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[en] Complete text of publication follows. The rotation averaged location of the heliospheric current sheet has been found to be systematically shifted southward for about three years in the late declining to minimum phase of each solar cycle. This behaviour, called now by the concept of the Bashful ballerina, has been shown to be valid at least during the active solar cycles of the last century since the late 1920s. The IHY CIP program number 67 'Steps of the Bashful Ballerina: Global structure of the Solar/Inner Heliospheric Magnetic Field' studies these interesting global solar developments and their heliospheric/magnetospheric consequences. Recently, Zhao et al have analysed the WSO solar magnetic observations and conclude that there is no southward shift in HCS or north-south difference in the heliospheric magnetic field during the late declining phase of solar cycle 23. In disagreement with these results, we now find, using the HMF observations at 1 AU and their coronal sources as given by the WSO PFSS model, that there is a similar but smaller southward shift of the HCS during solar cycle 23, as in all previous solar cycles. This is further verified by the direct observations of the HCS location by Ulysses during its third fast latitude scan pass in 2007. The smaller asymmetry in SC 23 is in agreement with an earlier observation based on long-term geomagnetic activity that solar hemispheric asymmetry is larger during highly active solar cycles.
[en] A simple phenomenology is developed for the decay and transport of turbulence in a constant-speed, uniformly expanding medium. The fluctuations are assumed to be locally incompressible, and either of the hydrodynamic or non-Alfvenic magnetohydrodynamic (MHD) type. In order to represent local effects of nonlinearities, a simple model of the Karman-Dryden type for locally homogeneous turbulent decay is adopted. A detailed discussion of the parameters of this familiar one-point hydrodynamic closure is given, which has been shown recently to be applicable to non-Alfvenic MHD as well. The effects of the large-scale flow and expansion are incorporated using a two-scale approach, in which assumptions of particular turbulence symmetries provide simplifications. The derived model is tractable and provides a basis for understanding turbulence in the outer heliosphere, as well as in other astrophysical applications. (Author)
[en] The program was based on simultaneous observations of the same solar region with the Universal Birefringent Filter (UBF) at the Vacuum Tower Telescope (VTT) and with the Big Dome BD Universal Spectrograph (USG). For the UBF images analysis it is referred to the June 13, 1980 RG 2502/2511 (N12-E11) observations. Selected pictures present the line profiles for H-alpha, H-beta, Mg-b1 and Na-D2 at some interesting pixels of the analyzed AR. The detailed photometric morphology of the observed active area and the longitudinal velocity field pattern are presented. A comparison with the corresponding UVSP data is given
[en] The dynamics of surges is investigated from the series of the Hsub(α)-filtergrams obtained 29 September 1980 at the Ussurijsk Solar station. For the data tpeatment+ the spline method is used. The values of velocities and accelerations of the surges are estimated. Possible models of their evolution are discussed
[en] It is shown that the differential rotation rates estimated with the use of weak remnants of magnetic fields measured at a very low resolution during the periods of low solar activity and in the regions of the photosphere with a very low density of new magnetic flux sources lie between the differential rotation values obtained with the aid of highly averaged sunspot data and from daily magnetic field measurements. The effects disturbing the smooth changes in solar rotation velocity values with heliographic latitude, seen clearly in the distribution of magnetic fields as solar differential rotation parabolas, are briefly discussed. The predominance is shown of fields of one polarity over fields of the opposite polarity in the formation of the characteristic distribution and disturbance patterns in the background fields. The sign of this polarity changes with the sign of the solar magnetic fields in the polar regions. (author). 7 figs., 14 refs
[en] We study the dynamics of large dust grains ∼>1 μm with orbits outside of the heliosphere (beyond 250 AU). Motion of the solar system through the interstellar medium (ISM) at a velocity of 26 km s-1 subjects these particles to gas and Coulomb drag (grains are expected to be photoelectrically charged) as well as the Lorentz force and the electric force caused by the induction electric field. We show that to zeroth order the combined effect of these forces can be well described in the framework of the classical Stark problem: particle motion in a Keplerian potential subject to an additional constant force. Based on this analogy, we elucidate the circumstances in which the motion becomes unbound, and show that under local ISM conditions dust grains smaller than ∼100 μm originating in the Oort Cloud (e.g., in collisions of comets) beyond 104 AU are ejected from the solar system under the action of the electric force. Orbital motion of larger, bound grains is described analytically using the orbit-averaged Hamiltonian approach and consists of orbital plane precession at a fixed semimajor axis, accompanied by the periodic variations of the inclination and eccentricity (the latter may approach unity in some cases). A more detailed analysis of the combined effect of gas and Coulomb drag shows it is possible to reduce particle semimajor axes, but that the degree of orbital decay is limited (a factor of several at best) by passages through atomic and molecular clouds, which easily eject small particles.
[en] The Committee on Solar and Space Physics (CSSP) has provided NASA with guidance in the areas of solar, heliospheric, magnetospheric, and upper atmospheric research. The budgetary sitation confronted by NASA has called for a prioritized plane for the implementation of solar and space plasma physics programs. CSSP has developed the following recommendations: (1) continue implementation of both the Upper Atmosphere Research Satellite and Solar Optical Telescope programs; (2) initiate the International Solar Terrestrial Physics program; (3) plan for later major free-flying missions and carry out the technology development they require; (4) launch an average of one solar and space physics Explorer per yr beginning in 1990; (5) enhance current Shuttle/Spacelab programs; (6) develop facility-class instrumentation; (7) augment the solar terrestrial theory program by FY 1990; (8) support a compute modeling program; (9) strengthen the research and analysis program; and (10) maintain a stable suborbital program for flexible science objectives in upper atmosphere and space plasma physics
[en] We briefly outline the scientific and instrumental aspects of ESA's Solar Orbiter mission. Special emphasis is given to the Polarimetric and Helioseismic Imager, the instrument with the highest relevance for helioseismology applications, which will observe gas motions and the vector magnetic field in the photosphere at high spatial and temporal resolution.
[en] Solar coronal loops show significant plasma motions during their formation and eruption stages. Dynamic cool coronal structures, on the other hand, are often observed to propagate along coronal loops. We report on the discovery of two types of dynamic cool coronal structures, and characterize their fundamental properties. Using the EUV 304 A images from the Extreme Ultra Violet Imager (EUVI) telescope on the Solar TErrestrial RElation Observatory (STEREO) and the Ca II filtergrams from the Solar Optical Telescope (SOT) instrument on Hinode, we study the evolution of an EUV arch and the kinematics of cool coronal structures. The EUV 304 A observations show that a missile-like plasmoid moves along an arch-shaped trajectory, with an average velocity of 31 km s-1. About three hours later, a plasma arch forms along the trajectory, subsequently the top part of the arch fades away and disappears; meanwhile the plasma belonging to the two legs of the arch flows downward to the arch's feet. During the arch formation and disappearance, SOT Ca II images explore dynamic cool coronal structures beneath the arch. By tracking these structures, we classify them into two types. Type I is threadlike in shape and flows downward with a greater average velocity of 72 km s -1; finally it combines with a loop fibril at a chromospheric altitude. Type II is shape-transformable and sometimes rolling as it flows downward with a smaller velocity of 37 km s -1, then disappears insularly in the chromosphere. It is suggested that the two types of structures are possibly controlled by different magnetic configurations.