direction nearly radial outward from the Sun at supersonic bulk velocities around 400 km/s. Since the dust particles carry an electric surface charge they are subject to electromagnetic forces and the nanodust particles are efficiently accelerated to velocities of order of solar wind speed. The acceleration of the nanodust is similar, but not identical to the formation of pick-up ions. The S/WAVES radio wave instrument on STEREO measured a flux of nanodust at 1 AU [1]. The nanodust probably forms in the region inward of 1 AU and is accelerated by the solar wind as discussed. We also discuss the different paths of dust - plasma interactions in the <span class="hlt">interplanetary</span> medium and their observations with space experiments. Comparing these interactions we show that the <span class="hlt">interplanetary</span> medium near 1 AU can in many cases be described as “dust in plasma" rather than "dusty plasma”. [1] S. Belheouane, N. Meyer-Vernet, K. Issautier, G. Le Chat, A. Zaslavsky, Y. Zouganelis, I. Mann, A. Czechowski: Dynamics of nanoparticles detected at 1 AU by S/WAVES onboard STEREO spacecraft, in this session.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20060042062&hterms=balogh&qs=N%3D0%26Ntk%3DAuthor-Name%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dbalogh','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20060042062&hterms=balogh&qs=N%3D0%26Ntk%3DAuthor-Name%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dbalogh"><span id="translatedtitle"><span class="hlt">Interplanetary</span> Shock Waves and Large-Scale Structures: Ulysses' Observations in and out of the Ecliptic Plane</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gonzalez-Esparza, J. A.; Balogh, A.; Forsyth, R. J.; Neugebauer, M.; Smith, E. J.; Phillips, J. L.</p> <p>1995-01-01</p> <p>A study is presented of 153 fast shock waves and their relation to other large-scale features in the solar wind: corotating interaction regions (CIRs), <span class="hlt">interplanetary</span> counterparts of coronal mass ejections (ICMEs) and the <span class="hlt">magnetic</span> sector structure, observed by Ulysses from October 1990 to the south solar pass in the summer of 1994.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19750016564','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19750016564"><span id="translatedtitle">A New Look at Jupiter: Results at the Now Frontier. [Pioneer 10, <span class="hlt">interplanetary</span> space, and Jupiter atmosphere</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>Pioneer 10's encounter with Jupiter is discussed along with the <span class="hlt">interplanetary</span> space beyond the orbit of Mars. Other topics discussed include the size of Jupiter, the Galilean satellites, the <span class="hlt">magnetic</span> field of Jupiter, radiation belts, Jupiter's weather and interior, and future exploration possibilities. Educational projects are also included.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19960021482&hterms=streaming&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dstreaming','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19960021482&hterms=streaming&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dstreaming"><span id="translatedtitle">Bi-directional streaming of halo electrons in <span class="hlt">interplanetary</span> plasma clouds observed between 0.3 and 1 AU</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ivory, K.; Schwenn, R.</p> <p>1995-01-01</p> <p>The solar wind data obtained from the two Helios solar probes in the years 1974 to 1986 were systematically searched for the occurrence of bi-directional electron events. Most often these events are found in conjunction with shock associated <span class="hlt">magnetic</span> clouds. The implications of these observations for the topology of <span class="hlt">interplanetary</span> plasma clouds are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSH43B4199Q','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSH43B4199Q"><span id="translatedtitle">Simulations of Solar Energetic Particles Response to <span class="hlt">Interplanetary</span> Coronal Mass Ejections in the Gradual Events</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Qin, G.; Wang, Y.</p> <p>2014-12-01</p> <p>The gradual Solar Energetic Particle (SEP) events are usually associated with shock waves driven by <span class="hlt">Interplanetary</span> Coronal Mass Ejections (ICMEs). Multi-spacecraft observations show that low-energy (<20 MeV) proton intensities may decrease when the spacecraft enters into the ICMEs. Based on a numerical solution of a focused transport equation, we obtained the fluxes of solar energetic particles (SEPs) accelerated by an <span class="hlt">interplanetary</span> shock in a three-dimensional <span class="hlt">magnetic</span> field. The shock is treated as a moving source of energetic particles with an assumed particle distribution function, while the <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field (IMF) disturbances generated by an ICME behind the shock are modeled by a Stokes' stream function with a spherical boundary. We computed the time profiles of particle flux and anisotropy as measured by multi-spacecraft. With perpendicular diffusion, energetic particles can cross <span class="hlt">magnetic</span> field lines, and they can still be detected after the spacecraft enters into the ICMEs. By comparing our simulations with observations, the particle perpendicular diffusion coefficients can be qualitatively determined, and the radial and latitudinal variations of SEPs response to ICMEs have been studied.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19950046657&hterms=solar+vortex&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dsolar%2Bvortex','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950046657&hterms=solar+vortex&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dsolar%2Bvortex"><span id="translatedtitle">Magnetospheric response to solar wind dynamic pressure variations: Interaction of <span class="hlt">interplanetary</span> tangential discontinuities with the bow shock</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wu, Bor-Han; Mandt, M. E.; Lee, L. C.; Chao, J. K.</p> <p>1993-01-01</p> <p>Some <span class="hlt">magnetic</span> impulse events observed in the polar region are related to vortices associated with plasma convection in the ionosphere. Recent analyses of satellite and ground data suggest that the interaction of solar wind dynamic pressure pulses and the magnetosphere may lead to the formation of velocity vortices in the magnetopause boundary layer region. This can in turn lead to the presence of vortices in the polar ionosphere. However, before reaching the Earth's magnetopause, these <span class="hlt">interplanetary</span> pressure pulses must interact with and pass through the bow shock. A variation of the solar wind dynamic pressure may be associated with shocks, <span class="hlt">magnetic</span> holes, or tangential discontinuities (TDs) in the <span class="hlt">interplanetary</span> medium. We study the interaction of <span class="hlt">interplanetary</span> TDs with the Earth's bow shock (BS) using both theoretical analysis and MHD computer simulations. It is found that as a result of the collision between a TD and the BS, the jump in the solar wind dynamic pressure associated with the TD is significantly modified, the bow shock moves, and a new fast shock or fast rarefaction wave, which propagates in the downstream direction, is excited. Our theoretical analysis shows that the change in the plasma density across the <span class="hlt">interplanetary</span> TD plays the most important role in the collision process. In the case with an enhanced dynamic pressure behind the <span class="hlt">interplanetary</span> TD, the bow shock is intensified in strength and moves in the earthward direction. The dynamic pressure jump associated with the transmitted TD is generally reduced from the value before the interaction. A fast compressional shock is excited ahead of the transmitted TD and propagates toward the Earth's magnetosphere. For the case in which the dynamic pressure is reduced behind the <span class="hlt">interplanetary</span> TD, the pressure jump across the transmitted TD is substantially weakened, the bow shock moves in the sunward direction, and a rarefaction wave which propagates downstream is excited. We also simulate and discuss the interaction of a pair of tangential discontinuities, which may correspond to a <span class="hlt">magnetic</span> hole, with the BS.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992AIPC..246..130G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992AIPC..246..130G"><span id="translatedtitle">Integrated shielding systems for manned <span class="hlt">interplanetary</span> spaceflight</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>George, Jeffrey A.</p> <p>1992-01-01</p> <p>The radiation environment encountered by manned <span class="hlt">interplanetary</span> missions can have a severe impact on both vehicle design and mission performance. This study investigates the potential impact of radiation protection on <span class="hlt">interplanetary</span> vehicle design for a manned Mars mission. A systems approach was used to investigate the radiation protection requirements of the sum <span class="hlt">interplanetary</span> environment. Radiation budgets were developed which result in minimum integrated shielding system masses for both nuclear and non-nuclear powered missions. A variety of system configurations and geometries were assessed over a range of dose constraints. For an annual dose equivalent rate limit of 50 rem/yr, an environmental shielding system composed of a habitat shield and storm shelter was found to result in the lowest total mass. For a limit of 65 rem/yr, a system composed of a sleeping quarters shield was least massive, and resulted in significantly reduced system mass. At a limit of 75 rem/yr, a storm shelter alone was found to be sufficient, and exhibited a further mass reduction. Optimal shielding system results for 10 MWe nuclear powered missions were found to follow along similar lines, with the addition of a reactor shadow shield. A solar minimum galactic cosmic ray spectrum and one anomalously large solar particle event during the course of a two year mission were assumed. Water was assumed for environmental radiation shielding.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19850007338&hterms=trauma&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dtrauma','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850007338&hterms=trauma&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dtrauma"><span id="translatedtitle">Discovery of nuclear tracks in <span class="hlt">interplanetary</span> dust</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bradley, J. P.; Brownlee, D. E.</p> <p>1984-01-01</p> <p>Prior to capture by the Earth's atmosphere individual <span class="hlt">interplanetary</span> dust particles (IDP's) have allegedly spent up to 10 to the 5th power years as discrete bodies within the <span class="hlt">interplanetary</span> medium. Observation of tracks in IDP's in the form of solar flare tracks would provide hitherto unknown data about micrometeorites such as: (1) whether an IDP existed in space as an individual particle or as part of a larger meteroid; (2) the degree to which a particle was heated during the trauma of atmospheric entry; (3) residence time of an IDP within the <span class="hlt">interplanetary</span> medium; and (4) possible hints as to the pre-accretional exposure of component mineral grains to solar or galactic irradiation. Using transmission electron microscopy tracks in several micrometeorites have been successfully identified. All of the studied particles had been retrieved from the stratosphere by U-2 aircraft. Three pristine IDP's (between 5 and 15 micro m diameter) have so far been searched for solar flare tracks, and they have been found in the two smaller particles U2-20B11 (11 micro m) and U2-20B37 (8 micro m).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/11542693','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/11542693"><span id="translatedtitle">Manned <span class="hlt">interplanetary</span> missions: prospective medical problems.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Grigoriev, A I; Svetaylo, E N; Egorov, A D</p> <p>1998-12-01</p> <p>The present review aimed to suggest approaches to prospective medical problems related to the health maintenance of space crews during future manned <span class="hlt">interplanetary</span>, particularly Martian, missions up to 2-3 years with a possible stay on a planet with gravity different from that on Earth. The approaches are based on knowledge so far obtained from our analysis of the medical support of long-term orbital flights up to one year, as well as on the consideration of specific conditions of <span class="hlt">interplanetary</span> missions. These specific conditions include not only long-term exposure to microgravity, but also a prolonged stay of unpredictable duration (2-3 years) on board a spacecraft or on a planet without direct contact with Earth, and living in a team with a risk of psychological incompatibility and the impossibility of an urgent return to Earth. These conditions necessitate a highly trained medical person in the crew, diagnostic tools and equipment, psychophysiological support, countermeasures, as well as the means for urgent, including surgical, treatment on board a spacecraft or on a planet. In this review, the discussion was focused on the following predictable medical problems during an <span class="hlt">interplanetary</span> mission; 1) unfavorable effects of prolonged exposure to microgravity, 2) specific problems related to Martian missions, 3) medical monitoring, 4) countermeasures, 5) psychophysiological support and 6) the medical care system. PMID:11542693</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19740023172','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19740023172"><span id="translatedtitle">Solar rotating <span class="hlt">magnetic</span> dipole?. [around axis perpendicular to rotation axis of the sun</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Antonucci, E.</p> <p>1974-01-01</p> <p>A <span class="hlt">magnetic</span> dipole rotating around an axis perpendicular to the rotation axis of the sun can account for the characteristics of the surface large-scale solar <span class="hlt">magnetic</span> fields through the solar cycle. The polarity patterns of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field, predictable from this model, agree with the observed <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> sector structure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.U34A..04L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.U34A..04L"><span id="translatedtitle">Mapping the Sun's Atmosphere Into <span class="hlt">Interplanetary</span> Space: How Recent Changes in the Solar Dynamo are Affecting the Solar Wind Around Us (Invited)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Luhmann, J. G.; Lee, C. O.; Hoeksema, J. T.</p> <p>2009-12-01</p> <p>The photospheric <span class="hlt">magnetic</span> field provides the key boundary conditions for the <span class="hlt">interplanetary</span> medium, including the solar wind plasma and the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field. Thus any changes in the solar interior that affect either the emergence, dispersion, and decay of active region <span class="hlt">magnetic</span> fields, or the evolution of the quiet Sun fields, can have locally measurable effects. Each solar cycle for which we have sufficient solar and in-situ observations has followed a similar pattern, but in the most recent cycle the solar dynamo has produced a generally weaker photospheric field together with a spatial distribution of photospheric flux that differs from the previous two. The result is distinctive <span class="hlt">interplanetary</span> conditions with solar wind streams and <span class="hlt">magnetic</span> fields significantly different from earlier space age cycles, and a better appreciation for variations the dynamo has likely caused (and will cause) in our 'space weather'.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19950046290&hterms=balogh&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAuthor-Name%26N%3D0%26No%3D70%26Ntt%3Dbalogh','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950046290&hterms=balogh&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAuthor-Name%26N%3D0%26No%3D70%26Ntt%3Dbalogh"><span id="translatedtitle">An analysis of whistler waves at <span class="hlt">interplanetary</span> shocks</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lengyel-Frey, D.; Farrell, W. M.; Stone, R. G.; Balogh, A.; Forsyth, R.</p> <p>1994-01-01</p> <p>We present an analysis of whistler wave <span class="hlt">magnetic</span> and electric field amplitude ratios from which we compute wave propagation angles and energies of electrons in resonance with the waves. To do this analysis, we compute the theoretical dependence of ratios of wave components on the whistler wave propagation angle Theta for various combinations of orthogonal wave components. Ratios of wave components that would be observed by a spinning spacecraft are determined, and the effects of arbitrary inclinations of the spacecraft to the ambient <span class="hlt">magnetic</span> field and to the whistler wave vector are studied. This analysis clearly demonstrates that B/E, the ratio of <span class="hlt">magnetic</span> to electric field amplitudes, cannot be assumed to be the wave index of refraction, contrary to assumptions of some earlier studies. Therefore previous interpretations of whistler wave observations based on this assumption must be reinvestigated. B/E ratios derived using three orthogonal wave components can be used to unambiguously determine Theta. Using spin plane observations alone, a significant uncertainty occurs in the determination of Theta. Nevertheless, for whistler waves observed downstream of several <span class="hlt">interplanetary</span> shocks by the Ulysses plasma wave experiment we find that Theta is highly oblique. We suggest that the analysis of wave amplitude ratios used in conjunction with traditional stability analyses provide a promising tool for determining which particle distributions and resonances are likely to be dominant contributors to wave growth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19900003168','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19900003168"><span id="translatedtitle"><span class="hlt">Interplanetary</span> energetic particle observations of the March 1989 events</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sarris, E. T.; Krimigis, S. M.</p> <p>1989-01-01</p> <p>The IMP-8 spacecraft placed in an elongated orbit of approximately R(sub E) x R(sub E) orbit around the Earth was the only monitor of the energetic particle environment of the near <span class="hlt">interplanetary</span> space during the period of the solar particle events associated with the Active Region 5395 in March 1989. Measurements of energetic ion and electron intensities were obtained in a series of channels within the energy range: 0.3 to 440 MeV for photons, 0.6 to 52 MeV/nuc for alpha particles, 0.7 to 3.3 MeV/nuc for nuclei with Z greater than or equal to 3, 3 to 9 MeV/nuc with Z greater than or equal to 20, and 0.2 to 2.5 MeV for electrons. The responses of selected energy channels during the period 5 to 23 March 1989 are displayed. It is clearly noted that the most prominent energetic ion intensity enhancements in that time interval were associated with the <span class="hlt">interplanetary</span> shock wave of March 13 (07:42 UT) as well as that of March 8 (17:56 UT), which have distinct particle acceleration signatures. These shock waves play a major role in determining the near Earth energetic ion intensities during the above period by accelerating and modulating the ambient solar energetic particle population, which was already present in high intensities in the <span class="hlt">interplanetary</span> medium due to the superposition of a series of solar flare particle events originating in AR 5395. The differential ion intensities at the lowest energy channel of the CPME experiment, which were associated with the March 13 shock wave, reached the highest level in the life of the IMP-8 spacecraft at this energy. At high energies, the shock associated intensity peak was smaller by less than a factor of 3 than the maxima of solar flare particle intensities from some other major flares, in particular from those with sites well connected to the Earth's <span class="hlt">magnetic</span> flux tubes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015TESS....111001R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015TESS....111001R"><span id="translatedtitle">Inter-Relationship of Solar and <span class="hlt">interplanetary</span> Phenomena During Solar Cycles 23 and 24</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Richardson, Ian; von Rosenvinge, Tycho; Cane, Hilary</p> <p>2015-04-01</p> <p>We examine the variation of various phenomena, for example, the sunspot number and area, occurrence rate of solar energetic particle events, coronal mass ejections and <span class="hlt">interplanetary</span> coronal mass ejections, the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field, solar <span class="hlt">magnetic</span> field (“Sun as a star”), geomagnetic activity and the cosmic ray intensity during solar cycles 23 to 24. As we have discussed for previous cycles, there is a close association between these phenomena. For example, the onset of long-term cosmic ray modulation in cycle 24 is closely associated with not only an increase in the tilt angle of the heliospheric current sheet but also with abrupt increases in the solar and <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field intensity at the Earth and the STEREO spacecraft, a temporary increase in the rate of <span class="hlt">interplanetary</span> coronal mass ejections, an increase in the occurrence of corotating streams and solar energetic particle events, including the first 25 MeV proton event observed at both STEREO spacecraft and at Earth, and increases in geomagnetic activity (e.g., Dst, Kp, aa). Subsequent “steps down” in the cosmic ray intensity are associated with increases in the IMF strength, as is typical for the rising phases of cycles when the global solar field has A< 0. We also note the remarkably different time development of activity in the northern and southern hemispheres during cycle 24 compared to cycle 23, and evidence of short term (˜6 month) quasi-periodicities in several of these phenomena that appear to characterize the development of this solar cycle, with periods of enhanced activity separated by intervals of lower activity.</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('http://adsabs.harvard.edu/abs/2014AcASn..55..381W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AcASn..55..381W"><span id="translatedtitle">Primary Analysis on the <span class="hlt">Interplanetary</span> Cause of Geomagnetically Induced Current and Its Effects on Power System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, K. R.; Liu, L. G.; Li, Y.</p> <p>2014-09-01</p> <p>In this paper, we use the measured data of geomagnetically induced current (GIC) in Ling'ao nuclear power plant from 2004 to 2005 to analyze its solar driving source and <span class="hlt">interplanetary</span> solar wind structure, focus on the <span class="hlt">interplanetary</span> cause and its effects on power system, and apply the wavelet analysis to the greatest GIC event. We conclude that: (1) Most GIC events were driven by halo coronal mass ejections, and the sheath, the <span class="hlt">magnetic</span> cloud, and the multiple <span class="hlt">interplanetary</span> solar structure are the <span class="hlt">interplanetary</span> cause of GIC events. (2) Based on the strongest event on 2004 November 9, we find that the fluctuation of GIC in the earlier stage was related to the <span class="hlt">magnetic</span> cloud boundary layer, and the variation of GIC intensity in the later stage was caused by <span class="hlt">magnetic</span> cloud itself. (3) Compared to the frequency of the power system (50 Hz), the GIC can be equivalent to the quasi direct current. The energy of the GIC is embodied in the two time intervals within the wavelet power spectrum: the first interval is shown as the pulse type and with a weaker intensity, and the second one is stronger. Regarding to the cumulative time of the transformer temperature rise caused by GIC, the second interval has a longer duration than the first one. So during the second interval, it is more harmful to the power system and the equipments. (4) The correlations of SYM-H, and dBx/dt to GIC are significantly closer than those of other geomagnetic indices to GIC.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ChA%26A..39...78W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ChA%26A..39...78W"><span id="translatedtitle">Preliminary Analysis on the <span class="hlt">Interplanetary</span> Cause of Geomagnetically Induced Current and Its Effect on Power Systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Kai-Rang; Liu, Lian-Guang; Li, Yan</p> <p>2015-01-01</p> <p>Using the detected events of geomagnetically induced current (GIC) in the Ling'ao nuclear power plant from 2004 to 2005, and focusing on the <span class="hlt">interplanetary</span> cause of GIC and its effect on power systems, we have analyzed the corresponding solar driving sources and <span class="hlt">interplanetary</span> solar wind structures, and performed spectral analysis on the most intense GIC event by means of wavelet transform. The results of this study show that: (1) Most GIC events were driven mainly by the halo coronal mass ejections, the <span class="hlt">interplanetary</span> cause of GIC events includes the shock sheath, <span class="hlt">magnetic</span> cloud, and multiplex <span class="hlt">interplanetary</span> solar wind structure. (2) Based on the strongest GIC event on 2001 November 9, we find that the fluctuation of GIC in the earlier stage was related to the <span class="hlt">magnetic</span> cloud boundary layer, and the variation of GIC intensity in the later stage was caused by <span class="hlt">magnetic</span> cloud itself. (3) Compared to the frequency of the power system (50 Hz), the GIC can be equivalent to a quasi direct current. The energy of the GIC is embodied in the two time intervals in the wavelet power spectrum: the first interval is shown as an impulsive type and with a weaker intensity, and the second one is stronger. Regarding to the cumulative time of the transformer temperature rise caused by GIC, the second interval has a longer duration than the first one. Hence, during the second interval, it is more harmful to the power systems and devices. (4) With a correlation analysis, the correlations of the SYM-H index and dBx/dt with the GIC are significantly stronger than those of other geomagnetic indices with the GIC.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996JGR...10124393K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996JGR...10124393K"><span id="translatedtitle">A statistical survey of 5-MeV proton events at transient <span class="hlt">interplanetary</span> shocks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kallenrode, May-Britt</p> <p>1996-11-01</p> <p>Between 1974 and 1985 the two Helios spacecraft observed 351 transient <span class="hlt">interplanetary</span> shocks. For 5-MeV protons the particle events associated with these shocks can be divided into three groups: (1) events without intensity increase above quiet time or increased background (47%), (2) solar and <span class="hlt">interplanetary</span> particle (SIP) events consisting of particles accelerated on or close to the Sun (solar or near-Sun component) as well as at the <span class="hlt">interplanetary</span> shock (24%), and (3) pure <span class="hlt">interplanetary</span> particle (PIP) events (29%) which consist of particles accelerated at the shock in <span class="hlt">interplanetary</span> space but do not show evidence for significant or even excess particle acceleration on the Sun. This classification shows that (1) only about half of the shocks accelerate MeV protons in <span class="hlt">interplanetary</span> space and (2) MeV protons accelerated on the Sun are neither a necessary nor a sufficient condition for the acceleration of MeV protons in <span class="hlt">interplanetary</span> space. Shock parameters such as speed or shock strength alone do not give an indication for the class of the associated particle event, because in the parameter range which covers most of the shocks, all three classes are distributed rather evenly. However, the shocks strongest in these parameters tend to accelerate particles. The intensity at the time of shock-passage, which can be used as a crude measure for the local acceleration efficiency, is correlated with the local shock speed and the <span class="hlt">magnetic</span> compression. The correlation coefficients are small but statistically significant, indicating that (1) the correlations are real and (2) the intensity is influenced by additional parameters, which are not necessarily shock inherent. As an example I will show that the local acceleration at the shock decreases roughly symmetrically with increasing distance from the nose of the shock with a median e-folding angle of 10°. Occasionally, larger e-folding angles are observed close to the nose of the shock. The question of how the shock accelerates protons in the MeV range could not be answered here, but I will suggest future studies that could shed a new light on this problem.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20080036103&hterms=MCS&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DMCS','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20080036103&hterms=MCS&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DMCS"><span id="translatedtitle">CAWSES November 7-8, 2004, Superstorm: Complex Solar and <span class="hlt">Interplanetary</span> Features in the Post-Solar Maximum Phase</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tsurutani, Bruce T.; Echer, Ezequiel; Guarnieri, Fernando L.; Kozyra, J. U.</p> <p>2008-01-01</p> <p>The complex <span class="hlt">interplanetary</span> structures during 7 to 8 Nov 2004 are analyzed to identify their properties as well as resultant geomagnetic effects and the solar origins. Three fast forward shocks, three directional discontinuities and two reverse waves were detected and analyzed in detail. The three fast forward shocks 'pump' up the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field from a value of approx.4 nT to 44 nT. However, the fields after the shocks were northward, and <span class="hlt">magnetic</span> storms did not result. The three ram pressure increases were associated with major sudden impulses (SI + s) at Earth. A <span class="hlt">magnetic</span> cloud followed the third forward shock and the southward Bz associated with the latter was responsible for the superstorm. Two reverse waves were detected, one at the edge and one near the center of the <span class="hlt">magnetic</span> cloud (MC). It is suspected that these 'waves' were once reverse shocks which were becoming evanescent when they propagated into the low plasma beta MC. The second reverse wave caused a decrease in the southward component of the IMF and initiated the storm recovery phase. It is determined that flares located at large longitudinal distances from the subsolar point were the most likely causes of the first two shocks without associated <span class="hlt">magnetic</span> clouds. It is thus unlikely that the shocks were 'blast waves' or that <span class="hlt">magnetic</span> reconnection eroded away the two associated MCs. This <span class="hlt">interplanetary</span>/solar event is an example of the extremely complex <span class="hlt">magnetic</span> storms which can occur in the post-solar maximum phase.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008GeoRL..35.6S05T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008GeoRL..35.6S05T"><span id="translatedtitle">CAWSES November 7-8, 2004, superstorm: Complex solar and <span class="hlt">interplanetary</span> features in the post-solar maximum phase</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tsurutani, Bruce T.; Echer, Ezequiel; Guarnieri, Fernando L.; Kozyra, J. U.</p> <p>2008-02-01</p> <p>The complex <span class="hlt">interplanetary</span> structures during 7 to 8 Nov 2004 are analyzed to identify their properties as well as resultant geomagnetic effects and the solar origins. Three fast forward shocks, three directional discontinuities and two reverse waves were detected and analyzed in detail. The three fast forward shocks ``pump'' up the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field from a value of ~4 nT to ~44 nT. However, the fields after the shocks were northward, and <span class="hlt">magnetic</span> storms did not result. The three ram pressure increases were associated with major sudden impulses (SI + s) at Earth. A <span class="hlt">magnetic</span> cloud followed the third forward shock and the southward Bz associated with the latter was responsible for the superstorm. Two reverse waves were detected, one at the edge and one near the center of the <span class="hlt">magnetic</span> cloud (MC). It is suspected that these ``waves'' were once reverse shocks which were becoming evanescent when they propagated into the low plasma beta MC. The second reverse wave caused a decrease in the southward component of the IMF and initiated the storm recovery phase. It is determined that flares located at large longitudinal distances from the subsolar point were the most likely causes of the first two shocks without associated <span class="hlt">magnetic</span> clouds. It is thus unlikely that the shocks were ``blast waves'' or that <span class="hlt">magnetic</span> reconnection eroded away the two associated MCs. This <span class="hlt">interplanetary</span>/solar event is an example of the extremely complex <span class="hlt">magnetic</span> storms which can occur in the post-solar maximum phase.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19730053720&hterms=random+fields&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Drandom%2Bfields','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19730053720&hterms=random+fields&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Drandom%2Bfields"><span id="translatedtitle">The rate of separation of <span class="hlt">magnetic</span> lines of force in a random <span class="hlt">magnetic</span> field.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jokipii, J. R.</p> <p>1973-01-01</p> <p>The mixing of <span class="hlt">magnetic</span> lines of force, as represented by their rate of separation, as a function of distance along the <span class="hlt">magnetic</span> field, is considered with emphasis on neighboring lines of force. This effect is particularly important in understanding the transport of charged particles perpendicular to the <span class="hlt">average</span> <span class="hlt">magnetic</span> field. The calculation is carried out in the approximation that the separation changes by an amount small compared with the correlation scale normal to the field, in a distance along the field of a few correlation scales. It is found that the rate of separation is very sensitive to the precise form of the power spectrum. Application to the <span class="hlt">interplanetary</span> and interstellar <span class="hlt">magnetic</span> fields is discussed, and it is shown that in some cases field lines, much closer together than the correlation scale, separate at a rate which is effectively as rapid as if they were many correlation lengths apart.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JASTP.114...19A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JASTP.114...19A"><span id="translatedtitle">Correlations between sunspot numbers, <span class="hlt">interplanetary</span> parameters and geomagnetic trends over solar cycles 21-23</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Arora, Kusumita; Chandrasekhar, N. Phani; Nagarajan, Nandini; Singh, Ankit</p> <p>2014-07-01</p> <p>We have analysed correlations between sunspot numbers, solar wind, ion density, <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field vis-à-vis <span class="hlt">magnetic</span> activity. Planetary geomagnetic index (Ap) and local residual measure of <span class="hlt">magnetic</span> activity (IΔH) from low-latitude <span class="hlt">Magnetic</span> Observatory, CSIR-NGRI, Hyderabad (IMO-HYB) spanning solar cycles 21-23 are used for this study. Using correlation coefficients between and wavelet decomposition of sunspot numbers, <span class="hlt">interplanetary</span> parameters and measures of <span class="hlt">magnetic</span> activity, the complex and time varying nature of these inter-relationships are brought out. The overall influence of sunspot number could be separated and combined episodic effects of other solar parameters could be distinguished. The demonstrated correlation or lack of it, between measures of <span class="hlt">magnetic</span> activity (Ap and IΔH), and all the parameters of solar activity, presented here corroborate established mechanisms as well as delineated clearly the relative impact of different solar mechanisms over phases of three solar cycles. The possible role of non-sunspot related activity from high latitude regions of the sun is indicated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GeoRL..43..978A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GeoRL..43..978A"><span id="translatedtitle">Outer radiation belt dropout dynamics following the arrival of two <span class="hlt">interplanetary</span> coronal mass ejections</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alves, L. R.; Da Silva, L. A.; Souza, V. M.; Sibeck, D. G.; Jauer, P. R.; Vieira, L. E. A.; Walsh, B. M.; Silveira, M. V. D.; Marchezi, J. P.; Rockenbach, M.; Lago, A. Dal; Mendes, O.; Tsurutani, B. T.; Koga, D.; Kanekal, S. G.; Baker, D. N.; Wygant, J. R.; Kletzing, C. A.</p> <p>2016-02-01</p> <p>Magnetopause shadowing and wave-particle interactions are recognized as the two primary mechanisms for losses of electrons from the outer radiation belt. We investigate these mechanisms, using satellite observations both in <span class="hlt">interplanetary</span> space and within the magnetosphere and particle drift modeling. Two <span class="hlt">interplanetary</span> shocks/sheaths impinged upon the magnetopause causing a relativistic electron flux dropout. The <span class="hlt">magnetic</span> cloud (MC) and <span class="hlt">interplanetary</span> structure sunward of the MC had primarily northward <span class="hlt">magnetic</span> field, perhaps leading to a concomitant lack of substorm activity and a 10 daylong quiescent period. The arrival of two shocks caused an unusual electron flux dropout. Test-particle simulations have shown ˜ 2 to 5 MeV energy, equatorially mirroring electrons with initial values of L≥5.5 can be lost to the magnetosheath via magnetopause shadowing alone. For electron losses at lower L-shells, coherent chorus wave-driven pitch angle scattering and ULF wave-driven radial transport have been shown to be viable mechanisms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19770044461&hterms=1086&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3D%2526%25231086','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19770044461&hterms=1086&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3D%2526%25231086"><span id="translatedtitle">August 1972 solar-terrestrial events - Observations of <span class="hlt">interplanetary</span> shocks at 2.2 AU</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Smith, E. J.; Davis, L., Jr.; Coleman, P. J., Jr.; Colburn, D. S.; Dyal, P.; Jones, D. E.</p> <p>1977-01-01</p> <p>Simultaneous <span class="hlt">magnetic</span> field and plasma observations on Pioneer 10 were used to identify three shocks and a plasma driver (possible flare ejecta) at 2.2 AU caused by the four large solar flares of August 2-7, 1972. Two shocks, the first and third, were forward shocks, while the second was a reverse shock. The local inertial velocities of all three shocks were estimated under the assumption of quasi-perpendicularity, i.e., the shocks were assumed to be propagating principally across, rather than along, the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFMSH33A1478A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFMSH33A1478A"><span id="translatedtitle">Solar flare electrons at the Sun and near the Earth. Insights from <span class="hlt">interplanetary</span> transport simulations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Agueda, N.; Krucker, S.; Lin, R. P.; Vainio, R. O.; Lario, D. D.; Sanahuja, B.</p> <p>2009-12-01</p> <p>We study 15 prompt 3He-rich electron events observed near 1 AU by Wind/3DP above 50 keV. The events are associated with <span class="hlt">magnetically</span> well-connected flares (between W10 and W85) with rather short soft X-ray duration (~10 min) and HXR sources seen by RHESSI on the visible solar disk. We compare the Wind/3DP observations with the results of <span class="hlt">interplanetary</span> transport simulations, to infer the properties of the propagation and constrain the injection of solar energetic electrons in the <span class="hlt">interplanetary</span> medium. We discuss the correlation between the inferred total number of injected electrons with the number of electrons required to produce the observed X-ray flux.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20110007813&hterms=2010-12-01&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3D2010-12-01','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20110007813&hterms=2010-12-01&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3D2010-12-01"><span id="translatedtitle">Large-Amplitude Electrostatic Waves Observed at a Supercritical <span class="hlt">Interplanetary</span> Shock</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wilson, L. B., III; Cattell, C. A.; Kellogg, P. J.; Goetz, K.; Kersten, K.; Kasper, J. C.; Szabo, A.; Wilber, M.</p> <p>2010-01-01</p> <p>We present the first observations at an <span class="hlt">interplanetary</span> shock of large-amplitude (> 100 mV/m pk-pk) solitary waves and large-amplitude (approx.30 mV/m pk-pk) waves exhibiting characteristics consistent with electron Bernstein waves. The Bernstein-like waves show enhanced power at integer and half-integer harmonics of the cyclotron frequency with a broadened power spectrum at higher frequencies, consistent with the electron cyclotron drift instability. The Bernstein-like waves are obliquely polarized with respect to the <span class="hlt">magnetic</span> field but parallel to the shock normal direction. Strong particle heating is observed in both the electrons and ions. The observed heating and waveforms are likely due to instabilities driven by the free energy provided by reflected ions at this supercritical <span class="hlt">interplanetary</span> shock. These results offer new insights into collisionless shock dissipation and wave-particle interactions in the solar wind.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008IAUS..251..315L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008IAUS..251..315L"><span id="translatedtitle">Organics in cometary and <span class="hlt">interplanetary</span> dust</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Levasseur-Regourd, A. Chantal; Lasue, Jeremie</p> <p>2008-10-01</p> <p>While gaseous carbon-rich species in cometary comae (coming from the nuclei icy component) are extensively studied by spectroscopic remote observations, so-called CHONs dust particles, i. e. organic compounds coming from the nuclei refractory component, have mostly been studied by dust mass spectrometers flying through the comae of comets 1P/Halley and 81P/Wild 2. However, remote observations of the light scattered by dust in cometary comae and in the <span class="hlt">interplanetary</span> medium, coupled with both numerical and experimental simulations, have recently allowed us to confirm that such particles harbor a significant fraction of absorbing material, presumably consisting of organic compounds (Levasseur-Regourd et al. PSS 2007, Lasue et al. A&A 2007). We estimate the fraction of absorbing material present in cometary dust for extensively observed comets (e.g., 1P/Halley, C/1995 O1 Hale-Bopp) and in the <span class="hlt">interplanetary</span> dust (from zodiacal light observations). We also establish that, besides compact particles, fluffy aggregates are definitely present in these media. The properties (e.g., size distribution, morphology, composition) of the cometary and <span class="hlt">interplanetary</span> dust particles, as inferred from light scattering data analysis, are compared with those of the IDPS collected in the upper Earth atmosphere and of the unique samples returned by the Stardust mission at Wild 2. The results are discussed in terms of the formation of comets in the protosolar nebula, and of the possible survival, at the epoch of late early bombardment, of cometary organics embedded in fluffy aggregates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GeoRL..42.6155K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GeoRL..42.6155K"><span id="translatedtitle">Revisit of relationship between geosynchronous relativistic electron enhancements and <span class="hlt">magnetic</span> storms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kim, Hee-Jeong; Lyons, Larry; Pinto, Victor; Wang, Chih-Ping; Kim, Kyung-Chan</p> <p>2015-08-01</p> <p>We find evidence that <span class="hlt">magnetic</span> storms are not only unnecessary for geosynchronous relativistic electron enhancements but also not directly relevant to the electron enhancements even if the enhancements are accompanied by <span class="hlt">magnetic</span> storms. What is crucial for electron enhancements at geosynchronous orbit are sustained south-oriented or north-south fluctuating <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) Bz that drives sufficiently large substorm activity and small solar wind density Nsw that likely leads to low loss rate of relativistic electrons to the ionosphere and/or to the magnetopause for an extended time period. Specifically, almost all the abrupt, large electron increases in our data set took place under the condition of <span class="hlt">average</span> AE > 235 nT and <span class="hlt">average</span> Nsw ? 5 cm-3. Examination of detailed time profiles clearly shows that electron flux starts to increase quite immediately with arrival of the right IMF and solar wind conditions, regardless of a <span class="hlt">magnetic</span> storm, leaving the accompanied <span class="hlt">magnetic</span> storms merely coincident.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19950037085&hterms=living+depression&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dliving%2Bdepression','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950037085&hterms=living+depression&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dliving%2Bdepression"><span id="translatedtitle">Galactic cosmic ray modulation and <span class="hlt">interplanetary</span> medium perturbations due to a long-living active region during October 1989</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bavassano, B.; Iucci, N.; Lepping, R. P.; Signorini, C.; Smith, E. J.; Villoresi, G.</p> <p>1994-01-01</p> <p>During October 1989, three very energetic flares were ejected by the same active region at longitudes 9 deg E, 32 deg W, and 57 deg W, respectively. The shape of the galactic cosmic ray variations suggests the presence of large <span class="hlt">magnetic</span> cloud structures (Nagashima et al., 1990) following the shock-associated perturbations. In spite of long data gaps the <span class="hlt">interplanetary</span> observations at <span class="hlt">Interplanetary</span> Monitoring Platform (IMP) 8 (near the Earth) and International Cometary Explorer (ICE)(approximately 1 AU, approximately 65 deg W) confirm this possibility for the event related to the 9 deg E flare; the principal axes analysis shows that the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field variations at both spacecraft locations are mainly confined on a meridian plane. This result suggests that the western longitudinal extension of this cloud is indeed very large (greater than or equal to 5 deg). The nonnegligible depression in the cosmic ray intensity observed inside the possible cloud related to the 57 deg W flare indicates that also the eastern extension could be very wide. The analysis of neutron monitor data shows clearly the cosmic ray trapping effect of <span class="hlt">magnetic</span> clouds; this mechanism seems to be responsible for the enhanced diurnal effect often observed during the recovery phase of Forbush decreases. We give an interpretation for the anisotropic cosmic ray peak occurring in the third event, and, related to that, we suggest that the Forbush decrease modulated region at the Earth's orbit could be somewhat wider than the <span class="hlt">magnetic</span> cloud, as already anticipated by Nagashima et al. (1990). By this analysis, based mainly on cosmic ray data, we show that it is possible to do reasonable inferences on the large-scale structure of flare-related <span class="hlt">interplanetary</span> perturbations when <span class="hlt">interplanetary</span> medium data are not completely present.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AstPo...6...95H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AstPo...6...95H"><span id="translatedtitle">Problems of <span class="hlt">Interplanetary</span> and Interstellar Trade</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hickman, John</p> <p>2008-01-01</p> <p>If and when <span class="hlt">interplanetary</span> and interstellar trade develops, it will be novel in two respects. First, the distances and time spans involved will reduce all or nearly all trade to the exchange of intangible goods. That threatens the possibility of conducting business in a genuinely common currency and of enforcing debt agreements, especially those involving sovereign debt. Second, interstellar trade suggests trade between humans and aliens. Cultural distance is a probable obstacle to initiating and sustaining such trade. Such exchange also threatens the release of new and potentially toxic memes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19850035588&hterms=monsanto&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dmonsanto','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850035588&hterms=monsanto&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dmonsanto"><span id="translatedtitle">Discovery of nuclear tracks in <span class="hlt">interplanetary</span> dust</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bradley, J. P.; Brownlee, D. E.; Fraundorf, P.</p> <p>1984-01-01</p> <p>Nuclear tracks have been identified in <span class="hlt">interplanetary</span> dust particles (IDP's) collected from the stratosphere. The presence of tracks unambiguously confirms the extraterrestrial nature of IDP's, and the high track densities (10 to the 10th to 10 to the 11th per square centimeter) suggest an exposure age of approximately 10,000 years within the inner solar system. Tracks also provide an upper temperature limit for the heating of IDP's during atmospheric entry, thereby making it possible to distinguish between pristine and thermally modified micrometeorites.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19880050877&hterms=CANE&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DCANE','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19880050877&hterms=CANE&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DCANE"><span id="translatedtitle">Radio emission from coronal and <span class="hlt">interplanetary</span> shocks</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cane, H. V.</p> <p>1987-01-01</p> <p>Observational data on coronal and <span class="hlt">interplanetary</span> (IP) type II burst events associated with shock-wave propagation are reviewed, with a focus on the past and potential future contributions of space-based observatories. The evidence presented by Cane (1983 and 1984) in support of the hypothesis that the coronal (metric) and IP (kilometric) bursts are due to different shocks is summarized, and the fast-drift kilometric events seen at the same time as metric type II bursts (and designated shock-accelerated or shock-associated events) are characterized. The need for further observations at 0.5-20 MHz is indicated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19880001349','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19880001349"><span id="translatedtitle">Coronal and <span class="hlt">interplanetary</span> Type 2 radio emission</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cane, H. V.</p> <p>1987-01-01</p> <p>Several observations suggest that the disturbances which generate coronal (meter wavelength) type II radio bursts are not driven by coronal mass ejections (CMEs). A new analysis using a large sample of metric radio bursts and associated soft X-ray events provides further support for the original hypothesis that type II-producing disturbances are blast waves generated at the time of impulsive energy release in flares. <span class="hlt">Interplanetary</span> (IP) shocks, however, are closely associated with CMEs. The shocks responsible for IP type II events (observed at kilometer wavelengths) are associated with the most energetic CMEs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19830036690&hterms=galileo+mission&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dgalileo%2Bmission','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19830036690&hterms=galileo+mission&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dgalileo%2Bmission"><span id="translatedtitle"><span class="hlt">Interplanetary</span> trajectory design for the Galileo mission</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Damario, L. A.; Byrnes, D. V.</p> <p>1983-01-01</p> <p>The Galileo mission has been reprogrammed to use a direct earth-Jupiter trajectory with a May 1986 launch date and with arrival at Jupiter occurring in mid-1988. Within the constraints of Shuttle/Centaur launch vehicle capability and total spacecraft mass and performance, optimal broken-plane trajectories are generated, and the region of positive propellant margin in the launch/arrival space is determined. Mission constraints are used to define a launch/arrival strategy. It is also shown that a close flyby of any one of several asteroids or a comet is possible on the <span class="hlt">interplanetary</span> transfer with minimal impact on mission performance.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000NuPhS..85....3S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000NuPhS..85....3S"><span id="translatedtitle">Radiation shielding of spacecraft's in manned <span class="hlt">interplanetary</span> flights</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Spillantini, Piero</p> <p>2000-05-01</p> <p>The high energy protons of the Solar Cosmic Rays (SCR) are by far the most dangerous for the health of the astronauts in manned flights outside the protection of the Earth <span class="hlt">magnetic</span> field. However, since the astronauts are in any case protected by the walls of the spaceship, only protons with kinetic energy exceeding 20 MeV must be taken into consideration. They have a small dispersion around the direction of the solar wind, what makes easier the protection against their action because absorber's of adequate thickness can be located in the side of their arrival direction. The mass of the required absorber rapidly increases with the energy of the proton, and is already 1,400 kg/m2 for stopping protons of 500 MeV. It is therefore necessary to have recourse to the use of <span class="hlt">magnetic</span> superconducting lenses for defocussing the beam of the arriving protons and protect the astronauts behind them. It is presented and discussed a scheme of toroidal lens protecting a volume of 10 m2 cross section at all energies of interest and weighing a few hundred kg. It is presented the program for developing a prototype of such a lens to be validated on board of the International Space Station and for sending an <span class="hlt">interplanetary</span> probe for mapping the characteristics of the high energy SCR from Earth to Mars and correlating them with the solar activity phenomena</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://hdl.handle.net/2060/20120011758','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120011758"><span id="translatedtitle">Observations of Electromagnetic Whistler Precursors at Supercritical <span class="hlt">Interplanetary</span> Shocks</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wilson, L. B., III; Koval, A.; Szabo, Adam; Breneman, A.; Cattell, C. A.; Goetz, K.; Kellogg, P. J.; Kersten, K.; Kasper, J. C.; Maruca, B. A.; Pulupa, M.</p> <p>2012-01-01</p> <p>We present observations of electromagnetic precursor waves, identified as whistler mode waves, at supercritical <span class="hlt">interplanetary</span> shocks using the Wind search coil magnetometer. The precursors propagate obliquely with respect to the local <span class="hlt">magnetic</span> field, shock normal vector, solar wind velocity, and they are not phase standing structures. All are right-hand polarized with respect to the <span class="hlt">magnetic</span> field (spacecraft frame), and all but one are right-hand polarized with respect to the shock normal vector in the normal incidence frame. They have rest frame frequencies f(sub ci) < f much < f(sub ce) and wave numbers 0.02 approx < k rho (sub ce) approx <. 5.0. Particle distributions show signatures of specularly reflected gyrating ions, which may be a source of free energy for the observed modes. In one event, we simultaneously observe perpendicular ion heating and parallel electron acceleration, consistent with wave heating/acceleration due to these waves. Al though the precursors can have delta B/B(sub o) as large as 2, fluxgate magnetometer measurements show relatively laminar shock transitions in three of the four events.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19850032873&hterms=Sun+earth+magnetic+current&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DSun%2Bearth%2Bmagnetic%2Bcurrent','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850032873&hterms=Sun+earth+magnetic+current&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DSun%2Bearth%2Bmagnetic%2Bcurrent"><span id="translatedtitle">Magnetohydrodynamic modelling of <span class="hlt">interplanetary</span> disturbances between the sun and earth</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Dryer, M.; Smith, Z. K.; Wu, S. T.; Wang, J. F.; Gislason, G.; Han, S. M.; Smart, D. F.; Shea, M. A.</p> <p>1984-01-01</p> <p>A time-dependent, nonplanar, two-dimensional magnetohydrodynamic computer model is used to simulate a series, separately examined, of solar flare-generated shock waves and their subsequent disturbances in <span class="hlt">interplanetary</span> space between the sun and the earth's magnetosphere. The 'canonical' or ansatz series of shock waves include initial velocities near the sun over the range 500 to 3500 km/s. The ambient solar wind, through which they propagate, is taken to be a steady state homogeneous plasma (that is, independent of heliolongitude) with a representative set of plasma and <span class="hlt">magnetic</span> field parameters. Complete sets of solar wind plasma and <span class="hlt">magnetic</span> field parameters are presented and discussed. Particular attention is addressed to the MHD model's ability to address fundamental operational questions vis-a-vis the long-range forecasting of geomagnetic disturbances. These questions are: (1) will a disturbance (such as the present canonical series of solar flare shock waves) produce a magnetospheric and ionospheric disturbance, and, if so, (2) when will it start, (3) how severe will it be, and (4) how long will it last? The model's output is used to compute various solar wind indices of current interest as a demonstration of the model's potential for providing 'answers' to these questions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010P%26SS...58.1180P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010P%26SS...58.1180P"><span id="translatedtitle">Laboratory simulation of <span class="hlt">interplanetary</span> ultraviolet radiation (broad spectrum) and its effects on Deinococcus radiodurans</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Paulino-Lima, Ivan Gláucio; Pilling, Sérgio; Janot-Pacheco, Eduardo; de Brito, Arnaldo Naves; Barbosa, João Alexandre Ribeiro Gonçalves; Leitão, Alvaro Costa; Lage, Claudia de Alencar Santos</p> <p>2010-08-01</p> <p>The radiation-resistant bacterium Deinococcus radiodurans was exposed to a simulated <span class="hlt">interplanetary</span> UV radiation at the Brazilian Synchrotron Light Laboratory (LNLS). Bacterial samples were irradiated on different substrates to investigate the influence of surface relief on cell survival. The effects of cell multi-layers were also investigated. The ratio of viable microorganisms remained virtually the same (<span class="hlt">average</span> 2%) for integrated doses from 1.2 to 12 kJ m -2, corresponding to 16 h of irradiation at most. The asymptotic profiles of the curves, clearly connected to a shielding effect provided by multi-layering cells on a cavitary substrate (carbon tape), means that the inactivation rate may not change significantly along extended periods of exposure to radiation. Such high survival rates reinforce the possibility of an <span class="hlt">interplanetary</span> transfer of viable microbes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19820054343&hterms=anisotropy+earth&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Danisotropy%2Bearth','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19820054343&hterms=anisotropy+earth&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Danisotropy%2Bearth"><span id="translatedtitle">Energetic <span class="hlt">interplanetary</span> nucleon flux anisotropies - The effect of earth's bow shock and magnetosheath on sunward flow</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Christon, S. P.</p> <p>1982-01-01</p> <p>Attention is given to the combined, <span class="hlt">average</span> effects of the bow shock and magnetosheath on the diffusive flow of <span class="hlt">interplanetary</span> nuclei. The observations presented show that differences between 'connected' and 'unconnected' data subsets are apparent from the beginning of the analysis. Through an investigation of the mean unconnected diffusive anisotropy (those fluxes least affected by the earth's bow shock and magnetosheath) it is confirmed that the cross-field transport of MeV energy nuclei in <span class="hlt">interplanetary</span> space is statistically significant and in the direction expected from the large-scale particle flux gradients. The direction of particle flow relative to the IMF is then used to show that nucleon flow characteristics on connected IMF differ from those on unconnected IMF. A scenario for producing this difference is then presented. It is concluded that the inclusion of the bow shock connected information biases measurements of the flux anisotropies of MeV energy H.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150018049','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150018049"><span id="translatedtitle">A Free-Return Earth-Moon Cycler Orbit for an <span class="hlt">Interplanetary</span> Cruise Ship</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Genova, Anthony L.; Aldrin, Buzz</p> <p>2015-01-01</p> <p>A periodic circumlunar orbit is presented that can be used by an <span class="hlt">interplanetary</span> cruise ship for regular travel between Earth and the Moon. This Earth-Moon cycler orbit was revealed by introducing solar gravity and modest phasing maneuvers (<span class="hlt">average</span> of 39 m/s per month) which yields close-Earth encounters every 7 or 10 days. Lunar encounters occur every 26 days and offer the chance for a smaller craft to depart the cycler and enter lunar orbit, or head for a Lagrange point (e.g., EM-L2 halo orbit), distant retrograde orbit (DRO), or <span class="hlt">interplanetary</span> destination such as a near-Earth object (NEO) or Mars. Additionally, return-to-Earth abort options are available from many points along the cycling trajectory.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20060042021&hterms=balogh&qs=N%3D0%26Ntk%3DAuthor-Name%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dbalogh','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20060042021&hterms=balogh&qs=N%3D0%26Ntk%3DAuthor-Name%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dbalogh"><span id="translatedtitle"><span class="hlt">Interplanetary</span> Discontinuities and Alfven Waves at High Heliographic Latitudes, Ulysses</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tsurutani, B. T.; Ho, C. M.; Arballo, J. K.; Smith, E. J.; Goldstein, B. E.; Neugebauer, M.; Balogh, A.; Feldman, W. C.</p> <p>1995-01-01</p> <p>This paper presents results from the first statistical study of <span class="hlt">interplanetary</span> directional discontinuities at high heliographic latitudes. Ulysses data showed that the rate of occurrence of <span class="hlt">interplanetary</span> discontinuities (ROIDs) increased dramatically from the ecliptic plane to high (-80 degrees) heliographic latitudes. The high speed streams included Alfven waves.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995MNRAS.277.1274G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995MNRAS.277.1274G"><span id="translatedtitle">Detection of <span class="hlt">interplanetary</span> activity using artificial neural networks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gothoskar, Pradeep; Khobragade, Shyam</p> <p>1995-12-01</p> <p>Early detection of <span class="hlt">interplanetary</span> activity is important when attempting to associate, with better accuracy, <span class="hlt">interplanetary</span> phenomena with solar activity and geomagnetic disturbances. However, for a large number of <span class="hlt">interplanetary</span> observations to be done every day, extensive data analysis is required, leading to a delay in the detection of transient <span class="hlt">interplanetary</span> activity. In particular, the <span class="hlt">interplanetary</span> scintillation (IPS) observations done with Ooty Radio Telescope (ORT) need extensive human effort to reduce the data and to model, often subjectively, the scintillation power spectra. We have implemented an artificial neural network (ANN) to detect <span class="hlt">interplanetary</span> activity using the power spectrum scintillation. The ANN was trained to detect the disturbed power spectra, used as an indicator of the <span class="hlt">interplanetary</span> activity, and to recognize normal and strong scattering spectra from a large data base of IPS spectra. The coincidence efficiency of classification by the network compared with the experts' judgement to detect the normal, disturbed and strong scattering spectra was found to be greater than 80 per cent. The neural network, when applied during the IPS mapping programme to provide early indication of <span class="hlt">interplanetary</span> activity, would significantly help the ongoing efforts to predict geomagnetic disturbances.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ARep...59..888P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ARep...59..888P"><span id="translatedtitle">Acceleration of solar cosmic rays in a flare current sheet and their propagation in <span class="hlt">interplanetary</span> space</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Podgorny, A. I.; Podgorny, I. M.</p> <p>2015-09-01</p> <p>Analyses of GOES spacecraft data show that the prompt component of high-energy protons arrive at the Earth after a time corresponding to their generation in flares in the western part of the solar disk, while the delayed component is detected several hours later. All protons in flares are accelerated by a single mechanism. The particles of the prompt component propagate along <span class="hlt">magnetic</span> lines of the Archimedean spiral connectng the flare with the Earth. The prompt component generated by flares in the eastern part of the solar disk is not observed at the Earth, since particles accelerated by these flares do not intersect <span class="hlt">magnetic</span>-field lines connecting the flare with the Earth. These particles arrive at the Earth via their motion across the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field. These particles are trapped by the <span class="hlt">magnetic</span> field and transported by the solar wind, since the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field is frozen in the wind plasma, and these particles also diffuse across the field. The duration of the delay reaches several days.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110011249','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110011249"><span id="translatedtitle"><span class="hlt">Interplanetary</span> Propagation of Coronal Mass Ejections</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gopalswamy, Nat</p> <p>2011-01-01</p> <p>Although more than ten thousand coronal mass ejections (CMEs) are produced during each solar cycle at the Sun, only a small fraction hits the Earth. Only a small fraction of the Earth-directed CMEs ultimately arrive at Earth depending on their interaction with the solar wind and other large-scale structures such as coronal holes and CMEs. The <span class="hlt">interplanetary</span> propagation is essentially controlled by the drag force because the propelling force and the solar gravity are significant only near the Sun. Combined remote-sensing and in situ observations have helped us estimate the influence of the solar wind on the propagation of CMEs. However, these measurements have severe limitations because the remote-sensed and in-situ observations correspond to different portions of the CME. Attempts to overcome this problem are made in two ways: the first is to model the CME and get the space speed of the CME, which can be compared with the in situ speed. The second method is to use stereoscopic observation so that the remote-sensed and in-situ observations make measurements on the Earth-arriving part of CMEs. The Solar Terrestrial Relations Observatory (STEREO) mission observed several such CMEs, which helped understand the <span class="hlt">interplanetary</span> evolution of these CMEs and to test earlier model results. This paper discusses some of these issues and updates the CME/shock travel time estimates for a number of CMEs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002cosp...34E1276C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002cosp...34E1276C"><span id="translatedtitle">The <span class="hlt">interplanetary</span> gamma ray burst network</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cline, T.</p> <p></p> <p>The <span class="hlt">Interplanetary</span> Gamma-Ray Burst Network (IPN) is providing gamma-ray burst (GRB) alerts and localizations at the maximum rate anticipated before the launch of the Swift mission. The arc-minute source precision of the IPN is again permitting searches for GRB afterglows in the radio and optical regimes with delays of only hours up to 2 days. The successful addition of the Mars Odyssey mission has compensated for the loss of the asteroid mission NEAR, to reconstitute a fully long- baseline <span class="hlt">interplanetary</span> network, with Ulysses at > 5 AU and Konus-Wind and HETE-2 near the Earth. In addition to making unassisted GRB localizations that enable a renewed supply of counterpart observations, the Mars/Ulysses/Wind IPN is confirming and reinforcing GRB source localizations with HETE-2. It has also confirmed and reinforced localizations with the BeppoSAX mission before the BeppoSAX termination in May and has detected and localized both SGRs and an unusual hard x-ray transient that is neither an SGR nor a GRB. This IPN is expected to operate until at least 2004.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080048006','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080048006"><span id="translatedtitle">The <span class="hlt">Interplanetary</span> Overlay Networking Protocol Accelerator</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pang, Jackson; Torgerson, Jordan L.; Clare, Loren P.</p> <p>2008-01-01</p> <p>A document describes the <span class="hlt">Interplanetary</span> Overlay Networking Protocol Accelerator (IONAC) an electronic apparatus, now under development, for relaying data at high rates in spacecraft and <span class="hlt">interplanetary</span> radio-communication systems utilizing a delay-tolerant networking protocol. The protocol includes provisions for transmission and reception of data in bundles (essentially, messages), transfer of custody of a bundle to a recipient relay station at each step of a relay, and return receipts. Because of limitations on energy resources available for such relays, data rates attainable in a conventional software implementation of the protocol are lower than those needed, at any given reasonable energy-consumption rate. Therefore, a main goal in developing the IONAC is to reduce the energy consumption by an order of magnitude and the data-throughput capability by two orders of magnitude. The IONAC prototype is a field-programmable gate array that serves as a reconfigurable hybrid (hardware/ firmware) system for implementation of the protocol. The prototype can decode 108,000 bundles per second and encode 100,000 bundles per second. It includes a bundle-cache static randomaccess memory that enables maintenance of a throughput of 2.7Gb/s, and an Ethernet convergence layer that supports a duplex throughput of 1Gb/s.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/17801776','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/17801776"><span id="translatedtitle">Magnesium isotopic composition of <span class="hlt">interplanetary</span> dust particles.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Esat, T M; Brownlee, D E; Papanastassiou, D A; Wasserburg, G J</p> <p>1979-10-12</p> <p>The magnesium isotopic composition of some extraterrestrial dust particles has been measured. The particles are believed to be samples of <span class="hlt">interplanetary</span> dust, a significant fraction of which originated from the disaggregation of comets and may contain preserved isotopic anomalies. Improvements in mass spectrometric and sample preparation techniques have made it possible to measure the magnesium isotopic composition of the dust particles, which are typically 10 micrometers in size and contain on the order of 10(-10) gram of magnesium. Of the 13 samples analyzed, nine have the terrestrial magnesium isotopic composition within 2 parts per thousand, and one shows isotopic mass fractionation of 1.1 percent per mass unit. A subset of the particles, described as chondritic aggregates, are very close to normal isotopic composition, but their normalized isotopic ratios appear to show nonlinear effects of 3 to 4 parts per thousand, which is near the present limit of detection for samples of this size. The isotopic composition of calcium was also determined in one particle and found to be normal within 2 percent. It is clear that the isotopic composition of <span class="hlt">interplanetary</span> dust particles can be determined with good precision. Collection of dust particles during the earth's passage through a comet tail or an intense meteor stream may permit laboratory analysis of material from a known comet. PMID:17801776</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMSH41B1795T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMSH41B1795T"><span id="translatedtitle">Solar Modes in the <span class="hlt">Interplanetary</span> Medium</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thomson, D. J.; Lanzerotti, L. J.</p> <p>2010-12-01</p> <p>Because very low frequency solar modes provide the only way to determine conditions in the Sun's core, their detection and accurately measuring their frequencies has been described by Chaplin as the "Holy Grail of observational helioseismology" A recent review paper (Appourchaux 2010) concludes that "there is currently no undisputed detections of solar g modes". Reported here is an update on the study of frequencies in the <span class="hlt">interplanetary</span> medium in the range of expected normal modes of the Sun. Data from several instruments on the ACE and Ulysses spacecraft are time series analyzed and inter-compared. Doing a combined search of the spectra in both frequency and frequency splitting (and allowing for known frequency shifts due to the different orbits of the two spacecraft) we find several instances where the same frequencies (modes) are detected in two and more data sets at high confidence levels on both spacecraft. The frequencies occur reasonably close to predicted solar mode frequencies. Moreover, these detections include all 2l+1 singlets expected for modes of degree l at high significance levels. Implications for the <span class="hlt">interplanetary</span> medium and for the internal structure of the Sun will be presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.4630P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.4630P"><span id="translatedtitle">Evolution of turbulence through <span class="hlt">interplanetary</span> shocks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pitna, Alexander; Safrankova, Jana; Nemecek, Zdenek; Nemec, Frantisek; Prech, Lubomir; Chen, Christopher H. K.; Zastenker, Georgy N.</p> <p>2015-04-01</p> <p>The solar wind plasma is a turbulent medium in which Alfvenic MHD turbulence is assumed to be a prime candidate for a transfer of large scale variations into smaller spatial scales, up to the ion kinetic scale related to a thermal gyroradius or an ion inertial length. <span class="hlt">Interplanetary</span> shocks are naturally occurring in the solar wind and provide a unique opportunity to compare a relatively quiet solar wind upstream with the shocked plasma downstream. The BMSW instrument onboard the Spektr-R spacecraft has detected tens of <span class="hlt">interplanetary</span> (IP) shocks in a course of the 2011-2014 years. The high-time resolution (31 ms) of the ion flux, density and solar wind speed measurements allows us to study spectral properties in the transition region between MHD and kinetic scales. We have found that the overall power of the ion flow fluctuations at all spatial scales increases roughly ten times. The spectral slope of the power spectra in the kinetic range (3-8 Hz) is steeper downstream IP shocks than in the upstream solar wind. If the fluctuation level increases the power law decay of ion kinetic structures gradually changes to the exponential decay already reported for turbulence in interstellar plasmas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995JGR...10012201K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995JGR...10012201K"><span id="translatedtitle">Coherent radar estimates of <span class="hlt">average</span> high-latitude ionospheric Joule heating</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kosch, M. J.; Nielsen, E.</p> <p>1995-07-01</p> <p>The Scandinavian Twin Auroral Radar Experiment (STARE) and Sweden and Britain Radar Experiment (SABRE) bistatic coherent radar systems have been employed to estimate the spatial and temporal variation of the ionospheric Joule heating in the combined geographic latitude range 63.8 deg - 72.6 deg (corrected geomagnetic latitude 61.5 deg - 69.3 deg) over Scandinavia. The 173 days of good observations with all four radars have been analyzed during the period 1982 to 1986 to estimate the <span class="hlt">average</span> ionospheric electric field versus time and latitude. The AE dependent empirical model of ionospheric Pedersen conductivity of Spiro et al. (1982) has been used to calculate the Joule heating. The latitudinal and diurnal variation of Joule heating as well as the estimated mean hemispherical heating of 1.7 x 10(exp 11) W are in good agreement with earlier results. <span class="hlt">Average</span> Joule heating was found to vary linearly with the AE, AU, and AL indices and as a second-order power law with Kp. The <span class="hlt">average</span> Joule heating was also examined as a function of the direction and magnitude of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field. It has been shown for the first time that the ionospheric electric field magnitude as well as the Joule heating increase with increasingly negative (southward) Bz.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015A%26A...582A..52A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015A%26A...582A..52A"><span id="translatedtitle">A tiny event producing an <span class="hlt">interplanetary</span> type III burst</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alissandrakis, C. E.; Nindos, A.; Patsourakos, S.; Kontogeorgos, A.; Tsitsipis, P.</p> <p>2015-10-01</p> <p>Aims: We investigate the conditions under which small-scale energy release events in the low corona gave rise to strong <span class="hlt">interplanetary</span> (IP) type III bursts. Methods: We analyzed observations of three tiny events, detected by the Nançay Radio Heliograph (NRH), two of which produced IP type III bursts. We took advantage of the NRH positioning information and of the high cadence of AIA/SDO data to identify the associated extreme-UV (EUV) emissions. We measured positions and time profiles of the metric and EUV sources. Results: We found that the EUV events that produced IP type III bursts were located near a coronal hole boundary, while the one that did not was located in a closed <span class="hlt">magnetic</span> field region. In all three cases tiny flaring loops were involved, without any associated mass eruption. In the best observed case, the radio emission at the highest frequency (435 MHz) was displaced by ~55'' with respect to the small flaring loop. The metric type III emission shows a complex structure in space and in time, indicative of multiple electron beams, despite the low intensity of the events. From the combined analysis of dynamic spectra and NRH images, we derived the electron beam velocity as well as the height, ambient plasma temperature, and density at the level of formation of the 160 MHz emission. From the analysis of the differential emission measure derived from the AIA images, we found that the first evidence of energy release was at the footpoints, and this was followed by the development of flaring loops and subsequent cooling. Conclusions: Even small energy release events can accelerate enough electrons to give rise to powerful IP type III bursts. The proximity of the electron acceleration site to open <span class="hlt">magnetic</span> field lines facilitates the escape of the electrons into the <span class="hlt">interplanetary</span> space. The offset between the site of energy release and the metric type III location warrants further investigation. The movie is available in electronic form at http://www.aanda.org</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ChA%26A..39..487B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ChA%26A..39..487B"><span id="translatedtitle">The Study on a Solar Storm and Its <span class="hlt">Interplanetary</span> and Geomagnetic Effects</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bai-han, Qiu; Chuan, LI</p> <p>2015-10-01</p> <p>We present a detailed study on a solar storm occurred on 2014 January 7. By using the remote-sensing observations of solar activities at multiple wavelengths from the Solar Dynamics Observatory (SDO) and the Solar and Heliospheric Observatory (SOHO), the eruptions of the solar flare and coronal mass ejection (CME) are investigated. Based on the measurement of energetic protons from the Geostationary Operational Environmental Satellite (GOES) and the in-situ plasma measurement from the Advanced Composition Explorer (ACE) at the solar-terrestrial L1 point, the solar energetic particle (SEP) event and <span class="hlt">interplanetary</span> CME (ICME) accompanied by the solar storm, and the shock driven by the ICME are analyzed. The influence of the solar storm on the geomagnetic fields is also analyzed with the ground-based <span class="hlt">magnetic</span> data. The results in this study show that: (1) The initial time of impulsive phase of the solar flare and the ejection time of the CME are temporally in accordance with each other. (2) The solar protons are mainly accelerated by the CME-driven shock, rather than by the <span class="hlt">magnetic</span> reconnection in the flare, and the protons are released when the CME travels to 7.7 solar radius. (3) The widths of the <span class="hlt">interplanetary</span> shock sheath and the ICME itself are derived to be 0.22 AU and 0.26 AU, respectively. (4) The <span class="hlt">interplanetary</span> shock and the ICME give rise to substorms and aurora, whereas no obvious geomagnetic storm is detected. The reason is that the ICME does not contain a regular structure of <span class="hlt">magnetic</span> cloud (MC) or evident southward component of <span class="hlt">magnetic</span> field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=EL-1994-00329&hterms=B12&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DB12','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=EL-1994-00329&hterms=B12&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DB12"><span id="translatedtitle">LDEF (Prelaunch), AO201 : <span class="hlt">Interplanetary</span> Dust Experiment, Tray B12</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1984-01-01</p> <p>LDEF (Prelaunch), AO201 : <span class="hlt">Interplanetary</span> Dust Experiment, Tray B12 The prelaunch photograph shows the six (6) inch deep <span class="hlt">Interplanetary</span> Dust Experiment (IDE) master control tray. The tray has three (3) mounting/cover plates elevated on fiberglass stand-offs to provide clearance and protection for hardware and electronics located underneath. The stand-offs also raise the plates to a level that minimizes shading of detectors by the tray sidewalls. The mounting plate located at the left hand end of the tray is populated with eighty (80) metaloxide-silicon (MOS) capacitor-type impact sensors and one (1) solar sensor that is located approximately in the center of the mounting plate. The IDE sensors are two (2) inch diameter MOS capacitor structures approximately 250 um thick. The detectors are formed by growing either 0.4um or 1.0um thick silicon oxide, SiO2, layer on the 250um thick, B-doped polished silicon wafer. The top metal contact, the visible surface, was formed by vapor deposition of 1000A of aluminum on the SiO2 surface. Aluminum was also vapor deposited on the backside to form the contact with the silicon substrate. Gold wires are bonded to the front and back aluminum layers for use in connecting the detectors to the circuits. The complete wafers, IDE detectors, are mounted on chromic anodized aluminum frames by bonding the detector backside to the aluminum frame with a space qualified RTV silicon adhesive, de-volatized RTV-511. The difference in colors of the detectors is caused by reflections in the metallized surfaces. A reflection of one of the technicians is visible in the three (3) rows of detector on the left hand side of the mounting plate. The solar sensor, located at the mounting plate center, consist of four (4) silicon solar cells connected in series and associated circuity bonded to an aluminum baseplate. The solar sensor registered each orbital sunrise independant of LDEF orientation at the time of sunrise. When IDE solar sensor data from the six (6) orthogonal faces of the LDEF was correlated, the <span class="hlt">Interplanetary</span> Dust Experiment clock could be precisely calibrated. The center 1/3rd tray cover is a chromic anodized aluminum plate that protects the IDE data conditioning and control electronics mounted underneath. The cover plate also serves as a mounting platform for ten (10) individual specimen holders provided by one of the IDE investigators.The material specimen, consisting of germanium, sapphire and zinc sulfide of different sizes, shapes and colors, are bonded to the specimen holders with an RTV adhesive. The specimen holders are attached to the cover plate with stainless steel non-<span class="hlt">magnetic</span> fasteners. The 1/3rd tray cover plate in the right hand end of the experiment tray is an aluminum plate painted white with Chemglaze II A-276 paint and used as a thermal cover for the Experiment Power and Data System (EPDS). The EPDS is a system provided by the LDEF Project Office that processes and stores, on <span class="hlt">magnetic</span> tape, the orbital experiment and housekeeping data from six (6) experiment locations on the LDEF.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22420353','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22420353"><span id="translatedtitle">Comprehensive Population-<span class="hlt">Averaged</span> Arterial Input Function for Dynamic Contrast–Enhanced v<span class="hlt">Magnetic</span> Resonance Imaging of Head and Neck Cancer</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Onxley, Jennifer D.; Yoo, David S.; Muradyan, Naira; MacFall, James R.; Brizel, David M.; Craciunescu, Oana I.</p> <p>2014-07-01</p> <p>Purpose: To generate a population-<span class="hlt">averaged</span> arterial input function (PA-AIF) for quantitative analysis of dynamic contrast-enhanced MRI data in head and neck cancer patients. Methods and Materials: Twenty patients underwent dynamic contrast-enhanced MRI during concurrent chemoradiation therapy. Imaging consisted of 2 baseline scans 1 week apart (B1/B2) and 1 scan after 1 week of chemoradiation therapy (Wk1). Regions of interest (ROIs) in the right and left carotid arteries were drawn on coronal images. Plasma concentration curves of all ROIs were <span class="hlt">averaged</span> and fit to a biexponential decay function to obtain the final PA-AIF (AvgAll). Right-sided and left-sided ROI plasma concentration curves were <span class="hlt">averaged</span> separately to obtain side-specific AIFs (AvgRight/AvgLeft). Regions of interest were divided by time point to obtain time-point-specific AIFs (AvgB1/AvgB2/AvgWk1). The vascular transfer constant (K{sub trans}) and the fractional extravascular, extracellular space volume (V{sub e}) for primaries and nodes were calculated using the AvgAll AIF, the appropriate side-specific AIF, and the appropriate time-point-specific AIF. Median K{sub trans} and V{sub e} values derived from AvgAll were compared with those obtained from the side-specific and time-point-specific AIFs. The effect of using individual AIFs was also investigated. Results: The plasma parameters for AvgAll were a{sub 1,2} = 27.11/17.65 kg/L, m{sub 1,2} = 11.75/0.21 min{sup −1}. The coefficients of repeatability (CRs) for AvgAll versus AvgLeft were 0.04 min{sup −1} for K{sub trans} and 0.02 for V{sub e}. For AvgAll versus AvgRight, the CRs were 0.08 min{sup −1} for K{sub trans} and 0.02 for V{sub e}. When AvgAll was compared with AvgB1/AvgB2/AvgWk1, the CRs were slightly higher: 0.32/0.19/0.78 min{sup −1}, respectively, for K{sub trans}; and 0.07/0.08/0.09 for V{sub e}. Use of a PA-AIF was not significantly different from use of individual AIFs. Conclusion: A PA-AIF for head and neck cancer was generated that accounts for differences in right carotid artery versus left carotid artery, day-to-day fluctuations, and early treatment-induced changes. The small CRs obtained for K{sub trans} and V{sub e} indicate that side-specific AIFs are not necessary. However, a time-point-specific AIF may improve pharmacokinetic accuracy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19920018015&hterms=Rare+earth+metals&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3D%2528%2528Rare%2Bearth%2529%2Bmetals%2529','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19920018015&hterms=Rare+earth+metals&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3D%2528%2528Rare%2Bearth%2529%2Bmetals%2529"><span id="translatedtitle"><span class="hlt">Interplanetary</span> meteoroid debris in LDEF metal craters</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Brownlee, D. E.; Horz, F.; Bradley, J.</p> <p>1992-01-01</p> <p>The extraterrestrial meteoroid residue found lining craters in the Long Duration Exposure Facility (LDEF) aluminum and gold targets is highly variable in both quantity and type. In typical craters only a minor amount of residue is found and for these craters it is evident that most of the impacting projectile was ejected during crater formation. Less than 10 percent of the craters greater than 100 microns contain abundant residue consistent with survival of a major fraction of the projectile. In these cases the residue can be seen optically as a dark liner and it can easily be analyzed by SEM-EDX techniques. Because they are rare, the craters with abundant residue must be a biased sampling of the meteoroids reaching the earth. Factors that favor residue retention are low impact velocity and material properties such as high melting point. In general, the SEM-EDX observations of crater residues are consistent with the properties of chondritic meteorites and <span class="hlt">interplanetary</span> dust particles collected in the stratosphere. Except for impacts by particles dominated by single minerals such as FeS and olivine, most of the residue compositions are in broad agreement with the major element compositions of chondrites. In most cases the residue is a thin liner on the crater floor and these craters are difficult to quantitatively analyze by EDX techniques because the electron beam excites both residue and underlying metal substrate. In favorable cases, the liner is thick and composed of vesicular glass with imbedded FeNi, sulfide and silicate grains. In the best cases of meteoroid preservation, the crater is lined with large numbers of unmelted mineral grains. The projectiles fragmented into micron sized pieces but the fragments survived without melting. In one case, the grains contain linear defects that appear to be solar flare tracks. Solar flare tracks are common properties of small <span class="hlt">interplanetary</span> particles and their preservation during impact implies that the fragments were not heated above 600 C. We are investigating the meteoroid fragments in LDEF metal craters to determine the properties of <span class="hlt">interplanetary</span> dust and to determine if there are meteoroid types that are overlooked or otherwise undetected in cosmic dust collections obtained from the stratosphere and polar ice.</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><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><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <center> <div class="footer-extlink text-muted"><small>Some links on this page may take you to non-federal websites. 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