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  • 1
    Electronic Resource
    Electronic Resource
    Satellite observations of type III solar radio bursts at low frequencies (1974)
    Springer
    Space science reviews 16 (1974), S. 145-188 
    Details
    ISSN: 1572-9672
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Type III solar radio bursts have been observed from 10 MHz to 10 kHz by satellite experiments above the terrestrial plasmasphere. Solar radio emission in this frequency range results from excitation of the interplanetary plasma by energetic particles propagating outward along open field lines over distances from 5 R ⊙ to at least 1 AU from the Sun. This review summarizes the morphology, characteristics and analysis of individual as well as storms of bursts. Substantial evidence is available to show that the radio emission is observed at the second harmonic instead of the fundamental of the plasma frequency. This brings the density scale derived by radio observations into better agreement with direct solar wind density measurements at 1 AU and relaxes the requirement for type III propagation along large density-enhanced regions. This density scale with the measured direction of arrival of the radio burst allows the trajectory of the exciter path to be determined from 10 R ⊙ to 1 AU. Thus, for example, the dynamics and gross structure of the interplanetary magnetic field can be investigated by this method. Burst rise times are interpreted in terms of exciter length and dispersion while decay times refer to the radiation damping process. The combination of radio observations at the lower frequencies and in-situ measurements on non-relativistic electrons at 1 AU provide data on the energy range and efficiency of the wave-particle interactions responsible for the radio emission.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00240885
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    Comparisons of interplanetary type III storm footpoints with solar features (1971)
    Springer
    Solar physics 109 (1971), S. 107-118 
    Details
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The trajectories of 38 type III storms in the interplanetary medium have been deduced from ISEE-3 radio observations and extrapolated back to the Sun to determine the Carrington coordinates of their footpoints. The analysis assumes radial motion of the solar wind, and the trajectories are projected radially back toward the surface for the last few solar radii. To identify the storm sources, the footpoints were compared to a variety of solar features: to the large-scale neutral line at the base of the current sheet, to active regions, to the small-scale neutral lines and Hα filaments which trace out active regions, and to coronal holes. Most of the footpoints were found to lie near active regions, in agreement with metric storm locations. There is a weak correlation with Hα filaments, no apparent association with the current sheet, and an anticorrelation with coronal holes. There is a small excess of storms in the leading half of magnetic sectors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00167402
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Type III solar radio burst storms observed at low frequencies (1970)
    Springer
    Solar physics 15 (1970), S. 222-233 
    Details
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Storms of type III solar radio bursts observed from 5.4 to 0.2 MHz, indicate the quasicontinuous production of type III events observable for a half solar rotation but persisting in some cases for well over a complete rotation. The characteristics of these storms, including the dependance of occurrence and apparent drift rates on the disc position of the associated active region are discussed. The drift rate dependance is shown to be a consequence of the propagation time of emission from the source to the observer. The occurrence rate of a burst every 10 sec observed near CMP implies that if this level of activity persists, then about a quarter of a million exciter packets are released into the interplanetary plasma during a complete rotation. Storm bursts are less intense than most isolated type III's and occur over a more limited frequency range. There appears to be a very close relation between these storms and decametric continuum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00149487
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  • 4
    Electronic Resource
    Electronic Resource
    Type III solar radio burst storms observed at low frequencies (1970)
    Springer
    Solar physics 15 (1970), S. 433-445 
    Details
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Storms of type III solar radio bursts observed from 5.4 ot 0.2 MHz consist of a quasi-continuous production of type III events observable for half a solar rotation but persisting in some cases for well over a complete rotation (Fainberg and Stone, 1970). The observed burst drift rates are a function of the heliographic longitude of the associated active region. This apparent drift rate dependence is a consequence of the radio emission propagation time from source to observer. Based on this dependence, a least squares analysis of 2500 drift rates between frequencies in the 2.8 to 0.7 MHz range yields an average exciter speed of 0.38 c for the height range from approximately 11 to 30 R ⊙. In conjunction with the available determinations of exciter speeds of 0.33 c close to the sun, i.e. less than 3 R ⊙, and with in situ measurements of 40 keV solar electrons by space probes, the present results suggest that the exciters are electron packets which propagate with little deceleration over distances of at least 1 AU.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00151850
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  • 5
    Electronic Resource
    Electronic Resource
    A comparison of type III solar radio burst theories using satellite radio observations and particle measurements (1971)
    Springer
    Solar physics 21 (1971), S. 198-203 
    Details
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The required electron density to excite a type III solar burst can be predicted from different theories, using the low frequency radio observations of the RAE-1 satellite. Electron flux measurements by satellite in the vicinity of 1 AU then give an independent means of comparing these predicted exciter electron densities to the measured density. On this basis, one theory predicts the electron density in closest agreement with the measured values.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00155790
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  • 6
    Electronic Resource
    Electronic Resource
    Radio evidence for an expanding magnetic arch beyond 20 solar radii (1975)
    Springer
    Solar physics 42 (1975), S. 179-181 
    Details
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A magnetic loop located beyond 20 R ⊙ appears to be the later evolution of an expanding magnetic arch observed at 2 r ⊙. The expansion speed is of the order of 100 km s−1.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00153294
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    Paper (German National Licenses)
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  • 7
    Electronic Resource
    Electronic Resource
    Type III solar radio burst storms observed at low frequencies (1971)
    Springer
    Solar physics 17 (1971), S. 392-401 
    Details
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The analysis of a storm of type III solar radio bursts observed in August 1968 between 5 and 0.2 MHz by the RAE-1 satellite has yielded the storm morphology, a possible relation to meter and decameter storms, and an average exciter speed of 0.37 c between 10 and 40 R ⊙ (Fainberg and Stone, 1970a, b). A continuation of the analysis, based on the apparent dependence of burst drift rate on heliographic longitude of the associated active region, now provides a distance scale between plasma levels in the streamer, an upper limit to the scale size of coronal streamer density inhomogeneities, and an estimate of the solar wind speed. By fixing one level the distance scale is utilized to determine the electron density distribution along the streamer between 10 and 40 R ⊙. The streamer density is found to be 16 times that expected for the solar minimum quiet solar wind. An upper limit to the scale size of streamer density inhomogeneities is estimated to be of the order of 1 or 2 solar radii over the same height range. From the progressive delay of the central meridian passage (CMP) of the lower frequency emission, a streamer curvature is inferred which in turn implies an average solar wind speed of 380 km/sec between 14 and 36 R ⊙ within the streamer.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00150042
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  • 8
    Electronic Resource
    Electronic Resource
    A U-type solar radio burst originating in the outer corona (1971)
    Springer
    Solar physics 20 (1971), S. 106-111 
    Details
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The observation of a U-type solar radio burst with a reversing frequency of approximately 0.7 MHz suggests the presence of a magnetic bottle extending out to about 35 R ⊙. A possible model of this loop structure is developed from the data. The occurrence of low-frequency U-bursts seems to be extremely rare although magnetic bottles may develop frequently during solar maximum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00146101
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  • 9
    Electronic Resource
    Electronic Resource
    A new high-speed solar spectrograph for meter and decameter wavelengths (1975)
    Springer
    Solar physics 40 (1975), S. 501-510 
    Details
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A new high-speed digital solar radio spectrograph has been designed and is being operated at the Clark Lake Radio Observatory in California. The spectrograph design attempts to optimize sensitivity, dynamic range, and frequency-time resolution while utilizing modern high-speed computer data-handling techniques. The system is described and initial data observations are presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00162394
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