Solar rotation, 1966–1978     

W. Livingston  T. L. Duvall Jr. 《Solar physics》1979,61(2):219-231

Photospheric and chromospheric spectroscopic Doppler rotation rates for the full solar disk are analyzed for the period July, 1966 to July, 1978. An approximately linear secular increase of the equatorial rate of 3.7% for these 12 years is found (in confirmation of Howard, 1976). The high latitude rates above 65 ° appear to vary with a peak-to-peak amplitude of 8%, or more, phased to the sunspot cycle such that the most rapid rotation occurs at, or following, solar maximum. The chromosphere, as indicated by H, has continued to rotate on the average 3% faster than the photosphere agreeing with past observations. Sources of error are discussed and evaluated.Operated by the Association of Universities for Research in Astronomy, Inc., under contract with the National Science Foundation.  相似文献   

The Solar Corona 530.3 nm in the 20th cycle     

V. Rušin  M. Rybanský  L. Scheirich 《Solar physics》1979,61(2):301-310

The paper presents an analysis of the coronal data of emission line 530.3 nm. The analysis was carried out with data recorded at the coronal station of Lomnický tít for the period 1965–1976. Up till now the observed time and latitudal changes of the shape of the corona as well as the existence of two maxima have been fully proved. The development of intensities has, in many cases, different characters in the southern and northern hemispheres. Apart from this, the third increase of intensities in the course of the cycle was observed nearly at all latitudes in the coincidence with sunspot numbers in 1974–1975 years. The maximum of intensities of this impulse of activity was observed at latitudes around 60° in both hemispheres.  相似文献   

Potential and inductive electric fields in the magnetosphere during auroras     

Walter J. Heikkila  R.J. Pellinen  C.-G. Fälthammar  L.P. Block 《Planetary and Space Science》1979,27(11):1383-1389

During quiescent auroras the large-scale electric field is essentially irrotational. The volume formed by the plasma sheet and its extension into the auroral oval is connected to an external source by electric currents, which enter and leave the volume at different electric potentials and which supply sufficient energy to support the auroral activity. The location of the actual acceleration of particles depends on the internal distribution of electric fields and currents. One important feature is the energization of the carriers of the cross-tail current and another is the acceleration of electrons precipitated through relatively low-altitude magnetic-field-aligned potential drops.Substorm auroras depend on rapid and (especially initially) localized release of energy that can only be supplied by tapping stored magnetic energy. The energy is transmitted to the charged particle via electric inductive fields.The primary electric field due to changing electric currents is redistributed in a complicated way—but never extinguished—by polarization of charges. As a consequence, any tendency of the plasma to suppress magnetic-field-aligned components of the electric fields leads to a corresponding enhancement of the transverse component.  相似文献   

On the discrepancy between the magnetic D-component and the overhead horizontal current at high-latitudes     

L. Jalonen  T. Nygrén 《Planetary and Space Science》1979,27(7):1027-1032

The discrepancy between the overhead E-region current and the magnetic D-component is studied using data obtained by the Chatanika incoherent scatter radar (L = 5.6). The F-region horizontal current is estimated to be too small to cause the observed D-deflection. Also, the assumption that the magnetic effects of the Pedersen and field-aligned currents cancel each other on the ground is shown to be inadequate to solve the problem. The significance of the inclination angle in the data analysis and the importance of the field-aligned current sheets are discussed.  相似文献   

Spectroscopic observations of winds on Venus: I. Technique and data reduction     

A.T. Young  R.A. Schorn  L.D.G. Young  D. Crisp  E.S. Barker 《Icarus》1979,38(3):435-450

We present out methods of measurement and reduction of high-dispersion photographic spectra of Venus. Our preliminary results are consistent with slow direct or no rotation at the level we sample, and disagree strongly with a 4-day retrograde rotation. A serious systematic error, which affects much published work, is due to blending of solar lines in the sky with those reflected from the planet. This always tends to produce a spurious retrograde “rotation.” Only data obtained in a dark sky, or daytime observations from which the sky lines have been accurately subtracted, can be relied upon. All such data give low wind speeds.  相似文献   

The excitation of ionic lines and molecular bands in meteor wakes     

L.M.G. Poole 《Planetary and Space Science》1979,27(1):59-61

The appearance of multiplets arising from the 4²P state of CaII (the H and K lines and an infrared triplet), the 1st positive band of N₂ and possibly certain multiplets of FeII in meteor wake spectra is explained semi-quantitatively in terms of the two-step sequence: collisional ionization of major atmospheric species O₂ and N₂ followed by resonant charge exchange with ablated meteoric atoms. Many other features which could arise through this mechanism (multiplets of MgII, SiII and FeII, and bands of O₂ and N₂) are likely to be weak or to have escaped detection owing to observational selection.  相似文献   

Influences of the interplanetary magnetic field on the auroral dynamics     

V.L. Zverev  G.V. Starkov  Y.I. Feldstein 《Planetary and Space Science》1979,27(5):665-667

This paper reports the study concerning the latitudinal dispalacement of the auroral oval as a function of the northward orientation of the B_z-component IMF and the relation between southward B_z and the auroral dynamics in the night sector.  相似文献   

Existence of the continuations in theN-body problem     

L. K. Babadzanjanz 《Celestial Mechanics and Dynamical Astronomy》1979,20(1):43-57

The method of obtaining the estimates of the maximalt-interval ( _–, ₊) on which the solution of theN-body problem exists and which is such that some fixed mutual distance (e. g. ₁₂) exceeds some fixed non-negative lower bound, for allt contained in ( _–, ₊), is considered. For given masses and initial data, the increasing sequences of the numbers _k , each of which provides the estimate ₊ > _k , are constructed. It appears that if ₊ = +, then .  相似文献   

High dispersion spectroscopic observations of Venus near superior conjunction IV. Results for the carbon dioxide bands in the IV-N photographic region     

L.D.G. Young  R.A.J. Schorn  A.T. Young 《Icarus》1980,41(2):309-311

Phase curves for the CO₂ bands at 7883, 7820, and 8689 Å are presented. While the weaker bands at 7820 and 7883 Å show a definite “inverse phase effect,” the band at 8689 Å shows a more normal phase curve; it also exhibited much larger day-to-day variations in the CO₂ abundance near superior conjunction in 1971. Because the variation of the phase curves with band strength is comparable to temporal variations on Venus, simultaneous observations of strong and weak bands are still needed to determine the dependence on band strength accurately.  相似文献   

Io's sodium emission cloud and the voyager 1 encounter     

B.A. Goldberg  Yu. Mekler  R.W. Carlson  T.V. Johnson  D.L. Matson 《Icarus》1980,44(2):305-317

Io's neutral sodium emission cloud was monitored during the period of Voyager 1 encounter from two independent ground-based sites. Observations from Table Mountain Observatory verified the continued existence of the “near-Io cloud” (d < 1.5 × 10⁵ km, for 4πI > 1 kR; R denotes Rayleigh) while those from Wise Observatory showed a deficiency in the weaker emission at greater distances from Io. The sodium cloud has been monitored from both observatories for several years. These and other observations demonstrate that the behavior of the cloud is complex since it undergoes a variety of changes, both systematic and secular, which can have both time and spatial dependencies. The cloud also displays some characteristics of stability. Table Mountain images and high-dispersion spectra (resolution $\text{～0.2}\text{A}\text{?}$) indicate that the basic shape and intensity of the “near cloud” have remained relatively constant at least since imaging observations began in 1976. Wise Observatory low-dispersion spectra (resolution $\text{～1}\text{A}\text{?}$) which have been obtained since 1974 demonstrate substantial variability of the size and intensity of the “far cloud” (d ? 1.5 × 10⁵ km) on a time scale of months or less. Corresponding changes in the state of the plasma associated with the Io torus are suggested, with the period of Voyager 1 encounter represented as a time of unusually high plasma temperature and/or density. Dynamic models of the sodium cloud employing Voyager 1 plasma data provide a reasonable fit to the Table Mountain encounter images. The modeling assumptions of anisotropic ejection of neutral sodium atoms from the leading, inner hemisphere of Io with a velocity distribution characteristic of sputtering adequately explain the overall intensity distribution of the “near cloud”. During the Voyager 1 encounter period there appeared a region of enhanced intensity projecting outward from Io's orbit and inclined to the orbital plane. This region is clearly distinguished from the sodium emission normally aligned with the plane of Io's orbit. The process responsible for this phenomenon is not yet understood. Similar but less pronounced features are also present in several Table Mountain images obtained over the past few years.  相似文献