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1

Average high latitude magnetic field - Variation with interplanetary sector and with season. II  

NASA Technical Reports Server (NTRS)

Average high-latitude magnetic-field data from northern observatories are examined for three ranges of magnetic disturbance level, Kp = 1- to 1+, 2- to 3+ and greater than or equal to 4-. Except for 0 to 0800 hr MLT, 55 to 78 deg invariant latitude, during away interplanetary magnetic field sectors, the variations between season and sector have the same characteristics at all Kp ranges. Because the amplitude of sector differences is much larger at sunlit local times than in the midnight sector, it is concluded that the current system of Svalgaard (1973) is not adequate to describe the sector variations in magnetic disturbance. Other current systems are discussed briefly. The disturbance morphology and seasonal variation at all Kp levels confirms the results of previous studies which indicate that latitudinally broad current systems and nonionospheric sources are present in addition to latitudinally narrow electrojet currents.

Langel, R.; Brown, N.

1974-01-01

2

Interplanetary magnetic holes: theory  

Microsoft Academic Search

Magnetic holes in the interplanetary medium are explained as stationary nonpropagating equilibrium structures in which there are field-aligned enhancements of the plasma density and\\/or temperature. Magnetic antiholes 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

L. F. Burlaga; J. F. Lemaire

1978-01-01

3

Interplanetary Magnetic Field Lines  

NSDL National Science Digital Library

This web page provides information and a graphical exercise for students regarding the interaction between magnetic field lines and a plasma. The activity involves tracing a typical interplanetary magnetic field line, dragged out of a location on the Sun by the radial flow of the solar wind. This illustrates the way magnetic field lines are "frozen to the plasma" and the wrapping of field lines due to the rotation of the sun. This is part of the work "The Exploration of the Earth's Magnetosphere". A Spanish translation is available.

Stern, David

2005-04-27

4

Interplanetary magnetic holes: Theory  

NASA Technical Reports Server (NTRS)

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.

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

1978-01-01

5

Interplanetary magnetic holes - Theory  

NASA Technical Reports Server (NTRS)

Magnetic holes in the interplanetary medium are explained as stationary nonpropagating equilibrium structures in which there are field-aligned enhancements of the plasma density and/or temperature. Magnetic antiholes 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 that we consider 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 have been observed.

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

1978-01-01

6

Interplanetary magnetic field data book  

NASA Technical Reports Server (NTRS)

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.

King, J. H.

1975-01-01

7

The interplanetary magnetic field  

NASA Technical Reports Server (NTRS)

Large-scale properties of the interplanetary magnetic field as determined by the solar wind velocity structure are examined. The various ways in which magnetic fields affect phenomena in the solar wind are summarized. The dominant role of high and low velocity solar wind streams that persist, with fluctuations and evolution, for weeks or months is emphasized. It is suggested that for most purposes the sector structure is better identified with the stream structure than with the magnetic polarity and that the polarity does not necessarily change from one velocity sector to the next. Several mechanisms that might produce the stream structure are considered. The interaction of the high and low velocity streams is analyzed in a model that is steady state when viewed in a frame that corotates with the sun.

Davis, L., Jr.

1972-01-01

8

Evolution of the interplanetary magnetic field  

SciTech Connect

Remote observations of magnetic field topologies in the solar corona and in situ observations of the solar wind and interplanetary magnetic field (IMF) in interplanetary space are used to examine the temporal evolution of the spatial distribution of open and closed field regions emanating from the Sun. The simple ``open`` configuration of inward and outward pointing sectors in the IMF is periodically disrupted by magnetically distinct coronal mass ejections (CMEs) which erupt from previously closed magnetic field regions in the corona into interplanetary space. At 1 AU, CMEs contain counterstreaming halo electrons which indicate their distinct magnetic topologies. This topology is generally thought to be: plasmoids that are completely disconnected from the Sun; magnetic ``bottles,`` still tied to the corona at both ends; or flux ropes which are only partially disconnected. Fully disconnected plasmoids would have no long term effect on the amount of open flux; however, both in situ observations of details of the halo electron distributions and remote coronagraph observations of radial fields following CMEs indicate that CMEs generally do retain at least partial attached to the Sun. Both the magnetic-bottle and flux rope geometries require some mitigating process to close off previously open fields in order to avoid a flux catastrophe. In addition, the average amount of magnetic flux observed in interplanetary space varies over the solar cycle, also indicating that there must be ways in which new flux is opened and previously open flux is closed off. The most likely scenario for closing off open magnetic fields is for reconnection to occurs above helmet streamers, where oppositely directed field regions are juxtaposed in the corona. These events would serve to return closed field arches to the Sun and release open, U-shaped structures into the solar wind.

McComas, D.J.

1993-05-01

9

Evolution of the interplanetary magnetic field  

SciTech Connect

Remote observations of magnetic field topologies in the solar corona and in situ observations of the solar wind and interplanetary magnetic field (IMF) in interplanetary space are used to examine the temporal evolution of the spatial distribution of open and closed field regions emanating from the Sun. The simple open'' configuration of inward and outward pointing sectors in the IMF is periodically disrupted by magnetically distinct coronal mass ejections (CMEs) which erupt from previously closed magnetic field regions in the corona into interplanetary space. At 1 AU, CMEs contain counterstreaming halo electrons which indicate their distinct magnetic topologies. This topology is generally thought to be: plasmoids that are completely disconnected from the Sun; magnetic bottles,'' still tied to the corona at both ends; or flux ropes which are only partially disconnected. Fully disconnected plasmoids would have no long term effect on the amount of open flux; however, both in situ observations of details of the halo electron distributions and remote coronagraph observations of radial fields following CMEs indicate that CMEs generally do retain at least partial attached to the Sun. Both the magnetic-bottle and flux rope geometries require some mitigating process to close off previously open fields in order to avoid a flux catastrophe. In addition, the average amount of magnetic flux observed in interplanetary space varies over the solar cycle, also indicating that there must be ways in which new flux is opened and previously open flux is closed off. The most likely scenario for closing off open magnetic fields is for reconnection to occurs above helmet streamers, where oppositely directed field regions are juxtaposed in the corona. These events would serve to return closed field arches to the Sun and release open, U-shaped structures into the solar wind.

McComas, D.J.

1993-01-01

10

The interplanetary magnetic field. Solar origin and terrestrial effects  

Microsoft Academic Search

Many observations related to the large-scale structure of the interplanetary magnetic field, its solar origin and terrestrial effects are discussed. During the period observed by spacecraft the interplanetary field was dominated by a sector structure corotating with the sun in which the field is predominantly away from the sun (on the average in the Archimedes spiral direction) for several days

John M. Wilcox

1968-01-01

11

The structure of helical interplanetary magnetic fields  

NASA Technical Reports Server (NTRS)

The interplanetary magnetic field is known to be highly helical. Although the detailed spatial structure of the fields has yet to be elucidated, the helicity spectrum has been conjectured to result from a random walk in the direction of a constant magnitude magnetic field vector. A model using three-dimensional fluctuations with variations in B is demonstrated giving a good fit to the helicity spectrum as well as to other properties of the interplanetary magnetic field.

Goldstein, M. L.; Roberts, D. A.; Fitch, C. A.

1991-01-01

12

Interplanetary magnetic clouds: Topology and driving mechanism  

Microsoft Academic Search

A model is developed to study the origin and propagation of magnetic clouds. Starting with an equilibrium current loop embedded in an ambient plasma consistent with the solar corona, magnetic energy is injected by increasing the loop current. This causes the loop to rise, propelling plasma and magnetic field away from the Sun. Using a simple model of the interplanetary

James Chen; David A. Garren

1993-01-01

13

Intermittent character of interplanetary magnetic field fluctuations  

SciTech Connect

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.

Bruno, Roberto; Carbone, Vincenzo; Chapman, Sandra; Hnat, Bogdan; Noullez, Alain; Sorriso-Valvo, Luca [IFSI/INAF, via Fosso del Cavaliere, I-00133 Rome (Italy); Dipartimento di Fisica, Universita della Calabria, and CNISM, Unita di Cosenza, Arcavacata di Rende I-87036 (Italy); Centre for Fusion, Space and Astrophysics, University of Warwick, Warwick CV4 7AL (United Kingdom); Observatoire de la Cote d'Azur, Boulevard de l'Observatoire, F-06304 Nice (France); LICRYL, INFM/CNR, I-87036 Arcavacata di Rende (Italy)

2007-03-15

14

Interplanetary Magnetic Field Guiding Relativistic Particles  

NASA Technical Reports Server (NTRS)

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.

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

2011-01-01

15

Interplanetary Magnetic Sector Polarity from Polar Geomagnetic Field Observations.  

National Technical Information Service (NTIS)

It has recently been reported that the interplanetary magnetic sector polarity has an influence on the diurnal variation of the polar geomagnetic field. An investigation to infer the interplanetary magnetic sector polarity from the geomagnetic observation...

J. M. Wilcox W. Gonzalez E. Friis-Christensen K. Lassen D. S. Colburn

1971-01-01

16

Effect of Cyclic Variations in Solar Magnetic Fields on Characteristics of Interplanetary Medium  

NASA Astrophysics Data System (ADS)

Yearly averages of dynamical parameters of the solar wind and interplanetary magnetic field, as well as their determination errors, are obtained from the data of an electronic version of King's catalog. With these data in use, 11-year cycles of all the characteristics of the interplanetary plasma and their connection with cycles of different solar magnetic fields were analyzed. Differences in the cycles of principal characteristics of the interplanetary medium are demonstrated by this analysis. Attention was given to systematic errors in deter- mination of plasma density before the beginning of the 1970s and to the inadequacy of variations in the vector of the initial interplanetary magnetic field and its components.

Rivin, Yu. R.; Gromova, L. I.

17

Distributions of the interplanetary magnetic field revisited  

NASA Technical Reports Server (NTRS)

The adequacy of the power spectrum to characterize the variations of a parameter depends on whether or not the parameter has a Gaussian distribution. We here perform very simple tests of Gaussianity on the distribution. We here perform very simple tests of Gaussianity on the distributions of the magnitudes of the interplanetary magnetic field, and on the distributions of the components; that is, we find the first four cumulants of the distributions (mean, variance, skewness, and kurtosis) and their solar cycle variations. We find, consistent with other recent analyses, that the traditional distributions of the 1-hour averaged magnitude are not distributed normally or lognomally as has often been assumed and the 1-hour averaged z component is found to have a nonzero kurtosis. Thus the power spectrum is insufficient to completely characterize these variations and polyspectra are needed. We have isolated variations in the 1/f frequency region of the spectrum and show that the distributions of the magnitudes have nonzero skewness and kurtosis, the magnitudes are not distributed lognormally, and the distributions of the components have nonzero kurtosis. Thus higher-order spectra are again needed for a full characterization.

Feynman, Joan; Ruzmaikin, Alexander

1994-01-01

18

Distributions of the interplanetary magnetic field revisited  

NASA Astrophysics Data System (ADS)

The adequacy of the power spectrum to characterize the variations of a parameter depends on whether or not the parameter has a Gaussian distribution. We here perform very simple tests of Gaussianity on the distribution. We here perform very simple tests of Gaussianity on the distributions of the magnitudes of the interplanetary magnetic field, and on the distributions of the components; that is, we find the first four cumulants of the distributions (mean, variance, skewness, and kurtosis) and their solar cycle variations. We find, consistent with other recent analyses, that the traditional distributions of the 1-hour averaged magnitude are not distributed normally or lognomally as has often been assumed and the 1-hour averaged z component is found to have a nonzero kurtosis. Thus the power spectrum is insufficient to completely characterize these variations and polyspectra are needed. We have isolated variations in the 1/f frequency region of the spectrum and show that the distributions of the magnitudes have nonzero skewness and kurtosis, the magnitudes are not distributed lognormally, and the distributions of the components have nonzero kurtosis. Thus higher-order spectra are again needed for a full characterization.

Feynman, Joan; Ruzmaikin, Alexander

1994-09-01

19

Spatial distribution of average vorticity in the high-latitude ionosphere and its variation with interplanetary magnetic field direction and season  

Microsoft Academic Search

We present a technique to measure the magnetic field-aligned vorticity of mesoscale plasma flows in the F region ionosphere using line-of-sight velocity measurements made by the Super Dual Auroral Radar Network (SuperDARN). Vorticity is often used as a proxy for magnetic field-aligned current (FAC) intensity in the ionosphere but also provides information about turbulent processes in the ionosphere and magnetosphere.

G. Chisham; M. P. Freeman; G. A. Abel; W. A. Bristow; A. Marchaudon; J. M. Ruohoniemi; G. J. Sofko

2009-01-01

20

Cusp latitude magnetic impulse events. 2. Interplanetary magnetic field and solar wind conditions  

Microsoft Academic Search

The interplanetary magnetic field (IMF) conditions and solar wind plasma parameters prevailing during the magnetic impulse events identified by Lanzerotti et al. at the near cusp latitude stations Iqaluit, Canada, and South Pole Station, Antarctica, are examined. The impulse events are found to occur during periods of high IMF variability. The prevailing IMF orientation, averaged over 11-min periods during the

R. M. Konik; L.J. Lanzerotti; A. Wolfe; C. G. Maclennan; D. Venkatesan

1994-01-01

21

Angular distribution of cosmic rays in the interplanetary magnetic field  

NASA Astrophysics Data System (ADS)

Cosmic ray propagation in the interplanetary medium is considered on the basis of kinetic equation describing the scattering of charged particles by magnetic irregularities and their focusing by regular interplanetary magnetic field. The relationship between cosmic ray distribution function and parameters of particle scattering in the interplanetary medium is investigated. Obtained results are applied to the analyses of solar proton events and galactic cosmic ray anisotropy. 1 COSMIC RAY DISTRIBUTION FUNCTION Angular distribution of energetic charged particles contains valuable information about particle scattering in the heliosphere and the geometry of interplanetary magnetic field (IMF) (Bieber and Pomerantz, 1983; Beeck and Wibberenz,1986; Wibberenz and Green, 1988; Hatzky and Wibberenz, 1997). In the present paper the relationship between the distribution function of cosmic rays (CR) and parameters of particle scattering is investigated. The kinetic equation describing CR propagation in the interplanetary medium, can be written as (Earl,1981; Toptygin,1985) ?f ?t + v ?f ?z + v 2? (1 - 2 ) ?f ? - ? ? D ?f ? = Q, (1) where f is CR distribution function, D is the diffusion coefficient in angular space, = cos ? and ? is the pitch angle, ? is the focusing length, and z is a coordinate directed along regular magnetic field. The particle source is included in the right hand side of Eq(1). One can present the distribution function as a superposition of isotropic f0 and anisotropic ?f() components f(z, , t) = 1 2 f0(z, t) + ?f(z, , t). (2) Assuming that the particle source Q is isotropic and subtracting from Eq.(1) averaged over equation, we obtain

Fedorov, Yu. I.

2001-08-01

22

Interplanetary planar magnetic structures associated with expanding active regions  

NASA Technical Reports Server (NTRS)

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.

Nakagawa, Tomoko; Uchida, Yutaka

1995-01-01

23

Coronal and interplanetary magnetic field models  

NASA Astrophysics Data System (ADS)

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.''

Schatten, Kenneth H.

1999-06-01

24

Regulation of the interplanetary magnetic flux  

SciTech Connect

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.

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

1991-01-01

25

Fractal structure of the interplanetary magnetic field  

NASA Technical Reports Server (NTRS)

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.

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

1986-01-01

26

The mean photospheric magnetic field from solar magnetograms Comparisons with the interplanetary magnetic field.  

NASA Technical Reports Server (NTRS)

Large-scale averages of daily solar magnetograms have been compared by cross-correlation with the interplanetary magnetic sector pattern during a 2.5 yr interval. A significant correlation was found at a lag of about 4.5 days, with the amplitude of the correlation depending on the area included in the magnetogram averages. The highest correlation was found when an area of one quarter of the solar disk was used, which is consistent with the idea that the photospheric features which are to be associated with the interplanetary sector pattern are large scale features.

Scherrer, P. H.; Wilcox, J. M.; Howard, R.

1972-01-01

27

On the geomagnetic effects of solar wind interplanetary magnetic structures  

Microsoft Academic Search

We present in this work a statistical study of the geoeffectiveness of the solar wind magnetic interplanetary structures over the entire observational period (19642003). The structures studied were magnetic clouds (MCs, 170 events), corotating interaction regions (CIRs, 727 events) and interplanetary shocks (830 events). The geoeffectiveness was assessed in terms of the geomagnetic index Kp, AE, and Dst peak values

E. Echer; W. D. Gonzalez; M. V. Alves

2006-01-01

28

Interplanetary magnetic sector polarity inferred from polar geomagnetic field observations  

NASA Technical Reports Server (NTRS)

In order to infer the interplanetary sector polarity from polar geomagnetic field diurnal variations, measurements were carried out at Godhavn and Thule (Denmark) Geomagnetic Observatories. The inferred interplanetary sector polarity was compared with the polarity observed at the same time by Explorer 33 and 35 magnetometers. It is shown that the polarity (toward or away from the sun) of the interplanetary magnetic field can be reliably inferred from observations of the polar cap geomagnetic fields.

Friis-Christensen, E.; Lassen, K.; Wilcox, J. M.; Gonzalez, W.; Colburn, D. S.

1971-01-01

29

Large-scale properties of the interplanetary magnetic field  

NASA Technical Reports Server (NTRS)

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.

Schatten, K. H.

1972-01-01

30

INFLUENCE OF INTERPLANETARY MAGNETIC FIELD AND PLASMA ON GEOMAGNETIC ACTIVITY DURING QUIET-SUN CONDITIONS  

Microsoft Academic Search

Observations by the IMP 1 satellite of the interplanetary magnetic field and plasma have been compared with the 3-hour geomagnetic activity index K. The average Kis approximately a linear function of the interplanetary field magnitude B in gammas (i -- (0.33 =k 0.02)B =k 0.2). It appears significant that this relation betweenand field magnitude passes through the origin, whereas the

John M. Wilcox; Kenneth H. Schatten; Norman F. Ness

1967-01-01

31

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

NASA Technical Reports Server (NTRS)

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.

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

1976-01-01

32

Cusp latitude impulse events. 2: Interplanetary magnetic field and solar wind conditions  

Microsoft Academic Search

The interplanetary magnetic field (IMF) conditions and solar wind plasma parameters prevailing during the magnetic impulse events identified by Lanzerotti et al. (1991) at the near cusp latitude stations Iqaluit, Northwest Territories, Canada, and South Pole Station, Antarctica, are examined. The impulse events are found to occur during periods of high IMF variability. The prevailing IMF orientation, averaged over 11-min

R. M. Konik; L. J. Lanzerotti; A. Wolfe; C. G. Maclennan; D. Venkatesan

1994-01-01

33

The interplanetary and solar magnetic field sector structures, 1962 - 1968  

NASA Technical Reports Server (NTRS)

The interplanetary magnetic field sector structure was observed from late 1962 through 1968. During this time it has been possible to study the manner in which the sector pattern and its relation to the photospheric magnetic field configuration changes from solar minimum to solar maximum. Observations were also made relating sector boundaries to specific regions on the solar disk. These and other observations related to the solar origin of the interplanetary field are briefly reviewed.

Jones, D. E.

1972-01-01

34

Effects of interplanetary magnetic field z component and the solar wind dynamic pressure on the geosynchronous magnetic field  

Microsoft Academic Search

A study of the correlation of the geosynchronous magnetic field with interplanetary magnetic field (IMF) Bz and the solar wind dynamic pressure (Pd) is presented. Hourly averages of 5 years of GOES 6 and 6 years of GOES 7 observations are correlated with IMF Bz and Pd. As previously reported, increases in Pd enhance geosynchronous Bz on the dayside, most

Simon Wing; David G. Sibeck

1997-01-01

35

High latitude electric fields and the modulations related to interplanetary magnetic field parameters  

NASA Technical Reports Server (NTRS)

The meaning and characteristics of basic and average convection (i.e., electric field) patterns are described. The continuous existence of the basic convection pattern argues against treating magnetic field merging mechanisms as the fundamental cause of magnetospheric convection. However, whether related to merging or to some other mechanism, interplanetary magnetic field conditions significantly modulate the distribution, magnitudes, and boundaries of the convection pattern. A previous correlation between azimuthal angles of the interplanetary magnetic field and asymmetries in polar cap electric field distributions as seen by OGO-6 is reviewed. A new approach is taken to reveal correlations with the north-south angle and magnitude of the interplanetary field as well as additional features which correlate with the azimuthal angle. Both significant correlations and conditions which show a lack of correlation are found. Several aspects of the correlations appear to be particularly important.

Heppner, J. P.

1973-01-01

36

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

NASA Technical Reports Server (NTRS)

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.

Svalgaard, L.; Wilcox, J. M.

1974-01-01

37

Solar sources of the interplanetary magnetic field and solar wind  

NASA Technical Reports Server (NTRS)

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.

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

1977-01-01

38

Interplanetary magnetic field effects on high latitude ionospheric convection  

NASA Technical Reports Server (NTRS)

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.

Heelis, R. A.

1985-01-01

39

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

NASA Technical Reports Server (NTRS)

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.

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

1993-01-01

40

The interplanetary magnetic field during solar cycle 21: ISEE-3\\/ICE observations  

Microsoft Academic Search

Magnetic field observations from the JPL vector helium magnetometer on the ISEE-3\\/ICE spacecraft are used to investigate long term temporal variations in the interplanetary magnetic field during solar cycle 21. As reported by previous studies, IMF intensity exhibited a broad decrease during the last sunspot minimum with average values of only 4.7 nT being measured in mid-1976. It is shown

J. A. Slavin; G. Jungman; E. J. Smith

1986-01-01

41

Radial and latitudinal variations of the interplanetary magnetic field  

Microsoft Academic Search

This paper presents observations of the radial and latitudinal variations of the interplanetary magnetic field measured by the Voyager 1 (V1) and Voyager 2 (V2) spacecraft from mid-1977 to mid-1985. Observations of the radial variation of the large-scale magnetic field strength in the ecliptic agree with the predictions of Parker's (1958, 1963) model when temporal variations in the magnetic field

Larry W. Klein; L. F. Burlaga; N. F. Ness

1987-01-01

42

Comparison of the mean photospheric magnetic field and the interplanetary magnetic field  

Microsoft Academic Search

The mean photospheric magnetic field of the sun seen as a star has been compared with the interplanetary magnetic field observed with spacecraft near the earth. Each change in polarity of the mean solar field is followed about 4 1\\/2 days later by a change in polarity of the interplanetary field (sector boundary). The scaling of the field magnitude from

A. Severny; J. M. Wilcox; P. H. Scherrer; D. S. Colburn

1970-01-01

43

Substorms associated with azimuthal turnings of the interplanetary magnetic field  

Microsoft Academic Search

Whether the magnetospheric substorms can be triggered by the interplanetary magnetic field (IMF) variations is an important issue in the substorm research. In this work we investigate observationally the relationship between substorm activities and IMF By variations, i.e., azimuthal turnings. We have searched for the IMF's azimuthal turning events for a period of one year using the data from multispacecraft

S. H Bae; D.-Y Lee; E Lee; K. W Min; K. H Choi

2001-01-01

44

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

SciTech Connect

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.

Tian Hui; Yao Shuo; Zong Qiugang; Qi Yu [School of Earth and Space Sciences, Peking University, 100871 Beijing (China); He Jiansen, E-mail: tianhui924@pku.edu.c [Max-Planck-Institut fuer Sonnensystemforschung, 37191 Katlenburg-Lindau (Germany)

2010-09-01

45

The extension of solar magnetic fields into interplanetary space  

SciTech Connect

The flow of coronal plasma into interplanetary space results in outward transport of the solar magnetic field. The prevailing open'' interplanetary magnetic field is rooted in the corona and wraps up into a spiral due to the rotation of the Sun. This simple configuration, however, is disrupted by magnetically distinct coronal mass ejections (CMEs) which erupt from the solar corona into interplanetary space. Observations of CMEs at 1 AU reveal electron signatures indicating a closed magnetic topology, postulated to be: (1) magnetic bottles,'' tied to the corona at both ends; (2) plasmoids that are completely disconnected from the Sun; or (3) flux ropes which have topologies intermediate between (1) and (2). With either the magnetic-bottle or flux rope hypothesis, the inward and outward flux at 1 AU should increase indefinitely as CMEs continue to erupt. Using a new techniques to calculate the 2-D flux through 1 AU from single spacecraft measurements, we show that while there is a solar cycle variation to the magnetic flux, it clearly does not grow without bound. This suggests that either CMEs are closed plasmoids which add to no new flux to the interplanetary medium, or that the opening of new flux by CMEs is balanced via reconnection elsewhere in the corona. We suggest that the this latter process may be dominant and describe observation from the Solar Maximum Mission coronagraph which are consistent with reconnection above helmet streamers in the corona. Such disconnections would serve to return closed field arches to the Sun and release open. U-shaped structures into the solar wind. Coronal disconnections appear in some cases to be triggered by pressure pulses caused by CME eruption elsewhere, suggesting a dynamic flux-balance process. We describe a class of solar wind structures, called heat flux dropouts, in which the solar wind electron heat flux, driven by magnetic connection to the hot corona, is absent or greatly reduced.

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

1991-01-01

46

Interplanetary magnetic clouds at 1 AU  

Microsoft Academic Search

Magnetic clouds are defined as regions;with a radial dimension roughly-equal0.25 AU (at 1 AU) in which the magnetic field strength is high and the magnetic field direction changes appreciably by means of rotation of one component of B> nearly parallel to a plane. The magnetic field geometry in such a magnetic cloud is consistent with that of a magnetic loop,

L. W. Klein; L. F. Burlaga

1982-01-01

47

On the limitations of geomagnetic measures of interplanetary magnetic polarity  

NASA Technical Reports Server (NTRS)

The maximum attainable accuracy in inferring the interplanetary magnetic polarity from polar cap magnetograms is about 88%. This is achieved in practice, when high-latitude polar cap stations are used during local summer months, and the signature in the ground records is strong. An attempt by Svalgaard (1972) to use this effect to infer an index of interplanetary magnetic polarity back to 1926 has not been so successful. Furthermore, some of the properties of the index have changed with time. Prior to 1963, the inferred polarities are strongly dependent on geomagnetic activity, while after this time they are not. Thus, this index should not be used to separate solar-magnetic from solar-activity effects prior to 1963.

Russell, C. T.; Rosenberg, R. L.

1974-01-01

48

Studies of the interplanetary magnetic field: IMP's to Voyager  

NASA Technical Reports Server (NTRS)

During the last two decades, spacecraft projects and individual experiments for which Frank McDonald was a leader have contributed very significantly to the current understanding of the structure of interplanetary space and the correlation between solar and interplanetary disturbances. Studies on the IMP, HELIOS, and Pioneer spin-stabilized spacecraft and the larger attitude-stabilized Voyager spacecraft have provided data sets from which the modern view of the heliosphere has evolved. That concept in which the inner solar system is shown to be dominated by individual streams associated with specific source regions on the Sun is illustrated. As these high-speed streams overtake the preexisting solar plasma, they coalesce and modify the characteristics so that at larger heliocentric distances, these disturbances appear as radially propagating concentric shells of compressed magnetic fields and enhanced fluctuations

Ness, Norman F.

1987-01-01

49

Remnant Kronian and Interplanetary magnetic fields at Titan: Cassini observations  

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

50

Magnetic reconnection in the interior of interplanetary coronal mass ejections.  

PubMed

Recent insitu 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=?B with ? 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 etal. 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. PMID:25083630

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

2014-07-18

51

Interplanetary Magnetic Field Power Spectrum Variations: A VHO Enabled Study  

NASA Technical Reports Server (NTRS)

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

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

2010-01-01

52

Interplanetary Magnetic Field Power Spectrum Variations: A VHO Enabled Study  

NASA Technical Reports Server (NTRS)

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

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

2011-01-01

53

Strong geomagnetic activity forecast by neural networks under dominant southern orientation of the interplanetary magnetic field  

NASA Astrophysics Data System (ADS)

The paper deals with the relation of the southern orientation of the north-south component Bz of the interplanetary magnetic field to geomagnetic activity (GA) and subsequently a method is suggested of using the found facts to forecast potentially dangerous high GA. We have found that on a day with very high GA hourly averages of Bz with a negative sign occur at least 16 times in typical cases. Since it is very difficult to estimate the orientation of Bz in the immediate vicinity of the Earth one day or even a few days in advance, we have suggested using a neural-network model, which assumes the worse of the possibilities to forecast the danger of high GA - the dominant southern orientation of the interplanetary magnetic field. The input quantities of the proposed model were information about X-ray flares, type II and IV radio bursts as well as information about coronal mass ejections (CME). In comparing the GA forecasts with observations, we obtain values of the Hanssen-Kuiper skill score ranging from 0.463 to 0.727, which are usual values for similar forecasts of space weather. The proposed model provides forecasts of potentially dangerous high geomagnetic activity should the interplanetary CME (ICME), the originator of geomagnetic storms, hit the Earth under the most unfavorable configuration of cosmic magnetic fields. We cannot know in advance whether the unfavorable configuration is going to occur or not; we just know that it will occur with the probability of 31%.

Valach, Fridrich; Bochn?ek, Josef; Hejda, Pavel; Revallo, Milo

2014-02-01

54

Ground state alignment as a tracer of interplanetary magnetic field  

NASA Astrophysics Data System (ADS)

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.

Yan, H.

2012-12-01

55

Interplanetary magnetic field variations and the electromagnetic state of the equatorial ionosphere  

NASA Technical Reports Server (NTRS)

The Esq phenomena were selected in order to examine the effect of the interplanetary magnetic field (IMF) on the ionospheric plasma and to obtain insight into the interplanetary ionospheric coupling processes. January-March 1973 interplanetary magnetic field data of Explorer 43, Huancayo ionograms, and surface equatorial magnetograms were used. The IMF observations from Explorer 43 in the form of 15-sec averages were examined around the time of disappearance of the Esq. The IMF z-component was observed to change from a negative to a positive value before the disappearance of the Esq in four events where simultaneous data were available. The general explanation is that the induced electric field becomes westward from a previous eastward direction, coinciding with the IMF z-component reversal. Thus, just before the Esq disappears, the magnetosphere is subjected to the westward electric field. If this field is impressed to the low-latitude ionosphere, the resultant electric field in the equatorial ionosphere changes from eastward (westward) to westward (eastward) in the daytime (nighttime).

Patel, V. L.

1978-01-01

56

Critical component of the interplanetary magnetic field responsible for large geomagnetic effects in the polar cap  

NASA Technical Reports Server (NTRS)

An observed influence is studied of the interplanetary magnetic sector structure on the geomagnetic variations in the polar cap which appears to be due to the component of the interplanetary magnetic field near the ecliptic perpendicular to the earth-sun direction. It is suggested that the observed effect on the ground originates in the front of the magnetosphere.

Friis-Christensen, E.; Lassen, K.; Wilhjelm, J.; Wilcox, J. M.; Gonzalez, W.; Colburn, D. S.

1972-01-01

57

Critical component of the interplanetary magnetic field responsible for large geomagnetic effects in the polar cap.  

NASA Technical Reports Server (NTRS)

An observed influence of the interplanetary magnetic-sector structure on the geomagnetic variations in the polar cap appears to be due to the component of the interplanetary magnetic field near the ecliptic perpendicular to the earth-sun direction. This suggests that the observed effect on the ground originates in the front of the magnetosphere.

Friis-Christensen, E.; Lassen, K.; Wilhjelm, J.; Wilcox, J. M.; Gonzalez, W.; Colburn, D. S.

1972-01-01

58

Numerical Simulation on a Possible Formation Mechanism of Interplanetary Magnetic Cloud Boundaries  

Microsoft Academic Search

The formation mechanism of the interplanetary magnetic cloud (MC) boundaries is numerically investigated by simulating the interactions between an MC of some initial momentum and a local interplanetary current sheet. The compressible 2.5D MHD equations are solved. Results show that the magnetic reconnection process is a possible formation mechanism when an MC interacts with a surrounding current sheet. A number

FAN Quan-Lin; WEI Feng-Si; FENG Xue-Shang

59

Study of interplanetary magnetic field with atomic realignment  

NASA Astrophysics Data System (ADS)

We demonstrate a new way of studying interplanetary magnetic field - atomic alignment. Instead of sending thousands of space probes, atomic alignment allows magnetic mapping with any ground telescope facilities equipped with spectrometer and polarimeter. The polarization of spectral lines that are pumped by the anisotropic radiation from the sun is influenced by the magnetic alignment, which happens for weak magnetic field (<1G). As a result, the linear polarization becomes an excellent tracer of the embedded magnetic field. The method is illustrated by our synthetic observations of Iofootnote{The third largest moon of Jupiter.} and comet Halley. A uniform density distribution of Na was considered and polarization at each point was then constructed. Both spatial and temporal variations of turbulent magnetic field can be traced with this technique as well. For remote regions like the boundary of interstellar medium, atomic alignment provides a unique diagnostics of magnetic field, which is crucial for understanding the physical processes such as the IBEX ribbons discovered recently.

Yan, H.; Shangguan, J.

2011-12-01

60

Comparison of the Mean Photospheric Magnetic Field and the Interplanetary Magnetic Field.  

National Technical Information Service (NTIS)

The mean photospheric magnetic field of the sun seen as a star has been compared with the interplanetary magnetic field observed with spacecraft near the earth. Each change in polarity of the mean solar field is followed about 4 1/2 days later by a change...

A. Severny J. M. Wilcox P. H. Scherrer D. S. Colburn

1970-01-01

61

Interplanetary magnetic field control of high-latitude electric fields and currents determined from Greenland magnetometer data  

Microsoft Academic Search

To determine the effects of the interplanetary magnetic field (IMF) on the electric potential as well as on ionospheric and field-aligned currents, a recently available numerical algorithm is applied to an empirical model of high-latitude magnetic perturbations, parameterized in terms of the B\\/sub y\\/ and B\\/sub z\\/ components of the IMF. The empirical model is derived from 20-min average magnetometer

E. Friis-Christensen; Y. Kamide; A. D. Richmond; S. Matsushita

1985-01-01

62

Interplanetary coronal mass ejection and ambient interplanetary magnetic field correlations during the Sun-Earth connection events of OctoberNovember 2003  

Microsoft Academic Search

Magnetic field observations made during 28 October to 1 November 2003, which included two fast interplanetary coronal mass ejections (ICMEs), allow a study of correlation lengths of magnetic field parameters for two types of interplanetary (IP) structures: ICMEs and ambient solar wind. Further, they permit the extension of such investigations to the magnetosheath and to a distance along the Sun-Earth

C. J. Farrugia; H. Matsui; H. Kucharek; R. B. Torbert; C. W. Smith; V. K. Jordanova; K. W. Ogilvie; R. P. Lepping; D. B. Berdichevsky; T. Terasawa; J. Kasper; T. Mukai; Y. Saito; R. Skoug

2005-01-01

63

Magnetic shielding of interplanetary spacecraft against solar flare radiation  

NASA Astrophysics Data System (ADS)

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.

Cocks, Franklin H.; Watkins, Seth

1993-07-01

64

Local variations of interplanetary magnetic field at Earth's bow shock  

NASA Astrophysics Data System (ADS)

We present interplanetary magnetic field (IMF) observations from Geotail and Wind in which the IMF was not uniform over spatial scales relevant to the magnetosphere. Geotail, at the dawn flank of the Earth's bow shock, measured magnetic field directions 60 to 120 different from the magnetic field measured by Wind on the duskside ~30 RE upstream, during a 2-hour interval. If there is a global connection between these observations, one possible explanation is a kink in the magnetic field near the Sun-Earth line. The different orientations of IMF at Wind and Geotail (and thus the kink) change during the 2-hour interval. Multiple shock crossings may have resulted from the changing orientations driving small surface waves on the shock surface. During this interval the bow shock does not fit a standard dawnside-quasi-parallel-duskside-quasi-perpendicular picture. Instead, both sides of the bow shock may have been locally quasi-perpendicular. The question of where a quasi-parallel bow shock and/or foreshock could form needs to be explored. Both before and after the 2-hour time interval, the IMF was close to uniform as measured by Wind, Geotail, and IMP8.

Kessel, R. L.; Quintana, E.; Peredo, M.

1999-11-01

65

Magnetic reconnection structures in the boundary layer of an interplanetary magnetic cloud  

Microsoft Academic Search

An interplanetary magnetic diffusion region was detected by WIND during 0735-0850 UT on May 15, 1997 when the front boundary\\u000a layer of a magnetic cloud passed through the spacecraft about 190 earth radii upstream of the earth. The main signals of magnetic\\u000a reconnection processes are: (i) Flow reversal was detected at about 0810 UT. The counter-streaming flows have the speeds

Fengsi Wei; Rui Liu; Xueshang Feng; Dingkun Zhong; Fang Yang

2004-01-01

66

Observations of an interplanetary slow shock associated with magnetic cloud boundary layer  

Microsoft Academic Search

(1) The observations of the slow shocks associated with the interplanetary coronal mass ejections near 1 AU have seldom been reported in the past several decades. In this paper we report the identification of an interplanetary slow shock observed by Wind on September 18, 1997. This slow shock is found to be just the front boundary of a magnetic cloud

P. B. Zuo; F. S. Wei; X. S. Feng

2006-01-01

67

High latitude electric fields an the modulations related to interplanetary magnetic field parameters  

NASA Technical Reports Server (NTRS)

The meaning and characteristics of basic and average convection (i.e., electric field) patterns are described. The continuous existence of the basic convection pattern argues against treating magnetic field merging mechanisms as the fundamental cause of magnetospheric convection. However, whether related to merging or some other mechanism, interplanetary (IP) magnetic field conditions significantly modulate the distribution, magnitudes, and boundaries of the convection pattern. A previous correlation between azimuthal angles of the IP magnetic field and asymmetries in polar cap electric field distributions as seen by OGO-6 was reviewed. A new approach was taken to reveal correlations with the north-south angle and magnitude of the IP field as well as additional features which correlate with the azimuthal angle. Both significant correlations and conditions which show a lack of correlation were found. Several aspects of the correlations appear to be particularly important.

Heppner, J. P.

1973-01-01

68

The Interplanetary Magnetic Field and Magnetospheric Current Systems  

NASA Technical Reports Server (NTRS)

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.

El-Alaoui, Mostafa

2003-01-01

69

A Statistical Study of Interplanetary Shocks and Pressure Pulses Internal to Magnetic Clouds  

NASA Astrophysics Data System (ADS)

We have canvassed the Wind magnetometer data from launch in November of 1994 through May of 2002 searching for cases of interplanetary shocks and pressure pulses internal to magnetic clouds. An internal shock or pressure pulse is defined as an unbalanced (in a pressure sense), sharp (quicker than 12 minutes), large (? B/B>0.23) change in the magnitude of the magnetic field within the boundaries of a magnetic cloud. We have found nine cases in 68 clouds, so that these shocks and pressure pulses occurred in about 13% of the Wind magnetic clouds. Of those nine cases, six occurred during the 1995-1998 period when the average sunspot number was less than 90 while only three occurred during the 1999-2002 period when the average sunspot number was greater than 90, although roughly equal numbers of magnetic clouds were observed over the two periods (38 versus 30). These ``internal" shocks tend to occur in the latter half of the clouds, i.e., time-wise, about two-thirds of the way through. In every case, the field change is highly compressive at the shock showing little or no change in angle during or after the magnitude jump. In three of the nine cases, potential external sources for these internal shocks and pressure pulses have been identified, but in at least one of these three cases, which identified a flare, no evidence for associated ejecta or shocks could be found [Collier et al., JGR, 106, 15,985, 2001].

Lepping, R. P.; Collier, M. R.; Berdichevsky, D. B.

2003-12-01

70

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

NASA Technical Reports Server (NTRS)

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.

Langel, R. A.

1973-01-01

71

The correlation length for interplanetary magnetic field fluctuations  

NASA Technical Reports Server (NTRS)

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).

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

1972-01-01

72

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

NASA Technical Reports Server (NTRS)

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.

Gonzalez, Walter D.; Tsurutani, Bruce T.

1987-01-01

73

Interplanetary magnetic field as a detector of turbulence in the inner heliosphere  

NASA Astrophysics Data System (ADS)

Analysis of the interplanetary magnetic field (IMF) behavior at different scales may give a key for understanding of turbulence spatial evolution in the heliosphere. It has been known that the solar wind plasma becomes more and more turbulent with heliocentric distance. Recent multi-spacecraft investigations of the large-scale IMF [1] show unexpectedly fast lost of the regular sector structure of the solar wind in the inner heliosphere. In the ecliptic plane, it seems to be broken at 3-4 AU, much closer to the Sun than the Parker spiral gets perpendicular to the sunward direction. At the same time, the high-latitude solar wind remains more structured at the same heliocentric distances [2]. This fact may bear evidence of radial increase of turbulence and intermittency in the solar wind due to magnetic reconnection. The magnetic reconnection recurrently occurs at the large-scale heliospheric current sheet (HCS) as well as at smaller-scale current sheets during the solar wind expansion [3]. As a result, a significant part of the heliosphere is filled with secondary current sheets as well as with waves and accelerated particles in some vicinity of the HCS. Under averaging, it looks as a radial increase of turbulence, especially in low latitudes. It also can be considered as one of the main causes of the break of the expected IMF radial dependence law [1, 2]. Results of the consequent multi-spacecraft analysis of plasma and magnetic filed turbulence characteristics at different heliocentric distances and heliolatitudes will be discussed. 1. O. Khabarova, V. Obridko, Puzzles of the Interplanetary Magnetic 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 2. O.V. Khabarova, The interplanetary magnetic field: radial and latitudinal dependences, Astronomy Reports, 2013, 57, 11, http://arxiv.org/ftp/arxiv/papers/1305/1305.1204.pdf 3. V. Zharkova, O. Khabarova, Particle Acceleration in the Reconnecting Heliospheric Current Sheet: Solar Wind Data Versus 3D PIC Simulations, Astrophysical Journal, 2012, V.752, 1, 35, doi:10.1088/0004-637X/752/1/35

Khabarova, O.

2013-12-01

74

PUZZLES OF THE INTERPLANETARY MAGNETIC FIELD IN THE INNER HELIOSPHERE  

SciTech Connect

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.

Khabarova, Olga; Obridko, Vladimir, E-mail: habarova@izmiran.ru [Heliophysical Laboratory, Institute of Terrestrial Magnetism, Ionosphere and Radiowave Propagation RAS (IZMIRAN), Troitsk, Moscow Region 142190 (Russian Federation)

2012-12-20

75

Puzzles of the Interplanetary Magnetic Field in the Inner Heliosphere  

NASA Astrophysics Data System (ADS)

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 as a whole, but there is some turbulent component that impacts the full picture of the IMF spatial and temporal distribution and damages it. 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 (|Br|~r^-5/3), the tangential component |Bt|~r^-1.1 and, the IMF strength B~r^-1.4. This means that the IMF is not completely frozen in the solar wind. Possibly, turbulent processes in the inner heliosphere significantly influence the IMF expansion. This is confirmed by the analysis of the Br distribution's radial evolution. Br has a well-known bimodal histogram's view only at 0.7-2.0 AU. The bimodality effect gradually disappears from 1 to 4 AU, and Br 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, as a key process responsible for the solar wind turbulization with heliocentric distance as well as for the break of the "frozen-in IMF" law.

Khabarova, O.; Obridko, V.

2012-12-01

76

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

NASA Astrophysics Data System (ADS)

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> <div class="credits"> <p class="dwt_author">Yang, Y. F.; Lu, J. Y.; Wang, J.-S.; Peng, Z.; Zhou, L.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">77</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.agu.org/journals/ja/v084/iA10/JA084iA10p05797/JA084iA10p05797.pdf"> <span id="translatedtitle">Equatorial electric fields during <span class="hlt">magnetically</span> disturned conditions 1. The effect of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Radar measurements of E and F region drift velocities have been used to look for correlations between changes in equatorial electric fields and the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF). The east-west component of the IMF appears to be unimportant, but the north-south component has some effect; rapid reversals from south to north are sometimes correlated with reversals of the equatorial east-west</p> <div class="credits"> <p class="dwt_author">B.G. Fejer; C.A. Gonzales; D.T. Farley; M.C. Kelley; R.F. Woodman</p> <p class="dwt_publisher"></p> <p class="publishDate">1979-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">78</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.agu.org/journals/ja/v086/iA08/JA086iA08p06673/JA086iA08p06673.pdf"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The flow behind an <span class="hlt">interplanetary</span> shock was analyzed through the use of <span class="hlt">magnetic</span> field and plasma data from five spacecraft, with emphasis on the <span class="hlt">magnetic</span> cloud identified by a characteristic variation of the latitude angle of the <span class="hlt">magnetic</span> field. The size of the cloud was found to be about 0.5 AU in radial extent and greater than 30 deg in</p> <div class="credits"> <p class="dwt_author">L. Burlaga; E. Sittler; F. Mariani; R. Schwenn</p> <p class="dwt_publisher"></p> <p class="publishDate">1981-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">79</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19770027122&hterms=CTL+1322&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DCTL%2BR%2B1322"> <span id="translatedtitle"><span class="hlt">Interplanetary</span> medium data book, appendix</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">King, J. H.</p> <p class="dwt_publisher"></p> <p class="publishDate">1977-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">80</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2005JGRA..11012301J"> <span id="translatedtitle">Characteristics of ion velocity structure at high latitudes during steady southward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field conditions</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Variability or structure in the ion velocity at high latitudes in the F region is an important consideration when calculating an accurate Joule heating rate. Velocity structure in time and space may contribute significantly to heating of the F region and its inclusion could help improve our understanding of the energy budget of the atmosphere. In this paper we neglect temporal changes over periods less than 16 s and discuss the characteristic spatial structure in the ion drift in the F region ionosphere and how it relates to the bulk ion flow, the gradient on the bulk ion flow, and the ion temperature in the polar cap and auroral zone. This investigation uses data from the Dynamics Explorer 2 satellite and is limited to times of stable southward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field. Under these conditions time <span class="hlt">averaged</span> enhancements in the Joule heating rate from the presence of spatial structure in the auroral zones have minimum values ranging from 4% to 13% depending on season.</p> <div class="credits"> <p class="dwt_author">Johnson, E. S.; Heelis, R. A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-12-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_3");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a style="font-weight: bold;">4</a> <a 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src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_4");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' href="#">4</a> <a style="font-weight: bold;">5</a> <a onClick='return showDiv("page_6");' href="#">6</a> <a onClick='return showDiv("page_7");' href="#">7</a> <a onClick='return showDiv("page_8");' href="#">8</a> <a onClick='return showDiv("page_9");' href="#">9</a> <a onClick='return showDiv("page_10");' href="#">10</a> <a onClick='return showDiv("page_11");' href="#">11</a> <a onClick='return showDiv("page_12");' href="#">12</a> <a onClick='return showDiv("page_13");' href="#">13</a> <a onClick='return showDiv("page_14");' href="#">14</a> <a onClick='return showDiv("page_15");' href="#">15</a> <a onClick='return showDiv("page_16");' href="#">16</a> <a onClick='return showDiv("page_17");' href="#">17</a> <a onClick='return showDiv("page_18");' href="#">18</a> <a onClick='return showDiv("page_19");' href="#">19</a> <a onClick='return showDiv("page_20");' href="#">20</a> <a onClick='return showDiv("page_21");' href="#">21</a> <a onClick='return showDiv("page_22");' href="#">22</a> <a onClick='return showDiv("page_23");' href="#">23</a> <a onClick='return showDiv("page_24");' href="#">24</a> <a onClick='return showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_6");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">81</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/41984543"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">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</p> <div class="credits"> <p class="dwt_author">C. J. Farrugia; L. F. Burlaga; R. P. Lepping; V. A. Osherovich; I. G. Richardson; M. P. Freeman; A. J. Lazarus</p> <p class="dwt_publisher"></p> <p class="publishDate">1993-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">82</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/7171210"> <span id="translatedtitle">Small scale <span class="hlt">magnetic</span> flux-<span class="hlt">averaged</span> magnetohydrodynamics</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">By relaxing exact <span class="hlt">magnetic</span> flux conservation below a scale [lambda] a system of flux-<span class="hlt">averaged</span> magnetohydrodynamic equations are derived from Hamilton's principle with modified constraints. An energy principle can be derived from the linearized <span class="hlt">averaged</span> system because the total system energy is conserved. This energy principle is employed to treat the resistive tearing instability and the exact growth rate is recovered when [lambda] is identified with the resistive skin depth. A necessary and sufficient stability criteria of the tearing instability with line tying at the ends for solar coronal loops is also obtained. The method is extended to both spatial and temporal <span class="hlt">averaging</span> in Hamilton's principle. The resulting system of equations not only allows flux reconnection but introduces irreversibility for appropriate choice of the <span class="hlt">averaging</span> function. Except for boundary contributions which are modified by the time <span class="hlt">averaging</span> process total energy and momentum are conserved over times much longer than the <span class="hlt">averaging</span> time [tau] but not for less than [tau]. These modified boundary contributions correspond to the existence, also, of damped waves and shock waves in this theory. Time and space <span class="hlt">averaging</span> is applied to electron magnetohydrodynamics and in one-dimensional geometry predicts solitons and shocks in different limits.</p> <div class="credits"> <p class="dwt_author">Pfirsch, D. (Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, D-8046 Garching (Germany)); Sudan, R.N. (Laboratory of Plasma Studies, Cornell University, Ithaca, New York 14853 (United States))</p> <p class="dwt_publisher"></p> <p class="publishDate">1994-08-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">83</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19930071539&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3D1.3"> <span id="translatedtitle">The spectrum of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field near 1.3 AU</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">A time series of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field measured near 1.3 AU by Phobos 2 is analyzed as a fractal. The fractal dimension of the curves corresponding to the components and to the strength of the <span class="hlt">magnetic</span> field are found to be close to 5/3. The corresponding spatial spectra are interpreted in the framework of MHD turbulence.</p> <div class="credits"> <p class="dwt_author">Ruzmaikin, Alexander; Lyannaya, I. P.; Styashkin, Valerij A.; Eroshenko, E.</p> <p class="dwt_publisher"></p> <p class="publishDate">1993-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">84</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/39824554"> <span id="translatedtitle"><span class="hlt">Interplanetary</span> sector structure, 19621966</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Some properties of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field observed by IMP-3 in the latter half of 1965 are discussed with relation to previous satellite observations of the <span class="hlt">interplanetary</span> field. The sector property remains a prominent feature of the observations, with the <span class="hlt">average</span> field direction at the Archimedes spiral angle. The sector pattern has a 27-day recurrence period from 1962 to 1964,</p> <div class="credits"> <p class="dwt_author">Norman F. Ness; John M. Wilcox</p> <p class="dwt_publisher"></p> <p class="publishDate">1967-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">85</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013JGRA..118.1899W"> <span id="translatedtitle">Estimating the open <span class="hlt">magnetic</span> flux from the <span class="hlt">interplanetary</span> and ionospheric conditions</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The open <span class="hlt">magnetic</span> flux (FPC) is a key parameter to study magnetospheric dynamical process, which is closely related to <span class="hlt">magnetic</span> reconnections in the dayside magnetopause and magnetotail. Using global MHD simulations, we find that the open <span class="hlt">magnetic</span> flux FPC can be estimated through a combined parameter f by FPC=0.89f/(f+0.20)+0.52, where the parameter f=vSWBSnSW1/5<mrow></mrow>?P1/3 is a function of the solar wind velocity (vSW), the solar wind number density (nSW), the southern <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) strength (BS), and the ionospheric Pederson conductance (?P). The comparison with the limited observational FPCdata available in the literature shows its promise in estimating the open <span class="hlt">magnetic</span> flux from the <span class="hlt">interplanetary</span> and ionospheric conditions. The open <span class="hlt">magnetic</span> flux (FPC) may be served as a key space weather forecast element in the future.</p> <div class="credits"> <p class="dwt_author">Wang, C.; Xia, Z. Y.; Peng, Z.; Lu, Q. M.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-05-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">86</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012AGUFM.P31C1909L"> <span id="translatedtitle">An <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field enhancement observed by five spacecraft: Deducing the <span class="hlt">magnetic</span> structure, size and mass</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary"><span class="hlt">Interplanetary</span> Field Enhancements (IFEs) were discovered almost 30 years ago in the PVO <span class="hlt">magnetic</span>-field records and attributed to the interaction between solar wind and dust particles from comets or asteroids, but the physics of this interaction remained obscure. Our current understanding is that IFEs result from collisions of small <span class="hlt">interplanetary</span> bodies that produce electrically charged nanometer-scale dust particles possibly enhanced by tribo-electric charging in the collision. These charged dust particles in turn interact with the <span class="hlt">magnetized</span> solar wind. Momentum is transferred from the solar wind to the dust cloud via the collective effect of the formation of a <span class="hlt">magnetic</span> barrier. This momentum transfer accelerates the particles to near the solar wind speed and moves the dust outward through the solar gravitational potential well. Multi-spacecraft observations can help us to determine the speed of the IFE and the orientation of the current sheet. They enable us to reconstruct the pressure profile of an IFE in three dimensions and estimate the mass contained in the IFE. We have done these reconstructions with an IFE observed on March 3, 2011 with Wind, ACE, ARTEMIS P1 and P2 and Geotail. We find that the <span class="hlt">magnetic</span> field near the center of the IFE is highly twisted indicating a complicated <span class="hlt">magnetic</span> topology as expected in a plasma-charged dust interaction. The <span class="hlt">magnetic</span> field and plasma properties during this event distinguish it from a typical flux rope. Based on the statistical results obtained at 1 AU and the assumption that all the IFEs are self-similar, we find that this IFE has a radial scale length several times longer than the cross flow radius and contains a mass of about 108 kg. The rates of collisions expected for objects of this size are consistent with the observed rates of these disturbances.</p> <div class="credits"> <p class="dwt_author">Lai, H.; Russell, C. T.; Delzanno, G.; Angelopoulos, V.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">87</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19770027121&hterms=manual+muscle+testing+validity&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dmanual%2Bmuscle%2Btesting%2Bvalidity"> <span id="translatedtitle"><span class="hlt">Interplanetary</span> medium data book</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">King, J. H.</p> <p class="dwt_publisher"></p> <p class="publishDate">1977-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">88</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Karelitz, A. M.; Lario, D.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">89</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/48923024"> <span id="translatedtitle">Formation of the theta aurora by a transient convection during northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Formation of the theta aurora, which appears under the conditions of northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) and greater IMF magnitude, is investigated from the analysis of solutions obtained from a magnetohydrodynamic (MHD) simulation. The theta aurora formation is caused by a transient convection after a sign change of IMF By. This transient convection must include a replacement of lobe field</p> <div class="credits"> <p class="dwt_author">T. Tanaka; T. Obara; M. Kunitake</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">90</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.agu.org/journals/ja/v082/i029/JA082i029p04837/JA082i029p04837.pdf"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">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 B\\/sub z\\/(GSM) component had been northward for more than 2 hours. It was found that when the IMF thus shifted southward and remained southward for at</p> <div class="credits"> <p class="dwt_author">Michael N. Caan; Robert L. McPherron; Christopher T. Russell</p> <p class="dwt_publisher"></p> <p class="publishDate">1977-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">91</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/56497934"> <span id="translatedtitle">Cusp region particle precipitation and ion convection for northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Data from Atmosphere Explorer D for periods of strong northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field show the following characteristic behavior in the dayside magnetospheric cusp region: energy-time spectrograms of suprathermal positive ion fluxes exhibit a characteristic 'V' pattern as the spacecraft moves toward higher latitudes; that is, with the peak in the energy spectrum falling in energy and then rising again. Convection</p> <div class="credits"> <p class="dwt_author">J. L. Burch; P. H. Reiff; R. W. Spiro; R. A. Heelis; S. A. Fields</p> <p class="dwt_publisher"></p> <p class="publishDate">1980-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">92</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/42030395"> <span id="translatedtitle">Cusp region particle precipitation and ion convection for northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Data from Atmosphere Explorer D for periods of strong northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field show the following characteristic behavior in the dayside magnetospheric cusp region: Energy-time spectrograms of suprathermal positive ion fluxes exhibit a characteristic 'V' pattern as the spacecraft moves toward higher latitudes; that is, with the peak in the energy spectrum falling in energy and then rising again. Convection</p> <div class="credits"> <p class="dwt_author">J. L. Burch; P. H. Reiff; R. W. Spiro; R.A. Heelis; S. A. Fields</p> <p class="dwt_publisher"></p> <p class="publishDate">1980-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">93</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ntis.gov/search/product.aspx?ABBR=AD755684"> <span id="translatedtitle">Inferring the <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field by Observing the Polar Geomagnetic Field.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ntis.gov/search/index.aspx">National Technical Information Service (NTIS)</a></p> <p class="result-summary">L. Svalgaard and S. M. Mansurov have shown that it is possible to infer the polarity of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field quite reliably from observations of the diurnal variation of polar geomagnetic fields. The effect is most prominent in the vertical c...</p> <div class="credits"> <p class="dwt_author">J. M. Wilcox</p> <p class="dwt_publisher"></p> <p class="publishDate">1972-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">94</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.agu.org/journals/jz/v069/i009/JZ069i009p01769/JZ069i009p01769.pdf"> <span id="translatedtitle">Effect of Oblique <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field on Shape and Behavior of the Magnetosphere</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The oblique angle made by the spiral <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field with the radially expanding solar wind is shown to result in an easterly deflection of the solar wind as it traverses the standing hydromagnetic shock wave a few earth radii upstream of the mag- netosphere. A quantitative estimate of the deflection angle can be obtained from the plasma shock relations,</p> <div class="credits"> <p class="dwt_author">G. K. Walters</p> <p class="dwt_publisher"></p> <p class="publishDate">1964-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">95</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/41984545"> <span id="translatedtitle">The Earth's magnetosphere under continued forcing: Substorm activity during the passage of an <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> cloud</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">This is the third of three papers dealing with the interaction of an <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field with the earth's magnetosphere in Jan 1988. Here the authors report on substorm observations made during this time period. They sampled information from six spacecraft and a larger number of ground based systems to serve as signals for the initiation of substorm behavior. They</p> <div class="credits"> <p class="dwt_author">C. J. Farrugia; L. F. Burlaga; R. P. Lepping; M. P. Freeman; K. Takahashi</p> <p class="dwt_publisher"></p> <p class="publishDate">1993-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">96</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014JGRA..119.3979W"> <span id="translatedtitle">Strong ionospheric field-aligned currents for radial <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> fields</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The present work has investigated the configuration of field-aligned currents (FACs) during a long period of radial <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) on 19 May 2002 by using high-resolution and precise vector <span class="hlt">magnetic</span> field measurements of CHAMP satellite. During the interest period IMF By and Bz are weakly positive and Bx keeps pointing to the Earth for almost 10 h. The geomagnetic indices Dst is about -40 nT and AE about 100 nT on <span class="hlt">average</span>. The cross polar cap potential calculated from Assimilative Mapping of Ionospheric Electrodynamics and derived from DMSP observations have <span class="hlt">average</span> values of 10-20 kV. Obvious hemispheric differences are shown in the configurations of FACs on the dayside and nightside. At the south pole FACs diminish in intensity to magnitudes of about 0.1 ?A/m2, the plasma convection maintains two-cell flow pattern, and the thermospheric density is quite low. However, there are obvious activities in the northern cusp region. One pair of FACs with a downward leg toward the pole and upward leg on the equatorward side emerge in the northern cusp region, exhibiting opposite polarity to FACs typical for duskward IMF orientation. An obvious sunward plasma flow channel persists during the whole period. These ionospheric features might be manifestations of an efficient <span class="hlt">magnetic</span> reconnection process occurring in the northern magnetospheric flanks at high latitude. The enhanced ionospheric current systems might deposit large amount of Joule heating into the thermosphere. The air densities in the cusp region get enhanced and subsequently propagate equatorward on the dayside. Although geomagnetic indices during the radial IMF indicate low-level activity, the present study demonstrates that there are prevailing energy inputs from the magnetosphere to both the ionosphere and thermosphere in the northern polar cusp region.</p> <div class="credits"> <p class="dwt_author">Wang, Hui; Lhr, Hermann; Shue, Jih-Hong; Frey, Harald. U.; Kervalishvili, Guram; Huang, Tao; Cao, Xue; Pi, Gilbert; Ridley, Aaron J.</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-05-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">97</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/6426849"> <span id="translatedtitle">The Earth's magnetosphere under continued forcing: Substorm activity during the passage of an <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> cloud</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">This is the third of three papers dealing with the interaction of an <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field with the earth's magnetosphere in Jan 1988. Here the authors report on substorm observations made during this time period. They sampled information from six spacecraft and a larger number of ground based systems to serve as signals for the initiation of substorm behavior. They relate the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field and plasma conditions to the time of observation of substorm initiation. Current models tie substorm occurrence to <span class="hlt">magnetic</span> reconnection in the magnetosphere. The IMF B[sub y] and B[sub z] components varied slowly over a range of 20 nT on both sides of zero during this observation period. During the period of northward IMF the magnetosphere was quiescent, but during the period of southward IMF a large <span class="hlt">magnetic</span> storm was initiated. During this interval substorms were observed roughly every 50 minutes.</p> <div class="credits"> <p class="dwt_author">Farrugia, C.J.; Burlaga, L.F.; Lepping, R.P. (NASA Goddard Space Flight Center, Greenbelt, MD (United States)); Freeman, M.P. (Imperial College, London (United Kingdom)); Takahashi, K. (Johns Hopkins Univ., Laurel, MD (United States))</p> <p class="dwt_publisher"></p> <p class="publishDate">1993-05-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">98</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19730028910&hterms=1926&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3D%252C%2B.%2B.%252C1926"> <span id="translatedtitle">Inferring the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field by observing the polar geomagnetic field.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Svalgaard (1968, 1972) and Mansurov (1969) have shown that it is possible to infer the polarity of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field quite reliably from observations of the diurnal variation of polar geomagnetic fields. The effect is most prominent in the vertical component of geomagnetic observatories near the geomagnetic poles during several hours near noon. The <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field observed with spacecraft near the earth is very similar to the mean solar <span class="hlt">magnetic</span> field (i.e., the sun observed as though it were a star); thus the fact that observations of the polar geomagnetic field have existed without interruption since 1926 at the Danish Meteorological Institute station at Godhavn, Greenland, means that in effect the inferred solar <span class="hlt">magnetic</span> field during five sunspot cycles is available for analysis.-</p> <div class="credits"> <p class="dwt_author">Wilcox, J. M.</p> <p class="dwt_publisher"></p> <p class="publishDate">1972-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">99</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20110008573&hterms=Flux&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3D%2522Flux%2522"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary"><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> <div class="credits"> <p class="dwt_author">Mitchell, E. J.; Lopez, R. E.; Fok, M.-C.; Deng, Y.; Wiltberger, M.; Lyon, J.</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">100</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014EGUGA..16.1263W"> <span id="translatedtitle">Response of ionosphere and thermosphere during radial <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The configurations of ionosphere and thermosphere have been investigated by using high-resolution measurements of CHAMP satellite. During the period IMF By and Bz components are weak and Bx keeps pointing to the Earth for almost 10 hours. The geomagnetic indices Dst is about -40 nT and AE about 100 nT on <span class="hlt">average</span> during the interest period. The CPCP (cross polar cap potential) output by AMIE and calculated from DMSP observations have <span class="hlt">average</span> values of 15-20 kV. Obvious hemispheric differences are shown in the configurations of FACs on the dayside and nightside. In the south pole FACs diminish in intensity with magnitudes below 0.25 A/m2, the plasma convection retains its quiet time two cell flow pattern, and the air density is quiet low. However, there are obvious activities in the north cusp FACs. One pair of FACs emerges in the north cusp region, which shows opposite polarities to DPY FACs. The new type of currents is accompanied by sunward plasma flow channels. These ionospheric features might be manifestations of the <span class="hlt">magnetic</span> reconnection processes occurring in the north magnetospheric flanks. The enhanced ionospheric current systems have deposited large amount of energies into the thermosphere, causing enhanced air densities in the cusp region, which subsequently propagate equatorward both on the dayside and nightside. Although the radial IMF is considered as geomagnetic quiet condition, the present study has demonstrated for the first time there are prevailing energy inputs from the magnetosphere to both the ionosphere and thermosphere in the polar cusp region.</p> <div class="credits"> <p class="dwt_author">Wang, Hui; Luehr, Hermann; Shue, Jihong</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-05-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_4");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" 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style="font-weight: bold;">6</a> <a onClick='return showDiv("page_7");' href="#">7</a> <a onClick='return showDiv("page_8");' href="#">8</a> <a onClick='return showDiv("page_9");' href="#">9</a> <a onClick='return showDiv("page_10");' href="#">10</a> <a onClick='return showDiv("page_11");' href="#">11</a> <a onClick='return showDiv("page_12");' href="#">12</a> <a onClick='return showDiv("page_13");' href="#">13</a> <a onClick='return showDiv("page_14");' href="#">14</a> <a onClick='return showDiv("page_15");' href="#">15</a> <a onClick='return showDiv("page_16");' href="#">16</a> <a onClick='return showDiv("page_17");' href="#">17</a> <a onClick='return showDiv("page_18");' href="#">18</a> <a onClick='return showDiv("page_19");' href="#">19</a> <a onClick='return showDiv("page_20");' href="#">20</a> <a onClick='return showDiv("page_21");' href="#">21</a> <a onClick='return showDiv("page_22");' href="#">22</a> <a onClick='return showDiv("page_23");' href="#">23</a> <a onClick='return showDiv("page_24");' href="#">24</a> <a onClick='return showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_7");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">101</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19930046797&hterms=pomerantz&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dpomerantz"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Bieber, John W.; Chen, Jiasheng; Matthaeus, William H.; Smith, Charles W.; Pomerantz, Martin A.</p> <p class="dwt_publisher"></p> <p class="publishDate">1993-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">102</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2011JGRA..116.5308Z"> <span id="translatedtitle">On the importance of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field ?By? on polar cap patch formation</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">A number of poleward moving events were observed between 1130 and 1300 UT on 11 February 2004, during periods of southward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF), while the steerable antenna of the European Incoherent Scatter (EISCAT) Svalbard radar (ESR) and the Troms VHF radar pointed nearly northward at low elevation. In this interval, simultaneous SuperDARN CUTLASS Finland radar measurements showed poleward moving radar aurora forms (PMRAFs) which appeared very similar to the density enhancements observed by the ESR northward pointing antenna. These events appeared quasiperiodically with a period of about 10 min. Comparing the observations from the above three radars, it is inferred that there is an almost one-to-one correspondence between the poleward moving plasma concentration enhancements (PMPCEs) observed by the ESR and the VHF radar and the PMRAFs measured by the CUTLASS Finland radar. These observations are consistent with the interpretation that the polar cap patch material was generated by photoionization at subauroral latitudes and that the plasma was structured by bursts of magnetopause reconnection giving access to the polar cap. There is clear evidence that plasma structuring into patches was dependent on the variability in IMF ?By?. The duration of these events implies that the <span class="hlt">average</span> evolution time of the newly opened flux tubes from the subauroral region to the polar cap was about 33 min.</p> <div class="credits"> <p class="dwt_author">Zhang, Q.-H.; Zhang, B.-C.; Liu, R.-Y.; Dunlop, M. W.; Lockwood, M.; Moen, J.; Yang, H.-G.; Hu, H.-Q.; Hu, Z.-J.; Liu, S.-L.; McCrea, I. W.; Lester, M.</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-05-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">103</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.springerlink.com/index/u01174598u132286.pdf"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The spatial organization of the observed photospheric <span class="hlt">magnetic</span> field, as well as its relation to the polarity of the <span class="hlt">interplanetary</span> field, have been studied using high resolution magnetograms from Kitt Peak National Observatory. Systematic patterns in the large scale field have been found to be due to contributions from both concentrated flux and more diffuse flux. It is not necessary</p> <div class="credits"> <p class="dwt_author">Randolph H. Levine</p> <p class="dwt_publisher"></p> <p class="publishDate">1979-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">104</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19810004452&hterms=Survey+Methods&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3D%2522Survey%2BMethods%2522"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Lepping, R. P.; Benhannon, K. W.</p> <p class="dwt_publisher"></p> <p class="publishDate">1980-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">105</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014JGRA..119..658Z"> <span id="translatedtitle">The source, statistical properties, and geoeffectiveness of long-duration southward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field intervals</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Geomagnetic activity is strongly controlled by solar wind and <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) conditions, especially the southward component of IMF (IMF Bs). We analyze the statistical properties of IMF Bs at 1 AU using in situ observations for more than a solar cycle (1995-2010). IMF Bs events are defined as continuous IMF Bs intervals with varying thresholds of Bs magnitude and duration and categorized by different solar wind structures, such as <span class="hlt">magnetic</span> cloud (MC), <span class="hlt">interplanetary</span> small-scale <span class="hlt">magnetic</span> flux rope, <span class="hlt">interplanetary</span> coronal mass ejection without MC signature (ejecta), stream interacting region, and Shock, as well as events unrelated with well-defined solar wind structures. The statistical properties of IMF Bs events and their geoeffectiveness are investigated in detail based on satellite and ground measurements. We find that the integrated duration and number of Bs events follow the sunspot number when Bz < -5 nT. We also find that in extreme Bs events (t> 6 h, Bz < -10 nT), a majority (53%) are related to MC and 10% are related with ejecta, but nearly a quarter are not associated with any well-defined solar wind structure. We find different geomagnetic responses for Bs events with comparable duration and magnitude depending on what type of solar wind structures they are associated with. We also find that great Bs events (t> 3 h, Bz < -10 nT) do not always trigger <span class="hlt">magnetic</span> storms.</p> <div class="credits"> <p class="dwt_author">Zhang, X.-Y.; Moldwin, M. B.</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-02-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">106</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2006cosp...36..677Y"> <span id="translatedtitle">Relationship between the <span class="hlt">magnetic</span> field of <span class="hlt">interplanetary</span> ejecta and their solar sources</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Solar coronal mass ejections CMEs are a principal link that connects the chain of events in the solar atmosphere <span class="hlt">interplanetary</span> space and the earth s <span class="hlt">magnetic</span> environment The occurrence of earth-directed CMEs is well associated with geomagnetic disturbances that can impose large negative <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> fields IMF across the dayside magnetosphere at 1 AU and large pressure-produced compressions of the dayside magnetopause Such geomagnetic storms can be the sources of impaired and even disrupted technological systems flying in space and operating on the earth s surface Recent research from our group has demonstrated that the size of a geomagnetic storm as measured by the geomagnetic index Dst appears to be well associated with the expansion speed of the halo CME that triggered the storm The relationship was found to be more pronounced for very fast ejecta v 1000 km s In addition we obtained new and original results that demonstrate the relationship between <span class="hlt">magnetic</span> fields of the solar source of a coronal eruption and <span class="hlt">magnetic</span> fields of the <span class="hlt">interplanetary</span> ejecta In this presentation we will investigate the very real possibility that the polarity of IMF near 1 AU can be deduced from key solar data -- photospheric magnetograms coronal images and the observed configurations of CMEs near the Sun This information is critical together with data on the CME arrival time velocity and plasma density for assessing geospace disturbances that might result from the solar eruption This research also contributes to deeper understandings of the</p> <div class="credits"> <p class="dwt_author">Yurchyshyn, V.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">107</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19840051835&hterms=high+magnetic+field&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dhigh%2Bmagnetic%2Bfield"> <span id="translatedtitle">The effects of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field orientation on dayside high-latitude ionospheric convection</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">The Atmosphere Explorer C data base of Northern Hemisphere ionospheric convection signatures at high latitudes is examined during times when the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field orientation is relatively stable. It is found that when the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) has its expected garden hose orientation, the center of a region where the ion flow rotates from sunward to antisunward is displaced from local noon toward dawn irrespective of the sign of By. Poleward of this rotation region, called the cleft, the ion convection is directed toward dawn or dusk depending on whether By is positive or negative, respectively. The observed flow geometry can be explained in terms of a magnetosphere solar wind interaction in which merging is favored in either the prenoon Northern Hemisphere or the prenoon Southern Hemisphere when the IMF has a normal sector structure that is toward or away, respectively.</p> <div class="credits"> <p class="dwt_author">Heelis, R. A.</p> <p class="dwt_publisher"></p> <p class="publishDate">1984-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">108</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19770031631&hterms=is+carried+out+for&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3D%2522is%2Bcarried%2Bout%2Bfor%2522"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Sari, J. W.; Valley, G. C.</p> <p class="dwt_publisher"></p> <p class="publishDate">1976-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">109</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.phy6.org/stargaze/Lsun6new.htm"> <span id="translatedtitle">Seeing the Sun in a New Light: <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field Lines</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://nsdl.org/nsdl_dds/services/ddsws1-1/service_explorer.jsp">NSDL National Science Digital Library</a></p> <p class="result-summary">This lesson discusses the Sun's corona, observed from spacecraft in the extreme ultra violet (EUV) and in x-rays, including coronal holes and coronal mass ejections (CME), their effect near Earth and their monitoring from space. This section also discusses related phenomena in <span class="hlt">interplanetary</span> space and on Earth and contains an optional class exercise in which students learn about field line preservation of flows in a highly conducting plasma, and use it to graphically obtain the shapes of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field lines. They also receive information about high-energy ions and electrons accelerated by solar activity, probably from <span class="hlt">magnetic</span> energy, and the hazard they pose to spacefarers. Students receive an introduction to NASA's great observatories, expanding the coverage of the electromagnetic spectrum by astronomers.</p> <div class="credits"> <p class="dwt_author">Stern, David</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">110</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.agu.org/journals/rs/v026/i004/91RS00586/91RS00586.pdf"> <span id="translatedtitle"><span class="hlt">Interplanetary</span> <span class="hlt">magnetic</span> field control of drifts and anisotropy of high-latitude irregularities</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The paper investigates the extent of the control exerted by the north-south component of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) on the large-scale plasma structures in the polar cap ionosphere, using data from spaced-receiver scintillation measurements at Thule and Sondrestrom (Greenland) obtained with the 250-MHz transmissions from quasi-geostationary polar beacon satellites. Results clearly demonstrate that the strength of F region irregularities, their</p> <div class="credits"> <p class="dwt_author">Sunanda Basu; C. Bryant; C. E. Valladares; Emanoel Costa; R. C. Livingston</p> <p class="dwt_publisher"></p> <p class="publishDate">1991-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">111</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19880053447&hterms=solar+energy+malaysia&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dsolar%2Benergy%2Bmalaysia"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Ng, C. K.</p> <p class="dwt_publisher"></p> <p class="publishDate">1988-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">112</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1996AdSpR..17..307L"> <span id="translatedtitle"><span class="hlt">Interplanetary</span> <span class="hlt">magnetic</span> field control of heavy ion abundnaces at approximately 5.2 AU</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The Heliosphere Instrument for Spectra, Composition, and Anistropy at Low Energies (HI-SCALE) on the Ulysses spacecraft measured a long-lasting heavy ion particle event from about day 304 to day 318, 1992, at a southern heliographic latitude of approximately 20 deg. An analysis is presented of the relative (to O) C and Fe abundance variations during this interval. The variations are associated with major <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field structures that corotate over the spacecraft.</p> <div class="credits"> <p class="dwt_author">Lanzerotti, L. J.; Maclennan, C. G.; Forsyth, R. J.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">113</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/51611963"> <span id="translatedtitle">Advanced Propulsion for <span class="hlt">Interplanetary</span> Flights using <span class="hlt">Magnetized</span> Target Fusion</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary"><span class="hlt">Magnetized</span> target fusion is an approach in which a <span class="hlt">magnetized</span> target plasma is compressed inertially by an imploding material wall. The use of a high energy plasma liner to provide the required implosion was recently proposed by Thio, et al. The plasma liner is formed by the merging of a number (nominally 60) of high momentum plasma jets converging towards</p> <div class="credits"> <p class="dwt_author">Y. C. F. Thio; B. Freeze; H. Gerrish; R. C. Kirkpatrick; D. B. Landrum; G. R. Schmidt</p> <p class="dwt_publisher"></p> <p class="publishDate">1998-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">114</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1995RvGeo..33..603M"> <span id="translatedtitle">Tongues, bottles, and disconnected loops: The opening and closing of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">For years the field of Space Physics has had a problem, a really big problem for it occurs on the largest spatial scales in Space Physics - across the entire region under the Sun's influence, the heliosphere. The problem is that the Sun appears to keep opening new <span class="hlt">magnetic</span> fields into <span class="hlt">interplanetary</span> space with no obvious way to close them back off again. This state of affairs, without some method for closing the open <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF), would lead to an ever growing IMF magnitude in <span class="hlt">interplanetary</span> space - a catastrophe that is clearly not observed. Figure 1 displays a composite picture of the Sun's outermost atmosphere or corona from 30 June 1973. The outer portion was taken in ordinary white light from the ground during a solar eclipse. The superposed soft X-ray image of the denser, near-Sun corona was taken from Skylab on the same day. The structure evident in the images is a consequence of the solar <span class="hlt">magnetic</span> field that permeates the corona; more and less populated <span class="hlt">magnetic</span> fields are mapped out as density structures in these images. Coronal holes are low-density regions where the <span class="hlt">magnetic</span> fields open out into <span class="hlt">interplanetary</span> space; a large coronal hole is displayed as the dark region near the top of Figure 1. In contrast, bright loop-like structures indicate closed field regions on the Sun that contain high-density plasma. The centers of helmet streamers (closed field loops overlaid by nearly radial high density streamer structures), such as those seen extending outwards to the left and right sides in Figure 1, map out to large reversals of the <span class="hlt">magnetic</span> field or current sheets in <span class="hlt">interplanetary</span> space. The solar wind flow from streamers is slower and higher density than it is from coronal holes [e.g., Borrini et al., 1981]. Coronagraph and soft X-ray observations over the past several decades have shown that the solar corona is highly dynamic with open and closed regions evolving over time scales as short as minutes and as long as the 22-year solar cycle.</p> <div class="credits"> <p class="dwt_author">McComas, David J.</p> <p class="dwt_publisher"></p> <p class="publishDate">1995-07-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">115</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013AGUSMSH41A..04B"> <span id="translatedtitle">SEPs Dropout Events Associated with Advected <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Structures</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The intensity profile of energetic particles from impulsive solar flares (SEP) often shows abrupt dropouts affecting all energies simultaneously, without time-dispersion. Part of the community thinks that these modulations are directly related to the presence of <span class="hlt">magnetic</span> structures with a different <span class="hlt">magnetic</span> topology advected by the wind, a sort of <span class="hlt">magnetic</span> flux tubes. During the expansion, following the dynamical interaction between plasma regions travelling at different speed, these structures would be partially tangled up in a sort of spaghetti-like bundle. These flux tubes would be alternatively connected or not connected with the flare site and, consequently, they would be filled or devoid of SEPs. When the observer passes through them, he would observe clear particles dropout signatures. We will report about results from a detailed analysis of SEP events which showed several signatures in the local <span class="hlt">magnetic</span> field and/or plasma parameters associated with SEP modulations. These findings corroborate the idea of a possible link between these particles events observed at the Earth's orbit and <span class="hlt">magnetic</span> connection or disconnection of the ambient <span class="hlt">magnetic</span> field with the flare region at the Sun. We will also discuss the advantages represented by future Solar Orbiter in-situ observations. As a matter of fact, Solar Orbiter, from its orbital vantage point during the quasi corotation phase, will be a priviledged observer of this kind of phenomenon since it will observe the advected structure of the solar wind not yet reprocessed by dynamical interaction due to wind expansion.</p> <div class="credits"> <p class="dwt_author">Bruno, R.; Trenchi, L.; Telloni, D.; D'Amicis, R.; Marcucci, F.; Zurbuchen, T.; Weberg, M. J.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-05-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">116</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19930005148&hterms=Internal+Control&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DInternal%2BControl"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Knudsen, W. C.</p> <p class="dwt_publisher"></p> <p class="publishDate">1992-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">117</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012AAS...22041101L"> <span id="translatedtitle">Are Polar Field <span class="hlt">Magnetic</span> Flux Concentrations Responsible for Missing <span class="hlt">Interplanetary</span> Flux?</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Magnetohydrodynamic (MHD) simulations are now routinely used to produce models of the solar corona and inner heliosphere for specific time periods. These models typically use <span class="hlt">magnetic</span> maps of the photospheric <span class="hlt">magnetic</span> field built up over a solar rotation, available from a number of ground-based and space-based solar observatories. The line-of-sight field at the Sun's poles is poorly observed, and the polar fields in these maps are filled with a variety of interpolation/extrapolation techniques. These models have been found to frequently underestimate the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> flux (Riley et al., 2012, in press, Stevens et al., 2012, in press) near the minimum part of the cycle unless mitigating correction factors are applied. Hinode SOT observations indicate that strong concentrations of <span class="hlt">magnetic</span> flux may be present at the poles (Tsuneta et al. 2008). The ADAPT flux evolution model (Arge et al. 2010) also predicts the appearance of such concentrations. In this paper, we explore the possibility that these flux concentrations may account for a significant amount of <span class="hlt">magnetic</span> flux and alleviate discrepancies in <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> flux predictions. Research supported by AFOSR, NASA, and NSF.</p> <div class="credits"> <p class="dwt_author">Linker, Jon A.; Downs, C.; Mikic, Z.; Riley, P.; Henney, C. J.; Arge, C. N.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-05-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">118</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19950046378&hterms=Maha&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DMaha"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Richard, Robert L.; Walker, Raymond J.; Ashour-Abdalla, Maha</p> <p class="dwt_publisher"></p> <p class="publishDate">1994-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">119</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19810059597&hterms=ROMA&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3D%2522ROMA%2522"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">The flow behind an <span class="hlt">interplanetary</span> shock was analyzed through the use of <span class="hlt">magnetic</span> field and plasma data from five spacecraft, with emphasis on the <span class="hlt">magnetic</span> cloud identified by a characteristic variation of the latitude angle of the <span class="hlt">magnetic</span> field. The size of the cloud was found to be about 0.5 AU in radial extent and greater than 30 deg in azimuthal extent, with its front boundary almost normal to the radial direction. Because the field direction of the <span class="hlt">magnetic</span> cloud as it moved past the spacecraft was observed to rotate nearly parallel to a plane, it is thought that the field configuration of the cloud was essentially two-dimensional. These results further suggest that the lines of force in the <span class="hlt">magnetic</span> cloud formed loops, but it could not be determined whether these loops were open or closed.</p> <div class="credits"> <p class="dwt_author">Burlaga, L.; Sittler, E.; Mariani, F.; Schwenn, R.</p> <p class="dwt_publisher"></p> <p class="publishDate">1981-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">120</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/48907276"> <span id="translatedtitle">Magnetohydrodynamic simulation of the interaction between <span class="hlt">interplanetary</span> strong shock and <span class="hlt">magnetic</span> cloud and its consequent geoeffectiveness: 2. Oblique collision</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Numerical studies of the <span class="hlt">interplanetary</span> shock overtaking <span class="hlt">magnetic</span> cloud (MC) event are continued by a 2.5-dimensional magnetohydrodynamic (MHD) model in heliospheric meridional plane. <span class="hlt">Interplanetary</span> direct collision (DC)\\/oblique collision (OC) between an MC and a shock results from their same\\/different initial propagation orientations. For radially erupted MC and shock in solar corona, the orientations are only determined respectively by their heliographic</p> <div class="credits"> <p class="dwt_author">Ming Xiong; Huinan Zheng; Yuming Wang; Shui Wang</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_5");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> 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showDiv("page_8");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">121</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2008AdSpR..41..160M"> <span id="translatedtitle"><span class="hlt">Interplanetary</span> medium A dusty plasma</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The <span class="hlt">average</span> mass of dust per volume in space equals that of the solar wind so that the <span class="hlt">interplanetary</span> medium should provide an obvious region to study dust plasma interactions. While dust collective behavior is typically not observed in the <span class="hlt">interplanetary</span> medium, the dust component rather consists of isolated grains screened by and interacting with the plasma. Space measurements have revealed several phenomena possibly resulting from dust plasma interactions, but most of the dust plasma interactions are at present not quantified. Examples are the production of neutrals and pick-up ions from the dust, dust impact generated field variations at spacecraft and <span class="hlt">magnetic</span> field variations possibly caused by solar wind interacting with dust trails. Since dust particles carry a surface charge, they are exposed to the Lorentz force in the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field and for grains of sub-micrometer sizes acceleration can be substantial.</p> <div class="credits"> <p class="dwt_author">Mann, Ingrid</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">122</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/41977707"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The origins of the <span class="hlt">interplanetary</span> southward B\\/sub z\\/ which cause the 10 major (D\\/sub s\\/\\/sub t\\/<-100 nT) <span class="hlt">magnetic</span> storms detected during the 500 days of study (August 16, 1978, to December 28, 1979) of the Gonzalez and Tsurutani (1987) work are examined in detail. A full complement of ISEE 3 plasma and field data, an 11-station AE index and the</p> <div class="credits"> <p class="dwt_author">Bruce T. Tsurutani; Walter D. Gonzalez; Frances Tang; Syun I. Akasofu; Edward J. Smith</p> <p class="dwt_publisher"></p> <p class="publishDate">1988-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">123</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/21367387"> <span id="translatedtitle">DRIFT ORBITS OF ENERGETIC PARTICLES IN AN <span class="hlt">INTERPLANETARY</span> <span class="hlt">MAGNETIC</span> FLUX ROPE</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary"><span class="hlt">Interplanetary</span> <span class="hlt">magnetic</span> flux ropes have significant effects on the distribution of energetic particles in space. Flux ropes can confine solar energetic particles (SEPs) for hours, and have relatively low densities of Galactic cosmic rays (GCRs), as seen during second-stage Forbush decreases. As particle diffusion is apparently inhibited across the flux rope boundary, we suggest that guiding center drifts could play a significant role in particle motion into and out of the flux ropes. We develop an analytic model of the <span class="hlt">magnetic</span> field in an <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> flux rope attached to the Sun at both ends, in quasi-toroidal coordinates, with the realistic features of a flux rope cross section that is small near the Sun, expanding with distance from the Sun, and field lines that are wound less tightly close to the Sun due to stretching by the solar wind. We calculate the particle drift velocity field due to the <span class="hlt">magnetic</span> field curvature and gradient as a function of position and pitch-angle cosine, and trace particle guiding center orbits numerically, assuming conservation of the first adiabatic invariant. We find that SEPs in the interior of a flux rope can have drift orbits that are trapped for long times, as in a tokamak configuration, with resonant escape features as a function of the winding number. For Forbush decreases of GCRs, the drifts should contribute to a unidirectional anisotropy and net flow from one leg of the loop to the other, in a direction determined by the poloidal field direction.</p> <div class="credits"> <p class="dwt_author">Krittinatham, W.; Ruffolo, D., E-mail: watcharawuth.krittinatham@gmail.co, E-mail: scdjr@mahidol.ac.t [Department of Physics, Faculty of Science, Mahidol University, Rama VI Road, Bangkok 10400 (Thailand)</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-10-10</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">124</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/5162423"> <span id="translatedtitle"><span class="hlt">Interplanetary</span> <span class="hlt">magnetic</span> field draping about fast coronal mass ejecta in the outer heliosphere</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">Considerable recent research on the draping of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) about the ionospheres of comets and Venus and about the Earth's magnetosphere, as well as draping of magnetospheric fields about Io's ionosphere and plasmoids, has indicated the fundamental and prevalent nature of this process. In this paper we consider the possibility of <span class="hlt">magnetic</span> field draping about fast coronal mass ejections (CMEs) which propagate into the outer heliosphere through slower moving, quiescent solar wind. In particular, when this velocity difference is appreciably greater than the local Alfven speed, draping should produce extended magnetotaillike configurations somewhat analogous to those observed behind Venus and comets. For CMEs, however, such tails would point sunward and form on scales comparable to these large ejecta. In the draped magnetotial regions sunward of fast CMEs in the outer heliosphere the IMF should be relatively radial, in contrast to the generally transverse orientation of the Parker spiral there. Low transverse flow velocities in the draped regions just upstream from fast CMEs suggest that swept-up <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> flux is hung up on these large structures (approx.1 AU in transverse dimension at 1 AU) for many days. We have searched for evidence of <span class="hlt">magnetic</span> field draping about fast CMEs and the existence of large draped magnetotails in the outer heliosphere by examining the Pioneer 11 data set between 6.9 and 9.4 AU. Several events consistent with such structures have been found, and two are displayed in the study. copyright American Geophysical Union 1988</p> <div class="credits"> <p class="dwt_author">McComas, D.J.; Gosling, J.T.; Winterhalter, D.; Smith, E.J.</p> <p class="dwt_publisher"></p> <p class="publishDate">1988-04-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">125</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1984JGR....89.7453Z"> <span id="translatedtitle">Ionospheric and Birkeland current distributions for northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field - Inferred polar convection</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">A comprehensive analysis of the total vector <span class="hlt">magnetic</span> disturbance field is presented. The analysis is based on satellite observations of the <span class="hlt">magnetic</span> disturbance field over the polar regions during a strong northward-moving <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field IMF. Specific attention is given to a determination of northward (NBZ) currents which accompany Birkeland currents. A Fourier technique is used to derive the physical parameters ionospheric system during two days of strong IMF activity, January 3, 1980 and November 11, 1979. The system shows a W-shaped pattern with an antisunward current over the <span class="hlt">magnetic</span> pole and return currents on either side. It is shown that the antisunward orientation of the system implies the presence of sunward convection. Suggestions are given for multicell patterns over the polar regions for northward IMF during an IMF sign change.</p> <div class="credits"> <p class="dwt_author">Zanetti, L. J.; Potemra, T. A.; Bythrow, P. F.; Iijima, T.; Baumjohann, W.</p> <p class="dwt_publisher"></p> <p class="publishDate">1984-09-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">126</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/43149270"> <span id="translatedtitle">Orinetation of the <span class="hlt">Magnetic</span> Fields in <span class="hlt">Interplanetary</span> Flux Ropes and Solar Filaments</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Coronal mass ejections are often associated with erupting <span class="hlt">magnetic</span> structures or disappearing filaments. Majority of CMEs headed directly toward the earth are observed at 1AU as <span class="hlt">magnetic</span> clouds --- region in the solar wind where the <span class="hlt">magnetic</span> field strength is higher than <span class="hlt">average</span> and smooth rotation of the <span class="hlt">magnetic</span> field vectors. The 3D structure of <span class="hlt">magnetic</span> clouds can be represented</p> <div class="credits"> <p class="dwt_author">Vasyl B. Yurchyshyn; Haimin Wang; P. R. Goode; Yuanyong Deng</p> <p class="dwt_publisher"></p> <p class="publishDate">2001-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">127</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012AGUFMSM11C2308P"> <span id="translatedtitle">Statistical study on nightside geosynchronous <span class="hlt">magnetic</span> field responses to <span class="hlt">interplanetary</span> shocks</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">When an <span class="hlt">interplanetary</span> (IP) shock passes over the Earth's magnetosphere, the geosynchronous <span class="hlt">magnetic</span> field strength near the noon is always enhanced, while the geosynchronous <span class="hlt">magnetic</span> field near the midnight decreases or increases. In order to understand what determines the positive or negative <span class="hlt">magnetic</span> field response at nightside geosynchronous orbit to sudden increases in the solar wind dynamic pressure, we have examined 120 IP shock-associated sudden commencements (SC) using <span class="hlt">magnetic</span> field data from the GOES spacecraft near the midnight (MLT = 2200~0200) and found the following <span class="hlt">magnetic</span> field perturbation characteristics. (1) There is a strong seasonal dependence of geosynchronous <span class="hlt">magnetic</span> field perturbations during the passage of IP shocks. That is, the SC-associated geosynchronous <span class="hlt">magnetic</span> field near the midnight increases (a positive response) in summer and decreases (a negative response) in winter. (2) These field perturbations are dominated by the radial <span class="hlt">magnetic</span> field component rather than the north-south <span class="hlt">magnetic</span> field component at nightside geosynchronous orbit. (3) The <span class="hlt">magnetic</span> elevation angles corresponding to positive and negative responses decrease and increase, respectively. These field perturbation properties can be explained by the location of the cross-tail current enhancement during SC interval with respect to geosynchronous spacecraft position.</p> <div class="credits"> <p class="dwt_author">Park, J.; Kim, K.; Araki, T. A.; Lee, D.; Lee, E.; Jin, H.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">128</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19930009958&hterms=Halley+Comet&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DHalley%2527s%2BComet"> <span id="translatedtitle"><span class="hlt">Interplanetary</span> <span class="hlt">magnetic</span> field changes and condensations in comet Halley's plasma tail</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">In a time-dependent three dimensional MHD simulation for cometary plasmas, Schmidt-Voigt (1989) could observe the formation of condensations in the plasma tail after a 90 degree change in the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) sweeping over the comet. We investigated the IMF measurements of the Vega SC in the vicinity of the comet Halley for 90 degree changes in the clock angle and studied the relation between them and optical observations of condensations in the plasma tail. For the time interval 24 Feb. 86 to 14 Mar. 86, we could not find a correlation between such changes and the release of condensations from the cometary head.</p> <div class="credits"> <p class="dwt_author">Delva, Magda; Schwingenschuh, K.</p> <p class="dwt_publisher"></p> <p class="publishDate">1992-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">129</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014JGRA..119.1887W"> <span id="translatedtitle">Effects of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field on the twisting of the magnetotail: Global MHD results</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We used the global magnetohydrodynamic (MHD) simulation to investigate effects of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) on the twisting of the magnetotail. It is shown that the cross section of the magnetotail is elongated along a certain direction close to the IMF orientation. The elongated direction twists with the IMF orientation, magnitude, and the distance away from Earth, and the quantitative relationship has been given. In addition, the current sheet has a similar twisting behavior as the magnetotail magnetopause, with a smaller twisting angle. Our simulated results fall within the range that people have deduced from observations.</p> <div class="credits"> <p class="dwt_author">Wang, J. Y.; Wang, C.; Huang, Z. H.; Sun, T. R.</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-03-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">130</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19790012789&hterms=microstate&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3D%2522microstate%2522"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Acuna, M. H.; Behannon, K. W.; Burlaga, L. F.; Lepping, R.; Ness, N.; Ogilvie, K.; Pizzo, J.</p> <p class="dwt_publisher"></p> <p class="publishDate">1979-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">131</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013EGUGA..15.7237T"> <span id="translatedtitle">Mercury's plasma belt under different <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field: hybrid simulations results compared to in-situ measurements</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The presence of plasma belt and trapped charged particles region in the Mercury's inner magnetosphere has been questionable due to small dimensions of the magnetosphere of Mercury compared to Earth, where these regions are formed. However, early and recent numerical simulations of the solar wind interaction with Mercury's <span class="hlt">magnetic</span> field suggested that a similar structure, consisting rather of quasi-trapped charged particles could be found also in the vicinity of Mercury. These simulated results have been recently confirmed by MESSENGER in-situ observations. We present a detailed analysis of the plasma belt structure of quasi-trapped plasma near the Mercury's surface and its characteristics and behaviour under different orientations of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field. The plasma belt region is constantly supplied with solar wind protons via magnetospheric flanks and tail current sheet region. Protons inside the plasma belt region are quasi-trapped in the <span class="hlt">magnetic</span> field of Mercury and perform westward drift along the planet. This region is well separated by a <span class="hlt">magnetic</span> shell and has higher <span class="hlt">average</span> temperatures and lower bulk proton current densities than surrounding area. On the day side the population exhibits loss cone distribution function matching the theoretical loss cone angle. Simulations results are also compared to in-situ measurements acquired by MESSENGER MAG and FIPS instruments.</p> <div class="credits"> <p class="dwt_author">Travnicek, Pavel M.; Hercik, David; Schriver, David; Hellinger, Petr; Anderson, Brian J.; Raines, Jim M.; Slavin, James A.; Zurbuchen, Thomas H.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-04-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">132</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20030014815&hterms=marchenko&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dmarchenko"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Richard, R. L.; El-Alaoui, M.; Ashour-Abdalla, M.; Walker, R. J.</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">133</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/41955744"> <span id="translatedtitle">ON THE EFFECT OF A WEAK <span class="hlt">INTERPLANETARY</span> <span class="hlt">MAGNETIC</span> FIELD ON THE INTERACTION BETWEEN THE SOLAR WIND AND THE GEOMAGNETIC FIELD</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">the presence of a weak <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field may lead to the ; formation of a collision-free shock wave upstream from the boundary of the ; geomagnetic field and to a transition region characterized by an irregular ; <span class="hlt">magnetic</span> field in the intervening space. Previous calculations of the ; coordinates of the shock wave are improved upon by application of</p> <div class="credits"> <p class="dwt_author">John R. Spreiter; Wm. Prichard Jones</p> <p class="dwt_publisher"></p> <p class="publishDate">1963-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">134</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/51570504"> <span id="translatedtitle">An Examination of Directional Discontinuities and <span class="hlt">Magnetic</span> Polarity Changes around <span class="hlt">Interplanetary</span> Sector Boundaries Using E > 2 keV Electrons</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Past studies of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> sector boundaries have been based on the assumption that one can determine the field polarities by comparing the field directions with those of the nominal Parker spiral angles. Previous investigators have found evidence for decreases of |B|, the magnitude of the <span class="hlt">magnetic</span> fieldB, and increases of Theta, the angle betweenB and the ecliptic plane, at</p> <div class="credits"> <p class="dwt_author">S. W. Kahler; R. P. Lin</p> <p class="dwt_publisher"></p> <p class="publishDate">1995-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">135</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.springerlink.com/index/j821628553324r28.pdf"> <span id="translatedtitle">An examination of directional discontinuities and <span class="hlt">magnetic</span> polarity changes around <span class="hlt">interplanetary</span> sector boundaries using E > 2 keV electrons</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Past studies of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> sector boundaries have been based on the assumption that one can determine the field polarities by comparing the field directions with those of the nominal Parker spiral angles. Previous investigators have found evidence for decreases of |B|, the magnitude of the <span class="hlt">magnetic</span> fieldB, and increases of T, the angle betweenB and the ecliptic plane, at</p> <div class="credits"> <p class="dwt_author">S. W. Kahler; R. P. Lin</p> <p class="dwt_publisher"></p> <p class="publishDate">1995-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">136</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19920059735&hterms=hanscom&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dhanscom"> <span id="translatedtitle">Small-scale electrodynamics of the cusp with northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Possible low-altitude field signatures of merging occurring at high latitudes during a period of strong northward directed <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field are reported. Large electric and <span class="hlt">magnetic</span> field spikes detected at the poleward edge of the magnetosheathlike particle precipitation are interpreted as field signatures of the low-altitude footprint of such merging line locations. A train of phase-shifted, almost linearly polarized electric and <span class="hlt">magnetic</span> field fluctuations was detected just equatorward of the large electromagnetic spike. It is argued that these may be due to either ion cyclotron waves excited by penetrating magnetosheath ions or transient oscillations in the frame of convecting plasma, brought about by the sudden change in the flow at the magnetospheric end of the field line.</p> <div class="credits"> <p class="dwt_author">Basinska, Ewa M.; Burke, William J.; Maynard, Nelson C.; Hughes, W. J.; Winningham, J. D.; Hanson, W. B.</p> <p class="dwt_publisher"></p> <p class="publishDate">1992-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">137</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014IAUS..300..245D"> <span id="translatedtitle">Evolution of <span class="hlt">interplanetary</span> coronal mass ejections and <span class="hlt">magnetic</span> clouds in the heliosphere</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary"><span class="hlt">Interplanetary</span> Coronal Mass Ejections (ICMEs), and more specifically <span class="hlt">Magnetic</span> Clouds (MCs), are detected with in situ plasma and <span class="hlt">magnetic</span> measurements. They are the continuation of the CMEs observed with imagers closer to the Sun. A review of their properties is presented with a focus on their <span class="hlt">magnetic</span> configuration and its evolution. Many recent observations, both in situ and with imagers, point to a key role of flux ropes, a conclusion which is also supported by present coronal eruptive models. Then, is a flux rope generically present in an ICME? How to quantify its 3D physical properties when it is detected locally as a MC? Is it a simple flux rope? How does it evolve in the solar wind? This paper reviews our present answers and limited understanding to these questions.</p> <div class="credits"> <p class="dwt_author">Dmoulin, Pascal</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">138</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Diaz, Ismael; Zhang, Ming; Rassoul, Hamid</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">139</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19930053282&hterms=Earth+magnetosphere&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DEarth%2527s%2Bmagnetosphere"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Farrugia, C. J.; Burlaga, L. F.; Osherovich, V. A.; Richardson, I. G.; Freeman, M. P.; Lepping, R. P.; Lazarus, A. J.</p> <p class="dwt_publisher"></p> <p class="publishDate">1993-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">140</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014AcAau..95...92C"> <span id="translatedtitle">The b-dot Earth <span class="hlt">average</span> <span class="hlt">magnetic</span> field</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The <span class="hlt">average</span> Earth's <span class="hlt">magnetic</span> field has been 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 new technique that takes advantage of the damping effects of the b-dot controller and is not dependent on the Earth <span class="hlt">magnetic</span> model. This new technique combines the intuitive notions of classical control system analysis with simple mathematics, reducing the estimation of the <span class="hlt">average</span> <span class="hlt">magnetic</span> field to a simple inverse Laplace transform problem. 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 has been in orbit for 3 years.</p> <div class="credits"> <p class="dwt_author">Capo-Lugo, Pedro A.; Rakoczy, John; Sanders, Devon</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-02-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_6");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> 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onClick='return showDiv("page_9");' href="#">9</a> <a onClick='return showDiv("page_10");' href="#">10</a> <a onClick='return showDiv("page_11");' href="#">11</a> <a onClick='return showDiv("page_12");' href="#">12</a> <a onClick='return showDiv("page_13");' href="#">13</a> <a onClick='return showDiv("page_14");' href="#">14</a> <a onClick='return showDiv("page_15");' href="#">15</a> <a onClick='return showDiv("page_16");' href="#">16</a> <a onClick='return showDiv("page_17");' href="#">17</a> <a onClick='return showDiv("page_18");' href="#">18</a> <a onClick='return showDiv("page_19");' href="#">19</a> <a onClick='return showDiv("page_20");' href="#">20</a> <a onClick='return showDiv("page_21");' href="#">21</a> <a onClick='return showDiv("page_22");' href="#">22</a> <a onClick='return showDiv("page_23");' href="#">23</a> <a onClick='return showDiv("page_24");' href="#">24</a> <a onClick='return showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_9");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">141</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/51270296"> <span id="translatedtitle">Orientation of the <span class="hlt">Magnetic</span> Fields in <span class="hlt">Interplanetary</span> Flux Ropes and Solar Filaments</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Coronal mass ejections (CMEs) are often associated with erupting <span class="hlt">magnetic</span> structures or disappearing filaments. The majority of CMEs headed directly toward the Earth are observed at 1 AU as <span class="hlt">magnetic</span> clouds-the region in the solar wind where the <span class="hlt">magnetic</span> field strength is higher than <span class="hlt">average</span> and there is a smooth rotation of the <span class="hlt">magnetic</span> field vectors. The three-dimensional structure of</p> <div class="credits"> <p class="dwt_author">Vasyl B. Yurchyshyn; Haimin Wang; Philip R. Goode; Yuanyong Deng</p> <p class="dwt_publisher"></p> <p class="publishDate">2001-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">142</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20020088125&hterms=long+distance+relationships&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dlong%2Bdistance%2Brelationships"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Richardson, I. G.; Cliver, E. W.; Cane, H. V.; White, Nicholas E. (Technical Monitor)</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">143</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013AGUFMSM41B2228K"> <span id="translatedtitle">Statistical analysis of nightside geosynchronous <span class="hlt">magnetic</span> field responses to <span class="hlt">interplanetary</span> shocks</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">When an <span class="hlt">interplanetary</span> (IP) shock passes over the Earth's magnetosphere, the geosynchronous <span class="hlt">magnetic</span> field strength near the noon is always enhanced. Near the midnight, however, it increases or decreases. This indicates that the nightside magnetosphere is not always compressed by a sudden increase in the solar wind dynamic pressure. To understand the characteristics of nightside geosynchronous <span class="hlt">magnetic</span> field responses to IP shocks, we statistically examined geosynchronous <span class="hlt">magnetic</span> field perturbations observed near midnight between 2200 and 0200 <span class="hlt">magnetic</span> local time during 120 sudden commencements (SC). We found that the SC-associated geosynchronous <span class="hlt">magnetic</span> field perturbations in the BH (north--south/parallel to the dipole axis) component in the local dipole VDH coordinates are mostly positive in summer. However, the geosynchronous <span class="hlt">magnetic</span> field perturbations in other seasons show no significant seasonal dependence in BH. Considering that the SC is accompanied by an increase in the cross-tail current (Jc) and that the SC-associated Jc is a main controlling factor of nightside geosynchronous <span class="hlt">magnetic</span> field perturbations, it is suggested that the observation of the positive or negative response is due to the geometry of geosynchronous spacecraft relative to the SC-associated Jc. We also suggest that the SC-associated Jc is enhanced around geosynchronous orbit.</p> <div class="credits"> <p class="dwt_author">Kim, K.; Park, J.; Lee, E.; Lee, D.; Jin, H.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">144</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19820058201&hterms=high+magnetic+field&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dhigh%2Bmagnetic%2Bfield"> <span id="translatedtitle"><span class="hlt">Interplanetary</span> <span class="hlt">magnetic</span> field control of high-latitude activity on July 29, 1977</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Multisatellite particle and <span class="hlt">magnetic</span> field data for the substorms of July 29, 1977, show auroral-like activity above 80 deg invariant latitude during the recovery period. The movement of auroral zone activity to high latitudes followed the substorm sequence, at which time the inferred <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) was strongly northward. Electron energy spectra indicative of a field-aligned potential drop, and the absence of supporting precipitating ions, are found at latitudes greater than 80 deg. The north-south symmetry of these observations suggests that the events are on closed field lines. It is noted the very strong northward IMF connected to the sunward tilted geomagnetic dipole field plays a role in the driving of strong Birkeland and ionospheric current systems in the northern polar regions, while eliminating them from the southern polar regions.</p> <div class="credits"> <p class="dwt_author">Zanetti, L. J.; Potemra, T. A.; Doering, J. P.; Lee, J. S.; Fennell, J. F.; Hoffman, R. A.</p> <p class="dwt_publisher"></p> <p class="publishDate">1982-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">145</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19930042362&hterms=Maha&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DMaha"> <span id="translatedtitle">A global magnetohydrodynamic simulation of the magnetosheath and magnetosphere when the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field is northward</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">We have used a new high-resolution global magnetohydrodynamic simulation model to investigate the configuration of the magnetosphere when the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) is northward. For northward IMF the magnetospheric configuration is dominated by <span class="hlt">magnetic</span> reconnection at the tail lobe magnetopause tailward of the polar cusp. This results in a local thickening of the plasma sheet equatorward of the region of reconnection and the establishment of a convection system with two cells in each lobe. In the magnetosheath the plasma density and pressure decrease near the subsolar magnetopause, forming a depletion region. Along the flanks of the magnetosphere the magnetosheath flow is accelerated to values larger than the solar wind velocity. The magnetopause shape from the simulations is consistent with the empirically determined shape.</p> <div class="credits"> <p class="dwt_author">Ogino, Tatsuki; Walker, Raymond I.; Ashour-Abdalla, Maha</p> <p class="dwt_publisher"></p> <p class="publishDate">1992-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">146</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013AGUFMSA41A2104M"> <span id="translatedtitle">Modeling Cleft-Region Particle Precipitation Using the <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field and Generalized Auroral Electrojet Indices</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Cleft-region particle precipitation affects several ionospheric processes including ionospheric outflow and ionospheric plasma formations. Cleft-region particle precipitation has been shown to be dependent on the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) clock angle, the dayside-merging rate/local <span class="hlt">magnetic</span> field changes, and the characteristic energy of the particles. The OVATION-SM particle precipitation model between 0800 and 1600 MLT is modified to include IMF clock angle effects and model individual characteristic energies. The resulting cleft-region particle precipitation model will be shown as well as data-model comparisons with Polar UVI dayside data. The inclusion of characteristic energy dependence and IMF clock angle effects is expected to provide better dayside auroral power predictions and better spatial-temporal location of the cleft-region.</p> <div class="credits"> <p class="dwt_author">Mitchell, E. J.; Newell, P. T.; Ridley, A. J.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">147</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/6059089"> <span id="translatedtitle">Eastward propagation of a plasma convection enhancement following a southward turning of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">On October 27th 1984, high-latitude ionospheric convection was observed by the European incoherent scatter (EISCAT) radar. For a nine-hour period, simultaneous observations of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) were obtained sunward of the Earth's bow shock. During this period, the IMF abruptly turned southward, having previously been predominantly northward for approximately three hours, and a strong enhancement in convection was observed 11 +- 1 minutes later. Using the very high time resolution of the EISCAT data, it is shown that the convection enhancement propagated eastward, around the afternoon <span class="hlt">magnetic</span> local time sector, at a speed of the order of 1 kms/sup -1/. These results are interpreted in terms of the effects of an onset of steady IMF-geomagnetic field merging and are the first to show how a new pattern of enhanced convection is established in the high latitude ionosphere.</p> <div class="credits"> <p class="dwt_author">Lockwood, M.; van Eyken, A.P.; Bromage, B.J.I.; Willis, D.M.; Cowley, S.W.H.</p> <p class="dwt_publisher"></p> <p class="publishDate">1986-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">148</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19860056292&hterms=media+violen+effect&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dmedia%2Bviolen*%2Beffect"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Wilson, R. M.; Hildner, E.</p> <p class="dwt_publisher"></p> <p class="publishDate">1986-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">149</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.agu.org/journals/ja/v078/i019/JA078i019p03761/JA078i019p03761.pdf"> <span id="translatedtitle">Dependence of the polar cusp on the north--south component of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Ogo 5 observations of the polar cusp on November 1, 1968. show that the ; north-south component of the <span class="hlt">interplanetary</span> field exhibits control over both the ; location of and the physical processes occurring in the polar cusp. When the ; <span class="hlt">interplanetary</span> field turned from north to south, the polar cusp moved equatorward. ; During intervals when the <span class="hlt">interplanetary</span> field</p> <div class="credits"> <p class="dwt_author">Margaret G. Kivelson; Christopher T. Russell; Marcia Neugebauer; Frederick L. Scarf; Robert W. Fredricks</p> <p class="dwt_publisher"></p> <p class="publishDate">1973-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">150</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19760019713&hterms=Examples+moderate-intensity+amounts+physical+activity&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DExamples%2Bmoderate-intensity%2Bamounts%2Bphysical%2Bactivity"> <span id="translatedtitle">Physical characteristics of <span class="hlt">interplanetary</span> space</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">The most important properties of the <span class="hlt">interplanetary</span> medium are its <span class="hlt">interplanetary</span> plasma (solar wind), <span class="hlt">magnetic</span> field, galactic and solar cosmic rays, and micrometeorite material. Also considered is electromagnetic radiation from the sun, stars, and the galaxy.</p> <div class="credits"> <p class="dwt_author">Vernov, S. N.; Logachev, Y. I.; Pisarenko, N. F.</p> <p class="dwt_publisher"></p> <p class="publishDate">1975-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">151</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013AGUFMSM51C2194D"> <span id="translatedtitle"><span class="hlt">Magnetic</span> and plasma response of the Earth's magnetosphere to <span class="hlt">interplanetary</span> shock</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">In this paper, we investigate the global response of magnetosphere to <span class="hlt">interplanetary</span> shock, and focus on the <span class="hlt">magnetic</span> and plasma variations related to aurora. The analysis utilizes data from simultaneous observations of <span class="hlt">interplanetary</span> shocks from available spacecraft in the solar wind and the Earth's magnetosphere such as ACE, Wind and SOHO in solar wind, LANL and GOES in outer magnetosphere, TC1 in the midinight neutral plasma sheet, Geotail and Polar in dusk side of plasma sheet, and Cluster in downside LLBL. The shock front speed is ~1051 km/s in the solar wind, and ~981km/s in the Earth's magnetosphere. The shock is propagating anti-sunward (toward the Earth) in the plasma frame with a speed of ~320 km/s. After the shock bumps at the magnetopause, the dayside aurora brightens, then nightside aurora brightens and expanses to poleward. During the aurora activity period, the fast earthward and tailward flows in plasma sheet are observed by TC1 (X~7.1 Re, Y~1.2 Re). The variation of <span class="hlt">magnetic</span> field and plasma in duskside of magnetosphere is weaker than that in dawnside. At low latitude boundary layer (LLBL), the Cluster spacecraft detected rolled-up large scale vortices generated by the Kelvin-Helmholtz instability (KHI). Toroidal oscillations of the <span class="hlt">magnetic</span> field in the LLBL might be driven by the Kelvin-Helmholtz instability. The strong IP shock highly compresses the magnetopause and the outer magnetosphere. This process may also lead to particle precipitation and auroral brightening (Zhou and Tsurutani, 1999; Tsurutani et al., 2001 and 2003).</p> <div class="credits"> <p class="dwt_author">Du, A.; Cao, X.; Wang, R.; Zhang, Y.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">152</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ntis.gov/search/product.aspx?ABBR=N20020088125"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ntis.gov/search/index.aspx">National Technical Information Service (NTIS)</a></p> <p class="result-summary">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 conse...</p> <div class="credits"> <p class="dwt_author">I. G. Richardson E. W. Cliver H. V. Cane</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">153</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/53687202"> <span id="translatedtitle">Response of the ionospheric convection pattern to a rotation of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field on January 14, 1988</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Ionospheric convection signatures observed over the polar regions are provided by the DMSP F8 satellite. We consider five passes over the Southern summer Hemisphere during a time when the z component of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field was stable and positive and the y component changed slowly from positive to negative. Large-scale regions of sunward flow are observed at very high</p> <div class="credits"> <p class="dwt_author">J. A. Cumnock; R. A. Heelis; M. R. Hairston</p> <p class="dwt_publisher"></p> <p class="publishDate">1992-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">154</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/42030069"> <span id="translatedtitle">Explanation for anomalous equatorial ionospheric electric fields associated with a northward turning of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Anomalous reversals of the zonal equatorial electric field component have sometimes been observed when the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field turns northward from a steady southerly direction. We suggest that this reversal is associated with a sudden change in the convection electric field in the magnetosphere and present measurements to support this explanation. Although slower variations in the convection field are shielded</p> <div class="credits"> <p class="dwt_author">M. C. Kelley; B.G. Fejer; C.A. Gonzales</p> <p class="dwt_publisher"></p> <p class="publishDate">1979-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">155</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/48942495"> <span id="translatedtitle">Waves on the dusk flank boundary layer during very northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field conditions: Observations and simulation</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The Geotail spacecraft made an inbound passage perpendicular to the dusk equatorial magnetopause on 1 August 1998 when the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field had been very northward for more than 10 hours. As the spacecraft moved through the low-latitude boundary layer, it detected waves with ?3 min period that caused transitions between cool dense magnetosheath plasma and mixed magnetosheath and magnetosphere</p> <div class="credits"> <p class="dwt_author">D. H. Fairfield; M. M. Kuznetsova; T. Mukai; T. Nagai; T. I. Gombosi; A. J. Ridley</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">156</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20110023374&hterms=meaningful&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dmeaningful"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Szabo, Adam; Koval, A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">157</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014AAS...22421812Q"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Whether a <span class="hlt">magnetic</span> flux rope is pre-existing or in-situ formed 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: whether and how does the <span class="hlt">magnetic</span> reconnection change the flux rope structure? In this work, we continue with the original study by Qiu et al. (2007) by using a larger sample (19) of events to compare properties of ICME/MC flux ropes measured at 1 AU and properties of associated signatures (flares, CMEs, filaments) on the Sun. 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 systematicallyderived and examined. The analysis results show that these flux ropes exhibit either a rather flat twist distribution from center to edge or a high twist at the core which decreases toward the edge. We also present detailed case studies for selected events with the corresponding solar source regions either or not dominated by erupting filaments, and discuss how reconnection properties reflected in the flare morphology may be related to the structure of the enfant flux rope formed on the Sun.</p> <div class="credits"> <p class="dwt_author">Qiu, Jiong; Hu, Qiang</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-06-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">158</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014JGRA..119.1994M"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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.</p> <div class="credits"> <p class="dwt_author">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 class="dwt_publisher"></p> <p class="publishDate">2014-03-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">159</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2008AGUFMSM53A1669J"> <span id="translatedtitle">Response of the Equatorward Boundary of the Ion Auroral Oval to the Southward turning of the <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The response of the equatorward boundary of the ion aural oval in the dusk-midnight sector to the southward turning of the <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field (IMF), using ground based SuperDARN radars, is detailed in this paper. The equatorward boundary moves equatorward in response to the southward turning of the IMF. The equatorward motion is always delayed with respect to the southward turning of the IMF. We have estimated the boundary response delay using two methods. In the first method, we have directly used the measurement of the IMF by an upstream solar wind monitor and corrected for the propagation delay of the IMF change from the satellite to the ionosphere and estimated delay of the boundary response. This method yielded an <span class="hlt">average</span> delay of ~37 minutes. In the second method, in order to avoid the uncertainty in the estimation of the propagation delay from the IMF monitor to the ionosphere, we have used changes in the polar cap convection as a indicator of the arrival of the change in the IMF at the ionosphere and estimated the boundary response delay from the time of the polar cap convection change. This method yielded an <span class="hlt">average</span> delay of ~28 minutes. This confirms that the boundary response is always delayed with respect to the changes in the IMF and suggests the boundary response is consistent with the progressive propagating scenario of the changes associated with the transitions of the IMF.</p> <div class="credits"> <p class="dwt_author">Jayachandran, P. T.; MacDougall, J. W.; Sato, N.; Yikimatu, A. S.; Ebihara, Y.; Hamza, A. M.</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">160</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Humble, J. E.; Fenton, A. G.</p> <p class="dwt_publisher"></p> <p class="publishDate">1985-08-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_7");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' 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src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_8");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' href="#">4</a> <a onClick='return showDiv("page_5");' href="#">5</a> <a onClick='return showDiv("page_6");' href="#">6</a> <a onClick='return showDiv("page_7");' href="#">7</a> <a onClick='return showDiv("page_8");' href="#">8</a> <a style="font-weight: bold;">9</a> <a onClick='return showDiv("page_10");' href="#">10</a> <a onClick='return showDiv("page_11");' href="#">11</a> <a onClick='return showDiv("page_12");' href="#">12</a> <a onClick='return showDiv("page_13");' href="#">13</a> <a onClick='return showDiv("page_14");' href="#">14</a> <a onClick='return showDiv("page_15");' href="#">15</a> <a onClick='return showDiv("page_16");' href="#">16</a> <a onClick='return showDiv("page_17");' href="#">17</a> <a onClick='return showDiv("page_18");' href="#">18</a> <a onClick='return showDiv("page_19");' href="#">19</a> <a onClick='return showDiv("page_20");' href="#">20</a> <a onClick='return showDiv("page_21");' href="#">21</a> <a onClick='return showDiv("page_22");' href="#">22</a> <a onClick='return showDiv("page_23");' href="#">23</a> <a onClick='return showDiv("page_24");' href="#">24</a> <a onClick='return showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_10");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">161</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19850058891&hterms=high+magnetic+field&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dhigh%2Bmagnetic%2Bfield"> <span id="translatedtitle">Effect of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field y component on the high-latitude nightside convection</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Sondrestrom radar observations reveal that the dawn-dusk (By) component of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) strongly influences the nightside polar convection. This effect is quite complex. The convection for one orientation of By is not the mirror image of the other orientation. A positive By (i.e., pointing toward dusk) seems to organize the velocities such that, at all local times, they are predominantly westward within the radar field-of-view (approximately 68 deg-to-82 deg invariant latitude). Between dusk and midnight, on one such occasion, sunward flow is observed within the polar cap. In the midnight and dawn sectors, when By is negative, the plasma velocities often appear shifted toward early hours such that large southward velocities are observed about 3 hours before midnight. These are the only times when the predominant velocity component is southward.</p> <div class="credits"> <p class="dwt_author">De La Beaujardiere, O.; Wickwar, V. B.; Kelly, J. D.; King, J. H.</p> <p class="dwt_publisher"></p> <p class="publishDate">1985-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">162</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19780029186&hterms=GSM&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3D%2522GSM%2522"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Caan, M. N.; Mcpherron, R. L.; Russell, C. T.</p> <p class="dwt_publisher"></p> <p class="publishDate">1977-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">163</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Shue, J.-H.; Chao, J.-K.; Song, P.; McFadden, J. P.; Suvorova, A.; Angelopoulos, V.; Glassmeier, K. H.; Plaschke, F.</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-09-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">164</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Shue, J.; Chao, J. K.; Song, P.; McFadden, J. P.; Suvorova, A.; Angelopoulos, V.; Glassmeier, K.; Plaschke, F.</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">165</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/21562438"> <span id="translatedtitle">ON THE INTERNAL STRUCTURE OF THE <span class="hlt">MAGNETIC</span> FIELD IN <span class="hlt">MAGNETIC</span> CLOUDS AND <span class="hlt">INTERPLANETARY</span> CORONAL MASS EJECTIONS: WRITHE VERSUS TWIST</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">In this study, we test the flux rope paradigm by performing a 'blind' reconstruction of the <span class="hlt">magnetic</span> field structure of a simulated <span class="hlt">interplanetary</span> coronal mass ejection (ICME). The ICME is the result of a magnetohydrodynamic numerical simulation and does not exhibit much <span class="hlt">magnetic</span> twist, but appears to have some characteristics of a <span class="hlt">magnetic</span> cloud, due to a writhe in the <span class="hlt">magnetic</span> field lines. We use the Grad-Shafranov technique with simulated spacecraft measurements at two different distances and compare the reconstructed <span class="hlt">magnetic</span> field with that of the ICME in the simulation. While the reconstructed <span class="hlt">magnetic</span> field is similar to the simulated one as seen in two dimensions, it yields a helically twisted <span class="hlt">magnetic</span> field in three dimensions. To further verify the results, we perform the reconstruction at three different position angles at every distance point, and all results are found to be in agreement. This work demonstrates that the current paradigm of associating <span class="hlt">magnetic</span> clouds with flux ropes may have to be revised.</p> <div class="credits"> <p class="dwt_author">Al-Haddad, N.; Roussev, I. I.; Lugaz, N. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Moestl, C. [Space Research Institute, Austrian Academy of Sciences, Graz 8042 (Austria); Jacobs, C.; Poedts, S. [Centrum voor Plasma-Astrofysica, Katholieke Universiteit Leuven, Celestijnenlaan 200B, 3001 Leuven (Belgium); Farrugia, C. J., E-mail: iroussev@ifa.hawaii.edu, E-mail: nlugaz@ifa.hawaii.edu, E-mail: christian.moestl@oeaw.ac.at [Space Science Center and Department of Physics, University of New Hampshire, Durham, NH 03824 (United States)</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-09-10</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">166</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2002cosp...34E1781W"> <span id="translatedtitle">Modeling of galactic cosmic rays transport in the three dimensional <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Model of galactic cosmic rays (GCR) transport based on the generalized anisotropic diffusion tensor for the three dimensional <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) taking into account diffusion, convection, energy change due to interaction of GCR with the diverged solar wind and drifts of particles due to gradient and curvature of the regular IMF and on the heliospheric neutral sheet (HNS) has been considered. The components of the HNS drift velocity have been found for the various types of the three dimensional IMF suggested by different authors. The spatial distribution of different components of the generalized anisotropic diffusion tensor were calculated in the case of the existence of the latitudinal component of the IMF and their roles in the GCR modulation in the inner and outer heliosphere have been estim ated. It is shown that in equal other conditions a modulation of GCR is deeper for any kind of types of the three dimensional IMF in comparing with the two dimensional IMF if the existence of the latitudinal component leads to the increase of the module of the IMF. The expected spatial distributions of the density, gradients, fluxes and anisotropy of GCR have been found for the different values of the regular latitudinal component B of the IMF, B =1.5 nT and B = 2.5 nT. The expected anisotropy obtained from the numerical solution of transport equation is compared with the results of the anisotropy of GCR calculated by the experimental data of neutron monitors for different solar <span class="hlt">magnetic</span> cycles of the qA>0 and qA<0. An importance of the modeling of GCR transport in the <span class="hlt">interplanetary</span> space based on the generalized anisotropic diffusion tensor for the three dimensional IMF has been widely discussed.</p> <div class="credits"> <p class="dwt_author">Wawrzynczak, A.; Alania, M.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">167</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013SoPh..284..129A"> <span id="translatedtitle"><span class="hlt">Magnetic</span> Field Configuration Models and Reconstruction Methods for <span class="hlt">Interplanetary</span> Coronal Mass Ejections</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">This study aims to provide a reference for different <span class="hlt">magnetic</span> field models and reconstruction methods for <span class="hlt">interplanetary</span> coronal mass ejections (ICMEs). To understand the differences in the outputs of these models and codes, we analyzed 59 events from the Coordinated Data Analysis Workshop (CDAW) list, using four different <span class="hlt">magnetic</span> field models and reconstruction techniques; force-free fitting, magnetostatic reconstruction using a numerical solution to the Grad-Shafranov equation, fitting to a self-similarly expanding cylindrical configuration and elliptical, non-force-free fitting. The resulting parameters of the reconstructions for the 59 events are compared statistically and in selected case studies. The ability of a method to fit or reconstruct an event is found to vary greatly; this depends on whether the event is a <span class="hlt">magnetic</span> cloud or not. We find that the magnitude of the axial field is relatively consistent across models, but that the axis orientation of the ejecta is not. We also find that there are a few cases with different signs of the <span class="hlt">magnetic</span> helicity for the same event when we leave the boundaries free to vary, which illustrates that this simplest of parameters is not necessarily always clearly constrained by fitting and reconstruction models. Finally, we examine three unique cases in depth to provide a comprehensive idea of the different aspects of how the fitting and reconstruction codes work.</p> <div class="credits"> <p class="dwt_author">Al-Haddad, N.; Nieves-Chinchilla, T.; Savani, N. P.; Mstl, C.; Marubashi, K.; Hidalgo, M. A.; Roussev, I. I.; Poedts, S.; Farrugia, C. J.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-05-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">168</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2011SoPh..270..609R"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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 80% of cases, the GCR intensity decreased during the passage of these structures, i.e., a "Forbush decrease" occurred, while in 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 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. J. 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> <div class="credits"> <p class="dwt_author">Richardson, I. G.; Cane, H. V.</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-06-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">169</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/6371333"> <span id="translatedtitle">A global simulation of the magnetosphere with a long tail: Southward and northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">The authors report on a simulation of the earth's magnetosphere interacting with the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF), studied on a global scale. Questions such as the response time of the magnetosphere to changes in the solar wind orientation, or explanations for the origin of magnetospheric substorms have to be addressed on global rather than local scales. Several theories have produced promising results for explaining the interaction of the solar wind and the magnetosphere, and recent data analyses of ISEE 1 and 2 data have provided more information bearing on this issue. The authors ask two main questions: first, how does the magnetospheric response change with northward vs southward orientation of the IMF; and second, how do the northward or southward components of the IMF impact on <span class="hlt">magnetic</span> reconnection processes in the plasma sheet This computerized simulation uses a model and code previously developed, and studies the questions in the framework of resistive MHD equations. The authors conclude that a southward IMF does reconnect along the dayside magnetopause, and the initiation of this reconnection serves to induce plasma sheet reconnection. As a consequence plasmoids are formed in the magnetotail, and accelerated both earthward and tailward. A northward IMF acts to stop plasma sheet reconnection, by removing <span class="hlt">magnetic</span> flux from the outer part of the magnetosphere, which decreases cross-tail currents, inhibiting plasma sheet reconnection. <span class="hlt">Magnetic</span> pressure effects due to the presence of a northward IMF also cause the shape of the magnetosphere to change from its more normal cometlike tail to something resembling a tadpole.</p> <div class="credits"> <p class="dwt_author">Usadi, A.; Kageyama, A. (Hiroshima Univ. (Japan)); Watanabe, K.; Sato, T. (National Inst. for Fusion Science, Nagoya (Japan))</p> <p class="dwt_publisher"></p> <p class="publishDate">1993-05-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">170</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Chian, Abraham C.-L. [California Institute of Technology, Pasadena, CA 91125 (United States); Munoz, Pablo R., E-mail: abraham.chian@gmail.com, E-mail: pablocus@gmail.com [National Institute for Space Research (INPE) and World Institute for Space Environment Research (WISER), P.O. Box 515, Sao Jose dos Campos SP 12227-010 (Brazil)</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-06-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">171</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/60030903"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">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 was</p> <div class="credits"> <p class="dwt_author">M. Yamauchi; T. Araki</p> <p class="dwt_publisher"></p> <p class="publishDate">1989-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">172</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19750032142&hterms=solar+photospheric+magnetic&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dsolar%2Bphotospheric%2Bmagnetic"> <span id="translatedtitle">Solar cycle variation of large-scale coronal structures. [relationship to <span class="hlt">interplanetary</span> and photospheric <span class="hlt">magnetic</span> field configurations</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">A green line intensity variation is associated with the <span class="hlt">interplanetary</span> and photospheric <span class="hlt">magnetic</span> sector structure. This effect depends on the solar cycle and occurs with the same amplitude in the latitude range 60 N-60 S. Extended longitudinal coronal structures are suggested, which indicate the existence of closed <span class="hlt">magnetic</span> field lines over the neutral line, separating adjacent regions of opposite polarities on the photospheric surface.</p> <div class="credits"> <p class="dwt_author">Antonucci, E.; Duvall, T. L.</p> <p class="dwt_publisher"></p> <p class="publishDate">1974-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">173</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012JGRA..117.4218N"> <span id="translatedtitle">Substorm-like magnetospheric response to a discontinuity in the Bx component of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We examined the magnetospheric <span class="hlt">magnetic</span> field and plasma responses to an encounter of a discontinuity in the Bx component of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF). The striking variations of simultaneous solar wind dynamic pressure and IMF-Bz were not observed. Furthermore, we found that this IMF-Bx discontinuity was a heliospheric current sheet, separating two high-speed solar wind streams with different velocity and <span class="hlt">magnetic</span> polarity. In this study, the <span class="hlt">magnetic</span> field and plasma data were obtained from Time History of Events and Macroscale Interactions during Substorms (THEMIS), Cluster, and GOES to investigate the magnetospheric responses, and those were taken from ACE and Geotail to monitor the solar wind conditions. Simultaneous geomagnetic field variations from the ground observatories and aurora activity from Polar were also examined. When the discontinuity encountered the magnetosphere, THEMIS-D, -E, and THEMIS-A observed abrupt and transient <span class="hlt">magnetic</span> field and plasma variations in the dawnside near-Earth magnetotail and tail-flank magnetopause. Significant <span class="hlt">magnetic</span> field perturbations were not observed by Cluster as located in the duskside magnetotail at this time interval. Although simultaneous dipolarization and negative bay variations with Pi2 waves were observed by GOES and the ground observatories, global auroral activities were not found. Around the dawnside tail-flank magnetopause, THEMIS-C and -A experienced the magnetopause crossings due to the magnetopause surface waves induced by Kelvin-Helmholtz instability. These results suggest that the <span class="hlt">magnetic</span> field and plasma variations in the near-Earth magnetotail and tail-flank magnetopause were caused by moderate substorm-like phenomena and magnetopause surface waves. They also indicate that clear magnetospheric disturbances can be brought even without significant variations in the solar wind.</p> <div class="credits"> <p class="dwt_author">Nowada, M.; Lin, C.-H.; Pu, Z.-Y.; Fu, S.-Y.; Angelopoulos, V.; Carlson, C. W.; Auster, H.-U.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-04-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">174</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012AGUFMSH11A2189B"> <span id="translatedtitle">The Role of the Interstellar and <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Fields in the Heliopause Stability</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The heliopause (HP) is a tangential discontinuity that separates the interacting streams of the solar wind and local interstellar medium. As Voyagers approach the heliopause, the issues related to the HP structure and dynamics are of fundamental importance for interpreting the spacecraft observations. The heliopause is subject to different types instabilities, such as the Rayleigh-Taylor instability driven and mediated by interstellar neutral atoms and the Kelvin-Helmholtz instability of the heliopause flanks driven by secondary hot neutral hydrogen atoms created by charge exchange of interstellar neutrals with the hot heliosheath plasma. It is known the <span class="hlt">magnetic</span> field tension is the only physical effect that may stabilize the heliopause. We analyze role of <span class="hlt">interplanetary</span> and interstellar <span class="hlt">magnetic</span> fields in the development and evolution of the heliopause instabilities using 3D, high-resolution, adaptive mesh refinement calculations of the solar wind interaction with the local interstellar medium. Numerical results are compared with analytical stability considerations of a tangential discontinuity, with an arbitrary orientation and strength of the <span class="hlt">magnetic</span> field on both sides, in a stream of hydrogen atoms.</p> <div class="credits"> <p class="dwt_author">Borovikov, S. N.; Pogorelov, N. V.; Avinash, K.; Dasgupta, B.; Zank, G. P.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">175</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/21576547"> <span id="translatedtitle">CORONAL JETS, <span class="hlt">MAGNETIC</span> TOPOLOGIES, AND THE PRODUCTION OF <span class="hlt">INTERPLANETARY</span> ELECTRON STREAMS</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">We investigate the acceleration source of the impulsive solar energetic particle (SEP) events on 2007 January 24. Combining the in situ electron measurements and remote-sensing solar observations, as well as the calculated <span class="hlt">magnetic</span> fields obtained from a potential-field source-surface model, we demonstrate that the jets associated with the hard X-ray flares and type-III radio bursts, rather than the slow and partial coronal mass ejections, are closely related to the production of <span class="hlt">interplanetary</span> electron streams. The jets, originated from the well-connected active region (AR 10939) whose <span class="hlt">magnetic</span> polarity structure favors the eruption, are observed to be forming in a coronal site, extending to a few solar radii, and having a good temporal correlation with the electron solar release. The open-field lines near the jet site are rooted in a negative polarity, along which energetic particles escape from the flaring AR to the near-Earth space, consistent with the in situ electron pitch angle distribution. The analysis enables us to propose a coronal <span class="hlt">magnetic</span> topology relating the impulsive SEP events to their solar source.</p> <div class="credits"> <p class="dwt_author">Li, C.; Matthews, S. A.; Van Driel-Gesztelyi, L.; Sun, J.; Owen, C. J., E-mail: cl2@mssl.ucl.ac.uk [Mullard Space Science Laboratory, University College London, Dorking, Surrey RH5 6NT (United Kingdom)</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-07-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">176</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/5103583"> <span id="translatedtitle">Polar region Birkeland current, convection, and aurora for northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">Viking <span class="hlt">magnetic</span> field, electric field, and image data have been used to assess polar region phenomena for steady state northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) conditions. Regions of polar Birkeland current and convection and their extent from the vicinity of the <span class="hlt">magnetic</span> pole are determined. Also discussed are mechanisms that could produce polar aurora in general; two suggestions are (1) converging electric fields from convection patterns alone and (2) the bifurcation of the magnetotail with its associated plasma transport from convection patterns. Macroscopic (> 1{degree} latitude) systems of Birkeland currents and convection in the polar regions have been established for a case on April 9, 1986, from Viking spacecraft data. The current systems were confined to the highest latitudes of the polar regions and occurred during strongly northward IMF with a significantly negative B{sub x}. An arc extends across the polar region within the dawn cell of Birkeland current. The arc is located at a sunward to antisunward convection reversal that corresponds to a converging electric field. A converging electric field ({gradient} {center dot} E < 0) alone is suggested as the cause of this polar arc. The signature of both transverse disturbance vectors indicates that the polar region dawn NBZ Birkeland current does not connect to the dayside auroral region. It is inferred that the dawn polar region convection cell associated with this Birkeland current is also limited in the sunward direction and does not connect to the dayside auroral region convection.</p> <div class="credits"> <p class="dwt_author">Zanetti, L.J.; Potemra, T.A.; Erlandson, R.E.; Bythrow, P.F.; Anderson, B.J. (Johns Hopkins Univ., Laurel, MD (United States)); Murphree, J.S. (Univ. of Calgary, Alberta (Canada)); Marklund, G.T. (Royal Inst. of Tech., Stockholm (Sweden))</p> <p class="dwt_publisher"></p> <p class="publishDate">1990-05-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">177</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2007JGRD..112.4103B"> <span id="translatedtitle"><span class="hlt">Interplanetary</span> <span class="hlt">magnetic</span> field and atmospheric electric circuit influences on ground-level pressure at Vostok</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The Mansurov effect, which for the Southern Hemisphere consists of a positive association between the By component (east-west) of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) and the ground-level pressure for stations poleward of ~80 <span class="hlt">magnetic</span> latitude, is confirmed for Vostok (78.5S, 106.9E <span class="hlt">magnetic</span> latitude 83.6S) using modern data. The magnitude of the association is small (0.19 hP per nT; 1.2% common covariance) but statistically significant (at the 96.1% level). A more substantial association exists, with a slight delay (2-3 days) and a cumulative influence, between the Vostok station pressure and the local vertical electric field, a proxy for the air-Earth current Jz. A composite series constructed as a weighted sum of vertical electric field values at lags between 1 and 4 days yields a linear regression gradient with respect to Vostok station-level pressure of 0.10 hP per Vm-1, 10.0% common covariance and is statistically significant at the 99.9% level. We confirm a previously reported Sun-weather linkage (the Mansurov effect), provide evidence that the mechanism operates via the atmospheric electric circuit and present data supporting an inferred and more substantial surface pressure response to changes in the global atmospheric circuit.</p> <div class="credits"> <p class="dwt_author">Burns, G. B.; Tinsley, B. A.; Frank-Kamenetsky, A. V.; Bering, E. A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-02-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">178</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19820005721&hterms=max+klein&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dmax%2Bklein"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Burlaga, L. F.; Lepping, R. P.; Behannon, K. W.; Klein, L. W.; Neubauer, F. M.</p> <p class="dwt_publisher"></p> <p class="publishDate">1981-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">179</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/49919591"> <span id="translatedtitle">High <span class="hlt">average</span> power <span class="hlt">magnetic</span> modulator for copper lasers</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary"><span class="hlt">Magnetic</span> compression circuits show the promise of long life for operation at high <span class="hlt">average</span> powers and high repetition rates. When the Atomic Vapor Laser Isotope Separation (AVLIS) Program at Lawrence Livermore National Laboratory needed new modulators to drive their higher power copper lasers in the Laser Demonstration Facility (LDF), existing technology using thyratron switched capacitor inversion circuits did not meet</p> <div class="credits"> <p class="dwt_author">E. G. Cook; D. G. Ball; D. L. Birx; J. D. Branum; S. E. Peluso; M. D. Langford; R. D. Speer; J. S. Sullivan; P. G. Woods</p> <p class="dwt_publisher"></p> <p class="publishDate">1991-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">180</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014JGRA..119.2550G"> <span id="translatedtitle">A survey of quiet auroral arc orientation and the effects of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Using data from the THEMIS All-Sky Imager array, we have carried out an extensive study of the orientation of quiet auroral arcs relative to the <span class="hlt">magnetic</span> east-west direction. We used over 7500 images of quiet auroral arcs that were collected during extended solar minimum and at various geomagnetic latitudes and longitudes. For each arc, we determined its "tilt" (the angle the arc makes with the local <span class="hlt">magnetic</span> east-west direction) and its "multiplicity" (whether or not the arc was part of a multiple-arc system). We have found that at more equatorward latitudes, arc tilts are within ?SD = 7.7?. We determined that both single- and multiple-arc systems tend to tilt a few degrees to the south-east prior to 23 <span class="hlt">magnetic</span> local time (MLT) and to the north-east afterward. This tilt appears to be more prominent at higher latitudes. We compared the auroral arc orientations to the mapping of equatorial contours of constant <span class="hlt">magnetic</span> field strength into the ionosphere, where we used the T87 and T89 <span class="hlt">magnetic</span> field models for quiet (Kp = 1,3) conditions for the mappings and to determine the constant equatorial <span class="hlt">magnetic</span> field strength contours. We found that the MLT trends of the tilts are such that arc alignment appears to follow the constant <span class="hlt">magnetic</span> field strength contours as projected into the ionosphere. We assert that the systematic dependencies of the orientation of auroral arcs indicate that arc morphology is governed by the large-scale structure of the magnetosphere as opposed to localized processes within the ionosphere. In addition, we studied the effects of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) on the location in MLT of the reversal of the arc tilts. We found that negative IMF Bxand Byconditions cause the reversal location to shift duskward of 23 MLT. Alternately, a positive IMF Bx, coupled with a negative By, results in a shift in reversal location toward <span class="hlt">magnetic</span> midnight. This behavior is consistent with that found in studies of the MLT distribution of substorm onsets.</p> <div class="credits"> <p class="dwt_author">Gillies, D. M.; Knudsen, D. J.; Donovan, E. F.; Spanswick, E. L.; Hansen, C.; Keating, D.; Erion, S.</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-04-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_8");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a 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<img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_9");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' href="#">4</a> <a onClick='return showDiv("page_5");' href="#">5</a> <a onClick='return showDiv("page_6");' href="#">6</a> <a onClick='return showDiv("page_7");' href="#">7</a> <a onClick='return showDiv("page_8");' href="#">8</a> <a onClick='return showDiv("page_9");' href="#">9</a> <a style="font-weight: bold;">10</a> <a onClick='return showDiv("page_11");' href="#">11</a> <a onClick='return showDiv("page_12");' href="#">12</a> <a onClick='return showDiv("page_13");' href="#">13</a> <a onClick='return showDiv("page_14");' href="#">14</a> <a onClick='return showDiv("page_15");' href="#">15</a> <a onClick='return showDiv("page_16");' href="#">16</a> <a onClick='return showDiv("page_17");' href="#">17</a> <a onClick='return showDiv("page_18");' href="#">18</a> <a onClick='return showDiv("page_19");' href="#">19</a> <a onClick='return showDiv("page_20");' href="#">20</a> <a onClick='return showDiv("page_21");' href="#">21</a> <a onClick='return showDiv("page_22");' href="#">22</a> <a onClick='return showDiv("page_23");' href="#">23</a> <a onClick='return showDiv("page_24");' href="#">24</a> <a onClick='return showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_11");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">181</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19970026617&hterms=equia&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dequia"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Hau, L.-N.; Erickson, G. M.</p> <p class="dwt_publisher"></p> <p class="publishDate">1995-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">182</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2007AGUFMSH23A1165L"> <span id="translatedtitle">Search for Persistent Quasi-Periodicities in the Solar and <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Fields</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Previous analysis of the radial component of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field from 1962 - 1998 has revealed a dominant frequency of 27.03 days to 0.02 day accuracy (Neugebauer, et al., 2000). We have repeated and extended this analysis with OMNI data from 1963 - 2007 obtained from the Coordinated Heliospheric Observations (COHO) database. Over this longer data string we find that the 27.03 day Lomb-Scargle periodogram peak is reduced while two side peaks near 26.8 days and 27.6 days become almost as strong. In the interval 1999-2007 there are two dominant periods near 26.5 days and 27.2 days. As a solar counterpart to the above analysis we have searched for persistent rotation periods near 27 days of global patterns of photospheric <span class="hlt">magnetic</span> fields derived from Wilcox Solar Observatory synoptic Carrington rotation maps. Techniques applied include, principal components analysis, independent component analysis, singular spectrum analysis, wavelet spectral analysis, and complex demodulation. We find a variety of quasi- periodicities between 26 and 29 days that remain coherent for 1 - 2 years. In the southern solar hemisphere the strongest periodicity is at 28.2 days, while in the northern hemisphere it is around 26.5 days. Neugebauer, M., Smith, Smith, E.J., Ruzmaikin, A., Feynman, J., Vaughan, A.H. 2000, J. Geophys. Res., 106, A5, 8363.</p> <div class="credits"> <p class="dwt_author">Lawrence, J. K.; Cadavid, A. C.; Ruzmaikin, A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">183</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1998JGR...103.9351L"> <span id="translatedtitle">Space weather: Response of large-scale geopotentials to an <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> cloud</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The interaction of solar wind disturbances with the Earth's magnetosphere can produce disturbances, and at times complete disruptions, of technological systems on the Earth and in the space around the Earth. This brief report shows the changes induced in the large-scale geopotentials of the Earth (as provided from measurements across transoceanic cables) produced by a well-documented <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> cloud event. The study of such a well-measured event can be used to begin to make empirical space weather phenomena more quantitative. We show that geopotentials at low geomagnetic latitudes can be used to infer the time derivative of the near-equatorial <span class="hlt">magnetic</span> disturbance index, Dst. At low geomagnetic latitudes, a peak geopotential of about 4 mV/km is found to correspond to a time rate of change of this index of about 50 nT/hr. Further, we show that in this event increases in the near-equatorial geopotential are linearly related to the energy input to the magnetosphere from the solar wind as given by the ? parameter [e.g., Akasofu, 1979]. We find that an increase in the geopotential of about 4 mV/km corresponds to an energy input of about 2.81011W for the event analyzed here.</p> <div class="credits"> <p class="dwt_author">Lanzerotti, L. J.; Medford, L. V.; Sayres, D. S.; Maclennan, C. G.; Lepping, R. P.; Szabo, A.</p> <p class="dwt_publisher"></p> <p class="publishDate">1998-05-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">184</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/5289367"> <span id="translatedtitle">Nonlocal plasma turbulence associated with <span class="hlt">interplanetary</span> shocks</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">The plasma wave instrument on ISEE 3 has detected regions of plasma turbulence that extend several tenths of an astronomical unit upstream or downstream of <span class="hlt">interplanetary</span> shocks. The plasma waves fall into four categories. Highly impulsive 1- 10-kHz electric field bursts were found hours upstream of quasi-parallel <span class="hlt">interplanetary</span> shocks. On occasion their <span class="hlt">average</span> and peak amplitudes increased monotonically until the shock crossing, at which time they were suppressed. A lower frequency electric field (0.1--1 kHz) component was enhanced at nearly all shocks and persisted downstream. Broadband low-frequency (typically <178 Hz) <span class="hlt">magnetic</span> fluctuations increased at, and persisted hours downstream of, every <span class="hlt">interplanetary</span> shock in our sample. A smooth high-frequency continuum, near and above the local electron plasma frequency, was enhanced at, and persisted well downstream of, every <span class="hlt">interplanetary</span> shock we studied. Impulsive electron plasma wave bursts were occasionally found near the shocks. The shock-associated plasma waves we found to extend over large spatial scales are similar to those found previously in local studies of <span class="hlt">interplanetary</span> shocks. While no single <span class="hlt">interplanetary</span> shock showed every effect, the ensemble of shocks contained at least one example of each type of plasma wave found upstream of the earth's bow shock. The 1- to 10-kHz spectra upstream of <span class="hlt">interplanetary</span> shocks and the earth's bow shock are similar. The low-frequency electric and <span class="hlt">magnetic</span> fluctuations downstream of <span class="hlt">interplanetary</span> shocks and the bow shock have similar spectra. They seem to be ubieuitous features of flowing plasmas made turbulent by a shock.</p> <div class="credits"> <p class="dwt_author">Kennel, C.F.; Scarf, F.L.; Coroniti, F.V.; Smith, E.J.; Gurnett, D.A.</p> <p class="dwt_publisher"></p> <p class="publishDate">1982-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">185</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19740021616&hterms=high+magnetic+field&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dhigh%2Bmagnetic%2Bfield"> <span id="translatedtitle">The relation of variations in total <span class="hlt">magnetic</span> field at high latitude with the parameters of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field and with DP2 fluctuations. [using OGO -3-C, and -4 observations</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">The maximum disturbances from the positive and negative regions of delta B (Bp and Bn, respectively) are investigated with respect to their correlation with (1) the <span class="hlt">average</span> N-S component, Bz, (2) the <span class="hlt">average</span> angle with respect to the solar magnetospheric equatorial plane, theta (3) the variance, sigma sub i, and (4) the magnitude, Bi, of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field. These quantities were <span class="hlt">averaged</span> over a period, T, ranging from 20 min. to 8 hours prior to the measurement of Bp or Bn. Variations (i.e., disturbances) in total <span class="hlt">magnetic</span> field magnitude were studied utilizing data from the Polar Orbiting Geophysical Observatory satellites (OGO 2, 4, and 6), unofficially referred to as POGO.</p> <div class="credits"> <p class="dwt_author">Langel, R. A.</p> <p class="dwt_publisher"></p> <p class="publishDate">1974-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">186</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/49167442"> <span id="translatedtitle">Superconducting <span class="hlt">magnets</span> and mission strategies for protection from ionizing radiation in <span class="hlt">interplanetary</span> manned missions and <span class="hlt">interplanetary</span> habitats</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">First order evaluations for active shielding based on superconducting <span class="hlt">magnetic</span> lenses were made in the past in ESA supported studies. The present increasing interest of permanent space complexes, to be considered in the far future as bases rather than stations, located in deep space (as it has been proposed for the L1 librations point between Earth and Moon, or for</p> <div class="credits"> <p class="dwt_author">Piero Spillantini</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">187</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.agu.org/journals/ja/v076/i022/JA076i022p05189/JA076i022p05189.pdf"> <span id="translatedtitle">SIGNATURE IN THE <span class="hlt">INTERPLANETARY</span> MEDIUM FOR SUBSTORMS</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">A detailed signature for individual substorms is sought in the <span class="hlt">interplanetary</span> medium. Hourly values of <span class="hlt">interplanetary</span> field and plasma parameters are correlated with hourly <span class="hlt">averages</span> of the AE index. An <span class="hlt">interplanetary</span> variable involving the southward component of the <span class="hlt">interplanetary</span> field in the solar magnetospheric coordinate system is shown to be singularly important for the generation of substorms. The parameter best</p> <div class="credits"> <p class="dwt_author">Roger L. Arnoldy</p> <p class="dwt_publisher"></p> <p class="publishDate">1971-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">188</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2010cosp...38.2067J"> <span id="translatedtitle">Magnetohydrodynamic Simulation of the Earth's Magnetotail Response to the <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field Variations</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">In the present work, a study of the dynamical response of the macroscopic parameters, den-sity, pressure, and velocity, of the Earth's magnetotail, was carried out. The goal of this work was to study the variation of such parameters as a response to the different topologies of the <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field (IMF) present in some of the geoeffective solar wind <span class="hlt">magnetic</span> structures. We used Magnetohydrodynamic simulation in order to approach this problem. The bi-dimensional Magnetohydrodynamic code was originally developed by Ogino et al. (1986), being restricted to the formation of the terrestrial magnetosphere with a stationary IMF. After we performed the necessary modifications in the original code, the magnetospheric dynamics was observed. Based on that, we investigated the response of the different regions of the magne-tosphere (specially the magnetotail) to different IMF conditions. Four different configurations of the IMF were analyzed when interacting with the Earth's magnetosphere. Among these different topologies, one could find a representative for a positive shock, i.e, a shock with a pos-itive Bz , another for a negative shock, i.e, a shock with a negative Bz , an idealized HILDCAA event with a Bz squared fluctuation similar to an Alfvnic one, and, finally, a structure similar to a <span class="hlt">Magnetic</span> Cloud. The considered changes in the IMF configuration favored the observation of different physical processes. Among these processes, it was possible to observe the forma-tion of the Near-Earth Neutral Line for the IMF configuration representative of a negative Bz (negative shock). Furthermore, a plasmoid release was observed, which is associated with one of the most dynamics phenomena in the terrestrial magnetosphere: the substorm.</p> <div class="credits"> <p class="dwt_author">Jauer, Paulo Ricardo; Echer, Ezequiel; Alves, Maria Virginia</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">189</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/48456770"> <span id="translatedtitle"><span class="hlt">Averaging</span> of the <span class="hlt">magnetic</span> properties of fibrous ferromagnetic composites</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Within the framework of the model of regular structures, we <span class="hlt">average</span> the <span class="hlt">magnetic</span> properties of fibrous ferromagnetic composites\\u000a with biperiodic structure. For the general case of packing of the fibers in any cross section, the problem is reduced to finding\\u000a certain functionals determined from the solutions of a regular integral equation of the corresponding boundary-value problem\\u000a of magnetostatics for the</p> <div class="credits"> <p class="dwt_author">L. A. Filshtynskyi; Yu. V. Shramko; D. S. Kovalenko</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">190</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2000GeoRL..27..617A"> <span id="translatedtitle">Galactic cosmic ray diurnal modulation, <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field intensity and the planetary index Ap</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We have studied the data strings for the limiting rigidity (Rc) for the galactic cosmic ray (GCR) solar diurnal anisotropy, the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) intensity (B), and the planetary index Ap for the period 1963 to 1998. The study covers three sunspot number (SSN) cycles (20, 21, 22). Our analysis brings out some of the steady state characteristics of the long term changes in Rc and other data strings and their interrelationships. Among other things, we relate the observed changes in Rc values to changes in B which are not related to SSN; the largest value of Rc occurs near 1982 when B has a high value 3 years away from SSN maximum for cycle 21. Rc bears a linear correlation with B and Ap but shows a low correlation with the power in the low frequency turbulence in IMF. The fit parameters with Ap data may be used to compute the values of Rc when in situ measurements of B do not exist; they may be applied to the cosmic ray data (available since 1937) to compute the amplitude and the phase of the diurnal anisotropy and to estimate more accurately the values of the key heliospheric transport parameters at high GCR rigidities near earth's orbit.</p> <div class="credits"> <p class="dwt_author">Ahluwalia, H. S.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">191</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2010JGRA..115.9210M"> <span id="translatedtitle">Varying <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field By effects on interhemispheric conjugate auroral features during a weak substorm</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Interhemispheric conjugate auroral features during a weak substorm interval were investigated using simultaneous all-sky camera (ASC) measurements at the northern and southern geomagnetic conjugate points at Tjrnes (TJO; 66.2N, 342.9E) in Iceland and Syowa Station (SYO; 69.0S, 39.6E) in Antarctica. Around postmidnight, just after the substorm onset, the ASC field of view (FOV) at TJO was first filled with dynamic auroral activations; however, its counterpart was not detected over the zenith at SYO at that time. In contrast, in the late stage (about 20 min after the onset) of substorm development we observed spiral-like auroral arcs with a similar shape drifting eastward across the center of each ASC FOV, although the one at TJO preceded the one at SYO. The time sequence of the interhemispheric conjugate auroral features was well reflected in the geomagnetic field variations at both stations. On the basis of a detailed comparison of both ASC images, we identified that the northern geomagnetic footprint of SYO was displaced poleward of TJO by up to 3.0 or more in the initial stage of substorm development, whereas in the late stage it was displaced eastward by up to 1 h relative to TJO and then moved closer to TJO. We emphasize that the dynamic motion of the conjugate points is a consequence of the time-dependent magnetotail field reconfiguration process, controlled by the varying <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field By polarity.</p> <div class="credits"> <p class="dwt_author">Motoba, T.; Hosokawa, K.; Sato, N.; Kadokura, A.; Bjornsson, G.</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-09-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">192</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2006EP%26S...58..679A"> <span id="translatedtitle">Influence of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field on the ring current injection rate</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">In order to check the validity of Akasofu's ? parameter and of the Vasyliunas et al. (1982) general formula, we examine the dependence of the ring current injection rate, calculated from the Dst index for the period of 1965-1990, on the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF). We compare the influence of the Bz component with the influence of the combination of sin ?/2, where ? is the IMF clock angle, and the IMF magnitude, B, (or the transverse component of the IMF, BT = (By2 + Bz2)1/2) by using the regression analysis in a power law form. The main results are as follows: (1) the exponent for Bz shows higher consistency than that for sin(?/2); (2) we never obtain B2 sin4(?/2) or B2T sin4(?/2), which is the IMF dependence expected from the ? parameter; and (3) the ring current injection rate has a very low correlation with the Alfven Mach number, from which the IMF dependence of the Vasyliunas et al. general formula is assumed to arise. On the basis of the above results we conclude that the ? parameter and the Vasyliunas et al. general formula are less appropriate than a function of Bz, and that the energy coupling function between the solar wind and the Earth's magnetosphere is described better by Bz than by the combination of B (or BT) and sin (?/2). The above results and conclusions are the same as those obtained by Aoki (2005) through the analysis of the AL index.</p> <div class="credits"> <p class="dwt_author">Aoki, T.</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-05-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">193</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2009JGRA..114.3216Y"> <span id="translatedtitle">Response of the magnetosphere-ionosphere system to a sudden southward turning of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">A sudden southward turning of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) is simulated by the University of Michigan's BATS-R-US model. The main goal of this study is to determine the time delay as well as physical processes between when an IMF discontinuity reaches the bow shock, when reconnection is initiated at the magnetopause, and when the ionosphere starts to react. While observations or empirical models might give an estimate of the time delay for the propagation of the discontinuity from the bow shock to the magnetopause, the global MHD simulation provides a more comprehensive insight of responses of the magnetosphere-ionosphere system. An idealized north-to-south IMF transition is modeled, using a solar wind velocity of 400 km/s. After the southward IMF encounters the bow shock, it takes about 6 min for the north-to-south IMF transition front to arrive at the subsolar geomagnetic field. The ionospheric response to this sudden southward IMF turning is delayed by another ~4 min, during which the magnetosphere undergoes a conversion from cusp reconnection to subsolar reconnection and the Alfvn wave propagation to the ionosphere takes place. Thereafter, changes in the ionosphere and ground <span class="hlt">magnetic</span> perturbations associated with the southward IMF are observed. These responses appear to be globally onset as described in many other studies. The time it takes from the encounter of the IMF transition with the bow shock to when the ionospheric reaction takes place varies with the solar wind speed, ranging from nearly 15 min for a solar wind speed of 300 km/s to just over 6 min for solar wind speeds of 600 km/s.</p> <div class="credits"> <p class="dwt_author">Yu, Yiqun; Ridley, Aaron J.</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-03-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">194</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Juusola, L.; Milan, S. E.; Lester, M.; Grocott, A.; Imber, S. M.</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-04-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">195</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19730018611&hterms=spiral+line&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3D%2522spiral%2Bline%2522"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Svalgaard, L.</p> <p class="dwt_publisher"></p> <p class="publishDate">1973-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">196</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2011AcAau..68.1430S"> <span id="translatedtitle">Superconducting <span class="hlt">magnets</span> and mission strategies for protection from ionizing radiation in <span class="hlt">interplanetary</span> manned missions and <span class="hlt">interplanetary</span> habitats</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">First order evaluations for active shielding based on superconducting <span class="hlt">magnetic</span> lenses were made in the past in ESA supported studies. The present increasing interest of permanent space complexes, to be considered in the far future as 'bases' rather than 'stations', located in 'deep' space (as it has been proposed for the L1 libration's point between Earth and Moon, or for Stations in orbit around Mars), requires that this preliminary activity continues, envisaging the problem of the protection from cosmic ray (CR) action at a scale allowing long permanence in 'deep' space, not only for a relatively small number of dedicated astronauts but also to citizens conducting there 'normal' activities. Part of the personnel of such a 'deep space base' should stay and work there for a long period of time. It is proposed that the activities and life of these personnel will be concentrated in a sector protected from Galactic CR (GCR) during the whole duration of their mission. In the exceptional case of an intense flux of Solar Energetic Protons (SEP), this sector could be of use as a shelter for all the other personnel normally located in other sectors of the Space Base. The realization of the <span class="hlt">magnetic</span> protection of the long permanence sector by well-established current materials and techniques is in principle possible, but not workable in practice for the huge required mass of the superconductor, the too low operating temperature (10-15 K) and the corresponding required cooling power and thermal shielding. However the fast progress in the production of reliable High Temperature Superconducting (HTS) or MgB 2 cables and of cryocoolers suitable for space operation opens the perspective of practicable solutions. In fact these cables, when used at relatively low temperature, but in any case higher than for NbTi and Nb 3Sn, show a thermodynamically much better behavior. Quantitative evaluations for the protection of the sector of the 'Space Base' to be protected from GCRs (and therefore from SEPs also) are presented. For possible large outer radius solutions it must in the meantime solve the problem of the assembling or deploying in space the conductors for returning the electric current.</p> <div class="credits"> <p class="dwt_author">Spillantini, Piero</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-05-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">197</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012AnGeo..30..733N"> <span id="translatedtitle">Bounce-<span class="hlt">averaged</span> Fokker-Planck diffusion equation in non-dipolar <span class="hlt">magnetic</span> fields with applications to the Dungey magnetosphere</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We perform a detailed derivation of the bounce-<span class="hlt">averaged</span> relativistic Fokker-Planck diffusion equation applicable to arbitrary <span class="hlt">magnetic</span> field at a constant Roederer L. The form of the bounce-<span class="hlt">averaged</span> diffusion equation is found regardless of details of the mirror geometry, suggesting that the numerical schemes developed for solving the modified two-dimensional (2-D) Fokker-Planck equation in a <span class="hlt">magnetic</span> dipole should be feasible for similar computation efforts on modeling wave-induced particle diffusion processes in any non-dipolar <span class="hlt">magnetic</span> field. However, bounce period related terms and bounce-<span class="hlt">averaged</span> diffusion coefficients are required to be computed in realistic <span class="hlt">magnetic</span> fields. With the application to the Dungey magnetosphere that is controlled by the intensity of southward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF), we show that with enhanced southward IMF the normalized bounce period related term decreases accordingly, and bounce-<span class="hlt">averaged</span> diffusion coefficients cover a broader range of electron energy and equatorial pitch angle with a tendency of increased magnitude and peaking at lower energies. The compression of the Dungey magnetosphere can generally produce scattering loss of plasma sheet electrons <~4 keV and radiation belt electrons >~100 keV on a timescale shorter than that in a dipolar field, and induce momentum diffusion at high pitch angles closer to 90. Correspondingly, the strong diffusion rate drops considerably as a product of changes in both the equatorial loss cone and the bounce period. The extent of differences in all the parameters introduced by the southward IMF intensification also becomes larger for a field line with higher equatorial crossing. With the derived general formulism of bounce-<span class="hlt">averaged</span> diffusion equation for arbitrary 2-D <span class="hlt">magnetic</span> field, our results confirm the need for the adoption of realistic <span class="hlt">magnetic</span> fields to perform accurate determination of electron resonant scattering rates and precise multi-dimensional diffusion simulations of magnetospheric electron dynamics.</p> <div class="credits"> <p class="dwt_author">Ni, B.; Thorne, R. M.; Ma, Q.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-04-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">198</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20110023536&hterms=shortest+path&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dshortest%2Bpath"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Kahler, S. W.; Haggerty, D. K.; Richardson, I. G.</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">199</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2008cosp...37.2948S"> <span id="translatedtitle">MESSENGER observations of the response of Mercury's magnetosphere to northward and southward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> fields</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">M. H. Ac?a (2), B. J. Anderson (3), D. N. Baker (4), M. Benna (2), S. A. Boardsen (1), G. n Gloeckler (5), R. E. Gold (3), G. C. Ho (3), H. Korth (3), S. M. Krimigis (3), S. A. Livi (6), R. L. McNutt Jr. (3), J. M. Raines (5), M. Sarantos (1), D. Schriver (7), S. C. Solomon (8), P. Travnicek (9), and T. H. Zurbuchen (5) (1) Heliophysics Science Division, NASA GSFC, Greenbelt, MD 20771, USA, (2) Solar System Exploration Division, NASA GSFC, Greenbelt, MD 20771, USA, (3) The Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA, (4) Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80303, USA, (5) Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, Ann Arbor, MI 48109, USA (6) Southwest Research Institute, San Antonio, TX 28510, USA, (7) Institute for Geophysics and Planetary Physics, University of California, Los Angeles, CA 90024, USA, (8) Department of Terrestrial <span class="hlt">Magnetism</span>, Carnegie Institution of Washington, DC 20015, USA, and (9) Institute of Atmospheric Physics, Prague, Czech Republic, 14131 MESSENGER's 14 January 2008 encounter with Mercury has provided new observations of the solar wind interaction with this planet. Here we report initial results concerning this miniature magnetosphere's response to the north-south component of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF). This is the component of the IMF that is expected to exert the greatest influence over the structure of the magnetopause and the processes responsible for energy transfer into the magnetosphere. The IMF was northward immediately prior to and following the passage of the MESSENGER spacecraft through this small magnetosphere. However, several-minute episodes of southward IMF were observed in the magnetosheath during the inbound portion of the encounter. Evidence for reconnection at the dayside magnetopause in the form of welldeveloped flux transfer events (FTEs) was observed in the magnetosheath following some of these southward-Bz intervals. The inbound magnetopause crossing in the <span class="hlt">magnetic</span> field measurements is consistent with a transition from the magnetosheath into the plasma sheet. Immediately following MESSENGER's entry into the magnetosphere, rotational perturbations in the <span class="hlt">magnetic</span> field similar to those seen at the Earth in association with large-scale plasma sheet vortices driven by Kelvin-Helmholtz waves along the magnetotail boundary at the Earth are observed. The outbound magnetopause occurred during northward IMF Bz and had the characteristics of a tangential discontinuity. These new observations have important implications for our understanding of energy transfer into Mercury's magnetosphere.</p> <div class="credits"> <p class="dwt_author">Slavin, James</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">200</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Kahler, S. W. [Air Force Research Laboratory, RVBXS, 29 Randolph Rd, Hanscom AFB, MA 01731 (United States); Haggerty, D. K. [Johns Hopkins University, Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723 (United States); Richardson, I. G., E-mail: AFRL.RVB.PA@hanscom.af.mil [Code 661, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-08-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_9");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' 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id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_10");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' href="#">4</a> <a onClick='return showDiv("page_5");' href="#">5</a> <a onClick='return showDiv("page_6");' href="#">6</a> <a onClick='return showDiv("page_7");' href="#">7</a> <a onClick='return showDiv("page_8");' href="#">8</a> <a onClick='return showDiv("page_9");' href="#">9</a> <a onClick='return 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src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">201</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19950046667&hterms=edmond&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3D%2522edmond%2522"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Roelof, Edmond C.; Sibeck, David G.</p> <p class="dwt_publisher"></p> <p class="publishDate">1993-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">202</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1991pupo.confT..17C"> <span id="translatedtitle">High <span class="hlt">average</span> power <span class="hlt">magnetic</span> modulator for copper lasers</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary"><span class="hlt">Magnetic</span> compression circuits show the promise of long life for operation at high <span class="hlt">average</span> powers and high repetition rates. When the Atomic Vapor Laser Isotope Separation (AVLIS) Program at Lawrence Livermore National Laboratory needed new modulators to drive their higher power copper lasers in the Laser Demonstration Facility (LDF), existing technology using thyratron switched capacitor inversion circuits did not meet the goal for long lifetimes at the required power levels. We have demonstrated that <span class="hlt">magnetic</span> compression circuits can achieve this goal. Improving thyratron lifetime is achieved by increasing the thyratron conduction time, thereby reducing the effect of cathode depletion. This paper describes a three stage <span class="hlt">magnetic</span> modulator designed to provide a 60 kV pulse to a copper laser at a 4.5 kHz repetition rate. This modulator operates at 34 kW input power and has exhibited MTBF of approximately 1000 hours when using thyratrons and even longer MTBF's with a series stack of SCR's for the main switch. Within this paper, the electrical and mechanical designs for the <span class="hlt">magnetic</span> compression circuits are discussed as are the important performance parameters of lifetime and jitter. Ancillary circuits such as the charge circuit and reset circuit are shown.</p> <div class="credits"> <p class="dwt_author">Cook, E. G.; Ball, D. G.; Birx, D. L.; Branum, J. D.; Peluso, S. E.; Langford, M. D.; Speer, R. D.; Sullivan, J. R.; Woods, P. G.</p> <p class="dwt_publisher"></p> <p class="publishDate">1991-06-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">203</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012AGUFMSM14B..07P"> <span id="translatedtitle">Preliminary testing of global hybrid-Vlasov simulation: Magnetosheath and cusps under northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Global magnetohydrodynamic (MHD) simulations have been successful in describing systems where the important spatial scales are larger than ion inertial length and the plasma has a well-defined temperature. The weakness of global one-fluid MHD simulations is their inability to model the multi-temperature, multi-component plasmas in the inner magnetosphere, where most of space-borne technology, including communication and navigation systems reside. We are developing a global hybrid-Vlasov simulation, where electrons are MHD fluid, but protons are modeled as distribution functions evolved in time using the Vlasov equation. This approach does not include the noise present in kinetic-hybrid simulations, but is computationally extremely challenging requiring petascale computations with thousands of cores. Here, we briefly review the status of our new parallel six-dimensional Vlasov solver. We carry out a test particle simulation and propagate the distribution functions using the electromagnetic fields of the GUMICS-4 global MHD simulation. Our main goal is to test the broad features of the Vlasov solver in a global setup against the standalone GUMICS-4 global MHD simulation. The results shown here are obtained during due northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF). We find that the magnetosheath and magnetopause plasma properties from the test particle simulation are in rough agreement with the results from the GUMICS-4 simulation. Furthermore, we show that the cusp injection patterns reproduce the expected behavior of northward IMF. The results indicate that our solver behaves sufficiently well, indicating that global hybrid-Vlasov simulations of this kind are becoming possible, promising improved global simulation capabilities in the future.</p> <div class="credits"> <p class="dwt_author">Palmroth, M. M.; Honkonen, I. J.; Sandroos, A.; Kempf, Y.; von Alfthan, S.; Pokhotelov, D.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">204</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Cheng, Z. W.; Shi, J. K.; Dunlop, M.; Liu, Z. X.</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-08-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">205</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013JASTP..95....1Z"> <span id="translatedtitle">The geo-effectiveness of <span class="hlt">interplanetary</span> small-scale <span class="hlt">magnetic</span> fluxropes</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The geo-effectiveness of <span class="hlt">Interplanetary</span> small-scale <span class="hlt">magnetic</span> flux ropes (ISMFRs) are studied using multiple satellites (ACE, WIND, Geotail, Cluster, THEMIS, and geosynchronous spacecraft) and ground magnetometers. We identified 16 ISMFR events during 2007-2008 that had in situ observations of the near-Earth upstream solar wind in addition to observations from ACE and Wind at 1 AU, and observations from multiple spacecraft in the inner magnetosphere. All the upstream solar wind (and in many cases magnetosheath) satellite observations showed very similar flux rope signatures indicating that the flux rope propagates from 1 AU through the bow shock. Thirteen of the 16 events were associated with substorm activity while nine of them appeared to trigger isolated substorm onsets. Combined with earlier published databases of ISMFRs from 1995 to 2005, we also examined the geo-effectiveness using 1-min AE/AL indices. We found more than half of these events (73/141) were associated with substorms, while the rest were associated with quiet geomagnetic activity periods. Of the 73 substorm-related ISMFRs, 32 events had IMF Bz polarity signatures from south to north (SN), 31 from north to south (NS), and 10 were identified as By bipolar signature events. A superposed epoch analysis indicates that the timing of the substorm activity related to the ISMFRs is different between SN- and NS-events. Most of the ISMFRs associated with quiet geomagnetic activity were either By bipolar signature events or accompanied with complex Bz and By signatures. This study demonstrates that ISMFR with IMF Bz polarity signatures drive substorms, but not geomagnetic storms.</p> <div class="credits"> <p class="dwt_author">Zhang, X.-Y.; Moldwin, M. B.; Cartwright, M.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-04-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">206</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013JASTP..99...41P"> <span id="translatedtitle">Preliminary testing of global hybrid-Vlasov simulation: Magnetosheath and cusps under northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Global magnetohydrodynamic (MHD) simulations have been successful in describing systems where the important spatial scales are larger than ion inertial length and the plasma has a well-defined temperature. The weakness of global one-fluid MHD simulations is their inability to model the multi-temperature, multi-component plasmas in the inner magnetosphere, where most of space-borne technology, including communication and navigation systems reside. We are developing a global hybrid-Vlasov simulation, where electrons are MHD fluid, but protons are modeled as distribution functions evolved in time using the Vlasov equation. This approach does not include the noise present in kinetic-hybrid simulations, but is computationally extremely challenging requiring petascale computations with thousands of cores. Here, we briefly review the status of our new parallel six-dimensional Vlasov solver. We carry out a test particle simulation and propagate the distribution functions using the electromagnetic fields of the GUMICS-4 global MHD simulation. Our main goal is to test the Vlasov solver in a global setup against the standalone GUMICS-4 global MHD simulation. The results shown here are obtained during due northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF). We find that the magnetosheath and magnetopause plasma properties from the test particle simulation are in rough agreement with the results from the GUMICS-4 simulation. Furthermore, we show that the cusp injection patterns reproduce the expected behavior of northward IMF. The results indicate that our solver behaves sufficiently well, indicating that global hybrid-Vlasov simulations of this kind are feasible, promising improved global simulation capabilities in the future.</p> <div class="credits"> <p class="dwt_author">Palmroth, M.; Honkonen, I.; Sandroos, A.; Kempf, Y.; von Alfthan, S.; Pokhotelov, D.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-07-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">207</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20110007245&hterms=butterflies&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dbutterflies"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Gopalswamy, N.; Akiyama, S.; Yashiro, S.; Michalek, G.; Lepping, R. P.</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">208</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20080015820&hterms=MAGNETIC+THEORY&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DMAGNETIC%2BTHEORY"> <span id="translatedtitle">An Alternative Interpretation of the Relationship between the Inferred Open Solar Flux and the <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Photospheric observations at the Wilcox Solar Observatory (WSO) represent an uninterrupted data set of 32 years and are therefore unique for modeling variations in the <span class="hlt">magnetic</span> structure of the corona and inner heliosphere over three solar cycles. For many years, modelers have applied a latitudinal correction factor to these data, believing that it provided a better estimate of the line-of-sight <span class="hlt">magnetic</span> field. Its application was defended by arguing that the computed open flux matched observations of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) significantly better than the original WSO correction factor. However, no physically based argument could be made for its use. In this Letter we explore the implications of using the constant correction factor on the value and variation of the computed open solar flux and its relationship to the measured IMF. We find that it does not match the measured IMF at 1 AU except at and surrounding solar minimum. However, we argue that <span class="hlt">interplanetary</span> coronal mass ejections (ICMEs) may provide sufficient additional <span class="hlt">magnetic</span> flux to the extent that a remarkably good match is found between the sum of the computed open flux and inferred ICME flux and the measured flux at 1 AU. If further substantiated, the implications of this interpretation may be significant, including a better understanding of the structure and strength of the coronal field and I N providing constraints for theories of field line transport in the corona, the modulation of galactic cosmic rays, and even possibly terrestrial climate effects.</p> <div class="credits"> <p class="dwt_author">Riley, Pete</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">209</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2010JGRA..115.8204L"> <span id="translatedtitle">On the poleward boundary of the nightside auroral oval under northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field conditions</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">In this paper we examined the dependence of the poleward boundary of the nightside auroral oval on <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) conditions. In particular, we performed the study for periods after the IMF Bz becomes northward at or some time during the recovery phase of major storms. For the selected periods, we used the precipitating particle energy flux observed by the Defense Meteorological Satellite Program satellites to determine the poleward boundary of the nightside oval. The following results were obtained. (1) We confirmed the expected result that under a more strongly northward IMF Bz, the poleward boundary of the nightside oval tends to be located more poleward, implying a smaller polar cap. (2) However, it tends to take a very long time after the IMF Bz turns northward for the polar cap size to substantially reduce (e.g., 15 h or longer for a poleward movement by 5). This is likely because the magnetosphere during the selected northward IMF periods was still under the substantial influence of the preceding southward IMF conditions associated with the storm's main phase and also because a finite IMF By can support dayside reconnection to sustain an open polar cap region of substantial size. (3) We found that for a given sign of the IMF By, the poleward boundary of the nightside oval is asymmetric between premidnight and postmidnight regions in a given hemisphere and between hemispheres at a given <span class="hlt">magnetic</span> local time region. For example, for a positive IMF By, the Northern (Southern) Hemispheric oval boundary is more poleward (equatorward) in the premidnight region, and the situation is opposite in the postmidnight region and for a negative IMF By. We suggest a possible reason that may be responsible for the asymmetry. (4) A similar (in an opposite sense) asymmetric feature can be seen with the IMF Bx but only when the IMF happens to be of a Parker spiral angle type. We conclude that the magnetosphere during the recovery phase of major storms likely remains open even after the IMF turns northward and the polar cap field lines are still connected to the IMF. The role of the finite IMF By is prominent in determining both the size and shape of the polar cap, which can affect details of the dynamical evolution during the storm recovery phase.</p> <div class="credits"> <p class="dwt_author">Lee, D.-Y.; Ohtani, S.; Lee, J. H.</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-08-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">210</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2002cosp...34E..92M"> <span id="translatedtitle">Solar Energetic Electrons propagation in converging <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> structures by the Ulysses spacecraft (event of day 081,1995)</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Fine time resolution observations of energetic (40-112 KeV) electrons made by the HI-SCALE experiment onboard the Ulysses spacecraft, during the onset of a major solar electron event on day 81 of the year 1995 and the technique of mapping the solar wind at the solar corona, are used, in order to obtain the large-angle scattering distance of these particles in a converging structure of the large scale <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field. Consequently, effective mean free paths are determined.</p> <div class="credits"> <p class="dwt_author">Marhavilas, P.; Sarris, E.; Anagnostopoulos, G.; Trochoutsos, P.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">211</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/51449693"> <span id="translatedtitle">Difference Between <span class="hlt">Magnetic</span> Clouds and Non-cloud Ejecta in the <span class="hlt">Interplanetary</span> Medium</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Solar cycle 23 has witnessed the accumulation of data on an unprecedented number of coronal mass ejections (CMEs) at the Sun and in the <span class="hlt">interplanetary</span> (IP) medium, thanks to the large array of spaceborne observatories such as SOHO, Wind, and ACE. These observations have helped us make significant progress on the structure and evolution of CMEs in the inner heliosphere.</p> <div class="credits"> <p class="dwt_author">N. Gopalswamy</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">212</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2011JGRA..11612237L"> <span id="translatedtitle">Reversed two-cell convection in the Northern and Southern hemispheres during northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">This article presents a case study of large-scale ionospheric convection in the Northern and Southern Hemispheres under strongly northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) conditions on 9 November 2004. Using a comprehensive data set from both ground- and space-based instruments, the study shows the formation of reversed two-cell convection in both the Northern and Southern Hemispheres that lasted for nearly 2 hours. Examination of the concurrent satellite energy-time spectrograms of precipitating particles reveals that reverse convection occurs in the region filled mostly with the boundary plasma sheet (BPS) type precipitating electrons except that the electron number flux is much smaller than that in the normal BPS. We have named this region the northward Bz boundary layer (NBZBL), which we interpret as a consequence of double-lobe reconnection. This interpretation is corroborated by the global MHD simulations, which show that the NBZBL consists of mostly closed field lines, resulting from double-lobe reconnection in both the hemispheres, together with intermittent presence of overdraped open field lines, resulting from single-lobe reconnection in one of the hemispheres. In addition to reversed two-cell convection, the distribution of field-aligned currents (FACs) shows clearly the presence of a pair of the northward Bz (NBZ) currents near the central polar region in both the hemispheres. Intense downward Poynting flux with a peak value around 100 mW/m2 is also seen in the high-latitude polar region, which tends to surround the upward leg of the NBZ currents. Finally, the potential drop between the two reverse-convection cells exceeds 100 kV, which is far larger than the values reported in any previous studies of reverse convection under northward IMF conditions. The unusually large reverse potential drop in this case is attributed in part to the strong NBZ component of 35-40 nT and in part to the unusually large solar wind dynamic pressure that is about five times its nominal value.</p> <div class="credits"> <p class="dwt_author">Lu, G.; Li, W. H.; Raeder, J.; Deng, Y.; Rich, F.; Ober, D.; Zhang, Y. L.; Paxton, L.; Ruohoniemi, J. M.; Hairston, M.; Newell, P.</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">213</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014JASTP.115....7M"> <span id="translatedtitle"><span class="hlt">Interplanetary</span> <span class="hlt">magnetic</span> field By control of prompt total electron content increases during superstorms</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Large magnitude increases in ionospheric total electron content (TEC) that occur over 1-3 h on the dayside are a significant manifestation of the main phases of superstorms. For the largest superstorms of solar cycle 23 (based on the Dst index), ground networks of GPS receivers measured peak total electron content increases greater than a factor of 2 relative to quiet time TEC <span class="hlt">averaged</span> over the broad latitude band 40 for local times 1200-1600 LT. Near 30 latitude, the Halloween storms of October 29-30, 2003 appeared to produce storm-time TEC exceeding quiet time values by a factor of 5 within 2-3 h of storm onset, at 1300 LT. The physical cause of these large positive phase ionospheric storms is usually attributed to prompt penetration electric fields (PPEFs) initiated by Region 1 current closure through the ionosphere (Nopper and Carovillano, 1978 mechanism). An unresolved question is what determines variation of the TEC response for different superstorms. It has been suggested that the cross polar cap potential and Region 1 currents are significant factors in determining PPEF in the equatorial ionosphere, which are related to the solar wind reconnection electric field estimated by Kan-Lee and others. In this paper, we show evidence that suggests By may be a significant factor controlling the TEC response during the main phase of superstorms. We analyzed the <span class="hlt">interplanetary</span> conditions during the period that TEC was increasing for eight superstorms. We find that increasing daytime TEC during superstorms only occurs for large reconnection electric fields when By magnitude is less than Bz. The data suggest that Bz is a far more important factor in the TEC response than the reconnection electric field. We also find that TEC decreases following its peak storm-time value for two superstorms, even though Bz remains large and By magnitudes are less than Bz. Such decreases during the geomagnetic disturbance may indicate the role of magnetospheric shielding currents, or of changes in the thermosphere that have developed over the prolonged period of large solar wind electric field. Further analysis is warranted covering a wider range of storm intensities on the role of By in affecting the daytime TEC response for a range of storm intensities.</p> <div class="credits"> <p class="dwt_author">Mannucci, A. J.; Crowley, G.; Tsurutani, B. T.; Verkhoglyadova, O. P.; Komjathy, A.; Stephens, P.</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-08-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">214</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.agu.org/journals/ja/v083/iA02/JA083iA02p00541/JA083iA02p00541.pdf"> <span id="translatedtitle"><span class="hlt">Interplanetary</span> modulation and transport of Jovian electrons</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Simultaneous measurements by Pioneer 11 of the 3- to 6-MeV Jovian electron flux, <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field magnitude, and solar wind speed during the pre-Jupiter encounter period reveal that electron transport across the <span class="hlt">average</span> field direction was greatly inhibited in corotating interaction regions (CIR's) and enhanced in rarefaction regions. Since CIR's are regions of compressed solar wind plasma, these results suggest</p> <div class="credits"> <p class="dwt_author">T. F. Conlon</p> <p class="dwt_publisher"></p> <p class="publishDate">1978-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">215</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20040171393&hterms=plunkett&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dplunkett"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">"<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> <div class="credits"> <p class="dwt_author">Richardson, I. G.; Cane, H. V.</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">216</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19830030751&hterms=1061&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D1061"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Akasofu, S.-I.; Roederer, M.; Krimigis, S. M.</p> <p class="dwt_publisher"></p> <p class="publishDate">1982-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">217</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19950048767&hterms=30+kev&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3D30%2Bkev"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Kahler, S.; Lin, R. P.</p> <p class="dwt_publisher"></p> <p class="publishDate">1994-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">218</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">He, H.-Q.; Qin, G. [State Key Laboratory of Space Weather, Center for Space Science and Applied Research, Chinese Academy of Sciences, Beijing 100190 (China); Zhang, M., E-mail: hqhe@spaceweather.ac.cn, E-mail: gqin@spaceweather.ac.cn, E-mail: mzhang@fit.edu [Department of Physics and Space Science, Florida Institute of Technology, Melbourne, FL 32901 (United States)</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-06-20</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">219</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19950029575&hterms=hanscom&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dhanscom"> <span id="translatedtitle"><span class="hlt">Interplanetary</span> <span class="hlt">magnetic</span> field dependency of stable Sun-aligned polar cap arcs</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">This is the first analysis, using a statistically significant data set, of the morphological dependence of the presence, orientation, and motion of stable sun-aligned polar cap arcs upon the vector <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF). For the one winter season analyzed we had 1392 all-sky 630.0-nm images of 2-min resolution containing a total of 150 polar cap arcs, all with corresponding values of the IMF as measured by International Monitoring Platform (IMP) 8 or International Sun Earth Explorer (ISEE) 2. After demonstrating an unbiased data set with smooth normal distributions of events versus the dimensions of time, space, and IMF component, we examine IMF dependencies of the properties of the optical arcs. A well-defined dependence for B(sub z) is found for the presence/absence of stable Sun-aligned polar cap arcs. Consistent with previous statistical studies, the probability of observing polar cap aurora steadily increases for larger positive values of B(sub z), and linearly decreases when B(sub z) becomes more negative. The probability of observing Sun-aligned arcs within the polar cap is determined to vary sharply as a function of the arc location; arcs were observed 40% of the time on the dawnside and only 10% on the duskside. This implies an overall probability of at least 40% for the whole polar cap. 20% of the arcs were observed during 'southward IMF conditions,' but in fact under closer inspection were found to have been formed under northward IMF conditions; these 'residual' positive B(sub z) arcs ha d a delayed residence time in the polar cap of about what would be expected after a north to south transition of B(sub z). A firm dependence on B(sub y) is also found for both the orientation and the dawn-dusk direction of motion of the arcs. All the arcs are Sun-aligned to a first approximation, but present deviations from this orientation, depending primarily upon the location of the arc in corrected geomagnetic (CG) coordinates. The arcs populating the 06-12 and the 12-18 quadrants of the CG coordinate system point toward the cusp. The B(sub y) dependency of the arc alignment is consistent with a cusp displacement in local time according to the sign of B(sub y). We found that the arc direction of motion depended both on B(sub y) and the arc location within the polar cap. For a given value of B(sub y) two well-defined regions (or cells) exist. Within each cell the arcs move in the same direction toward the boundary between the cells. The arcs located in the duskside move dawnward; those in the dawnside move duskward. The relative size of these dusk and dawn regions (or cells) are controlled by the magnitude of B(sub y). This persistent dusk-dawn motion fo the polar cap arcs is interpreted in terms of newly open flux tubes entering the polar cap and exerting a displacement of the convective cells and the polar cap arcs that are embedded within them.</p> <div class="credits"> <p class="dwt_author">Valladares, C. E.; Carlson, H. C., Jr.; Fukui, K.</p> <p class="dwt_publisher"></p> <p class="publishDate">1994-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">220</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19740040398&hterms=multi+scale&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dmulti%2Bscale"> <span id="translatedtitle">Large-scale structure of the <span class="hlt">interplanetary</span> medium. II - Evolving <span class="hlt">magnetic</span> configurations deduced from multi-spacecraft observations</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Description of a method for constructing large-scale (about 0.25 AU) <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field lines using only solar wind velocity from well-separated appropriately located spacecraft. The technique is based on 'labeling' the field lines at each spacecraft with their coronal connection longitudes calculated in the EQRH (extrapolated quasi-radial hypervelocity) approximation. Even though the EQRH approximation is most applicable to quasi-steady solar wind, it is proposed that it should also be satisfactorily accurate for moderately evolving conditions. For strongly evolving conditions (e.g., flare-associated plasma) a straightforward correction based on the inferred coronal longitudinal velocity profile is proposed. To illustrate the multispacecraft EQRH technique, a calculation is performed in which the <span class="hlt">interplanetary</span> field lines in a model evolving solar wind disturbance are deduced from model observations at separated spacecraft. Since the expected agreement is found, data from Pioneers 8 and 9 and Vela are used to construct field lines for an unusually quiet period (Apr. 26-30, 1969) and for a flare-associated disturbance accompanied by a Forbush decrease (Mar. 23-25, 1969).</p> <div class="credits"> <p class="dwt_author">Nolte, J. T.; Roelof, E. C.</p> <p class="dwt_publisher"></p> <p class="publishDate">1973-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_10");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' 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class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_11");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' href="#">4</a> <a onClick='return showDiv("page_5");' href="#">5</a> <a onClick='return showDiv("page_6");' href="#">6</a> <a onClick='return showDiv("page_7");' href="#">7</a> <a onClick='return showDiv("page_8");' href="#">8</a> <a onClick='return showDiv("page_9");' href="#">9</a> <a onClick='return showDiv("page_10");' href="#">10</a> <a onClick='return showDiv("page_11");' href="#">11</a> <a style="font-weight: bold;">12</a> <a onClick='return showDiv("page_13");' href="#">13</a> <a onClick='return showDiv("page_14");' href="#">14</a> <a onClick='return showDiv("page_15");' href="#">15</a> <a onClick='return showDiv("page_16");' href="#">16</a> <a onClick='return showDiv("page_17");' href="#">17</a> <a onClick='return showDiv("page_18");' href="#">18</a> <a onClick='return showDiv("page_19");' href="#">19</a> <a onClick='return showDiv("page_20");' href="#">20</a> <a onClick='return showDiv("page_21");' href="#">21</a> <a onClick='return showDiv("page_22");' href="#">22</a> <a onClick='return showDiv("page_23");' href="#">23</a> <a onClick='return showDiv("page_24");' href="#">24</a> <a onClick='return showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_13");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">221</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19740020146&hterms=charles+darwin&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dcharles%2Bdarwin"> <span id="translatedtitle"><span class="hlt">Interplanetary</span> shock waves associated with solar flares</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Chao, J. K.; Sakurai, K.</p> <p class="dwt_publisher"></p> <p class="publishDate">1974-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">222</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2003AGUFMSH41B0466W"> <span id="translatedtitle">Near Real Time Prediction of <span class="hlt">Magnetic</span> Storm Intensity and Timing from Measurements of North to-South <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Clouds</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The importance of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> clouds to the study of geomagnetic activity has been known for many years, and because of the general characteristics of these large structures, such activity is often major. A program is developed from which we are able to predict the Dst index based on real-time measurements of a <span class="hlt">magnetic</span> cloud passing Earth, as well as from guidance from previously modeled <span class="hlt">magnetic</span> clouds (MCs) from WIND observations. The scheme could be applicable to ACE data, for example, or to that of any near real-time field and plasma monitoring platform. The program consists of five stages: (1) identification of the proximity of a cloud-complex (i.e., MC and immediate upstream region), (2) finding, relatively accurately, the front boundary of the MC, (3) estimating the MC's 'center time,' (4) predicting the speed and minimum IMF-BZ and the latter's timing within the MC (based on these earlier findings), and finally (5) estimating the associated Dst, based on reliable IMF-BZ vs. Dst relations. The initial identification of the cloud-complex is carried out by examining proton plasma beta, degree of smoothness of the <span class="hlt">magnetic</span> field's directional change, and field strength. These alone will help to pin down the front boundary of the MC to within about +/- 2 hr. This identification then triggers an attempt to determine this boundary to within +/- 1/2 hr using finer scale field data After viewing about 2/3 of a MC-passage and properly estimating the MC's center time, for North-to-South types of MCs, which are expected to be most common in the near future [Bothmer and Rust, 1997], we have sufficient information to predict min-Bz within the MC, provided reasonable front-to-back MC symmetry exist. Application of the scheme to MCs that occurred over the period 1995 through 2002 is used to determine its effectiveness in predicting Dst, as well as to simply determine the program's ability to identify MCs of any type (i.e., including S-to-N types) and their front boundary times. In the prediction mode (i.e., for N to-S types) the scheme does not strictly require that the observing spacecraft be upstream of Earth, since 7 or so hours lead-time, for the prediction, is gained for most MCs in Earth's vicinity, provided only that the spacecraft is outside the bow shock. However, for L1 based spacecraft, approximately an extra hour of 'prediction-time' is gained. As a test of its fidelity and consistency, the program is applied to many years of WIND data and some of the results are presented. Bothmer and Rust, in Coronal Mass Ejections, AGU Geophys. Monog. Ser, vol. 99, p 139, Washington DC., 1997.</p> <div class="credits"> <p class="dwt_author">Wu, C.; Lepping, R. P.; Berdichevsky, D. B.</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">223</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.agu.org/journals/ja/v103/iA03/97JA03328/97JA03328.pdf"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">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</p> <div class="credits"> <p class="dwt_author">A. J. Ridley; Gang Lu; C. R. Clauer; V. O. Papitashvili</p> <p class="dwt_publisher"></p> <p class="publishDate">1998-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">224</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/51983618"> <span id="translatedtitle">A deployable high temperature superconducting coil (DHTSC) - A novel concept for producing <span class="hlt">magnetic</span> shields against both solar flare and Galactic radiation during manned <span class="hlt">interplanetary</span> missions</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The discovery of materials which are superconducting above 100 K makes possible the use of superconducting coils deployed beyong the hull of an <span class="hlt">interplanetary</span> spacecraft to produce a <span class="hlt">magnetic</span> shield capable of giving protection not only against solar flare radiation, but also even against Galactic radiation. Such deployed coils can be of very large size and can thus achieve the</p> <div class="credits"> <p class="dwt_author">F. Hadley Cocks</p> <p class="dwt_publisher"></p> <p class="publishDate">1991-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">225</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ann-geophys.net/17/1306/1999/angeo-17-1306-1999.pdf"> <span id="translatedtitle">Observations of the response time of high-latitude ionospheric convection to variations in the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field using EISCAT and IMP8 data</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">We have combined 300 h of tristatic mea- surements of the field-perpendicular F region iono- spheric flow measured overhead at Troms by the EISCAT UHF radar, with simultaneous IMP-8 mea- surements of the solar wind and <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) upstream of the Earth's magnetosphere, in order to examine the response time of the ionospheric flow to changes in the</p> <div class="credits"> <p class="dwt_author">H. Khan; S. W. H. Cowley</p> <p class="dwt_publisher"></p> <p class="publishDate">1999-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">226</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/5313607"> <span id="translatedtitle">On the electrodynamical state of the auroral ionosphere during northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field: A transpolar arc case study</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">The ionospheric electrodynamical state has been reconstructed for a transpolar arc event during northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field conditions. An extensive set of observations by Viking and other satellites and by ground-based radars has been used to provide realistic model input data or to verify the modeling results. The resulting convection pattern is found to be consistent with the Viking electric field and intimately linked to the prevalent auroral distribution. It is characterized by a large evening cell, well extended across noon and split up by two separated potential minima, and a minor crescent-shaped morning cell. The convection signatures are found to vary a lot along the transpolar arc depending on the relative role of the arc-associated convection and the ambient convection. The transpolar arc is generally embedded in antisunward convective flow except near the connection points with the auroral oval, where sunward flow exists in localized regions.</p> <div class="credits"> <p class="dwt_author">Marklund, G.T.; Blomberg, L.G. (Royal Inst. of Tech., Stockholm (Sweden)); Murphree, J.S.; Elphinstone, R.D. (Univ. of Calgary, Alberta (Canada)); Zanetti, L.J.; Erlandson, R.E. (Johns Hopkins Univ., Laurel, MD (USA)); Sandahl, I. (Swedish Institute of Physics, Kiruna (Sweden)); de la Beaujardiere, O. (SRI International, Menlo Park, CA (USA)); Opgenoorth, H. (Swedish Inst. of Space Physics, Uppsala (Sweden)); Rich, F.J. (Air Force Geophysics Lab., Bedford, MA (USA))</p> <p class="dwt_publisher"></p> <p class="publishDate">1991-06-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">227</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2000JGR...10527497M"> <span id="translatedtitle">Evidence for <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field <formula>By controlled large-scale reconnection at the dayside magnetopause</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We report evidence of a long-lasting reconnection event during which the accelerated plasma flow direction changes in response to an <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) By reversal, indicating a change in the reconnection site location. The observations were made by Equator-S on the dawn flank of the magnetopause and consist of a large number of plasma jets detected mostly within magnetospheric flux transfer events. The plasma jets were found in quantitative agreement with the theoretical predictions for reconnection. The reversal of the plasma flow direction in the jets following the reversal of the By component not only confirms that the dayside reconnection configuration is controlled by the IMF, as opposed to local control, but also stresses the importance of the IMF dawn-dusk component, in addition to the north-south component, in determining the global configuration of the reconnection.</p> <div class="credits"> <p class="dwt_author">Marcucci, M. F.; Cattaneo, M. B. Bavassano; Di Lellis, A. M.; Irelli, P. Cerulli; Kistler, L. M.; Phan, T.-D.; Haerendel, G.; Klecker, B.; Paschmann, G.; Baumjohann, W.; Mbius, E.; Popecki, M. A.; Sauvaud, J. A.; Rme, H.; Korth, A.; Eliasson, L.; Carlson, C. W.; McCarthy, M.; Parks, G. K.</p> <p class="dwt_publisher"></p> <p class="publishDate">2000-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">228</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19800028172&hterms=ROMA&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3D%2522ROMA%2522"> <span id="translatedtitle">An extended investigation of Helios 1 and 2 observations - The <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field between 0.3 and 1 AU</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Helios 1 and 2 spacecraft allowed a detailed investigation of the radial dependence of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field components between 0.3 and 1 AU. The behavior of the radial component is in a very good agreement with Parker's model (approximately equal to the inverse square of the heliocentric distance) and the azimuthal component also shows a radial dependence which is close to theoretical predictions (approximately equal to the inverse of the heliocentric distance). Experimental results for the normal component and for the field magnitude are consistent with those from previous investigations. The relative amplitude of the directional fluctuations with periods less than 12 hr is essentially independent of heliocentric distance, while their power decreases approximately as the inverse cube of the heliocentric distance without any appreciable difference between higher and lower velocity regimes.</p> <div class="credits"> <p class="dwt_author">Mariani, F.; Villante, U.; Bruno, R.; Bavassano, B.; Ness, N. F.</p> <p class="dwt_publisher"></p> <p class="publishDate">1979-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">229</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20110023418&hterms=Tasmania&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DTasmania"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Richardson, I. G.; Cane, H. V.</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">230</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19900039383&hterms=IMPS&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DIMPS"> <span id="translatedtitle"><span class="hlt">Interplanetary</span> Alfven waves and auroral (substorm) activity - IMP 8</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Tsurutani, Bruce T.; Gould, Tom; Goldstein, Bruce E.; Gonzalez, Walter D.; Sugiura, Masahisa</p> <p class="dwt_publisher"></p> <p class="publishDate">1990-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">231</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/doepatents/biblio/869326"> <span id="translatedtitle">High <span class="hlt">average</span> power <span class="hlt">magnetic</span> modulator for metal vapor lasers</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Ball, Don G. (Livermore, CA); Birx, Daniel L. (Oakley, CA); Cook, Edward G. (Livermore, CA); Miller, John L. (Livermore, CA)</p> <p class="dwt_publisher"></p> <p class="publishDate">1994-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">232</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013P%26SS...79...56Z"> <span id="translatedtitle">ChangE-1 observations of pickup ions near the Moon under different <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field conditions</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Detailed features of the near-Moon pickup ions under different <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) conditions are investigated using data obtained from the solar wind ion detector (SWID-B) onboard Chang'E-1. In the event studied, Chang'E-1 was on a noon-midnight meridian orbit and the field-of-view of the SWID-B was in the satellite orbital plane. The observations show that the pickup energy detected depends not only on where these particles are detected but also on their incident angles. As the spacecraft moved into the wake from the South Pole along the midnight meridian, wider incident angle distributions were measured. When IMF Bx was significant, the pickup ions had a strong velocity component parallel to the <span class="hlt">magnetic</span> field, and the efficiency of acceleration was reduced when the IMF By decreased. The back tracking calculations show that the possible source of the pickup ions is solar wind ions scattered/reflected on the lunar surface in a wide area over the dayside of the Moon, from both <span class="hlt">magnetic</span> and nonmagnetic anomaly regions. A three dimensional analysis performed on the asymmetric properties of the pick-up ions can explain most of the particle behavior observed near the Moon under different IMF conditions.</p> <div class="credits"> <p class="dwt_author">Zhong, J.; Xie, L.; Zhang, H.; Li, J. X.; Pu, Z. Y.; Nowada, M.; Wang, X. D.; Wang, X. Y.; Parks, G. K.; Zong, Q. G.; Fu, S. Y.; Guo, R. L.; Yao, Z. H.; Zhang, X. G.; Reme, H.; Wang, S. J.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-05-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">233</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19950059014&hterms=hanscom&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dhanscom"> <span id="translatedtitle">Ionospheric convection response to slow, strong variations in a Northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field: A case study for January 14, 1988</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">We analyze ionospheric convection patterns over the polar regions during the passage of an <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> cloud on January 14, 1988, when the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) rotated slowly in direction and had a large amplitude. Using the assimilative mapping of ionospheric electrodynamics (AMIE) procedure, we combine simultaneous observations of ionspheric drifts and <span class="hlt">magnetic</span> perturbations from many different instruments into consistent patterns of high-latitude electrodynamics, focusing on the period of northward IMF. By combining satellite data with ground-based observations, we have generated one of the most comprehensive data sets yet assembled and used it to produce convection maps for both hemispheres. We present evidence that a lobe convection cell was embedded within normal merging convection during a period when the IMF B(sub y) and B(sub z) components were large and positive. As the IMF became predominantly northward, a strong reversed convection pattern (afternoon-to-morning potential drop of around 100 kV) appeared in the southern (summer) polar cap, while convection in the northern (winter) hemisphere became weak and disordered with a dawn-to-dust potential drop of the order of 30 kV. These patterns persisted for about 3 hours, until the IMF rotated significantly toward the west. We interpret this behavior in terms of a recently proposed merging model for northward IMF under solstice conditions, for which lobe field lines from the hemisphere tilted toward the Sun (summer hemisphere) drape over the dayside magnetosphere, producing reverse convection in the summer hemisphere and impeding direct contact between the solar wind and field lines connected to the winter polar cap. The positive IMF B(sub x) component present at this time could have contributed to the observed hemispheric asymmetry. Reverse convection in the summer hemisphere broke down rapidly after the ratio absolute value of B(sub y)/B(sub z) exceeded unity, while convection in the winter hemisphere strengthened. A dominant dawn-to-dusk potential drop was established in both hemispheres when the magnitude of B(sub y) exceeded that of B(sub z) with potential drops of the order of 100 kV, even while B(sub z) remained northward. The latter transition to southward B(sub z) produced a gradual intensification of the convection, but a greater qualitative change occurred at the transition through absolute value of B(sub y)/B(sub z) = 1 than at at the transition through B(sub z) = 0. The various convection patterns we derive under northward IMF conditions illustrate all possibilities previously discussed in the literature: nearly single-cell and multicell, distorted and symmetric, ordered and unordered, and sunward and antisunward.</p> <div class="credits"> <p class="dwt_author">Knipp, D. J.; Emery, B. A.; Richmond, A. D.; Crooker, N. U.; Hairston, M. R.; Cumnock, J. A.; Denig, W. F.; Rich, F. J.; De La Beaujardiere, O.; Ruohoniemi, J. M.</p> <p class="dwt_publisher"></p> <p class="publishDate">1993-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">234</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19910042730&hterms=coil&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dcoil"> <span id="translatedtitle">A deployable high temperature superconducting coil (DHTSC) - A novel concept for producing <span class="hlt">magnetic</span> shields against both solar flare and Galactic radiation during manned <span class="hlt">interplanetary</span> missions</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">The discovery of materials which are superconducting above 100 K makes possible the use of superconducting coils deployed beyong the hull of an <span class="hlt">interplanetary</span> spacecraft to produce a <span class="hlt">magnetic</span> shield capable of giving protection not only against solar flare radiation, but also even against Galactic radiation. Such deployed coils can be of very large size and can thus achieve the great <span class="hlt">magnetic</span> moments required using only relatively low currents. Deployable high-temperature-superconducting coil <span class="hlt">magnetic</span> shields appear to offer very substantial reductions in mass and energy compared to other concepts and could readily provide the radiation protection needed for a Mars mission or space colonies.</p> <div class="credits"> <p class="dwt_author">Cocks, F. Hadley</p> <p class="dwt_publisher"></p> <p class="publishDate">1991-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">235</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/20717503"> <span id="translatedtitle">Effect of the Global Topology of the <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field on the Properties of Impulsive Acceleration Processes in Distant Regions of the Earth's Magnetospheric Tail</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">The paper is devoted to a statistical study of high-speed ion beams (beamlets) observed by the Interball-1 and Interball-2 satellites in the boundary region of the plasma sheet of the geomagnetic tail and in the high-latitude auroral regions of the Earth's magnetosphere. Beamlets result from nonlinear acceleration processes occurring in the current sheet in the distant regions of the geomagnetic tail. They propagate toward the Earth along the <span class="hlt">magnetic</span> field lines and are detected in the boundary region of the plasma sheet and near the high-latitude boundary of the plasma sheet in the auroral region in the form of short (with a duration of 1-2 min) bursts of high-energy (with energies of about several tens of keV) ions. The sizes of the latitudinal zones where the beamlets are localized in the tail and in the auroral region are determined using the epoch superposition method. The relationship between the frequency of beamlet generation in the boundary region of the plasma sheet and the prehistory of the direction of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (the magnitude of a clock angle) is investigated. It was established that this direction exerts a global effect on the beamlet generation frequency; moreover, it was found that the beamlet generation frequency in the midnight local time sector of the tail and at the flanks depends differently on the direction of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field. In the midnight sector, the beamlets are observed at almost all directions of the <span class="hlt">interplanetary</span> field, whereas the frequency of their generation at the flanks is maximal only when the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field has a large y component.</p> <div class="credits"> <p class="dwt_author">Grigorenko, E.E. [Skobeltsyn Institute of Nuclear Physics, Moscow State University, Vorob'evy gory, Moscow, 119899 (Russian Federation); Institute for Space Research, Russian Academy of Sciences, Profsoyuznaya ul. 84/32, Moscow, 117810 (Russian Federation); Zelenyi, L.M. [Institute for Space Research, Russian Academy of Sciences, Profsoyuznaya ul. 84/32, Moscow, 117810 (Russian Federation); Fedorov, A.O.; Sauvaud, J.-A. [Centre d'Etude Spatiale des Rayonnements, 4346 31028 Toulouse (France)</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-03-15</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">236</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.agu.org/journals/ja/ja0608/2005JA011593/2005JA011593.pdf"> <span id="translatedtitle">Magnetohydrodynamic simulation of the interaction between <span class="hlt">interplanetary</span> strong shock and <span class="hlt">magnetic</span> cloud and its consequent geoeffectiveness</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Numerical studies have been performed to interpret the observed shock overtaking <span class="hlt">magnetic</span> cloud (MC) event by a 2.5 dimensional magnetohydrodynamic (MHD) model in the heliospheric meridional plane. Results of an individual MC simulation show that the MC travels with a constant bulk flow speed. The MC is injected with a very strong inherent <span class="hlt">magnetic</span> field over that in the ambient</p> <div class="credits"> <p class="dwt_author">Ming Xiong; Huinan Zheng; Yuming Wang; Shui Wang</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">237</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19840065451&hterms=friis&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3D%2522friis%2522"> <span id="translatedtitle">Observation of <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field and of ionospheric plasma convection in the vicinity of the dayside polar cleft</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Dayside ionosphere convection at high latitudes has been examined during a series of experiments using the Sondrestrom radar together with ancillary observations of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) by the IMP-8 spacecraft. The radar experiments obtained a latitude coverage of 67.6 to 81.3 deg Lambda and a temporal resolution of between 14 to 25 minutes. A total of 17 rotations through the dayside cleft region during April, June and July, 1983 have been examined. The observations show two convection cells with sunward flow at lower latitudes and antisunward flow at higher latitudes. The flow commonly rotates through a 180 deg angle resulting in the predominant appearance of east-west flows. Rapid temporal variations in the convection velocities are frequently observed. Many of the high latitude variations in convection velocity appear to be directly related to variations in the IMF By component, with eastward (westward) velocity associated with negative (positive) By. This is strong evidence for a direct electrical coupling between the solar wind and dayside high latitude ionosphere.</p> <div class="credits"> <p class="dwt_author">Clauer, C. R.; Banks, P. M.; Smith, A. Q.; Jorgensen, T. S.; Friis-Christensen, E.; Vennerstrom, S.; Wickwar, V. B.; Kelly, J. D.; Doupnik, J.</p> <p class="dwt_publisher"></p> <p class="publishDate">1984-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">238</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19930037009&hterms=electric+fields+inside+cell&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Delectric%2Bfields%2Binside%2Bcell"> <span id="translatedtitle">Response of the ionospheric convection pattern to a rotation of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field on January 14, 1988</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Ionospheric convection signatures observed over the polar regions are provided by the DMSP F8 satellite. We consider five passes over the Southern summer Hemisphere during a time when the z component of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field was stable and positive and the y component changed slowly from positive to negative. Large-scale regions of sunward flow are observed at very high latitudes consistent with a strong z component. When By and Bz are positive, but By is greater than Bz, strong evidence exists for dayside merging in a manner similar to that expected when Bz is negative. This signature is diminished as By decreases and becomes smaller than Bz, resulting in a four-cell convection pattern displaced toward the sunward side of the dawn-dusk meridian. In this case the sign of By affects the relative sizes of the two highest-latitude cells. In the Southern Hemisphere the duskside high-latitude cell is dominant for By positive and the dawnside high-latitude cell is dominant for By negative. The relative importance of possible electric field sources in the low-latitude boundary layer, the dayside cusp, and the lobe all need to be considered to adequately explain the observed evolution of the convection pattern.</p> <div class="credits"> <p class="dwt_author">Cumnock, J. A.; Heelis, R. A.; Hairston, M. R.</p> <p class="dwt_publisher"></p> <p class="publishDate">1992-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">239</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013GeoRL..40.2489W"> <span id="translatedtitle">Field-aligned current reconfiguration and magnetospheric response to an impulse in the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field BY component</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) is dawnward or duskward, <span class="hlt">magnetic</span> merging between the IMF and the geomagnetic field occurs near the cusp on the dayside flanks of the magnetosphere. During these intervals, flow channels in the ionosphere with velocities in excess of 2 km/s have been observed, which can deposit large amounts of energy into the high-latitude thermosphere. In this study, we analyze an interval on 5 April 2010 where there was a strong dawnward impulse in the IMF, followed by a gradual decay in IMF magnitude at constant clock angle. Data from the Sondrestrom incoherent scatter radar and the Defense Meteorological Satellite Program spacecraft were used to investigate ionospheric convection during this interval, and data from the Active Magnetospheric and Planetary Electrodynamics Response Experiment (AMPERE) were used to investigate the associated Field-Aligned Current (FAC) system. Additionally, data from AMPERE were used to investigate the time response of the dawnside FAC pair. We find there is a delay of approximately 1.25 h between the arrival of the dawnward IMF impulse at the magnetopause and strength of the dawnward FAC pair, which is comparable to substorm growth and expansion time scales under southward IMF. Additionally, we find at the time of the peak FAC, there is evidence of a reconfiguring four-sheet FAC system in the morning local time sector of the ionosphere. Additionally, we find an inverse correlation between the dawn FAC strength and both the solar wind Alfvnic Mach number and the SYM-H index. No statistically significant correlation between the FAC strength and the solar wind dynamic pressure was found.</p> <div class="credits"> <p class="dwt_author">Wilder, F. D.; Eriksson, S.; Korth, H.; Baker, J. B. H.; Hairston, M. R.; Heinselman, C.; Anderson, B. J.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-06-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">240</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013AGUSMSM33A..02W"> <span id="translatedtitle">The Ionospheric Convection and Birkeland Current Response to an Impulse in the <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field BY Component</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">When the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) is dawnward or duskward, <span class="hlt">magnetic</span> merging between the IMF and the geomagnetic field occurs near the cusp on the dayside flanks of the magnetosphere. During these intervals, sunward flow channels on open field lines with velocities in excess of 2 km/s are generated in the polar ionosphere, which can deposit large amounts of energy into the cusp-region thermosphere. In this study, we analyze an interval on 5 April 2010 where there was a strong dawnward impulse in the IMF, followed by a gradual decay in IMF magnitude at constant clock angle. Data from ground based radars and the DMSP spacecraft were assimilated to investigate the global convection pattern during this interval, and data from the Active Magnetospheric and Planetary Electrodynamics Response Experiment (AMPERE) were used to investigate the associated Field-Aligned Current (FAC) system. Additionally, data from AMPERE and the Sondrestrom Incoherent Scatter Radar were used to investigate the time response of the flow channel and its associated FAC pair. We find that there is a delay of approximately 1.25 hours between the arrival of the dawnward IMF impulse at the magnetopause and the speed of the flow channel and strength of the FACs flanking it. In addition to correlation between the dawnward component of the IMF and the flanking FAC strength, we also find that there is inverse correlation between the flanking FAC strength and both the SYM-H index and Solar Wind Alfvenic Mach Number. No statistically significant correlation is found between the flanking FAC strength and solar wind dynamic pressure.</p> <div class="credits"> <p class="dwt_author">Wilder, F. D.; Eriksson, S.; Korth, H.; Baker, J. B.; Hairston, M. R.; Heinselman, C. J.; Anderson, B. J.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-05-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_11");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' 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onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">241</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013AGUFMSM13B2158H"> <span id="translatedtitle">Reconnection and Energy Conversion at the Magnetopause as Influenced by Earth's Dipole Tilt Angle and <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We study the effect of Earth's dipole tilt angle and <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) Bx and By components on the location of reconnection and the energy conversion at the magnetopause. We simulate southward IMF satisfying both inward- and outward-type Parker spiral conditions during three different dipole tilt angles using a global magnetohydrodynamic model GUMICS-4. Different combinations of dipole tilt angle and IMF Bx and By components change the magnetopause reconnection morphology and magnitude. This can be studied by comparing the location of the reconnection line and the location and strength of the energy conversion for different parameter combinations. We find that the IMF Bx and the dipole tilt angle modify the reconnection line location and both magnitude and location of the energy conversion. We discuss the relative role of the non-zero Bx and the dipole tilt angle in dayside reconnection first separately and then by letting the parameters change simultaneously. We find that positive (negative) Bx moves the reconnection line northward (southward) and positive (negative) tilt angle moves the line southward (northward). When both tilt angle and Bx are positive or negative they reverse each others effect so that the reconnection line location is almost the same as it is when both Bx and tilt angle are zero. When these two parameters have opposite signs they enhance each other's effects. We find evidence that reconnection-induced processes modify the shape of the magnetopause, which in turn has and effect on the reconnection location. Therefore intrinsic processes within the magnetosphere - the <span class="hlt">magnetic</span> flux transfer to nightside and the subsequent return of the closed flux - can influence the basic reconnection processes within the dayside magnetopause.</p> <div class="credits"> <p class="dwt_author">Hoilijoki, S.; Palmroth, M.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">242</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19860057089&hterms=latitudinal+gradients&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dlatitudinal%2Bgradients"> <span id="translatedtitle">Radial and latitudinal gradients in the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field - Evidence for meridional flux transport</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary"><span class="hlt">Magnetic</span> field data obtained by the Pioneer 10 and 11 spacecraft in the heliosphere from 1972-1982 and earth orbiting satellite data are examined in terms of radial and latitudinal gradients in the field components and magnitude. The data reveal that higher than expected gradients are observed in the <span class="hlt">magnetic</span> field and time variations affect the field throughout the low-latitude heliosphere. It is determined that the high radial gradient is caused by meridional flux transport with low-latitude field lines moving to higher heliographic latitudes. High pressure near the solar equator and pressure due to heating in compressive solar wind interaction regions and the large field magnitudes that occur in these regions are investigated as mechanisms that produce the meridional flux. A solar cycle variation in the level of flux transport is analyzed.</p> <div class="credits"> <p class="dwt_author">Thomas, B. T.; Slavin, J. A.; Smith, E. J.</p> <p class="dwt_publisher"></p> <p class="publishDate">1986-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">243</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19910062772&hterms=high+magnetic+field&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dhigh%2Bmagnetic%2Bfield"> <span id="translatedtitle">Observations of reconnection of <span class="hlt">interplanetary</span> and lobe <span class="hlt">magnetic</span> field lines at the high-latitude magnetopause</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Results are presented of ISEE 2 observations of plasma accelerations obtained at the high-latitude (lobe) magnetopause at a time when the local magnetosheath and magnetospheric <span class="hlt">magnetic</span> fields were nearly oppositely directed and the flow speed in the magnetosheath, V(s), was nearly equal to the local Alfven speed, V(A). The observations provide direct evidence for the rereconnection of the open field lines of the tail lobes with the IMF, when the <span class="hlt">magnetic</span> field shear is large. It is pointed out, however, that, since V(s) was almost equal to V(A), it is unlikely that the rereconnection is associated with the strong sunward convection in the polar cap.</p> <div class="credits"> <p class="dwt_author">Gosling, J. T.; Thomsen, M. F.; Bame, S. J.; Elphic, R. C.; Russell, C. T.</p> <p class="dwt_publisher"></p> <p class="publishDate">1991-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">244</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/53081934"> <span id="translatedtitle">An advanced magnetometric system for precise measurements of the <span class="hlt">interplanetary</span> and near earth <span class="hlt">magnetic</span> fields</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">A three-component flux-gate magnetometric system is described for precise <span class="hlt">magnetic</span> field investigations in a wide dynamic range with a high resolution. To allow inflight measurements of the spacecraft stray field, the system contains two flux-gate sensor triads, located 5 and 7 m from the spacecraft body. The outer triad is supplied with a double flipper system, allowing zero-offset determination of</p> <div class="credits"> <p class="dwt_author">I. S. Arshinkov; A. Z. Bochev; N. S. Abadzhiev; E. G. Zakharieva; K. I. Arshinkova</p> <p class="dwt_publisher"></p> <p class="publishDate">1985-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">245</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/3915538"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">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</p> <div class="credits"> <p class="dwt_author">J. A. Slavin; G. Jungman; E. J. Smith</p> <p class="dwt_publisher"></p> <p class="publishDate">1986-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">246</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19890001307&hterms=gsm&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D%2522gsm%2522"> <span id="translatedtitle"><span class="hlt">Interplanetary</span> medium data book: Supplement 3A, 1977-1985</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Couzens, David A.; King, Joseph H.</p> <p class="dwt_publisher"></p> <p class="publishDate">1986-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">247</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2007AnGeo..25.2641L"> <span id="translatedtitle">Comparison of <span class="hlt">magnetic</span> field observations of an <span class="hlt">average</span> <span class="hlt">magnetic</span> cloud with a simple force free model: the importance of field compression and expansion</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We investigate the ability of the cylindrically symmetric force-free <span class="hlt">magnetic</span> cloud (MC) fitting model of Lepping et al. (1990) to faithfully reproduce actual <span class="hlt">magnetic</span> field observations by examining two quantities: (1) a difference angle, called ?, i.e., the angle between the direction of the observed <span class="hlt">magnetic</span> field (Bobs) and the derived force free model field (Bmod) and (2) the difference in magnitudes between the observed and modeled fields, i.e., ?B(=|Bobs|-|Bmod|), and a normalized ?B (i.e., ?B/) is also examined, all for a judiciously chosen set of 50 WIND <span class="hlt">interplanetary</span> MCs, based on quality considerations. These three quantities are developed as a percent of MC duration and <span class="hlt">averaged</span> over this set of MCs to obtain <span class="hlt">average</span> profiles. It is found that, although <?B> and its normalize version are significantly enhanced (from a broad central <span class="hlt">average</span> value) early in an <span class="hlt">average</span> MC (and to a lesser extent also late in the MC), the angle <?> is small (less than 8) and approximately constant all throughout the MC. The field intensity enhancements are due mainly to interaction of the MC with the surrounding solar wind plasma causing field compression at front and rear. For example, for a typical MC, ?B/ is: 0.210.27 very early in the MC, -0.110.10 at the center (and -0.0850.12 <span class="hlt">averaged</span> over the full "central region," i.e., for 30% to 80% of duration), and 0.050.29 very late in the MC, showing a double sign change as we travel from front to center to back, in the MC. When individual MCs are examined we find that over 80% of them possess field enhancements within several to many hours of the front boundary, but only about 30% show such enhancements at their rear portions. The enhancement of the MC's front field is also due to MC expansion, but this is usually a lesser effect compared to compression. It is expected that this compression is manifested as significant distortion to the MC's cross-section from the ideal circle, first suggested by Crooker et al. (1990), into a more elliptical/oval shape, as some global MC studies seem to confirm (e.g., Riley and Crooker, 2004) and apparently also as confirmed for local studies of MCs (e.g., Hidalgo et al., 2002; Nieves-Chinchilla et al., 2005).</p> <div class="credits"> <p class="dwt_author">Lepping, R. P.; Narock, T. W.; Chen, H.</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">248</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2004AIPC..699..399M"> <span id="translatedtitle"><span class="hlt">Magnetically</span>-Channeled SIEC Array (MCSA) Fusion Device for <span class="hlt">Interplanetary</span> Missions</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">A radical new Inertial Electrostatic Confinement (IEC) concept, the <span class="hlt">Magnetically</span>-Channeled Spherical-IEC Array (MCSA) fusion propulsion system, was proposed earlier for use in the high performance Space Ship II fusion propulsion ship (Burton, 2003). This ship was designed for a fast manned round trip mission to Jupiter. The MCSA fusion power plant represents a key enabling technology needed for this mission. The details of the proposed MCSA design are presented here, along with a discussion of some possible experiments that could be performed to confirm key physics aspects.</p> <div class="credits"> <p class="dwt_author">Miley, G. H.; Stubbers, R.; Webber, J.; Momota, H.</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-02-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">249</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ntis.gov/search/product.aspx?ABBR=ADA167883"> <span id="translatedtitle"><span class="hlt">Average</span> Characteristics of the Polar Rain and Their Relationship to the Solar Wind and the <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ntis.gov/search/index.aspx">National Technical Information Service (NTIS)</a></p> <p class="result-summary">A study of the characteristics of the polar rain has been completed using data from the SSJ/3 sensor on the Defense Meteorological Satellite Program F2 satellite. Orbits were chosen which exhibited an extended region of polar rain and for which solar wind...</p> <div class="credits"> <p class="dwt_author">K. B. Riehl D. A. Hardy</p> <p class="dwt_publisher"></p> <p class="publishDate">1986-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">250</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013SoPh..284..217R"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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 (FR) 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- ? 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 continuous 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- ?, CME width, and the ratio O 7/ O 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> <div class="credits"> <p class="dwt_author">Riley, P.; Richardson, I. G.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-05-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">251</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20120016557&hterms=Gaussian+process+regression&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DGaussian%2Bprocess%2Bregression"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Riley, P.; Richardson, I. G.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">252</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Tylka, Allan J.; Ko, Yuan-Kuen; Keong Ng, Chee; Wang, Yi-Ming; Dietrich, William F.</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-05-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">253</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Tylka, A. J.; Ko, Y.; Ng, C. K.; Wang, Y.; Dietrich, W. F.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">254</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.agu.org/journals/ja/v082/i013/JA082i013p01933/JA082i013p01933.pdf"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">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> give opposite results. The better</p> <div class="credits"> <p class="dwt_author">N. U. Crooker; J. Feynman; J. T. Gosling</p> <p class="dwt_publisher"></p> <p class="publishDate">1977-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">255</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19790056764&hterms=compose&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dcompose"> <span id="translatedtitle">Initial ISEE magnetometer results - Shock observation. [<span class="hlt">magnetic</span> field profiles across terrestrial bow and <span class="hlt">interplanetary</span> shocks</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">A selection of early measurements is used to illustrate the three advantages brought by ISEE to the study of natural collisionless shocks. These advantages are the ability to resolve most space/time ambiguity by means of simultaneous two-point measurements, instrumentation to make comprehensive field and particle observations covering all important quantities, and the capacity to record data at high time resolution. <span class="hlt">Magnetic</span>-field records from shocks of various types are presented; the types of shock include laminar, supercritical, quasi-perpendicular, high-beta, and quasi-parallel. The spacing of the two spacecraft and the resolution of the system are employed to develop numerous kinematic descriptions of the shocks and the waves that compose and surround them. Data from a single particle experiment are correlated with field data for three cases to demonstrate the important role of comprehensive instrumentation.</p> <div class="credits"> <p class="dwt_author">Russell, C. T.; Greenstadt, E. W.</p> <p class="dwt_publisher"></p> <p class="publishDate">1979-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">256</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Du, A. M.; Tsurutani, B. T.; Sun, W.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-04-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">257</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Du, A. M.; Tsurutani, B. T.; Sun, W.</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">258</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Orlove, Steven T.; Smith, Charles W.; Vasquez, Bernard J.; Schwadron, Nathan A. [Physics Department and Space Science Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH (United States); Skoug, Ruth M. [Los Alamos National Laboratory, MS D466, Los Alamos, NM 87545 (United States); Zurbuchen, Thomas H.; Zhao Liang, E-mail: stx33@wildcats.unh.edu, E-mail: Charles.Smith@unh.edu, E-mail: Bernie.Vasquez@unh.edu, E-mail: N.Schwadron@unh.edu, E-mail: rskoug@lanl.gov, E-mail: thomasz@umich.edu, E-mail: lzh@umich.edu [Department of Atmospheric, Oceanic and Space Science, University of Michigan, Ann Arbor, MI (United States)</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-09-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">259</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1985stoc.iafcT....A"> <span id="translatedtitle">An advanced magnetometric system for precise measurements of the <span class="hlt">interplanetary</span> and near earth <span class="hlt">magnetic</span> fields</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">A three-component flux-gate magnetometric system is described for precise <span class="hlt">magnetic</span> field investigations in a wide dynamic range with a high resolution. To allow inflight measurements of the spacecraft stray field, the system contains two flux-gate sensor triads, located 5 and 7 m from the spacecraft body. The outer triad is supplied with a double flipper system, allowing zero-offset determination of all three sensors. A microprocessor controls all functions of the system and allows on-board processing of received data, including data reduction, event detection, ring-memory storage of preand post-event data, etc. Data are telemetered at a 1 vector/s rate during quiet periods and 8 vector/s in event periods. The measuring ranges are + or - 100 nT + or - 0.01 nT; + or - 1000 nT + or - 0.1 nT; + or - 8000 nT + or - 0.1 nT and + or 80,000 nT + or - 1 nT.</p> <div class="credits"> <p class="dwt_author">Arshinkov, I. S.; Bochev, A. Z.; Abadzhiev, N. S.; Zakharieva, E. G.; Arshinkova, K. I.</p> <p class="dwt_publisher"></p> <p class="publishDate">1985-10-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">260</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19950029559&hterms=taguchi&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dtaguchi"> <span id="translatedtitle">By-controlled convection and field-aligned currents near midnight auroral oval for northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Using the Dynamics Explorer (DE) 2 <span class="hlt">magnetic</span> and electric field and plasma data, B(sub y)- controlled convection and field-aligned currents in the midnight sector for northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) are examined. The results of an analysis of the electric field data show that when IMF is stable and when its magnitude is large, a coherent B(sub y)-controlled convection exists near the midnight auroral oval in the ionosphere having adequate conductivities. When B(sub y) is negative, the convection consists of a westward (eastward) plasma flow at the lower latitudes and an eastward (westward) plasma flow at the higher latitudes in the midnight sector in the northern (southern) ionosphere. When B(sub y) is positive, the flow directions are reversed. The distribution of the field-aligned currents associated with the B(sub y)-controlled convection, in most cases, shows a three-sheet structure. In accordance with the convection the directions of the three sheets are dependent on the sign of B(sub y). The location of disappearance of the precipitating intense electrons having energies of a few keV is close to the convection reversal surface. However, the more detailed relationship between the electron precipitation boundary and the convection reversal surface depends on the case. In some cases the precipitating electrons extend beyond the convection reversal surface, and in others the poleward boundary terminates at a latitude lower than the reversal surface. Previous studies suggest that the poleward boundary of the electrons having energies of a few keV is not necessarily coincident with an open/closed bounary. Thus the open/closed boundary may be at a latitude higher than the poleward boundary of the electron precipitation, or it may be at a latitude lower than the poleward boundary of the electron precipitation. We discuss relationships between the open/closed boundary and the convection reversal surface. When as a possible choice we adopt a view that the open/closed boundary agrees with the convection reversal surface, we can explain qualitatively the configuration of the B(sub y)-controlled convection on the open and close field line regions by proposing a mapping modified in accordance with IMF B(sub y).</p> <div class="credits"> <p class="dwt_author">Taguchi, S.; Sugiura, M.; Iyemori, T.; Winningham, J. D.; Slavin, J. A.</p> <p class="dwt_publisher"></p> <p class="publishDate">1994-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_12");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' 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onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">261</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/55240484"> <span id="translatedtitle">Understanding The Relationship Between Photospheric <span class="hlt">Magnetic</span> Field Observations And In Situ Observations Of The <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Understanding the Sun's open flux and its variability during the course of the solar cycle is important for a number of reasons. For example, recent claims that it has increased significantly over the last century may have had significant space- and even terrestrial-weather consequences. A key relationship in understanding this evolution lies between the observed photospheric <span class="hlt">magnetic</span> field and the</p> <div class="credits"> <p class="dwt_author">Pete Riley; Z. Mikic; J. A. Linker</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">262</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19970026618&hterms=south+pole+station+solar&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dsouth%2Bpole%2Bstation%2Bsolar"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Killeen, T. L.; Won, Y.-I.; Niciejewski, R. J.; Burns, A. G.</p> <p class="dwt_publisher"></p> <p class="publishDate">1995-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">263</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2003AdSpR..32..525M"> <span id="translatedtitle">Distinct shock acceleration processes Evaluation of the <span class="hlt">magnetic</span> trap dimensions formed upstream of an <span class="hlt">interplanetary</span> shock using measurements of the ulysses spacecraft</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We analyze the acceleration signatures of energetic ions (E > 50 keV) and electrons (E > 30 keV) being observed on day 256 of the year 1992 UT, in the vicinity of the surface of a fast-mode quasi-perpendicular <span class="hlt">interplanetary</span> hydromagnetic shock, using fine time resolution measurements by the HI-SCALE instrument onboard the Ulysses spacecraft,(s/c). The observations present strong evidence for the acceleration of energetic particles trapped within <span class="hlt">magnetic</span> structures on the surface of the fast-mode shock. We discuss the flux-times profiles and particle distributions near the shock in the context of previous theoretical studies and models. Moreover we are in the procedure of evaluating the width L and amplitude A of the <span class="hlt">magnetic</span> structure by using HI-SCALE measurements and a sinusoidal form geometry.</p> <div class="credits"> <p class="dwt_author">Marhavilas, P. K.; Sarris, E. T.; Anagnostopoulos, G. C.; Trochoutsos, P. C.</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-08-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">264</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary"><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> <div class="credits"> <p class="dwt_author">Vokhmyanin, M.; Ponyavin, D. I.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">265</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ship.code.u-air.ac.jp/~asai/openime/sol0308.pdf"> <span id="translatedtitle"><span class="hlt">Interplanetary</span> Field Visualization System</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">A prototype system of visualizing <span class="hlt">interplanetary</span> field has been developed using an immersive projection display. The system enables a user to observe global behavior of the <span class="hlt">interplanetary</span> plasma in a virtual environment. The velocity and density fluctuations are measured with <span class="hlt">interplanetary</span> scintillation method, and are analyzed by using computer topography technique. The analysis has produced unbiased results, but has made</p> <div class="credits"> <p class="dwt_author">Kikuo ASAI</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">266</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2005AGUFMSH52A..04K"> <span id="translatedtitle">Survey of <span class="hlt">interplanetary</span> shock characteristics</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We report on a comparison of more than one hundred <span class="hlt">interplanetary</span> shocks observed by both the Wind and ACE spacecraft. For each event, we use single spacecraft analysis methods such as the full Rankine-Hugoniot jump relations and the simpler velocity and <span class="hlt">magnetic</span> coplanarity techniques to determine the shock orientation, speed, and assorted mach numbers and angles. We present a comparison of the properties of the shocks as a function of the separation between the spacecraft to determine the accuracy of the analysis methods and the non-planarity of IP shocks. The accuracy of the derived shock parameters and the non-planarity of the shock fronts are quantified by comparing the observed shock transit time between the spacecraft with predicted transit times calculated from the derived shock properties. The <span class="hlt">average</span> timing errors for a given analysis method is the same using the Wind or ACE dataset; The Ranking-Hugoniot method performs best, with an RMS timing error of two minutes. We have studied the non-planarity of the shocks by comparing the implied radius of curvature determined by the difference between the two derived normals with the separation of the spacecraft. The variation is consistent with a five-degree error in shock direction and a typical radius of curvature of 0.1-0.3 AU. The shock parameters are made available through an online database (1). (1) http://space.mit.edu/home/jck/shockdb/shockdb.html</p> <div class="credits"> <p class="dwt_author">Kasper, J. C.; Lazarus, A. J.; Szabo, A.; Ogilvie, K. W.; Skoug, R.; Steinberg, J. T.; Smith, C.</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">267</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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) (?Pd>0.4 nPa, and IMF Bz<0 nT), and only ~18.4% changes are due to single dynamic pressure increase (?Pd >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 |?Pd|<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> <div class="credits"> <p class="dwt_author">Li, L.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">268</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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 _{?} 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> <div class="credits"> <p class="dwt_author">Alania, Michael; Modzelewska, Renata; Wawrzynczak-Szaban, Anna</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-07-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">269</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">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 class="dwt_publisher"></p> <p class="publishDate">1984-08-20</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">270</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19780042171&hterms=crossed+fields&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D%2522crossed%2Bfields%2522"> <span id="translatedtitle">The <span class="hlt">interplanetary</span> modulation and transport of Jovian electrons</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Based on simultaneous measurements by Pioneer 11 of the 3-6 MeV Jovian electron flux, <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field magnitude, and solar wind speed, the <span class="hlt">interplanetary</span> transport of energetic particles is studied. It is found that corotating interaction regions (CIR's) greatly inhibit electron transport across the <span class="hlt">average</span> field direction. Cross-field transport is also influenced by the degree of compression of the solar wind since CIR's are areas of compressed solar wind plasma. The propagation of Jovian electrons is studied by a model that includes the effects of CIR's. The model tests whether or not the three-dimensional convection-diffusion theory adequately describes the cross-field transport of electrons. The model is also valid for Jovian electron observations from earth-orbiting satellites. The model may be further applied to 1 AU from the sun where it is found that the cross-field diffusion of electrons explains why Jovian electrons are detected at the earth even during periods when the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field does not connect the earth directly to Jupiter.</p> <div class="credits"> <p class="dwt_author">Conlon, T. F.</p> <p class="dwt_publisher"></p> <p class="publishDate">1978-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">271</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20110007246&hterms=PP&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DPP%253F"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Gopalswamy, N.; Akiyama, S.; Yashiro, S.; Michalek, G.; Lepping, R. P.</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">272</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19950047166&hterms=Earth+magnetosphere&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DEarth%2527s%2Bmagnetosphere"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Fedder, J. A.; Lyon, J. G.</p> <p class="dwt_publisher"></p> <p class="publishDate">1995-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">273</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19790055689&hterms=solar+photospheric+magnetic&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dsolar%2Bphotospheric%2Bmagnetic"> <span id="translatedtitle"><span class="hlt">Average</span> photospheric poloidal and toroidal <span class="hlt">magnetic</span> field components near solar minimum</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary"><span class="hlt">Average</span> (over longitude and time) photospheric <span class="hlt">magnetic</span> field components are derived from 3-min Stanford magnetograms made near the solar minimum of cycle 21. The <span class="hlt">average</span> magnetograph signal is found to behave as the projection of a vector for measurements made across the disk. The poloidal field exhibits the familiar dipolar structure near the poles, with a measured signal in the line Fe I 5250 A of about 1 G. At low latitudes the poloidal field has the polarity of the poles, but is of reduced magnitude (about 0.1 G). A net photospheric toroidal field with a broad latitudinal extent is found. The polarity of the toroidal field is opposite in the northern and southern hemispheres and has the same sense as subsurface flux tubes giving rise to active regions of solar cycle 21. These observations are used to discuss large-scale electric currents crossing the photosphere and angular momentum loss to the solar wind.</p> <div class="credits"> <p class="dwt_author">Duvall, T. L., Jr.; Scherrer, P. H.; Svalgaard, L.; Wilcox, J. M.</p> <p class="dwt_publisher"></p> <p class="publishDate">1979-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">274</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2008cosp...37.1624K"> <span id="translatedtitle">Investigation of influence of hypomagnetic conditions closely similar to <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> filed on behavioral and vegetative reactions of higher mammals</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">To study the influence of long being under reduced <span class="hlt">magnetic</span> field on behavioral and vegetative reactions of higher mammals the white rat males were put into the 700-1000 times reduced geomagnetic field (50-70 nT) for 25 days. Such field was obtained by using automatic compensation of the horizontal and vertical components of the GMF at a frequencies up to 10 Hz by means of solenoids of the experimental <span class="hlt">magnetic</span> system. Control animals were located in the same room under usual laboratory GMF conditions (52 uT). Two days before the experiment the behavioral reactions were studied in the "open field" by means of a set of tests, characterizing the level of emotionality, moving and orientational-investigative activities of the animals under conditions of unimpeded behavior. 60 white underbred rat males with the initial body mass of 200 g were divided into three clusters. Animals with <span class="hlt">average</span> indices were selected for the experiment. We have judged behavioral reaction disturbances of the rats under hypomagnetic conditions using videotape recordings carried out in the entire course of the chronic experiment. According to the obtained results during the period of maximum activity (from 230 to 330 a.m.) the number of interrelations between the individuals increased appreciably for experimental rats including interrelations with aggressive character. This was real during all 25 days of observation. We observed a certain dynamics of this index differed from that of the control group. We have also analyzed the final period of observation from the 21th to the 25th days. In this period we studied the 24 hours' dynamics of interrelations which were noted during 5 minutes in every hour around the clock. In the control group the number of interrelation was at a constantly low level. For experimental animals the number of interrelations was higher in the night hours than in the day ones. Moreover it exceeded the similar indexes observed from the 1st to the 20th day. For example from 300 to 305 a.m. on the 23th day we recorded 27 contacts of aggressive character between the individuals. So, in hypomagnetic field conditions the irritability of the animals' central nervous system grows, that expresses itself in the increase of contacts of aggressive and non-aggressive character between the individuals. Also we have carried out the Spirman correlation analysis between studied indices of moving activity and chemiluminescence of blood plasma and urine, electrolytic composition of urine and muscles. For control animals the quantity of correlation connections between electrolyte concentrations in studied substrata was higher than for experimental animals. The physiological sense of these correlation connections is discussed.</p> <div class="credits"> <p class="dwt_author">Krivova, Natalie; Trukhanov, Kiril; Zamotshina, Tatyana; Zaeva, Olga; Khodanovich, Marina; Misina, Tatyana; Tukhvatulin, Ravil; Suhko, Valery</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">275</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012cosp...39.1177M"> <span id="translatedtitle"><span class="hlt">Interplanetary</span> Disturbances and Space Weather</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary"><span class="hlt">Interplanetary</span> disturbances associated with solar flares, coronal mass ejections (CMEs), and solar wind streams (co-rotating interaction regions, CIRs) are responsible for a significant fraction of the space weather effects occurring in the near-Earth environment. This talk reviews the radial evolution of the solar wind transients in the inner heliosphere, based on <span class="hlt">interplanetary</span> scintillation (IPS) images obtained from the Ooty Radio Telescope, combined with a wealth of data acquired from space missions, such as SDO, SOHO and STEREO. Results show that the interaction between the <span class="hlt">interplanetary</span> disturbance (CME or CIR) and the background solar wind determines the radial evolution of its speed and size. Further, the <span class="hlt">magnetic</span> energy associated with the propagating transient (the <span class="hlt">magnetic</span> cloud in the case of a CME and the high-speed stream for a CIR) is likely to play a crucial role in determining the effectiveness of the compression and propagation characteristics of the disturbance. These results are useful to quantify the drag force imposed on a disturbance by the interaction with the ambient solar wind and it is essential in modeling the propagation of a disturbance. This study also has a great importance in understanding the prediction of CME/CIR-associated space weather at the near-Earth environment.</p> <div class="credits"> <p class="dwt_author">Manoharan, P. K.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-07-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">276</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Newell, Patrick T.; Sibeck, David G.; Meng, Ching-I</p> <p class="dwt_publisher"></p> <p class="publishDate">1995-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">277</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2005RScI...76h3911A"> <span id="translatedtitle">HyReSpect: A broadband fast-<span class="hlt">averaging</span> spectrometer for nuclear <span class="hlt">magnetic</span> resonance of <span class="hlt">magnetic</span> materials</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We announce the successful development of a homemade frequency-swept nuclear <span class="hlt">magnetic</span> resonance (NMR) spectrometer entirely designed and built at the University of Parma, optimized for the study of <span class="hlt">magnetic</span> materials but also offering good performance as a general-purpose instrument for solid-state NMR. The spectrometer features heterodyne-based pulser and receiver with four-quadrant phase shifting and quadrature detection; a 150 MHz digital signal processor as a digital pulser for timing and control functions, capable of triggering events with a resolution of 6.6 ns; a two-channel 12 bit 25 MS/s digitizer hosted by a personal computer; and a graphical user interface control program running under Linux, which also integrates external field and temperature controls. The receiver exhibits a flat response from 8 up to 670 MHz, a frequency span suitable for the investigation of <span class="hlt">magnetic</span> transition metal compounds (V, Co, Mn, Cu), and intrinsic dead time of less than 2 ?s, as required with the fast-relaxing NMR signals often encountered in <span class="hlt">magnetic</span> materials. The rf design employing only one external signal generator, and the fast-<span class="hlt">averaging</span> performance of the system (more than 10 000 repetitions per second), are probably the most remarkable features of our apparatus.</p> <div class="credits"> <p class="dwt_author">Allodi, G.; Banderini, A.; de Renzi, R.; Vignali, C.</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-08-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">278</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19950058919&hterms=predicting+next+number&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dpredicting%2Bnext%2Bnumber"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Peredo, M.; Slavin, J. A.; Mazur, E.; Curtis, S. A.</p> <p class="dwt_publisher"></p> <p class="publishDate">1995-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">279</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19870017315&hterms=imf&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dimf"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Raeder, J.; Neubauer, F. M.; Ness, N.; Burlaga, L. F.</p> <p class="dwt_publisher"></p> <p class="publishDate">1986-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">280</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20140009615&hterms=wang&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dwang"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Hwang, K.-J.; Goldstein, M. L.; Kuznetsova, M. M.; Wang, Y.; Vinas, A. F.; Sibeck, D. G.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_13");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' 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class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_14");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' href="#">4</a> <a onClick='return showDiv("page_5");' href="#">5</a> <a onClick='return showDiv("page_6");' href="#">6</a> <a onClick='return showDiv("page_7");' href="#">7</a> <a onClick='return showDiv("page_8");' href="#">8</a> <a onClick='return showDiv("page_9");' href="#">9</a> <a onClick='return showDiv("page_10");' href="#">10</a> <a onClick='return showDiv("page_11");' href="#">11</a> <a onClick='return showDiv("page_12");' href="#">12</a> <a onClick='return showDiv("page_13");' href="#">13</a> <a onClick='return showDiv("page_14");' href="#">14</a> <a style="font-weight: bold;">15</a> <a onClick='return showDiv("page_16");' href="#">16</a> <a onClick='return showDiv("page_17");' href="#">17</a> <a onClick='return showDiv("page_18");' href="#">18</a> <a onClick='return showDiv("page_19");' href="#">19</a> <a onClick='return showDiv("page_20");' href="#">20</a> <a onClick='return showDiv("page_21");' href="#">21</a> <a onClick='return showDiv("page_22");' href="#">22</a> <a onClick='return showDiv("page_23");' href="#">23</a> <a onClick='return showDiv("page_24");' href="#">24</a> <a onClick='return showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_16");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">281</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19810034177&hterms=camillo&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dcamillo"> <span id="translatedtitle">Orbit-<span class="hlt">averaged</span> behavior of <span class="hlt">magnetic</span> control laws for momentum unloading</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Analytical formulas are derived for orbit-<span class="hlt">averaged</span> behavior of <span class="hlt">magnetic</span> control laws for unloading the excess angular momentum of a spacecraft reaction wheel control system in the presence of secular environmental torques. The specific example of an axially symmetric spacecraft with an inertially fixed attitude for which the dominant environmental torque is the gravity-gradient torque is treated in detail, but extensions of the general approach to other inertially fixed and earth-pointing spacecraft are discussed. The analytical formulas are compared to detailed simulations performed for the Solar Maximum Mission spacecraft, and agreement to within 10% is found. The analytical formulas can be used in place of detailed simulations for preliminary studies, and can be used to find selected cases giving the most stringent tests of momentum unloading capability for which detailed simulations may be performed.</p> <div class="credits"> <p class="dwt_author">Camillo, P. J.; Markley, F. L.</p> <p class="dwt_publisher"></p> <p class="publishDate">1980-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">282</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2010AGUFMSH33B1842M"> <span id="translatedtitle">Effects of <span class="hlt">Interplanetary</span> Transport on SEPs with Differing Charge-to-Mass ratios</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">In large SEP events that are well-connected to the observer it is often observed that particles with different charge-to-mass ratios (e.g, O vs. Fe) have different time-intensity histories, and different event-<span class="hlt">averaged</span> spectral shapes. Several explanations for this behavior have been suggested, such as a sequence of occurrences as an initial flare followed by acceleration in a CME-associated <span class="hlt">interplanetary</span> shock. Another mechanism may be differing responses of ions to waves generated by the streaming SEP protons. In this paper we investigate the possible role of <span class="hlt">interplanetary</span> transport in such effects by modeling the ion propagation using an advanced numerical transport model in which the particle pitch angle scattering is determined by the turbulence spectrum of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field. Because the turbulence level is a function of particle gyro-frequency, particles with the same speed but different charge-to-mass ratios will sample different portions of the turbulence spectrum and therefore can have different transport histories. We examine sample calculations for O and Fe ions to explore the transport induced effects on time-intensity profiles, spectral shape, and event-<span class="hlt">averaged</span> abundances for differing levels of <span class="hlt">interplanetary</span> turbulence. We will compare calculated time-intensity profiles with SEP observations from ACE instruments.</p> <div class="credits"> <p class="dwt_author">Mason, G. M.; Li, G.; Mewaldt, R. A.; Cohen, C. M.; Leske, R. A.; Desai, M. I.; Dayeh, M. A.; Haggerty, D. K.; Verkhoglyadova, O. P.; Zank, G. P.</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">283</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19860041563&hterms=high+magnetic+field&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dhigh%2Bmagnetic%2Bfield"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Rees, D.; Fuller-Rowell, T. J.; Gordon, R.; Smith, M. F.; Maynard, N. C.; Heppner, J. P.; Spencer, N. W.; Wharton, L.</p> <p class="dwt_publisher"></p> <p class="publishDate">1986-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">284</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1998AnGeo..16..764S"> <span id="translatedtitle">Interhemispheric contrasts in the ionospheric convection response to changes in the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field and substorm activity: a case-study</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Interhemispheric contrasts in the ionospheric convection response to variations of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) and substorm activity are examined, for an interval observed by the Polar Anglo-American Conjugate Experiment (PACE) radar system between ~1600 and ~2100 MLT on 4 March 1992. Representations of the ionospheric convection pattern associated with different orientations and magnitudes of the IMF and nightside driven enhancements of the auroral electrojet are employed to illustrate a possible explanation for the contrast in convection flow response observed in radar data at nominally conjugate points. Ion drift measurements from the Defence Meteorological Satellite Program (DMSP) confirm these ionospheric convection flows to be representative for the prevailing IMF orientation and magnitude. The location of the fields of view of the PACE radars with respect to these patterns suggest that the radar backscatter observed in each hemisphere is critically influenced by the position of the ionospheric convection reversal boundary (CRB) within the radar field of view and the influence it has on the generation of the irregularities required as scattering targets by high-frequency coherent radar systems. The position of the CRB in each hemisphere is strongly controlled by the relative magnitudes of the IMF Bz and By components, and hence so is the interhemispheric contrast in the radar observations.</p> <div class="credits"> <p class="dwt_author">Shand, B. A.; Yeoman, T. K.; Lewis, R. V.; Greenwald, R. A.; Hairston, M. R.</p> <p class="dwt_publisher"></p> <p class="publishDate">1998-07-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">285</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19780065152&hterms=studies+wind+structure&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dstudies%2Bwind%2Bstructure"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Knoll, R.; Epstein, G.; Hoang, S.; Huntzinger, G.; Steinberg, J. L.; Fainberg, J.; Grena, F.; Stone, R. G.; Mosier, S. R.</p> <p class="dwt_publisher"></p> <p class="publishDate">1978-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">286</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">liu, jing</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-05-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">287</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/41983246"> <span id="translatedtitle">Response of the ionospheric convection pattern to a rotation of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field on January 14, 1988</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Ionospheric convection signatures observed over the polar regions are provided by the DMSP F8 satellite. The authors consider five passes over the southern summer hemisphere during a time when the z component of the interplantary <span class="hlt">magnetic</span> field was stable and positive and the y component changed slowly from positive to negative. Large-scale regions of sunward flow are observed at very</p> <div class="credits"> <p class="dwt_author">J. A. Cumnock; R. A. Heelis; M. R. Hairston</p> <p class="dwt_publisher"></p> <p class="publishDate">1992-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">288</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1983JGZG...54...60D"> <span id="translatedtitle"><span class="hlt">Interplanetary</span> <span class="hlt">magnetic</span> field power spectra with frequencies from 2.4 X 10 to the -5th HZ to 470 HZ from HELIOS-observations during solar minimum conditions</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">HELIOS-2 observations of the <span class="hlt">interplanetary</span> vector <span class="hlt">magnetic</span> field are used to obtain power spectral density estimates from 2.4 x 10 to the -5th Hz up to 470 Hz. The instrumentation, measuring method, and raw data analysis are briefly described, and a short summary of the algorithm used for the computation of the density estimates from flux-gate magnetometer data is given. Examples are presented of <span class="hlt">magnetic</span> field power spectra observed at different heliocentric distances as well as the variation of the spectra in the course of a high-speed stream. The observed spectra are interpreted in terms of waves and of MHD turbulence.</p> <div class="credits"> <p class="dwt_author">Denskat, K. U.; Beinroth, H. J.; Neubauer, F. M.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">289</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19900054402&hterms=spiral+line&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dspiral%2Bline"> <span id="translatedtitle">An <span class="hlt">interplanetary</span> planar <span class="hlt">magnetic</span> structure oriented at a large (about 80 deg) angle to the Parker spiral</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary"><span class="hlt">Magnetic</span> field structures in the solar wind, characterized by a variation of the field vectors within a plane inclined to the ecliptic ('Planar <span class="hlt">Magnetic</span> Structures', PMSs), were reported recently (Nakagawa et al., 1989). These PMSs have the property that the plane of variation of the field also contains the nominal Parker spiral direction. An observation of a PMS where the direction of the line of intersection of the plane of field variation with the ecliptic plane makes a large (about 80 deg) angle to the Parker spiral direction is presented. Furthermore, the angular variables of the field (1) vary over a restricted range, and (2) are linearly related. The latter property is related to the former. Currently proposed models for the origin of PMS, inasmuch as they require field configurations which retain strict alignment with the Parker spiral direction from formation to observation, are probably incomplete.</p> <div class="credits"> <p class="dwt_author">Farrugia, M. W.; Dunlop, M. W.; Geurts, F.; Balogh, A.; Southwood, D. J.; Bryant, D. A.; Neugebauer, M.</p> <p class="dwt_publisher"></p> <p class="publishDate">1990-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">290</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/41978825"> <span id="translatedtitle">The <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field B(y)-dependent field-aligned current in the dayside polar cap under quiet conditions</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary"><span class="hlt">Magnetic</span> data from the Magsat satellite are used to study the spatial distribution and temporal variation of the IMF B(y)-dependent cusp region field-aligned currents (FACs) during quiet periods. It is shown that the FACs are located at about 86-87 deg invariant latitude local noon. The current density of this FAC is found to be greater than 4 muA\\/sq m for</p> <div class="credits"> <p class="dwt_author">M. Yamauchi; T. Araki</p> <p class="dwt_publisher"></p> <p class="publishDate">1989-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">291</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/245185"> <span id="translatedtitle">Viking observations of a reverse convection cell developing in response to a northward turning of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">The authors report the development of a reverse sense convection cell in the polar ionosphere from auroral images coming from UV Viking probes. The cell was observed to grow on the dusk side of the north polar oval, near the transpolar arcs. As it grew it seemed to displace the arc system toward dawn. They compare their observations with a model in which <span class="hlt">magnetic</span> merging in the magnetopause produces such convection cells, typically associated with horse-collar or teardrop auroral features.</p> <div class="credits"> <p class="dwt_author">Henderson, M.G. [Los Alamos National Laboratory, NM (United States)] [Los Alamos National Laboratory, NM (United States); Murphree, J.S. [Univ. of Calgary (Canada)] [Univ. of Calgary (Canada)</p> <p class="dwt_publisher"></p> <p class="publishDate">1996-04-15</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">292</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2008AGUFMSH44A..07C"> <span id="translatedtitle">The Flux of Open and Torroidal <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field as a Function of Heliolatitude and Solar Cycle</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Analyses performed during the previous 11-year phase of the solar cycle attempted to measure the flux of open and toroidal <span class="hlt">magnetic</span> field lines [Bieber and Rust, ApJ, 453, 911, 1995] and associate the toroidal flux with coronal mass ejections (CMEs) [Smith and Phillips, JGR, 102, 249, 1997]. Since that time Ulysses has made three polar passes and spent at least eight years at polar latitudes, enabling us to examine the underlying assumption of the earlier studies that using near-ecliptic latitude measurements could serve as a proxy for polar-latitude observations. We find confirmation of the claims that the present solar minimum has experienced a strong decrease in open flux, but we also find evidence of past conditions at this same level. We find that torroidal flux is virtually negligable at higher latitudes as measured by the Ulysses spacecraft, even during times of solar maximum, and attribute this to the sub-photospheric winding of the Sun's <span class="hlt">magnetic</span> field as illustrated by the familiar butterfly diagram. Our observations of the rate of toroidal flux ejection, 7 1022 Mx/year, sets a lower limit on the amount of <span class="hlt">magnetic</span> flux that can be ejected by CMEs near solar maximum.</p> <div class="credits"> <p class="dwt_author">Connick, D. E.; Smith, C. W.; Schwadron, N. A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">293</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19930039184&hterms=wave+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Song, P.; Russell, C. T.; Strangeway, R. J.; Wygant, J. R.; Cattell, C. A.; Fitzenreiter, R. J.; Anderson, R. R.</p> <p class="dwt_publisher"></p> <p class="publishDate">1993-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">294</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1992JGR....9719373S"> <span id="translatedtitle">Dayside ionospheric convection changes in response to long-period <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field oscillations - Determination of the ionospheric phase velocity</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Ground <span class="hlt">magnetic</span> field perturbations recorded by the CANOPUS magnetometer network in the 7 to 13 MLT sector are used to examine how reconfigurations of the dayside polar ionospheric flow take place in response to north-south changes of the IMF. During the 6-h interval in question, IMF Bz oscillates between +/- 7 nT with about a 1-h period. Corresponding variations in the ground <span class="hlt">magnetic</span> disturbance are observed which we infer are due to changes in ionospheric flow. Cross correlation of the data obtained from two ground stations at 73.5 deg <span class="hlt">magnetic</span> latitude, but separated by about 2 hours in MLT, shows that changes in the flow are initiated in the prenoon sector (about 10 MLT) and then spread outward toward dawn and dusk with a phase speed of about 5 km/s over the longitude range about 8 to 12 MLT, slowing to about 2 km/s outside this range. Cross correlating the data from these ground stations with IMP 8 IMF Bz records produces a MLT variation in the ground response delay relative to the IMF which is compatible with these deduced phase speeds.</p> <div class="credits"> <p class="dwt_author">Saunders, M. A.; Freeman, M. P.; Southwood, D. J.; Cowley, S. W.; Lockwood, M.; Samson, J. C.; Farrugia, C. J.; Hughes, T. J.</p> <p class="dwt_publisher"></p> <p class="publishDate">1992-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">295</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19870027662&hterms=Earth+magnetosphere&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DEarth%2527s%2Bmagnetosphere"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Ogino, T.; Walker, R. J.; Ashour-Abdalla, M.; Dawson, J. M.</p> <p class="dwt_publisher"></p> <p class="publishDate">1986-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">296</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ntis.gov/search/product.aspx?ABBR=N20120011758"> <span id="translatedtitle">Observations of Electromagnetic Whistler Precursors at Supercritical <span class="hlt">Interplanetary</span> Shocks.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ntis.gov/search/index.aspx">National Technical Information Service (NTIS)</a></p> <p class="result-summary">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, sho...</p> <div class="credits"> <p class="dwt_author">A. Breneman A. Koval A. Szabo B. A. Maruca C. A. Cattell J. C. Kasper K. Goetz K. Kersten L. B. Wilson M. Pulupa P. J. Kellogg</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">297</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19870025955&hterms=nss&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dnss"> <span id="translatedtitle">The relationship of the large-scale solar field to the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field - What will Ulysses find?</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Using photospheric <span class="hlt">magnetic</span> field observations obtained at the Stanford Wilcox Solar Observatory, results from a potential field model for the present solar cycle are given, and qualitative predictions of the IMF that Ulysses may encounter are presented. Results indicate that the IMF consists of large regions of opposite polarity separated by a neutral sheet (NS) (extended to at least 50 deg) and a four-sector structure near solar minimum (produced by small quadripolar NS warps). The latitudinal extent of the NS increases following minimum and the structure near maximum includes multiple NSs, while a simplified IMF is found during the declining phase.</p> <div class="credits"> <p class="dwt_author">Hoeksema, J. T.</p> <p class="dwt_publisher"></p> <p class="publishDate">1986-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">298</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19750017288&hterms=storms+Black&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dstorms%2BBlack"> <span id="translatedtitle"><span class="hlt">Interplanetary</span> field and plasma during initial phase of geomagnetic storms</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Patel, V. L.; Wiskerchen, M. J.</p> <p class="dwt_publisher"></p> <p class="publishDate">1975-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">299</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">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 class="dwt_publisher"></p> <p class="publishDate">2012-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">300</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Mishra, Rajesh Kumar; Agarwal Mishra, Rekha</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-07-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_14");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" 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showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_17");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">301</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1999JASTP..61.1357W"> <span id="translatedtitle">A statistical study of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field control of sporadic E-layer occurrence in the southern polar cap ionosphere</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The influence of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) on the occurrence of sporadic E (Es)-layers in the southern polar cap ionosphere has been investigated. We statistically analysed ionogram and Doppler velocity observations made using a HF digital ionosonde located at Casey, Antarctica (66.3S, 110.5E 81S <span class="hlt">magnetic</span> latitude) during the two summer campaign intervals 1 January to 18 February, and 1 November to 31 December 1997. The ionogram and Doppler velocity measurements were used to determine the Es-occurrence and electric field vectors (assuming EB/B2 drift), respectively. Concurrent IMF data were obtained from measurements made on board the Wind spacecraft. First, the gross properties of the IMF dependence of Es-formation were obtained: the occurrence rate was higher for negative By and/or positive Bz, and lower for positive By and/or negative Bz. To reconcile these gross properties with the electric field theory of Es-layer formation, the detailed diurnal variation of both Es-occurrence and the ionospheric electric field were obtained for different orientations of the IMF. The main statistical results are that: (1) the By component mainly controls the occurrence of the midnight Es-layers through its influence on the corresponding South West electric field; and (2) the Bz component mainly controls the occurrence of the evening Es-layers. However, the change in the occurrence rate for evening Es-layers was not related to the strength of the associated North West and North East electric fields. The total occurrence of Es-layers depended more on By than on Bz, owing to the dominance of By-controlled midnight Es-layers in the occurrence distribution. Nevertheless, the dependence of Es-occurrence on Bz was important. We suggest that the increase in Es-occurrence for positive Bz might be explained by the intermittent production of lower F-region ionisation by polar showers and squalls, which also increase in frequency and intensity for positive Bz. The importance of metallic ion transport within the ionosphere is also considered.</p> <div class="credits"> <p class="dwt_author">Wan, W.; Parkinson, M. L.; Dyson, P. L.; Breed, A. M.; Morris, R. J.</p> <p class="dwt_publisher"></p> <p class="publishDate">1999-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">302</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2008AIPC.1039..240B"> <span id="translatedtitle">Particle Acceleration at <span class="hlt">Interplanetary</span> Shocks</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The acceleration of interstellar pick-up ions as well as solar wind species has been observed at a multitude of <span class="hlt">interplanetary</span> (IP) shocks by different spacecraft. The efficiency of injection of the pick-up ion component differs from that of the solar wind, and is strongly enhanced at highly oblique and quasi-perpendicular shock events. This paper expands upon previous work modeling the phase space distributions of accelerated ions associated with the shock event encountered on day 292 of 1991 by the Ulysses mission at 4.5 AU. As in the prior work, a kinetic Monte Carlo simulation is employed here to model the diffusive acceleration process. This exposition presents recent developments pertaining to the incorporation into the simulation of the diffusive characteristics incurred by field line wandering (FLW), according to the work of Giacalone and Jokipii. Resulting ion distributions and upstream diffusion scales are presented and compared with Ulysses data. For a pure field-line wandering construct, it is determined that the upstream spatial ramp scales are too short to accommodate the HI-SCALE flux increases for 200 keV protons, and that the distribution function for H+ somewhat underpopulates the combined SWICS/HI-SCALE spectra at the shock. This contrasts our earlier theory/data comparison where it was demonstrated that diffusive transport in highly turbulent fields according to kinetic theory can successfully account for both the proton distribution data near the shock, and the observation of energetic protons upstream of this <span class="hlt">interplanetary</span> shock, using a single turbulence parameter. The principal conclusion here is that, in a FLW scenario, the transport of ions across the mean <span class="hlt">magnetic</span> field is slightly less efficient than is required to effectively trap energetic ions within a few Larmor radii of the shock layer, and thereby sustain acceleration at levels that match the observed distributions. This highlights the contrast between ion transport in highly turbulent shock environs and remote, less-disturbed <span class="hlt">interplanetary</span> regions.</p> <div class="credits"> <p class="dwt_author">Baring, Matthew G.; Summerlin, Errol J.</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-08-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">303</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20090019739&hterms=Bhat&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DBhat"> <span id="translatedtitle">Mars Reconnaissance Orbiter <span class="hlt">Interplanetary</span> Navigation</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">This viewgraph presentation reviews the Mars Reconnaissance Orbiter (MRO) <span class="hlt">interplanetary</span> navigation. An <span class="hlt">interplanetary</span> overview including dynamic models of outgassing, small force calibration and trending, solar radiation pressure and trajectory correction maneuvers are also described.</p> <div class="credits"> <p class="dwt_author">You, Tung-Han; Halsell, Allen; Graat, Eric J.; Highsmith, Dolan E.; Demcak, Stuart; Long, Stacia M.; Bhat, Ramachand S.; Mottinger, Neil A.; Higa, Earl; Jah, Moriba K.</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">304</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20060039008&hterms=feynman&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dfeynman"> <span id="translatedtitle"><span class="hlt">Interplanetary</span> Proton Model: JPL 1991</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">This study was carried out to increase the acuracy and energy range of predictive models of <span class="hlt">interplanetary</span> proton fluences. Such an estimate is often needed when spacecraft spend a signigicant amount of time in the <span class="hlt">interplanetary</span> environmnet.</p> <div class="credits"> <p class="dwt_author">Feynman, J.; Spitale, G.; Wang, J.</p> <p class="dwt_publisher"></p> <p class="publishDate">1993-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">305</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">McKenna-Lawlor, S.; Kallio, E.; Alho, M.; Jarvinen, R.; Afonin, V.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-04-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">306</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19810065275&hterms=wandering&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dwandering"> <span id="translatedtitle"><span class="hlt">Interplanetary</span> Alfvenic fluctuations - A stochastic model</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">The concept of minimum variance is investigated for nonplanar <span class="hlt">interplanetary</span> Alfvenic fluctuations in which the field direction varies randomly. The theory of the random wandering of a vector of constant length is developed as a representation of the <span class="hlt">magnetic</span> field, and it is found that the minimum variance tends to coincide with the mean field directions over the correlation time of the fluctuations. The Fokker-Planck limit of the theory is then developed and used to analyze the statistic distribution of field directions with and without a reflecting barrier. Results suggest that the tendency of the Alfvenic fluctuations to have a direction of minimum variance statistically aligned with the mean <span class="hlt">magnetic</span> field may be purely a consequence of the randomness of the fluctuation and not imply that the fluctuations are necessarily plane waves. Extensive statistical studies of the observed directional variations of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field are necessary to test this hypothesis.</p> <div class="credits"> <p class="dwt_author">Barnes, A.</p> <p class="dwt_publisher"></p> <p class="publishDate">1981-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">307</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1994CosRe..31..662K"> <span id="translatedtitle">Prediction of radiation environment in <span class="hlt">interplanetary</span> space.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The authors present experimental data on the electron and proton fluxes recorded on board the Prognoz-3 satellite in 1973, data on the parameters of the solar wind and the interplanetry <span class="hlt">magnetic</span> field and the GCR fluxes recorded by various neutron monitors, and also data on the <span class="hlt">magnetic</span> storms and the Kp-index. They analyze the preflare situation that is observed during one or two solar rotations prior to a flare. It is shown that this period is characterized by the apperance of active regions on the Sun, by the generation of coronal formations and their expulsion into <span class="hlt">interplanetary</span> space, by the appearance in <span class="hlt">interplanetary</span> space of ordered <span class="hlt">magnetic</span> structures that are filled with electrons and protons, and by reduction of the GCR fluxes. The preflare situation is also characterized by intensification of the activity of terrestrial origin. The <span class="hlt">magnetic</span> activity intensifies in certain regions, both on the Earth and on the Sun, as a consequence of which the amplitudes of the <span class="hlt">magnetic</span> storms in these regions intensify and particles that can be recorded by neutron monitors are generated. Perturbation of the Earth's magnetosphere takes place in these periods, as a result of which there appear in <span class="hlt">interplanetary</span> space protons with energy E ? 40 MeV of magnetospheric origin.</p> <div class="credits"> <p class="dwt_author">Kuzhevskij, B. M.; Petrov, V. M.; Shestopalov, I. P.</p> <p class="dwt_publisher"></p> <p class="publishDate">1994-05-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">308</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/41270376"> <span id="translatedtitle">Prediction of daily <span class="hlt">average</span> solar wind velocity from solar <span class="hlt">magnetic</span> field observations using hybrid intelligent systems</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">A hybrid intelligent system, combining theory driven and data driven models, is used to predict the daily solar wind velocity at 1 AU from solar <span class="hlt">magnetic</span> field observations. The Potential Field Model (theory driven) is used to calculate the coronal <span class="hlt">magnetic</span> field up to the source surface placed at 2.5R?. The Earth's position is projected onto the source surface using</p> <div class="credits"> <p class="dwt_author">P. Wintoft; H. Lundstedt</p> <p class="dwt_publisher"></p> <p class="publishDate">1997-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">309</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2004cosp...35.3394B"> <span id="translatedtitle">Geomagnetic effects on the <span class="hlt">average</span> surface temperature</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Several results have previously shown as the solar activity can be related to the cloudiness and the surface solar radiation intensity (Svensmark and Friis-Christensen, J. Atmos. Sol. Terr. Phys., 59, 1225, 1997; Veretenenkoand Pudovkin, J. Atmos. Sol. Terr. Phys., 61, 521, 1999). Here, the possible relationships between the <span class="hlt">averaged</span> surface temperature and the solar wind parameters or geomagnetic activity indices are investigated. The temperature data used are the monthly SST maps (generated at RAL and available from the related ESRIN/ESA database) that represent the <span class="hlt">averaged</span> surface temperature with a spatial resolution of 0.5x0.5 and cover the entire globe. The <span class="hlt">interplanetary</span> data and the geomagnetic data are from the USA National Space Science Data Center. The time interval considered is 1995-2000. Specifically, possible associations and/or correlations of the <span class="hlt">average</span> temperature with the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field Bz component and with the Kp index are considered and differentiated taking into account separate geographic and geomagnetic planetary regions.</p> <div class="credits"> <p class="dwt_author">Ballatore, P.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">310</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1998JGR...103.6703F"> <span id="translatedtitle">Charts of joint Kelvin-Helmholtz and Rayleigh-Taylor instabilites at the dayside magnetopause for strongly northward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We present maximum growth rate charts of the Kelvin-Helmholtz (KH) and Rayleigh-Taylor (RT) instabilities at the dayside magnetopause (MP), considering two orientations of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) (due north and 30 west of north). We input parameters in the plasma depletion layer calculated from an MHD code. We study both a sharp MP transition and an MP with an attached boundary layer (``thin'' and ``thick'' approximations, respectively). Our analysis applies to wavelengths (?) from ~2103km to <=9 RE. Thin model results are as follows: For a stationary MP and due north IMF, the off-noon, low-latitude MP is very low shear (<=10) and is substantially KH active. With an IMF inclined to north, extremely low shear, KH-active regions are confined to two strips, one in each hemisphere, where short ? perturbations are generated, which propagate as surface ripples on the high-latitude, duskside MP. For a sunward accelerating magnetopause and IMF north, a large part of the MP is unstable. With an inclined IMF, the KH+RT unstable strips are broader and growth rates are higher. Thick model results are as follows: For IMF due north and a stationary MP, the middle- to high-latitude MP is stable. At middle to low latitudes, the inner edge of the boundary layer (IEBL) is active, except for a 2-hour local time band on either side of noon. For the inclined IMF, the MP is stable for long ?, with activity for short ? confined to two strips, as before, with slightly reduced growth rates. For the IEBL, a clear dawn-dusk asymmetry in KH activity is evident. When the MP accelerates sunward and the IMF points north, we have to consider also the ? of the perturbation. For short ?, growth rates are enhanced with respect to stationarity at both the MP and the IEBL. While there are extensive regions of negligible growth at the MP, the entire IEBL is RT+KH unstable. We give an example of a long ? perturbation where both interfaces are coupled and oscillate together. Finally, for an inclined IMF, we have at the MP unstable strips which are wider and have higher growth rates. The IEBL, by contrast, is completely destabilized, with larger growth rates than under stationary conditions.</p> <div class="credits"> <p class="dwt_author">Farrugia, C. J.; Gratton, F. T.; Bender, L.; Biernat, H. K.; Erkaev, N. V.; Quinn, J. M.; Torbert, R. B.; Dennisenko, V.</p> <p class="dwt_publisher"></p> <p class="publishDate">1998-04-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">311</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ntis.gov/search/product.aspx?ABBR=CONF7507102"> <span id="translatedtitle">Current <span class="hlt">Averaging</span> and Coil Segmentation in the Protection of Larger Toroidal Superconducting <span class="hlt">Magnet</span> Systems.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ntis.gov/search/index.aspx">National Technical Information Service (NTIS)</a></p> <p class="result-summary">Various aspects of the electrical protection problems of a large toroidal superconducting <span class="hlt">magnet</span> system are discussed--especially the redistribution of coil currents and induced voltages both due to inductive coupling--and some possible solutions are sugg...</p> <div class="credits"> <p class="dwt_author">H. T. Yeh J. N. Luton</p> <p class="dwt_publisher"></p> <p class="publishDate">1974-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">312</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2009AGUFMSH22A..04C"> <span id="translatedtitle">Effects of <span class="hlt">Interplanetary</span> Transport on Derived Energetic Particle Source Strengths</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We study the transport of solar energetic particles (SEPs) in the inner heliosphere in order to relate observations made by an observer at 1 AU to the total energy content of particles at the source, assumed to be near the Sun. We use a numerical simulation that integrates the trajectories of a large number of individual particles moving in the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field. We model pitch-angle scattering and adiabatic cooling of energetic ions with energies from 50 keV/nucleon to 100 MeV/nucleon. Among other things, we determine the number of times that particles of a given energy cross 1 AU and the <span class="hlt">average</span> energy loss that they suffer due to adiabatic deceleration in the solar wind. We use a number of different forms of the <span class="hlt">interplanetary</span> spatial diffusion coefficient, a wide range of scattering mean-free paths, and consider a number of different ion species in order to generate a wide range of simulation results that can be applied to individual SEP events. Our results are used to estimate the total energy needed to accelerate particles for an event on 20 February 2002 based on observations made at 1 AU. We find that estimates of the source energy based on SEP measurements at 1 AU are relatively insensitive to mean free path and scattering scheme.</p> <div class="credits"> <p class="dwt_author">Chollet, E. E.; Giacalone, J.; Mewaldt, R. A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">313</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2010JGRA..115.6101C"> <span id="translatedtitle">Effects of <span class="hlt">interplanetary</span> transport on derived energetic particle source strengths</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We study the transport of solar energetic particles (SEPs) in the inner heliosphere in order to relate observations made by an observer at 1 AU to the number and total energy content of accelerated particles at the source, assumed to be near the Sun. We use a numerical simulation that integrates the trajectories of a large number of individual particles moving in the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field. We model pitch angle scattering and adiabatic cooling of energetic ions with energies from 50 keV nucleon-1 to 100 MeV nucleon-1. Among other things, we determine the number of times that particles of a given energy cross 1 AU and the <span class="hlt">average</span> energy loss that they suffer because of adiabatic deceleration in the solar wind. We use a number of different forms of the <span class="hlt">interplanetary</span> spatial diffusion coefficient and a wide range of scattering mean-free paths and consider a number of different ion species in order to generate a wide range of simulation results that can be applied to individual SEP events. We apply our simulation results to observations made at 1 AU of the 20 February 2002 solar energetic particle event, finding the original energy content of several species. We find that estimates of the source energy based on SEP measurements at 1 AU are relatively insensitive to the mean-free path and scattering scheme if adiabatic cooling and multiple crossings are taken into account.</p> <div class="credits"> <p class="dwt_author">Chollet, E. E.; Giacalone, J.; Mewaldt, R. A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-06-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">314</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/5058056"> <span id="translatedtitle">Liquid chromatography/proton nuclear <span class="hlt">magnetic</span> resonance spectrometry <span class="hlt">average</span> composition analysis of fuels</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">The use of a NMR spectrometer as a continuous flow liquid chromatographic detector (LC//sup 1/H NMR) generates a proton spectrum of each hydrocarbon class present in the sample. A detailed set of equations is presented which permits LC//sup 1/H NMR integration data from petroleum fuels to be interpreted as an <span class="hlt">average</span> composition for each chromatographic fraction. Quantities calculated for each aromatic fraction include: the number <span class="hlt">average</span> molecular weight, <span class="hlt">average</span> degree of substitution on aromatic rings, the absolute number of moles of each structural type of carbon, an <span class="hlt">average</span> structure (devoid of stereoisomer information), the total number of moles of carbon in each chromatographic fraction, and numerous other properties of interest in fuel characterization. The method is demonstrated for artifical fuels of known composition, for two experimental aviation fuels, and for a fuel blending stock sample which had been fully characterized at an independent laboratory by gas chromatography and GC/MS. The LC//sup 1/H NMR <span class="hlt">average</span> composition method is shown to be very accurate for the monocyclic aromatic (substituted benzenes and tetralins) and dicyclic aromatic (substituted naphthalenes and acenaphthenes) fractions of petroleum fuels. <span class="hlt">Average</span> molecular weights for these fractions can be routinely determined at an accuracy of +/-4 daltons. The other quantities are also determined at a high degree of accuracy. The applicability of the LC//sup 1/H NMR method to the aliphatic fraction of fuel samples is restricted by difficulties in accounting for quaternary carbons and cycloalkanes.</p> <div class="credits"> <p class="dwt_author">Haw, J.F.; Glass, T.E.; Dorn, H.C.</p> <p class="dwt_publisher"></p> <p class="publishDate">1983-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">315</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012EGUGA..14.6350O"> <span id="translatedtitle">Dependence of the bounce-<span class="hlt">averaged</span> diffusion coefficients on <span class="hlt">magnetic</span> field model in the outer radiation belt</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Bounce-<span class="hlt">averaged</span> scattering rates computed in the dipole <span class="hlt">magnetic</span> field are usually used for the diffusive simulations of the radiation belt diffusion codes. We present the results of calculations of the bounce-<span class="hlt">averaged</span> pitch angle <D??>, mixed <D?p>, and momentum <Dpp> diffusion coefficients in two Tsyganenko and dipole field models. We consider resonant interactions of the outer radiation belt electrons with oblique whistler-mode chorus waves. We assume the Gaussian wave frequency distribution and the Gaussian wave normal angle distribution. The bounce-<span class="hlt">averaged</span> scattering rates are calculated for geomagnetically quiet and disturbed conditions at two MLT locations. We concentrate at distance of 7 Earth radii near the geostationary orbit. We demonstrate that on the day side the effects of taking into account a realistic <span class="hlt">magnetic</span> field are only considerable for small equatorial pitch angles for energies larger than E=1 MeV. On the night side the differences in the bounce-<span class="hlt">averaged</span> scattering rates calculated in Tsyganenko and dipole field models can reach several orders of magnitude at various equatorial pitch angles for E?0.5 MeV electrons. To explain the differences in <D??>, <D?p>, and <Dpp> associated with a change of the <span class="hlt">magnetic</span> field model on the day and night sides we present the contribution of various resonant harmonics to the diffusion and examine the changes in the resonance condition. We show that with increasing electron energy a larger numbers of resonances can significantly contribute to the bounce-<span class="hlt">averaged</span> diffusion coefficients up to several tens of resonances in the realistic <span class="hlt">magnetic</span> fields. Our study shows that it is crucially important for radiation belt modeling to compute the scattering rates in a realistic field model.</p> <div class="credits"> <p class="dwt_author">Orlova, K.; Shprits, Y.; Ni, B.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-04-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">316</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/52631680"> <span id="translatedtitle">Regional, scale size, and <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field variability of <span class="hlt">magnetic</span> field and ion drift structures in the high-latitude ionosphere</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Using data from the Dynamics Explorer 2 satellite's ion drift meter and magnetometer, we have examined fluctuations in the high-latitude velocity and <span class="hlt">magnetic</span> field structure to better understand the coupling between the magnetosphere and ionosphere. Our study examines perturbations in the frequency range from 0.25 to 8 Hz, equivalent to static scale sizes between about 30 and 1 km. Seasonal</p> <div class="credits"> <p class="dwt_author">John P. Keady; R. A. Heelis</p> <p class="dwt_publisher"></p> <p class="publishDate">1999-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">317</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19910048949&hterms=inertia&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dinertia"> <span id="translatedtitle">Viscosity and inertia in cosmic-ray transport - Effects of an <span class="hlt">average</span> <span class="hlt">magnetic</span> field</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">A generalized transport equation is introduced which describes the transport and propagation of cosmic rays in a <span class="hlt">magnetized</span>, collisionless medium. The equation is valid if the cosmic-ray distribution function is nearly isotropic in momentum, if the ratio of fluid speed to fluid-flow particle speed is small, and if the ratio of collision time to time for change in the macroscopic flow is small. Five independent cosmic-ray viscosity coefficients are found, and the ralationship of this viscosity to particle orbits in a <span class="hlt">magnetic</span> field is presented.</p> <div class="credits"> <p class="dwt_author">Williams, L. L.; Jokipii, J. R.</p> <p class="dwt_publisher"></p> <p class="publishDate">1991-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">318</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19720005195&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3D6.1"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary"><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> <div class="credits"> <p class="dwt_author">Ness, N. F.; Ottens, F. W.</p> <p class="dwt_publisher"></p> <p class="publishDate">1971-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">319</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/52844615"> <span id="translatedtitle">HyReSpect: A broadband fast-<span class="hlt">averaging</span> spectrometer for nuclear <span class="hlt">magnetic</span> resonance of <span class="hlt">magnetic</span> materials</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">We announce the successful development of a homemade frequency-swept nuclear <span class="hlt">magnetic</span> resonance (NMR) spectrometer entirely designed and built at the University of Parma, optimized for the study of <span class="hlt">magnetic</span> materials but also offering good performance as a general-purpose instrument for solid-state NMR. The spectrometer features heterodyne-based pulser and receiver with four-quadrant phase shifting and quadrature detection; a 150 MHz digital</p> <div class="credits"> <p class="dwt_author">G. Allodi; A. Banderini; R. de Renzi; C. Vignali</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">320</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19740021009&hterms=iGel&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DiGel"> <span id="translatedtitle"><span class="hlt">Interplanetary</span> orbit determination</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">The logistical aspects of orbit determination (OD) in the <span class="hlt">interplanetary</span> phase of the Mariner Mars 1971 mission are described and the working arrangements for the OD personnel, both within the Navigation Team and with outside groups are given. Various types of data used in the OD process are presented along with sources of the data. Functional descriptions of the individual elements of the OD software and brief sketches of their modes of operation are provided.</p> <div class="credits"> <p class="dwt_author">Zielenbach, J. W.; Acton, C. H.; Born, G. H.; Breckenridge, W. G.; Chao, C. C.; Duxbury, T. C.; Green, D. W.; Jerath, N.; Jordan, J. F.; Mottinger, N. A.</p> <p class="dwt_publisher"></p> <p class="publishDate">1973-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_15");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' 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class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_16");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' href="#">4</a> <a onClick='return showDiv("page_5");' href="#">5</a> <a onClick='return showDiv("page_6");' href="#">6</a> <a onClick='return showDiv("page_7");' href="#">7</a> <a onClick='return showDiv("page_8");' href="#">8</a> <a onClick='return showDiv("page_9");' href="#">9</a> <a onClick='return showDiv("page_10");' href="#">10</a> <a onClick='return showDiv("page_11");' href="#">11</a> <a onClick='return showDiv("page_12");' href="#">12</a> <a onClick='return showDiv("page_13");' href="#">13</a> <a onClick='return showDiv("page_14");' href="#">14</a> <a onClick='return showDiv("page_15");' href="#">15</a> <a onClick='return showDiv("page_16");' href="#">16</a> <a style="font-weight: bold;">17</a> <a onClick='return showDiv("page_18");' href="#">18</a> <a onClick='return showDiv("page_19");' href="#">19</a> <a onClick='return showDiv("page_20");' href="#">20</a> <a onClick='return showDiv("page_21");' href="#">21</a> <a onClick='return showDiv("page_22");' href="#">22</a> <a onClick='return showDiv("page_23");' href="#">23</a> <a onClick='return showDiv("page_24");' href="#">24</a> <a onClick='return showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_18");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">321</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19740008403&hterms=geomagnetic+reversal&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dgeomagnetic%2Breversal"> <span id="translatedtitle">Observations of interactions between <span class="hlt">interplanetary</span> and geomagnetic fields</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Burch, J. L.</p> <p class="dwt_publisher"></p> <p class="publishDate">1973-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">322</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/23905712"> <span id="translatedtitle">Liquid chromatography\\/proton nuclear <span class="hlt">magnetic</span> resonance spectrometry <span class="hlt">average</span> composition analysis of fuels</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The use of a NMR spectrometer as a continuous flow liquid chromatographic detector (LC\\/¹H NMR) generates a proton spectrum of each hydrocarbon class present in the sample. A detailed set of equations is presented which permits LC\\/¹H NMR integration data from petroleum fuels to be interpreted as an <span class="hlt">average</span> composition for each chromatographic fraction. Quantities calculated for each aromatic fraction</p> <div class="credits"> <p class="dwt_author">James F. Haw; T. E. Glass; H. C. Dorn</p> <p class="dwt_publisher"></p> <p class="publishDate">1983-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">323</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/servlets/purl/6059621"> <span id="translatedtitle"><span class="hlt">Average</span> configuration of the induced venus magnetotail</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">In this paper we discuss the interaction of the solar wind flow with Venus and describe the morphology of <span class="hlt">magnetic</span> field line draping in the Venus magnetotail. In particular, we describe the importance of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) X-component in controlling the configuration of field draping in this induced magnetotail, and using the results of a recently developed technique, we examine the <span class="hlt">average</span> <span class="hlt">magnetic</span> configuration of this magnetotail. The derived J x B forces must balance the <span class="hlt">average</span>, steady state acceleration of, and pressure gradients in, the tail plasma. From this relation the <span class="hlt">average</span> tail plasma velocity, lobe and current sheet densities, and <span class="hlt">average</span> ion temperature have been derived. In this study we extend these results by making a connection between the derived consistent plasma flow speed and density, and the observational energy/charge range and sensitivity of the Pioneer Venus Orbiter (PVO) plasma analyzer, and demonstrate that if the tail is principally composed of O/sup +/, the bulk of the plasma should not be observable much of the time that the PVO is within the tail. Finally, we examine the importance of solar wind slowing upstream of the obstacle and its implications for the temperature of pick-up planetary ions, compare the derived ion temperatures with their theoretical maximum values, and discuss the implications of this process for comets and AMPTE-type releases.</p> <div class="credits"> <p class="dwt_author">McComas, D.J.; Spence, H.E.; Russell, C.T.</p> <p class="dwt_publisher"></p> <p class="publishDate">1985-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">324</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19830025541&hterms=ISEE-C+Vector+Helium+Magnetometer&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DISEE-C%2BVector%2BHelium%2BMagnetometer"> <span id="translatedtitle">Electron heating at <span class="hlt">interplanetary</span> shocks</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Feldman, W. C.; Asbridge, J. R.; Bame, S. J.; Gosling, J. T.; Zwickl, R. D.</p> <p class="dwt_publisher"></p> <p class="publishDate">1982-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">325</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19840005030&hterms=ISEE-C+Vector+Helium+Magnetometer&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DISEE-C%2BVector%2BHelium%2BMagnetometer"> <span id="translatedtitle">Electron heating at <span class="hlt">interplanetary</span> shocks</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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 more efficiently than they heat the electrons.</p> <div class="credits"> <p class="dwt_author">Feldman, W. C.; Asbridge, J. R.; Bame, S. J.; Gosling, J. T.; Zwickl, R. D.</p> <p class="dwt_publisher"></p> <p class="publishDate">1983-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">326</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19910005700&hterms=Berkeley+Pit&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DBerkeley%2BPit"> <span id="translatedtitle">Infrared emission from <span class="hlt">interplanetary</span> dust</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">The infrared sky is dominated on large scales by emission from <span class="hlt">interplanetary</span> dust, which produces the zodiacal emission (ZE), and interstellar dust. These two components of the infrared background differ in angular and spectral distribution, allowing the two to be separated easily in some places. A method of determining the emission from <span class="hlt">interplanetary</span> dust near the Earth's orbit is described, and the results are compared to predictions for realistic materials with the <span class="hlt">interplanetary</span> size distribution measured in situ.</p> <div class="credits"> <p class="dwt_author">Reach, William T.</p> <p class="dwt_publisher"></p> <p class="publishDate">1989-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">327</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/39830356"> <span id="translatedtitle">Calculating the plasma deformation tensor and kinetic vorticity from <span class="hlt">magnetic</span> field time series: Applications to the solar wind</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">It is shown that the <span class="hlt">magnetic</span> induction equation reduces to an autoregressive model equation. Assuming weakly ergodic field variations in steady mean plasma flow, this model permits the estimation of the mean flow deformation tensor, velocity divergence and kinetic vorticity from <span class="hlt">magnetic</span> field time series. Applications, made to hourly-<span class="hlt">averaged</span>, in-ecliptic <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF) measurements from Ulysses spacecraft, showed that</p> <div class="credits"> <p class="dwt_author">J. M. Polygiannakis; X. Moussas</p> <p class="dwt_publisher"></p> <p class="publishDate">1996-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">328</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20050070873&hterms=wavelet+power&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3D%2522wavelet%2Bpower%2522"> <span id="translatedtitle">The "Approximate 150 Day Quasi-Periodicity" in <span class="hlt">Interplanetary</span> and Solar Phenomena During Cycle 23</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Richardson, I. G.; Cane, H. V.</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">329</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2006Ap%26SS.305...73M"> <span id="translatedtitle">Characteristics of Enhanced and Low Amplitude Anisotropic Wave Trains and <span class="hlt">Interplanetary</span> Transients</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The occurrence of a large number of high and low amplitude anisotropic wave train events over the years 1981 1994 has been examined along with the different solar features. The results indicate that the time of maximum of diurnal variation significantly remains in the 18-h direction for majority of the high and low amplitude wave trains. The amplitude of diurnal anisotropy remains significantly high and phase shifts towards earlier hours as compared to the quite day annual <span class="hlt">average</span> values for majority of the HAEs. The diurnal amplitude remains significantly low and phase shifts towards earlier hours as compared to the quiet day annual <span class="hlt">average</span> values for majority of the LAEs. The occurrence of these enhanced/low amplitude events is found to be dominant during the positive polarity of the Bz component of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field. The amplitude of the diurnal anisotropy of these events is found to increase on the days of <span class="hlt">magnetic</span> cloud as compared to the days prior to the event and it found to decrease during the later period of the event as the cloud passes the Earth. The high-speed solar wind streams do not play any significant role in causing these types of events. The <span class="hlt">interplanetary</span> disturbances (<span class="hlt">magnetic</span> clouds) are also effective in producing cosmic ray decreases.</p> <div class="credits"> <p class="dwt_author">Mishra, Rajesh K.; Mishra, Rekha Agarwal</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-09-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">330</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2006JGRA..11112303E"> <span id="translatedtitle">Climatologies of nighttime upper thermospheric winds measured by ground-based Fabry-Perot interferometers during geomagnetically quiet conditions: 2. High-latitude circulation and <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field dependence</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We analyze upper thermospheric (250 km) nighttime horizontal neutral wind patterns, during geomagnetically quiet (Kp < 3) conditions, over the following locations: South Pole (90S), Halley (76S, 27W), Millstone Hill (43N, 72W), Sndre Strmfjord (67N, 51W), and Thule (77N, 68W). We examine the wind patterns as a function of <span class="hlt">magnetic</span> local time and latitude, solar cycle, day of year, and the dawn-dusk and north-south components of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field (IMF By and Bz). In <span class="hlt">magnetic</span> coordinates, the quiet time high-latitude wind patterns are dominated by antisunward flow over the polar cap, with wind speeds that generally increase with increasing solar extreme ultraviolet (EUV) irradiation. The winds are generally stronger during equinox than during winter, particularly over the South Pole in the direction of eastern longitudes. IMF By exerts a strong influence on the wind patterns, particularly in the midnight sector. During winter, By positive winds around midnight in the northern (southern) hemisphere are directed more toward the dusk (dawn) sector, compared to corresponding By negative winds; this behavior is consistent with the By-dependence of statistical ionospheric convection patterns. The strength of the wind response to By tends to increase with increasing solar EUV irradiation, roughly in proportion to the increased wind speeds. Quiet time By effects are detectable at latitudes as low as that of Millstone Hill (<span class="hlt">magnetic</span> latitude 53N). Quiet time Bz effects are negligible except over the <span class="hlt">magnetic</span> polar cap station of Thule.</p> <div class="credits"> <p class="dwt_author">Emmert, J. T.; Hernandez, G.; Jarvis, M. J.; Niciejewski, R. J.; Sipler, D. P.; Vennerstrom, S.</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">331</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1987Sci...237.1466Z"> <span id="translatedtitle">Refractory <span class="hlt">interplanetary</span> dust particles</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Criteria are described by which refractory <span class="hlt">interplanetary</span> dust particles (IDPs) can be differentiated from the products of spacecraft debris. These criteria have been used to discover and characterize IDPs that are composed predominantly of refractory phases. Two of these particles contain hibonite, perovskite, spinel, refractory glass, and a melilite; only hibonite was identified within a third. The grain size for all particles ranges from 0.05 to 1 micrometer, so that they are much finer grained than the refractory calcium- and aluminum-rich inclusions in meteorites. The glass-containing refractory IDPs may be primitive nebular condensates that never completely crystallized and thus have been preserved extant.</p> <div class="credits"> <p class="dwt_author">Zolensky, M. E.</p> <p class="dwt_publisher"></p> <p class="publishDate">1987-09-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">332</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">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 spinecho, 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> <div class="credits"> <p class="dwt_author">Mao, Kanmi [ExxonMobile Research and Engineering Co.; Kennedy, Gordon J. [ExxonMobile Research and Engineering Co.; Althaus, Stacey M. [Ames Laboratory; Pruski, Marek [Ames Laboratory</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-07</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">333</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19740002642&hterms=csr+activities&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dcsr%2Bactivities"> <span id="translatedtitle">A correlative study of SSC's, <span class="hlt">interplanetary</span> shocks, and solar activity</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">A total of 93 SSC's were examined during the four year period from 1968 to 1971 at and near the peak of the solar activity cycle. Of the 93 SSC's 81 could be associated with solar activity, such as solar flares and radio bursts of Type II and Type IV. The mean propagation speeds of these flare-associated events ranged from 400 to 1000 km/sec with an <span class="hlt">average</span> speed of 600-700 km/sec. Disturbances associated with 48 of the SSC's have been studied in detail using the corresponding <span class="hlt">interplanetary</span> (IP) <span class="hlt">magnetic</span> field, and plasma data when they were available. It was found that 41 of the 48 disturbances corresponded to IP shock waves, and the remaining seven events were tangential discontinuities. Thirty percent of the IP shocks had thick structure (i.e. the <span class="hlt">magnetic</span> field jump across the shock occurred over a distance much greater than 50 proton Larmor radii). Also given is a statistical study of the gross geometry of a typical or <span class="hlt">average</span> shock surface based on multiple spacecraft sightings and their relative orientation with respect to the solar flare. It is suggested that a typical shock front propagating out from the sun at l AU has a radius of curvature on the order of l AU. Also given are some general properties of oblique IP flare-shocks.</p> <div class="credits"> <p class="dwt_author">Chao, J. K.; Lepping, R. P.</p> <p class="dwt_publisher"></p> <p class="publishDate">1973-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">334</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2005IAUS..226..361M"> <span id="translatedtitle">Energetic Particle Tracing of <span class="hlt">Interplanetary</span> CMEs: ULYSSES/HI-SCALE and ACE/EPAM Results</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Solar energetic particle (SEP) fluxes measured by the ULYSSES (ULS)/HI-SCALE experiment during its second polar orbit as well as by the identical ACE/EPAM experiment at 1 AU are utilized as diagnostics of the large-scale structure and topology of the <span class="hlt">Interplanetary</span> <span class="hlt">Magnetic</span> Field (IMF) embedded within <span class="hlt">Interplanetary</span> Coronal Mass Ejections (ICMEs). Survey results are also reported.</p> <div class="credits"> <p class="dwt_author">Malandraki, Olga E.; Lario, D.; Sarris, T. E.; Tsaggas, N.; Sarris, E. T.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">335</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20140006630&hterms=Hybrid+simulation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3D%2522Hybrid%2Bsimulation%2522"> <span id="translatedtitle">Whistler Waves Associated with Weak <span class="hlt">Interplanetary</span> Shocks</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Velez, J. C. Ramirez; Blanco-Cano, X.; Aguilar-Rodriguez, E.; Russell, C. T.; Kajdic, P.; Jian,, L. K.; Luhmann, J. G.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">336</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Fortgang, C.M.</p> <p class="dwt_publisher"></p> <p class="publishDate">1996-11-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">337</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/34575566"> <span id="translatedtitle">The <span class="hlt">Interplanetary</span> Exchange of Photosynthesis</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Panspermia, the transfer of organisms from one planet to another, either through <span class="hlt">interplanetary</span> or interstellar space, remains\\u000a speculation. However, its potential can be experimentally tested. Conceptually, it is island biogeography on an <span class="hlt">interplanetary</span>\\u000a or interstellar scale. Of special interest is the possibility of the transfer of oxygenic photosynthesis between one planet\\u000a and another, as it can initiate large scale biospheric</p> <div class="credits"> <p class="dwt_author">Charles S. Cockell</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">338</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.springerlink.com/index/g1210211286v510l.pdf"> <span id="translatedtitle">The <span class="hlt">interplanetary</span> medium and its interaction with the Earth's magnetosphere</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">This paper reviews the principal results of direct measurements of the plasma and <span class="hlt">magnetic</span> field by spacecraft close to the Earth (within the heliocentric distance range 0.71.5 AU). The paper gives an interpretation of the results for periods of decrease, minimum and increase of the solar activity. The following problems are discussed: the <span class="hlt">interplanetary</span> plasma (chemical composition, density, solar wind</p> <div class="credits"> <p class="dwt_author">J. V. Kovalevsky</p> <p class="dwt_publisher"></p> <p class="publishDate">1971-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">339</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.agu.org/journals/ja/v079/i028/JA079i028p04157/JA079i028p04157.pdf"> <span id="translatedtitle">Effects of <span class="hlt">interplanetary</span> shock waves on energetic charged particles</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The influence of <span class="hlt">interplanetary</span> shock waves on energetic charged particles is studied in this work. Emphasis is given to the acceleration of protons in almost perpendicular shock waves (the angle between the shock normal and the upstream <span class="hlt">magnetic</span> field being greater than about 80). The special case of protons accelerated in ideal perpendicular shock waves is treated analytically. The</p> <div class="credits"> <p class="dwt_author">E. T. Sarris; J. A. Van Allen</p> <p class="dwt_publisher"></p> <p class="publishDate">1974-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">340</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/servlets/purl/5619090"> <span id="translatedtitle">Laser-fusion rocket for <span class="hlt">interplanetary</span> propulsion</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Hyde, R.A.</p> <p class="dwt_publisher"></p> <p class="publishDate">1983-09-27</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_16");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> 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showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_19");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">341</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012PhDT.......113C"> <span id="translatedtitle">Autonomous <span class="hlt">interplanetary</span> constellation design</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Chow, Cornelius Channing, II</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">342</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20120009632&hterms=search&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dsearch"> <span id="translatedtitle">Search Coil vs. Fluxgate Magnetometer Measurements at <span class="hlt">Interplanetary</span> Shocks</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Wilson, L.B., III</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">343</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013JGRA..118..385E"> <span id="translatedtitle"><span class="hlt">Interplanetary</span> origins of moderate (-100 nT < Dst ? -50 nT) geomagnetic storms during solar cycle 23 (1996-2008)</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The <span class="hlt">interplanetary</span> causes of 213 moderate-intensity (-100 nT < peak Dst ? -50 nT) geomagnetic storms that occurred in solar cycle 23 (1996-2008) are identified. <span class="hlt">Interplanetary</span> drivers such as corotating interaction regions (CIRs), pure high-speed streams (HSSs), <span class="hlt">interplanetary</span> coronal mass ejections (ICMEs) of two types [those with <span class="hlt">magnetic</span> clouds (MCs) and those without (nonmagnetic cloud or ICME_nc)], sheaths (compressed and/or draped sheath fields), as well as their combined occurrence were identified as causes of the storms. The annual rate of occurrence of moderate storms had two peaks, one near solar maximum and the other in the descending phase, around 3 years later. The highest rate of moderate storm occurrence was found in the declining phase (25 storms year-1). The lowest occurrence rate was 5.7 storms year-1 and occurred at solar minimum. All moderate-intensity storms were associated with southward <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> fields, indicating that <span class="hlt">magnetic</span> reconnection was the main mechanism for solar wind energy transfer to the magnetosphere. Most of these storms were associated with CIRs and pure HSSs (47.9%), followed by MCs and noncloud ICMEs (20.6%), pure sheath fields (10.8%), and sheath and ICME combined occurrence (9.9%). In terms of solar cycle dependence, CIRs and HSSs are the dominant drivers in the declining phase and at solar minimum. CIRs and HSSs combined have about the same level of importance as ICMEs plus their sheaths in the rising and maximum solar cycle phases. Thus, CIRs and HSSs are the main driver of moderate storms throughout a solar cycle but with variable contributions from ICMEs, their shocks (sheaths), and combined occurrence within the solar cycle. This result is significantly different than that for intense (Dst ? -100 nT) and superintense (Dst ? -250 nT) <span class="hlt">magnetic</span> storms shown in previous studies. For superintense geomagnetic storms, 100% of the events were due to ICME events, while for intense storms, ICMEs, sheaths, and their combination caused almost 80% of the storms. CIRs caused only 13% of the intense storms. The typical <span class="hlt">interplanetary</span> electric field (Ey) criteria for moderate <span class="hlt">magnetic</span> storms were identified. It was found that ~80.1% of the storms follow the criterion of Ey ? 2 mV m-1 for intervals longer than 2 h. It is concluded that southward directed <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> fields within CIRs/HSSs may be the main energy source for long-term <span class="hlt">averaged</span> geomagnetic activity on Earth.</p> <div class="credits"> <p class="dwt_author">Echer, E.; Tsurutani, B. T.; Gonzalez, W. D.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">344</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013AdSpR..51..395U"> <span id="translatedtitle">Solar and <span class="hlt">interplanetary</span> precursors of geomagnetic storms in solar cycle 23</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Estimating the <span class="hlt">magnetic</span> storm effectiveness of solar and associated <span class="hlt">interplanetary</span> phenomena is of practical importance for space weather modelling and prediction. This article presents results of a qualitative and quantitative analysis of the probable causes of geomagnetic storms during the 11-year period of solar cycle 23: 1996-2006. Potential solar causes of 229 <span class="hlt">magnetic</span> storms (Dst ? -50 nT) were investigated with a particular focus on halo coronal mass ejections (CMEs). A 5-day time window prior to the storm onset was considered to track backward the Sun's eruptions of halo CMEs using the SOHO/LASCO CMEs catalogue list. Solar and <span class="hlt">interplanetary</span> (IP) properties associated with halo CMEs were investigated and correlated to the resulting geomagnetic storms (GMS). In addition, a comparative analysis between full and partial halo CME-driven storms is established. The results obtained show that about 83% of intense storms (Dst ? -100 nT) were associated with halo CMEs. For moderate storms (-100 nT < Dst ? -50 nT), only 54% had halo CME background, while the remaining 46% were assumed to be associated with corotating interaction regions (CIRs) or undetected frontside CMEs. It was observed in this study that intense storms were mostly associated with full halo CMEs, while partial halo CMEs were generally followed by moderate storms. This analysis indicates that up to 86% of intense storms were associated with <span class="hlt">interplanetary</span> coronal mass ejections (ICMEs) at 1 AU, as compared to moderate storms with only 44% of ICME association. Many other quantitative results are presented in this paper, providing an estimate of solar and IP precursor properties of GMS within an <span class="hlt">average</span> 11-year solar activity cycle. The results of this study constitute a key step towards improving space weather modelling and prediction.</p> <div class="credits"> <p class="dwt_author">Uwamahoro, J.; McKinnell, L.-A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-02-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">345</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1996Ap%26SS.243..225G"> <span id="translatedtitle">IPS Observations of Short-Time Scale <span class="hlt">Interplanetary</span> Activity</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We have carried out a program of continuous <span class="hlt">Interplanetary</span> Scintillation (IPS) monitoring of the <span class="hlt">interplanetary</span> activity using Ooty Radio Telescope (ORT). From May 1990 to March 1991, during the 22nd, solar maximum, a few radio sources were monitored to provide long stretches of IPS data with a high-time resolution of few minutes. These observations covered 0.3 to 0.8 AU region (12 to 70 elongations) around the sun at several heliographic latitudes. During the observation, we detected 33 short-time scale IPS events which had significant variation in the scintillation index and solar wind velocity. These were considered to be due to travelling <span class="hlt">interplanetary</span> disturbances. A multi-component model of plasma density enhancement was developed to estimate the geometry and physical properties of these IPS events. Detailed analysis of 20 of these events suggests, 1. fast IPS events were <span class="hlt">interplanetary</span> signatures of Coronal Mass Ejections (CMEs), 2. the <span class="hlt">average</span> mass and energy of these events was 1016 gm and 1033 erg respectively,3. 80% of IPS events were associated with X-ray flares on the sun and 50% were associated with geomagnetic activity at earth. Detailed study of the multicomponent model suggests IPS observations at smaller elongations (hence at higher radio frequencies) are more suited to detect fast-moving <span class="hlt">interplanetary</span> disturbances such as produced by CMEs.</p> <div class="credits"> <p class="dwt_author">Gothoskar, Pradeep; Pramesh Rao, A.</p> <p class="dwt_publisher"></p> <p class="publishDate">1996-03-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">346</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20070016645&hterms=particles&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3D%2522particles%2522"> <span id="translatedtitle"><span class="hlt">Interplanetary</span> Shocks and "Suprathermal" Flare Particles</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Cane, H. V.; Richardson, I. G.; vonRosenvinge, T. T.</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">347</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/54303194"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">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</p> <div class="credits"> <p class="dwt_author">J. G. Luhmann; C. O. Lee; J. T. Hoeksema</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">348</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19830057071&hterms=shock+physics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dshock%2Bphysics"> <span id="translatedtitle">Magnetospheric and <span class="hlt">interplanetary</span> physics 1979-1982</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Major trends in the study of magnetospheric and <span class="hlt">interplanetary</span> physics during the 1979-1982 period are surveyed. Topics discussed include the exploration of the Saturnian and Jovian magnetospheres by Voyagers 1 and 2, the behavior of different ions in the earth magnetosphere, auroral kilometric radiation, computer modeling of global magnetospheric MHD flow, the <span class="hlt">magnetic</span> substorm, the quiet state, the earth's bow shock, the heliospheric current sheet, and new techniques such as electron beam experiments, 'active' injection experiments, auroral radars, and observations of the earth's distant <span class="hlt">magnetic</span> tail. The future of this area of research is seen in the combination of data from different spacecraft and ground observations in a single correlated data set, and in the consolidation of past gains by analysis of the large data backlog, while a small number of new missions goes forward.</p> <div class="credits"> <p class="dwt_author">Stern, D. P.</p> <p class="dwt_publisher"></p> <p class="publishDate">1983-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">349</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20120009629&hterms=Precursor&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DPrecursor"> <span id="translatedtitle">Electromagnetic Whistler Precursors at Supercritical <span class="hlt">Interplanetary</span> Shocks</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Wilson, L. B., III</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">350</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19810012468&hterms=ballerinas&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dballerinas"> <span id="translatedtitle">Fine-scale characteristics of <span class="hlt">interplanetary</span> sector</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Behannon, K. W.; Neubauer, F. M.; Barnstoff, H.</p> <p class="dwt_publisher"></p> <p class="publishDate">1980-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">351</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19870034276&hterms=perovskite+solar&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dperovskite%2Bsolar"> <span id="translatedtitle">Refractory minerals in <span class="hlt">interplanetary</span> dust</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Christoffersen, Roy; Buseck, Peter R.</p> <p class="dwt_publisher"></p> <p class="publishDate">1986-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">352</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/17835566"> <span id="translatedtitle">Refractory minerals in <span class="hlt">interplanetary</span> dust.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">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. PMID:17835566</p> <div class="credits"> <p class="dwt_author">Christoffersen, R; Buseck, P R</p> <p class="dwt_publisher"></p> <p class="publishDate">1986-10-31</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">353</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013AGUSMSH32A..01B"> <span id="translatedtitle">STEREO Observations of <span class="hlt">Interplanetary</span> Shocks</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">STEREO observations have been very valuable to study the characteristics of <span class="hlt">interplanetary</span> (IP) shocks. These shocks can be driven in the heliosphere by fast <span class="hlt">interplanetary</span> coronal mass ejections (CME) and by solar wind stream interaction (SI). In this work we will discuss the properties of IP shocks and the upstream and downstream regions associated to them. These regions are perturbed due to shock effects. Upstream from the shock a foreshock can develop and be permeated by suprathermal ions and electromagnetic waves. Downstream the plasma is heated and compressed. In this region the <span class="hlt">magnetic</span> field is also very perturbed. Shocks play a very important role in particle acceleration. During the years 2007-2010 STEREO observed around 80 IP forward shocks driven by stream interactions, and 19 shocks driven by ICMEs. Most of the SI shocks were locally quasi-perpendicular (?Bn >45) with only 20 quasi-parallel (?Bn < 45) shocks. In all cases the Mach number was moderate with values 1.1< Mms < 3.8, and the plasma beta reached values up to 29. During the same years the shocks driven by ICMEs have Mach numbers 1.2-4, and plasma beta up to 15. Observations upstream from the shocks have revealed a variety of waves, including whistlers and low frequency fluctuations. Upstream whistler waves may be generated at the shock and upstream ultra low frequency (ULF) waves can be driven locally by ion instabilities. In contrast to planetary bow shocks, most of the waves upstream of the quasi-parallel forward SI shocks observed to date by STEREO are mainly transverse and no steepening occurs. Another difference with Earth's bow shock is the fact that many locally quasi-perpendicular shocks can be accompanied by wave and ion foreshocks. This indicates that at an earlier time the geometry of the shock was quasi-parallel. The downstream wave spectra can be formed by both, locally generated perturbations, and shock transmitted waves. Downstream fluctuations associated with quasi-parallel shocks tend to have larger amplitudes than waves downstream of quasi-perpendicular shocks. Proton foreshocks of shocks driven by stream interactions have extensions dr ?0.05 AU. This is smaller than foreshock extensions for ICME driven shocks (dr ? 0.1 AU). The difference in foreshock extensions is related to the fact that ICME driven shocks are formed closer to the Sun and therefore begin to accelerate particles very early in their existence, while stream interaction shocks form at ~1 AU and have been producing suprathermal particles for a shorter time. It is possible that stronger shocks driven by fast ICMEs are observed in the following months as the solar cycle of activity reaches maximum. Stronger IP shocks may be able to drive more complex foreshocks, where steepened waves such as shocklets may be present.</p> <div class="credits"> <p class="dwt_author">Blanco-Cano, X.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-05-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">354</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2001AGUFMSH12B0752L"> <span id="translatedtitle">The Coronal and <span class="hlt">Interplanetary</span> Context of Geoeffective ICMEs</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Odstrcil and Pizzo (December 1999 JGR) recently simulated <span class="hlt">interplanetary</span> CME (ICME) propagation in a structured solar wind as a high velocity pressure pulse introduced into a bipolar fast flow bisected by a band of slow solar wind. Their results demonstrate how ejecta from different sides of a planar tilted helmet streamer belt produce different 1 AU <span class="hlt">interplanetary</span> signatures due to the ejecta/stream structure interaction. Using the combination of ACE archived plasma and field data, SOHO-MDI magnetograph and SOHO EIT 195A synoptic maps, and the Kyoto Dst <span class="hlt">magnetic</span> storm index, we examine the <span class="hlt">interplanetary</span> context of CME ejecta, and their inferred coronal context. At the Sun, we consider the prevailing coronal hole geometry and helmet streamer belt configuration together with the location of associated disk activity (e.g. filament disruption or flare). In the <span class="hlt">interplanetary</span> medium, we consider geoeffective parameters including the solar wind velocity and dynamic pressure, and the southward component of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field. These parameters have been shown to produce excellent approximations to Dst when used in the Burton et al. (1975) formula. The real coronal and solar wind structure is typically much more complicated than the Odstrcil and Pizzo model, but some basic characteristics can be found such as ICMEs riding the crest of a high speed stream, or nestled in the low speed wind preceding a high speed stream. The comparisons with the ACE observations illustrate how the combination of solar <span class="hlt">magnetic</span> field and solar wind stream structure conspires to make more or less geoeffective ICMEs, and provide a basis for future more realistic event modeling.</p> <div class="credits"> <p class="dwt_author">Luhmann, J. G.; Li, Y.; Russell, C. T.; Mulligan, T.; Arge, C. N.; Odstrcil, D.; Hoeksema, J. T.; Zhao, X.; Rich, N. B.; McComas, D. J.; Smith, C. W.</p> <p class="dwt_publisher"></p> <p class="publishDate">2001-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">355</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19970021679&hterms=imf&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dimf"> <span id="translatedtitle">Latitudinal Dependence of the Radial IMF Component - <span class="hlt">Interplanetary</span> Imprint</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Suess, S. T.; Smith, E. J.; Phillips, J.; Goldstein, B. E.; Nerney, S.</p> <p class="dwt_publisher"></p> <p class="publishDate">1996-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">356</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19870005698&hterms=hy+FBI&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dhy%2BFBI"> <span id="translatedtitle">Evolution and interaction of large <span class="hlt">interplanetary</span> streams</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">A computer simulation for the evolution and interaction of large <span class="hlt">interplanetary</span> streams based on multi-spacecraft observations and an unsteady, one-dimensional MHD model is presented. Two events, each observed by two or more spacecraft separated by a distance of the order of 10 AU, were studied. The first simulation is based on the plasma and <span class="hlt">magnetic</span> field observations made by two radially-aligned spacecraft. The second simulation is based on an event observed first by Helios-1 in May 1980 near 0.6 AU and later by Voyager-1 in June 1980 at 8.1 AU. These examples show that the dynamical evolution of large-scale solar wind structures is dominated by the shock process, including the formation, collision, and merging of shocks. The interaction of shocks with stream structures also causes a drastic decrease in the amplitude of the solar wind speed variation with increasing heliocentric distance, and as a result of interactions there is a large variation of shock-strengths and shock-speeds. The simulation results shed light on the interpretation for the interaction and evolution of large <span class="hlt">interplanetary</span> streams. Observations were made along a few limited trajectories, but simulation results can supplement these by providing the detailed evolution process for large-scale solar wind structures in the vast region not directly observed. The use of a quantitative nonlinear simulation model including shock merging process is crucial in the interpretation of data obtained in the outer heliosphere.</p> <div class="credits"> <p class="dwt_author">Whang, Y. C.; Burlaga, L. F.</p> <p class="dwt_publisher"></p> <p class="publishDate">1985-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">357</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.agu.org/journals/ja/ja0512/2005JA011332/2005JA011332.pdf"> <span id="translatedtitle">Effect of the latitudinal distribution of temperature at the coronal base on the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field configuration and the solar wind flow</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Using a two-dimensional MHD model of the corona and solar wind, we investigate the role of the temperature distribution with latitude at the coronal base on the global <span class="hlt">magnetic</span> field configuration and solar wind properties at 1 AU. The latitudinal distribution of temperature is aimed at modeling the transition in electron temperature at the Sun from a polar coronal hole</p> <div class="credits"> <p class="dwt_author">Bo Li; Shadia Rifai Habbal; Xing Li; Chris Mountford</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">358</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://users.aber.ac.uk/xxl/biblio/li_habbal_lijgr2005.pdf"> <span id="translatedtitle">Effect of the latitudinal distribution of temperature at the coronal base on the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field configuration and the solar wind flow</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Received 22 July 2005; revised 13 September 2005; accepted 26 October 2005; published 30 December 2005. (1) Using a two-dimensional MHD model of the corona and solar wind, we investigate the role of the temperature distribution with latitude at the coronal base on the global <span class="hlt">magnetic</span> field configuration and solar wind properties at 1 AU. The latitudinal distribution of temperature</p> <div class="credits"> <p class="dwt_author">Bo Li; Shadia Rifai Habbal; Xing Li; Chris Mountford</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">359</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/39222226"> <span id="translatedtitle">Information processing for <span class="hlt">interplanetary</span> exploration</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Payload limitations, environmental constraints, ignorance of the relevant human factors, cost and the generally hazardous conditions surrounding manned vehicles in <span class="hlt">interplanetary</span> space have combined to elect machines as the probable predecessors of men in the exploration of the Solar System. This, of course, is not to deny that man will soon follow--we may rest assured that he will. Indeed, manned</p> <div class="credits"> <p class="dwt_author">T. B. Steel Jr.</p> <p class="dwt_publisher"></p> <p class="publishDate">1962-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">360</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/1426837"> <span id="translatedtitle">Magnetohydrodynamic modeling of <span class="hlt">interplanetary</span> CMEs</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Heliospheric models of coronal mass ejection (CME) propagation and evolution provide an important insight into the dynamics of CMEs and are a valuable tool for interpretating <span class="hlt">interplanetary</span> in situ observations. Moreover, they represent a virtual laboratory for exploring conditions and regions of space that are not conveniently or currently accessible by spacecraft. We summarize our recent advances in modeling the</p> <div class="credits"> <p class="dwt_author">Pete Riley; Jon A. Linker; Zoran Mikic; Dusan Odstrcil</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_17");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a 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Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_18");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' href="#">4</a> <a onClick='return showDiv("page_5");' href="#">5</a> <a onClick='return showDiv("page_6");' href="#">6</a> <a onClick='return showDiv("page_7");' href="#">7</a> <a onClick='return showDiv("page_8");' href="#">8</a> <a onClick='return showDiv("page_9");' href="#">9</a> <a onClick='return showDiv("page_10");' href="#">10</a> <a onClick='return showDiv("page_11");' href="#">11</a> <a onClick='return showDiv("page_12");' href="#">12</a> <a onClick='return showDiv("page_13");' href="#">13</a> <a onClick='return showDiv("page_14");' href="#">14</a> <a onClick='return showDiv("page_15");' href="#">15</a> <a onClick='return showDiv("page_16");' href="#">16</a> <a onClick='return showDiv("page_17");' href="#">17</a> <a onClick='return showDiv("page_18");' href="#">18</a> <a style="font-weight: bold;">19</a> <a onClick='return showDiv("page_20");' href="#">20</a> <a onClick='return showDiv("page_21");' href="#">21</a> <a onClick='return showDiv("page_22");' href="#">22</a> <a onClick='return showDiv("page_23");' href="#">23</a> <a onClick='return showDiv("page_24");' href="#">24</a> <a onClick='return showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_20");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">361</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/27288351"> <span id="translatedtitle">New <span class="hlt">interplanetary</span> proton fluence model</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">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</p> <div class="credits"> <p class="dwt_author">Joan Feynman; T. P. Armstrong; L. Dao-Gibner; S. Silverman</p> <p class="dwt_publisher"></p> <p class="publishDate">1990-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">362</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19720000603&hterms=first+anal&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dfirst%2Banal"> <span id="translatedtitle"><span class="hlt">Interplanetary</span> Trajectories, Encke Method (ITEM)</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Whitlock, F. H.; Wolfe, H.; Lefton, L.; Levine, N.</p> <p class="dwt_publisher"></p> <p class="publishDate">1972-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">363</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19920050960&hterms=rarefaction&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Drarefaction"> <span id="translatedtitle">Intensity variations in the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field measured by Voyager 2 and the 11-year solar cycle modulation of galactic cosmic rays</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">New evidence is presented to support the hypothesis that the 11-yr solar cycle modulation of galactic cosmic rays is caused by strong diffusion inside long-lived merged interaction regions. To test this hypothesis, the 1D force-field approximation of the cosmic ray modulation equation is solved. It is assumed that a constant solar wind speed convects <span class="hlt">magnetic</span> field compressions and rarefactions unchanged through a model heliosphere. The result is a reasonable simulation of the integrated high-energy cosmic ray intensity profile from about 1982 to mid-1989. This period encompasses both the full recovery portion of the last profile from about 1982 to mid-1989. This model responds to the Voyager 2 <span class="hlt">magnetic</span> field data by correctly timing the beginning of the new modulation cycle in late 1987. It is concluded that the present hypothesis is consistent with the results of this simulation.</p> <div class="credits"> <p class="dwt_author">Perko, J. S.; Burlaga, L. F.</p> <p class="dwt_publisher"></p> <p class="publishDate">1992-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">364</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19850024742&hterms=latitudinal+gradients&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dlatitudinal%2Bgradients"> <span id="translatedtitle">Differential measurement of cosmic-ray gradient with respect to <span class="hlt">interplanetary</span> current sheet</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Christon, S. P.; Cummings, A. C.; Stone, E. C.; Behannon, K. W.; Burlaga, L. F.</p> <p class="dwt_publisher"></p> <p class="publishDate">1985-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">365</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012RScI...83j5108C"> <span id="translatedtitle">On the performance enhancement of adaptive signal <span class="hlt">averaging</span>: A means for improving the sensitivity and rate of data acquisition in <span class="hlt">magnetic</span> resonance and other analytical measurements</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">A few years back, our lab developed a signal <span class="hlt">averaging</span> technique that greatly reduces the number of scans required to achieve a comparable signal-to-noise ratio to that of conventional signal <span class="hlt">averaging</span> for continuous wave <span class="hlt">magnetic</span> resonance measurements. We utilize an adaptive filter in a signal <span class="hlt">averaging</span> scheme without any prior knowledge of the signal under observation. We termed this technique adaptive signal <span class="hlt">averaging</span> (ASA). The technique was successful in reducing the noise variance by a factor of at least 10 in a single trace and is shown to converge in time by the same factor. ASA can also be useful in many other applications where signal <span class="hlt">averaging</span> is utilized, such as medical imaging, electrocardiography, or electroencephalography. The purpose of this paper is to describe the advancements made to the technique, present a derivation of its performance enhancement, and illustrate the power of the technique through a set of simulations.</p> <div class="credits"> <p class="dwt_author">Cochrane, C. J.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-10-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">366</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ntis.gov/search/product.aspx?ABBR=PB219795"> <span id="translatedtitle">Description of <span class="hlt">Magnetic</span> Tape Containing <span class="hlt">Average</span> Elevations of Topography in California and Adjacent Regions for Areas of 1x1 Minute and 3x3 Minutes in Size.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ntis.gov/search/index.aspx">National Technical Information Service (NTIS)</a></p> <p class="result-summary"><span class="hlt">Average</span> elevations of about 199,000 1x1 minute and 51,000 3x3 minute 'compartments' in California and vicinity are recorded on a <span class="hlt">magnetic</span> tape. The 1x1 minute coverage extends about 15 miles and the 3x3 minute about 100 miles in all directions beyond the ...</p> <div class="credits"> <p class="dwt_author">S. L. Robbins H. W. Oliver D. Plouff</p> <p class="dwt_publisher"></p> <p class="publishDate">1973-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">367</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20110015529&hterms=Tasmania&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DTasmania"> <span id="translatedtitle"><span class="hlt">Interplanetary</span> Circumstances of Quasi-Perpendicular <span class="hlt">Interplanetary</span> Shocks in 1996-2005</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Richardson, I. G.; Cane, H. V.</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">368</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1999SoPh..185..361G"> <span id="translatedtitle">On observing mass ejections in the <span class="hlt">interplanetary</span> medium</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Scattering of radio waves by density fluctuations in the solar wind leads to rapid variation in the intensity of compact radio sources. This phenomenon, known as <span class="hlt">Interplanetary</span> Scintillation (IPS), provides a simple method to study <span class="hlt">interplanetary</span> activity in the inner heliosphere. During the solar maximum of cycle22, we carried out extensive, high-time-resolution IPS observations of fast moving <span class="hlt">interplanetary</span> plasma clouds (IPCs). The observations were done using the Ooty Radio Telescope (ORT) and covered the region between 0.2AU and 0.8AU around the Sun. We detected 33IPCs having velocities of 600 to 1400kms-1. A two-component model of scattering by time-varying solar wind was developed to analyse these IPCs. The model enabled us to estimate the mass, energy and geometry of each disturbance and to associate them with solar-geomagnetic activity. Detailed analysis suggests that these IPCs were <span class="hlt">interplanetary</span> signatures of massive and energetic Solar Mass Ejections (SMEs). The SMEs were found to have <span class="hlt">average</span> mass and kinetic energy of 5.3x1016g, 2.4x1032ergs. The <span class="hlt">average</span> span and width of the SME was found to be 42 deg and 8x106km. Association of these disturbances with solar-geomagnetic activity shows that about 80% of them are associated with Long-Duration X-ray Events (LDXE) and Solar Mass Ejections (SMEs). Only 50% of the events were associated with geomagnetic activity. The present experiment has demonstrated that continuous IPS monitoring is an effective technique to detect mass ejections in the <span class="hlt">interplanetary</span> medium and to study their evolution through the inner heliosphere.</p> <div class="credits"> <p class="dwt_author">Gothoskar, Pradeep; Rao, A. P.</p> <p class="dwt_publisher"></p> <p class="publishDate">1999-04-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">369</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2006AGUFMSH23B0356N"> <span id="translatedtitle">3-D MHD Model of the Solar Wind-<span class="hlt">Interplanetary</span> Space Combining System 1:Variation of Solar Wind Speed Associated with the Photospheric <span class="hlt">Magnetic</span> Field</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Existing global models of the solar-wind/IMF expanding to the Earth's orbit are basically grounded in the idea of "source surface." It is widely accepted that the sector structure and the solar wind speed are primarily controlled by the <span class="hlt">magnetic</span> field at the source surface and the so-called "expansion factor." On the other hand, 3-D MHD model is still off from practical use because both of scientific and technical problems. One of the former problems is the reproduction of supersonic solar-wind. From the viewpoint of the physics of the solar wind, coronal heating and outward acceleration mechanisms are invoked to explain the supersonic evolution of the solar wind. Since the mechanism responsible for the heating/acceleration is still one of the primary subjects of the physics of the solar wind, many MHD models have taken into account their effects by incorporating additional source terms corresponding to promising candidates such as thermal conductions, radiation losses and wave pressures. However there are few MHD models considering the effect of the expansion factor, which determines the solar-wind speed in the series of source surface models. In this study we newly incorporate the flux tube expansion rate into the MHD equation system including heat source function in the energy equation. Appling the unstructured grid system, we achieved the dense grid spacing at the inner boundary, which enable us to adopt realistic solar <span class="hlt">magnetic</span> fields, and a size of simulation space of 1AU. Photospheric <span class="hlt">magnetic</span> field data is used as the inner boundary condition.The simulation results are summarized as: (1) The variation of solar wind speed is well controlled by the structure of <span class="hlt">magnetic</span> fields at and little above the solar surface and (2) Far above the solar surface, the interface between high and low speed flows evolves to a structure suggestive of CIRs. Comparing the data from simulation with the actual solar wind data obtained by spacecrafts, we will discuss the future improvement of our model. Non-stationary phenomena such as CMEs are still beyond of this study. Acknowledgement: Wilcox Solar Observatory data used in this study was obtained via the web site http://quake.stanford.edu/~wso courtesy of J.T. Hoeksema.</p> <div class="credits"> <p class="dwt_author">Nakamizo, A.; Tanaka, T.</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">370</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/55894437"> <span id="translatedtitle">The flux gate <span class="hlt">magnetic</span> field experiment E2 in HELIOS A and B: Technical description</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The basic features of the three axis vector magnetometer used on HELIOS space probes for the E2 experiment are described with emphasis on the sensor and electronic system. The experiment includes not only continuously observing the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field, but also measuring its spiral structure and discontinuous appearance. The analog-digital conversion of the measured voltages, the flipper, the time <span class="hlt">average</span></p> <div class="credits"> <p class="dwt_author">G. Musmann</p> <p class="dwt_publisher"></p> <p class="publishDate">1979-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">371</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19830056372&hterms=Provo&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3D%2522Provo%2522"> <span id="translatedtitle">Waves observed upstream of <span class="hlt">interplanetary</span> shocks</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">The properties of the waves that are present upstream of <span class="hlt">interplanetary</span>, collisionless, quasi-parallel shocks are described. Two types of such waves have been detected, a higher frequency whistler mode wave and a lower frequency fast mode MHD wave. Both are typically circular or elliptically polarized right-hand waves which propagate along the ambient <span class="hlt">magnetic</span> field with a 15 deg angle cone. The high frequency waves have sufficient group velocities to outrun the shock, and may be generated by cyclotron resonance with 100 eV to 1 keV shock electrons. The lower frequency waves must be generated locally by particles upstream of the shock, probably by 1-10 keV ions flowing away from the shock. Distinct changes in the spectra of upstream waves as a function of distance from the shock have been noted.</p> <div class="credits"> <p class="dwt_author">Tsurutani, B. T.; Smith, E. J.; Jones, D. E.</p> <p class="dwt_publisher"></p> <p class="publishDate">1983-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">372</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1996SoPh..166..379J"> <span id="translatedtitle">Travelling <span class="hlt">Interplanetary</span> Disturbances Detected Using <span class="hlt">Interplanetary</span> Scintillation at 327 MHz</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Based on the advance predictions of two flare-generated shock fronts, obtained from the Space Environment Centre (SEC, NOAA, Boulder), observations of <span class="hlt">interplanetary</span> scintillation (IPS) were carried out with the Ooty Radio Telescope (ORT) on a grid of appropriately located sources during the period 31 October to 5 November, 1992. Solar wind velocities were derived by fitting model spectra to the observed spectra and two travelling <span class="hlt">interplanetary</span> disturbances were detected. Both disturbances were traced back to an active region on the Sun which was located close to a large coronal hole. The roles of flares and coronal holes in producing such disturbances are examined and it is shown that in the present case both the coronal hole and the active region probably played key roles in generating the two IPS disturbances.</p> <div class="credits"> <p class="dwt_author">Janardhan, P.; Balasubramanian, V.; Ananthakrishnan, S.; Dryer, M.; Bhatnagar, A.; McIntosh, P. S.</p> <p class="dwt_publisher"></p> <p class="publishDate">1996-07-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">373</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2000JGR...10525053G"> <span id="translatedtitle">Global three-dimensional MHD simulation of a space weather event: CME formation, <span class="hlt">interplanetary</span> propagation, and interaction with the magnetosphere</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">A parallel adaptive mesh refinement (AMR) finite-volume scheme for predicting ideal MHD flows is used to simulate the initiation, structure, and evolution of a coronal mass ejection (CME) and its interaction with the magnetosphere-ionosphere system. The simulated CME is driven by a local plasma density enhancement on the solar surface with the background initial state of the corona and solar wind represented by a newly devised ``steady state'' solution. The initial solution has been constructed to provide a reasonable description of the time-<span class="hlt">averaged</span> solar wind for conditions near solar minimum: (1) the computed <span class="hlt">magnetic</span> field near the Sun possesses high-latitude polar coronal holes, closed <span class="hlt">magnetic</span> field flux tubes at low latitudes, and a helmet streamer structure with a neutral line and current sheet; (2) the Archimedean spiral topology of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field is reproduced; (3) the observed two-state nature of the solar wind is also reproduced with the simulation yielding fast and slow solar wind streams at high and low latitudes, respectively; and (4) the predicted solar wind plasma properties at 1 AU are consistent with observations. Starting with the generation of a CME at the Sun, the simulation follows the evolution of the solar wind disturbance as it evolves into a <span class="hlt">magnetic</span> cloud and travels through <span class="hlt">interplanetary</span> space and subsequently interacts with the terrestrial magnetosphere-ionosphere system. The density-driven CME exhibits a two-step release process, with the front of the CME rapidly accelerating following the disruption of the near-Sun closed <span class="hlt">magnetic</span> field line structure and then moving at a nearly constant speed of ~560 km/s through <span class="hlt">interplanetary</span> space. The CME also produces a large <span class="hlt">magnetic</span> cloud (>100RS across) characterized by a <span class="hlt">magnetic</span> field that smoothly rotates northward and then back again over a period of ~2 days at 1 AU. The cloud does not contain a sustained period with a strong southward component of the <span class="hlt">magnetic</span> field, and, as a consequence, the simulated CME is somewhat ineffective in generating strong geo-<span class="hlt">magnetic</span> activity at Earth. Nevertheless, the simulation results illustrate the potential, as well as current limitations, of the MHD-based space weather model for enhancing the understanding of coronal physics, solar wind plasma processes, magnetospheric physics, and space weather phenomena. Such models will provide the foundation for future, more comprehensive space weather prediction tools.</p> <div class="credits"> <p class="dwt_author">Groth, Clinton P. T.; De Zeeuw, Darren L.; Gombosi, Tamas I.; Powell, Kenneth G.</p> <p class="dwt_publisher"></p> <p class="publishDate">2000-11-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">374</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013ApJ...777...32X"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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 ? 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 Ivpropr -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 sheath and the mass of plasma at that position M sheath can be inferred from the polarization of the shock-associated enhancement in WL radiance. From the FR measurements, the local B ?sheath at r 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> <div class="credits"> <p class="dwt_author">Xiong, Ming; Davies, Jackie A.; Feng, Xueshang; Owens, Mathew J.; Harrison, Richard A.; Davis, Chris J.; Liu, Ying D.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-11-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">375</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.agu.org/journals/ja/v080/i031/JA080i031p04204/JA080i031p04204.pdf"> <span id="translatedtitle">An Empirical Relationship Between <span class="hlt">Interplanetary</span> Conditions and Dst</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">An algorithm is presented for predicting the ground-based Dst index solely from a knowledge of the velocity and density of the solar wind and the north-south solar magnetospheric component of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field. The three key elements of this model are an adjustment for solar wind dynamic pressure, an injection rate linearly proportional to the dawn-to-dusk component of the</p> <div class="credits"> <p class="dwt_author">R. K. Burton; R. L. McPherron; C. T. Russell</p> <p class="dwt_publisher"></p> <p class="publishDate">1975-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">376</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013IAUS..294..505Z"> <span id="translatedtitle">Helicity transport from solar convection zone to <span class="hlt">interplanetary</span> space</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary"><span class="hlt">Magnetic</span> helicity is a physical quantity that describes field topology. It is also a conserved quantity as Berger in 1984 demonstrated that the total <span class="hlt">magnetic</span> helicity is still conserved in the corona even when there is a fast <span class="hlt">magnetic</span> reconnection. It is generally believed that solar <span class="hlt">magnetic</span> fields, together with their helicity, are created in the convection zone by various dynamo processes. These fields and helicity are transported into the corona through solar photosphere and finally released into the <span class="hlt">interplanetary</span> space via various processes such as coronal mass ejections (CMEs) and solar winds. Here I will give a brief review on our recent works, first on helicity observations on the photosphere and how to understand these observations via dynamo models. Mostly, I will talk about what are the possible consequences of <span class="hlt">magnetic</span> helicity accumulation in the corona, namely, the formation of <span class="hlt">magnetic</span> flux ropes, CMEs taking place as an unavoidable product of coronal evolution, and flux emergences as a trigger of CMEs. Finally, I will address on in what a form <span class="hlt">magnetic</span> field in the <span class="hlt">interplanetary</span> space would accommodate a large amount of <span class="hlt">magnetic</span> helicity that solar dynamo processes have been continuously producing.</p> <div class="credits"> <p class="dwt_author">Zhang, Mei</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-07-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">377</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2004JGRA..109.7106L"> <span id="translatedtitle">No increase of the <span class="hlt">interplanetary</span> electric field since 1926</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The long-term variation of the <span class="hlt">interplanetary</span> electric field is inferred back to 1926 from a correlation analysis with the magnetograms recorded at Godhavn and Thule, two polar cap geomagnetic observatories. The method is reliable because of the large dependence of the <span class="hlt">magnetic</span> perturbation on the cross-polar cap electric field, i.e., the penetration and mapping of the <span class="hlt">interplanetary</span> electric field into the magnetosphere-ionosphere system. This dependence is isolated by minimizing Sq and the Svalgaard-Mansurov effect. Both appear when an observatory moves closer to the polar cap boundary and are found to be a minimum in a direction almost perpendicular to the <span class="hlt">magnetic</span> north. Strictly speaking, no secular trend in the solar wind-magnetosphere large-scale coupling is indicated for the past 77 years. This suggests that there is no secular trend in the <span class="hlt">interplanetary</span> electric field and by inference in the Sun's open <span class="hlt">magnetic</span> flux and in the solar wind speed. The method is independent of the aa geomagnetic index and the sunspot cycle characteristics.</p> <div class="credits"> <p class="dwt_author">Le Sager, Philippe; Svalgaard, Leif</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-07-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">378</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Wu, Ji; Sun, Weiying; Zheng, Jianhua; Zhang, Cheng; Wang, Chi; Wang, C. B.; Wang, S.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">379</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://learningcenter.nsta.org/product_detail.aspx?id=10.2505/9781935155058.3"> <span id="translatedtitle"><span class="hlt">Average</span> Speed</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://nsdl.org/nsdl_dds/services/ddsws1-1/service_explorer.jsp">NSDL National Science Digital Library</a></p> <p class="result-summary">This lab is not an inquiry activity but will help students understand the meaning of <span class="hlt">average</span> velocity. Students do not easily understand from a textbook that an object's velocity changes over a period of acceleration. They have difficulty understanding wh</p> <div class="credits"> <p class="dwt_author">Horton, Michael</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-05-30</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">380</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.springerlink.com/index/w02120t514438243.pdf"> <span id="translatedtitle">Statistical Relationships between Solar, <span class="hlt">Interplanetary</span>, and Geomagnetic Disturbances, 19762000: 3</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">In this paper we continue the analysis of the influence of solar and <span class="hlt">interplanetary</span> events on <span class="hlt">magnetic</span> storms of the Earth that was started in [9, 10]. Different experimental results on solar-terrestrial physics are analyzed in the study and the effects are determined that arise due to differences in the methods used to analyze the data. The classifications of <span class="hlt">magnetic</span></p> <div class="credits"> <p class="dwt_author">Yu. I. Yermolaev; M. Yu. Yermolaev</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_18");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' 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onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">381</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.agu.org/journals/ja/v081/i001/JA081i001p00065/JA081i001p00065.pdf"> <span id="translatedtitle">Jovian Electron Bursts: Correlation With the <span class="hlt">Interplanetary</span> Field Direction and Hydromagnetic Waves</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">line. Abrupt changes in the field away from the preferred direction caused equally abrupt terminations of the waves with an accompanying reduction in the electron flux. These results are consistent with propagation of the electrons from Jupiter to Pioneer along, rather than across, the <span class="hlt">magnetic</span> field lines. The direction of the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field is apparently not affected by the</p> <div class="credits"> <p class="dwt_author">E. J. Smith; B. T. Tsurutani; D. L. Chenette; T. F. Conlon; J. A. Simpson</p> <p class="dwt_publisher"></p> <p class="publishDate">1976-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">382</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20050180487&hterms=HMF&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DHMF"> <span id="translatedtitle">Propagation of <span class="hlt">Interplanetary</span> Disturbances in the Outer Heliosphere</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Wang, Chi</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">383</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19730002067&hterms=Imp3&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3D%2522Imp3%2522"> <span id="translatedtitle"><span class="hlt">Interplanetary</span> shock waves and the structure of solar wind disturbances</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Observations and theoretical models of <span class="hlt">interplanetary</span> shock waves are reviewed, with emphasis on the large-scale characteristics of the associated solar wind disturbances and on the relationship of these disturbances to solar activity. The sum of observational knowledge indicates that shock waves propagate through the solar wind along a broad, roughly spherical front, ahead of plasma and <span class="hlt">magnetic</span> field ejected from solar flares. Typically, the shock front reaches 1 AU about two days after its flare origin, and is of intermediate strength. Not all large flares produce observable <span class="hlt">interplanetary</span> shock waves; the best indicator of shock production appears to be the generation of both type 2 and type 4 radio bursts by a flare. Theoretical models of shock propagation in the solar wind can account for the typically observed shock strength, transit time, and shape.</p> <div class="credits"> <p class="dwt_author">Hundhausen, A. J.</p> <p class="dwt_publisher"></p> <p class="publishDate">1972-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">384</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2007AGUFMSM43A1067P"> <span id="translatedtitle"><span class="hlt">Interplanetary</span> Shock Waves in the Earth Magnetosheath: Cluster Observations</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Shock waves collisions are a basic problem in plasma physics and play an important role in many processes occurring in space. In particular, the impacts of the <span class="hlt">interplanetary</span> shock waves (IPS) on the terrestrial bow shock are relevant to the Space Weather. In fact, understanding how the associated pressure pulses in magnetosheath are shaped after these impacts, can help to model in a more realistic way the perturbed magnetosphere and to gain a deeper knowledge into the fundamental mechanisms causing the geomagnetic activity. Here we present an event, seen by Cluster spacecraft, showing the complex and non-linear nature of the phenomenon. Actually the associated variations in plasma parameters and in the <span class="hlt">magnetic</span> field are due, besides the transmitted <span class="hlt">interplanetary</span> shocks, to other secondary (i.e. produced in the impact) discontinuities and waves.</p> <div class="credits"> <p class="dwt_author">Pallocchia, G.; Cattaneo, M. B.; Marcucci, M. F.; Reme, H.; Lucek, E.</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-12-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">385</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/5257231"> <span id="translatedtitle">Solar and <span class="hlt">interplanetary</span> control of the location of the Venus bow shock</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">The Venus box shock location has been measured at nearly 2,000 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 box shock cross section is circular and only weakly sensitive to changing EUV flux.</p> <div class="credits"> <p class="dwt_author">Russell, C.T.; Chou, E.; Luhmann, J.G. (Univ. of California, Los Angeles (USA)); Gazis, P. (NASA Ames Research Center, Moffett Field, CA (USA)); Brace, L.H.; Hoegy, W.R. (NASA Goddard Space Flight Center, Greenbelt, MD (USA))</p> <p class="dwt_publisher"></p> <p class="publishDate">1988-06-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">386</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19880052777&hterms=shock+sensitive&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dshock%2Bsensitive"> <span id="translatedtitle">Solar and <span class="hlt">interplanetary</span> control of the location of the Venus bow shock</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Russell, C. T.; Chou, E.; Luhmann, J. G.; Gazis, P.; Brace, L. H.; Hoegy, W. R.</p> <p class="dwt_publisher"></p> <p class="publishDate">1988-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">387</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/6119503"> <span id="translatedtitle">Solar cycle study of <span class="hlt">interplanetary</span> Lyman-alpha variations - Pioneer Venus Orbiter sky background results</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">PVO observations of the <span class="hlt">interplanetary</span> Ly-alpha (IPL) background, obtained over an entire solar cycle (SC) from 1979 to 1985, are compiled and analyzed statistically, along with data from other instruments and earlier solar cycles. The results are presented in extensive tables and graphs and characterized in detail. Findings reported include SC variation of 1.8 for the longitudinally <span class="hlt">averaged</span> IPL intensity (in agreement with the variation of the 27-d disk-<span class="hlt">averaged</span> integrated solar Ly-alpha flux), yearly <span class="hlt">averaged</span> ecliptic H-atom lifetime at 1 AU equal to 1.0 Ms at solar minimum and 1.5 Ms at solar maximum, <span class="hlt">interplanetary</span> H density equal to 0.07 + or - 0.01/cu cm, and <span class="hlt">interplanetary</span> H/He within the heliopause but far from the sun of 7 + or - 3. 74 references.</p> <div class="credits"> <p class="dwt_author">Ajello, J.M.; Stewart, A.I.; Thomas, G.E.; Graps, A.</p> <p class="dwt_publisher"></p> <p class="publishDate">1987-06-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">388</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1996LPI....27.1285S"> <span id="translatedtitle">Porosity of <span class="hlt">Interplanetary</span> Dust Particles</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We report here new information from our studies on the porosity of <span class="hlt">interplanetary</span> dust particles. We have resolved some of the problems we encountered earlier and we report new results for four hydrated IDPs and two meteorites. Determination of the porosity of IDPs is important in the dynamics of collisional and orbital evolution of small-sized particles. We are using an image analysis method to make these determinations from digitized photographs of thin-sectioned particles. Earlier determinations of porosity were derived from measures of density and suggested that particles had appreciable porosity, but that porosities were probably less than 70%.</p> <div class="credits"> <p class="dwt_author">Strait, M. M.; Thomas, K. L.; McKay, D. S.</p> <p class="dwt_publisher"></p> <p class="publishDate">1996-03-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">389</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/55584611"> <span id="translatedtitle">Dynamic Model Development for <span class="hlt">Interplanetary</span> Navigation</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">In this paper, the dynamic model development for <span class="hlt">interplanetary</span> navigation has been discussed. The Cowell method for special perturbation theories was employed to develop an <span class="hlt">interplanetary</span> trajectory propagator including the perturbations due to geopotential, the Earth's dynamic polar motion, the gravity of the Sun, the Moon and the other planets in the solar system, the relativistic effect of the Sun,</p> <div class="credits"> <p class="dwt_author">Eun-Seo Park; Young-Joo Song; Sung-Moon Yoo; Sang-Young Park; Kyu-Hong Choi; Jae-Cheol Yoon; Jo Ryeong Yim; Joon-Min Choi; Byung-Kyo Kim</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">390</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19770051690&hterms=feynman&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dfeynman"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Crooker, N. U.; Feynman, J.; Gosling, J. T.</p> <p class="dwt_publisher"></p> <p class="publishDate">1977-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">391</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/20711679"> <span id="translatedtitle">Reducing <span class="hlt">average</span> grain and domain size in high-coercivity Co/Pd perpendicular <span class="hlt">magnetic</span> recording media through seedlayer engineering</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">InSn seedlayers for Co/Pd multilayered media were engineered using dopants (Pd, O) to achieve grain size of 7.8{+-}1.8 nm ({sigma}=23%) and virgin <span class="hlt">magnetic</span> cluster size of less than 65 nm. H{sub N}=-5 kOe and H{sub c}=12.2 kOe make this media promising for extremely high-density recording. These parameters were all realized with room-temperature depositions without annealing. Media with O-doped 2-nm InSn seedlayers without other adhesion layers achieved H{sub c}=6.2 kOe, which will be beneficial in reducing spacing loss. There is evidence that the engineered seedlayers also reduce the anisotropy dispersion and therefore the switching field distributions of these media.</p> <div class="credits"> <p class="dwt_author">Speetzen, N.J.; Stadler, B.J.H. [Electrical and Computer Engineering, University of Minnesota, Minnesota 55455 (United States)</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-05-15</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">392</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19960021314&hterms=conservation+energy&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dconservation%2Benergy"> <span id="translatedtitle"><span class="hlt">Magnetic</span> clouds, helicity conservation, and intrinsic scale flux ropes</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Kumar, A.; Rust, D. M.</p> <p class="dwt_publisher"></p> <p class="publishDate">1995-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">393</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014PPCF...56f4006M"> <span id="translatedtitle">Flux rope evolution in <span class="hlt">interplanetary</span> coronal mass ejections: the 13 May 2005 event</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Coronal mass ejections (CMEs) are a dramatic manifestation of solar activity that release vast amounts of plasma into the heliosphere, and have many effects on the <span class="hlt">interplanetary</span> medium and on planetary atmospheres, and are the major driver of space weather. CMEs occur with the formation and expulsion of large-scale <span class="hlt">magnetic</span> flux ropes from the solar corona, which are routinely observed in <span class="hlt">interplanetary</span> space. Simulating and predicting the structure and dynamics of these <span class="hlt">interplanetary</span> CME <span class="hlt">magnetic</span> fields are essential to the progress of heliospheric science and space weather prediction. We discuss the simulation of the 13 May 2005 CME event in which we follow the propagation of a flux rope from the solar corona to beyond Earth orbit. In simulating this event, we find that the <span class="hlt">magnetic</span> flux rope reconnects with the <span class="hlt">interplanetary</span> <span class="hlt">magnetic</span> field, to evolve to an open configuration and later reconnects to reform a twisted structure sunward of the original rope. Observations of the 13 May 2005 CME <span class="hlt">magnetic</span> field near Earth suggest that such a rearrangement of <span class="hlt">magnetic</span> flux by reconnection may have occurred.</p> <div class="credits"> <p class="dwt_author">Manchester, W. B., IV; van der Holst, B.; Lavraud, B.</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-06-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">394</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19830066648&hterms=Provo&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3D%2522Provo%2522"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary"><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> <div class="credits"> <p class="dwt_author">Slavin, J. A.; Tsurutani, B. T.; Smith, E. J.; Jones, D. E.; Sibeck, D. G.</p> <p class="dwt_publisher"></p> <p class="publishDate">1983-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">395</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19990010034&hterms=Global+Libraries&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DGlobal%2BLibraries"> <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> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">McGuire, Tim</p> <p class="dwt_publisher"></p> <p class="publishDate">1998-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">396</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2010GeoRL..3712105R"> <span id="translatedtitle">Reflected ions at <span class="hlt">interplanetary</span> shocks</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">This paper shows that the shock dissipation mechanism changes profoundly from the inner to outer heliosphere and that pickup ions are responsible for shock dissipation beyond 35 AU. We make the first study of reflected ions in ICME sheaths downstream of <span class="hlt">interplanetary</span> shocks observed by Voyager 2 from 1-80 AU. A reflected ion population was present in 12 of 14 ICME sheaths inside 35 AU and in 0 of 6 sheaths outside 35 AU. Reflected ions comprised from 0-47% of the downstream ions. The ratio of the reflected to thermal ion temperature ranges from 2.6 to 9.3. The percent of reflected ions increases with sonic Mach number and the ratio of the reflected to thermal ion temperature increases with the speed jump at the shock. Energetic neutral atoms created from the heated pickup ions may be observable by IBEX.</p> <div class="credits"> <p class="dwt_author">Richardson, J. D.</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-06-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">397</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20110012255&hterms=Operating+systems+Computers&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3D%2522Operating%2Bsystems%2B%2528Computers%2529%2522"> <span id="translatedtitle">CFDP for <span class="hlt">Interplanetary</span> Overlay Network</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Burleigh, Scott C.</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">398</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1989ApJ...337..528T"> <span id="translatedtitle">Infrared emission from <span class="hlt">interplanetary</span> dust</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">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> <div class="credits"> <p class="dwt_author">Temi, P.; de Bernardis, P.; Masi, S.; Moreno, G.; Salama, A.</p> <p class="dwt_publisher"></p> <p class="publishDate">1989-02-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">399</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/49060716"> <span id="translatedtitle">Tomographic analysis of solar wind structure using <span class="hlt">interplanetary</span> scintillation</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">For space weather research it is important to know the quiet solar wind structure existing as background for transient <span class="hlt">interplanetary</span> phenomena. Once we know the quiet background structure, transient phenomena are easily recognized as soon as they appear in <span class="hlt">interplanetary</span> space. The background structure is also important to understand how <span class="hlt">interplanetary</span> disturbances propagate in it and interact with it. <span class="hlt">Interplanetary</span></p> <div class="credits"> <p class="dwt_author">M. Kojima; K. Fujiki; M. Tokumaru; T. Ohmi; Y. Shimizu; A. Yokobe; B. V. Jackson; P. L. Hick</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">400</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2002cosp...34E.625V"> <span id="translatedtitle">Real-time <span class="hlt">Interplanetary</span> Shock Prediciton System</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">A system is being developed to predict the arrival times and maximum intensities of energetic storm particle (ESP) events at the earth. Measurements of particle flux values at L1 being made by the Electron, Proton, and Alpha Monitor (EPAM) instrument aboard NASA's ACE spacecraft are made available in real-time by the NOAA Space Environment Center as 5 minute <span class="hlt">averages</span> of several proton and electron energy channels. Past EPAM flux measurements can be used to train forecasting algorithms which then run on the real-time data. Up to 3 days before the arrival of the <span class="hlt">interplanetary</span> shock associated with an ESP event, characteristic changes in the particle intensities (such as decreased spectral slope and increased overall flux level) are easily discernable. Once the onset of an event is detected, a neural net is used to forecast the arrival time and flux level for the event. We present results obtained with this technique for forecasting the largest of the ESP events detected by EPAM. Forecasting information will be made publicly available through http://sd-www.jhuapl.edu/ACE/EPAM/, the Johns Hopkins University Applied Physics Lab web site for the ACE/EPAM instrument.</p> <div class="credits"> <p class="dwt_author">Vandegriff, J.; Ho, G.; Plauger, J.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_19");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' href="#">4</a> <a onClick='return showDiv("page_5");' href="#">5</a> <a onClick='return showDiv("page_6");' href="#">6</a> <a onClick='return showDiv("page_7");' href="#">7</a> <a onClick='return showDiv("page_8");' href="#">8</a> <a onClick='return showDiv("page_9");' href="#">9</a> <a onClick='return showDiv("page_10");' href="#">10</a> <a onClick='return showDiv("page_11");' href="#">11</a> <a onClick='return showDiv("page_12");' href="#">12</a> <a onClick='return showDiv("page_13");' href="#">13</a> <a onClick='return showDiv("page_14");' href="#">14</a> <a onClick='return showDiv("page_15");' href="#">15</a> <a onClick='return showDiv("page_16");' href="#">16</a> <a onClick='return showDiv("page_17");' href="#">17</a> <a onClick='return showDiv("page_18");' href="#">18</a> <a onClick='return showDiv("page_19");' href="#">19</a> <a style="font-weight: bold;">20</a> <a onClick='return showDiv("page_21");' href="#">21</a> <a onClick='return showDiv("page_