CIR Morphology, Turbulence, Discontinuities, and Energetic Particles

Corotating interaction regions (CIRs) in the middle heliosphere have distinct morphological features and associated patterns of turbulence and energetic particles. This report summarizes current understanding of those features and patterns, discusses how they can vary from case to case and with distance from the Sun and possible causes of those variations, presents an analytical model of the morphological features found in earlier qualitative models and numerical simulations, and identifies aspects of the features and patterns that have yet to be resolved. This revised version was published online in August 2006 with corrections to the Cover Date.     

Temporal and Spatial Variation of the Ion Composition in the Ring Current

A global view of the ring current ions is presented using data acquired by the instrument MICS onboard the CRRES satellite during solar maximum. The variations of differential intensities, energy spectra, radial profile of the energetic particles and the origin of the magnetic local time (MLT) asymmetry of the ring current have been investigated in detail. O⁺ ions are an important contributor to the storm time ring current. Its abundance in terms of number density increases with increasing geomagnetic activity as well as its energy density. However, a saturation value for the energy density of O⁺ ions has been found. The low-energy H⁺ ions show a dramatic intensification and a rapid decay. However, its density ratio during the storm maximum is almost constant. On the other hand, high-energy H⁺ ions first exhibit a flux decrease followed by a delayed increase. Its density ratio shows an anti-correlation with the storm intensity. Both the positions of the maximum flux of O⁺ and He⁺ depend on storm activity: they move to lower altitudes in the early stage of a storm and move back to higher L-values during the recovery phase. Whereas the position of H⁺ and He⁺⁺ show almost no dependence on the Dst index. The energy density distributions in radial distance and magnetic local time show drastic differences for different ion species. It demonstrates that the ring current asymmetry mainly comes from oxygen and helium ions, but not from protons. The outward motion of O⁺ around local noon may have some implications for oxygen bursts in the magnetosheath during IMF Bz negative conditions as observed by GEOTAIL.     

The Galactic Environment of the Sun: Interstellar Material Inside and Outside of the Heliosphere

Interstellar material (ISMa) is observed both inside and outside of the heliosphere. Relating these diverse sets of ISMa data provides a richer understanding of both the interstellar medium and the heliosphere. The galactic environment of the Sun is dominated by warm, low-density, partially ionized interstellar material consisting of atoms and dust grains. The properties of the heliosphere are dependent on the pressure, composition, radiation field, ionization, and magnetic field of ambient ISMa. The very low-density interior of the Local Bubble, combined with an expanding superbubble shell associated with star formation in the Scorpius-Centaurus Association, dominate the properties of the local interstellar medium (LISM). Once the heliosphere boundaries and interaction mechanisms are understood, interstellar gas, dust, pickup ions, and anomalous cosmic rays inside of the heliosphere can be directly compared to ISMa outside of the heliosphere. Our understanding of ISMa at the Sun is further enriched when the circumheliospheric interstellar material is compared to observations of other nearby ISMa and the overall context of our galactic environment. The IBEX mission will map the interaction region between the heliosphere and ISMa, and improve the accuracy of comparisons between ISMa inside and outside the heliosphere.     

Magnetic Turbulence in the Geospace Environment

Magnetic turbulence is found in most space plasmas, including the Earth’s magnetosphere, and the interaction region between the magnetosphere and the solar wind. Recent spacecraft observations of magnetic turbulence in the ion foreshock, in the magnetosheath, in the polar cusp regions, in the magnetotail, and in the high latitude ionosphere are reviewed. It is found that: 1. A large share of magnetic turbulence in the geospace environment is generated locally, as due for instance to the reflected ion beams in the ion foreshock, to temperature anisotropy in the magnetosheath and the polar cusp regions, to velocity shear in the magnetosheath and magnetotail, and to magnetic reconnection at the magnetopause and in the magnetotail. 2. Spectral indices close to the Kolmogorov value can be recovered for low frequency turbulence when long enough intervals at relatively constant flow speed are analyzed in the magnetotail, or when fluctuations in the magnetosheath are considered far downstream from the bow shock. 3. For high frequency turbulence, a spectral index α?2.3 or larger is observed in most geospace regions, in agreement with what is observed in the solar wind. 4. More studies are needed to gain an understanding of turbulence dissipation in the geospace environment, also keeping in mind that the strong temperature anisotropies which are observed show that wave particle interactions can be a source of wave emission rather than of turbulence dissipation. 5. Several spacecraft observations show the existence of vortices in the magnetosheath, on the magnetopause, in the magnetotail, and in the ionosphere, so that they may have a primary role in the turbulent injection and evolution. The influence of such a turbulence on the plasma transport, dynamics, and energization will be described, also using the results of numerical simulations.     

Spectrophotometric diagnostics of energy characteristics and conductance of the auroral ionosphere from satellite: 1. Specific methods,accuracy problems,and instrumentation requirements

One of the most important tasks of space research is to find a way of real-time monitoring of the space environment conditions around the Earth. This is necessary in order to provide warning about the threats of critical failures in ground-based and space technological systems, thus providing for their stable and secure operation. In view of this concern, methods of diagnostics of ionospheric energy and electrodynamic characteristics continue to be developed on the basis of spectral and photometric measurements, analyzing the glow intensity of emissions of the upper atmosphere observed from above. Serial panoramic monochromatic maps of the intensity of luminosity of the upper atmosphere emissions measured from orbiting detectors can serve as a main data source for such an analysis. In this paper we consider the principal aspects of the method, and, on this basis, the instrumentation requirements are formulated.     

Statistical study of radio drifting pulsation structures with associated CMEs and other observations

Solar radio burst, especially the fine structures (FSs) and the drifting pulsation structures (DPSs), may be used as an important diagnostics tool to draw the evolution map of the flare loop in the initial phase of solar flares. In this work, 52 radio events were found accompanying with DPSs. They were all observed with the Solar Radio Spectrometers (0.625–7.6 GHz) of China during 1998–2004. Combining the radio observations with LASCO-C2, Goes-8 SXR, H_α, EUV and Trace observations, we analyzed all these events and obtained some statistic conclusions: First, 88% DPSs take place at the initial phase of the radio burst, and their rich spectrum characteristics are helpful to understand the events further. Second, 83% DPSs are associated with CMEs or ejection events, and all the events are accompanied by Goes SXR flare. Third, for CMEs and DPSs, which take the first step, there is no significant predominance of either of them. The relationship between the DPSs and CMEs is still not clear in this study because of the lack of spatial resolution in the centimeter–decimeter band. However, the EIT or Trace ejection happened during the onset/end time of DPSs. They are signatures of the initial phase of CMEs. Two events will be illustrated to explain this.     

Numerical analysis of the coefficients of temperature restitution and heat transfer in a turbulent dispersed flow

A technique is proposed and the results of the numerical investigation of the coefficients of temperature restitution and heat transfer on the surface streamlined by a turbulent dispersed flow are presented. The calculation data given involve that the coefficients of temperature restitution and heat transfer of the dispersed flow are significantly dependent on the nature of relative phase motion (with or without directional transverse particle displacement in the boundary layer), on the phase slip coefficients, and on the intensity of internal sources of heat and momentum in the boundary layer of the carrying medium.     

Special features of accelerated aerosol coagulation under subharmonic resonance in an open tube

The results of experimental studies of nonlinear aerosol oscillations in an open tube for a frequency equal to half the fundamental one are presented. The results can be used in designing aircraft engines.     

International scientific optical network for space debris research

A joint team of researchers under the auspices of the Center for Space Debris Information Collection, Processing and Analysis of the Russian Academy of Sciences collaborates with 15 observatories around the world to perform observations of space debris. For this purpose, 14 telescopes were equipped with charge-coupled device (CCD) cameras, Global Positioning System (GPS) receivers, CCD frame processing and ephemeris computation software, with the support of the European and Russian grants. Many of the observation campaigns were carried out in collaboration with the Astronomical Institute of the University of Bern (AIUB) team operating at the Zimmerwald observatory and conducting research for the European Space Agency (ESA), using the Tenerife/Teide telescope for searching and tracking of unknown objects in the geostationary region (GEO). More than 130,000 measurements of space objects along a GEO arc of 340.9°, collected and processed at Space Debris Data Base in the Ballistic Center of the Keldysh Institute of Applied Mathematics (KIAM) in 2005–2006, allowed us to find 288 GEO objects that are absent in the public orbital databases and to determine their orbital elements. Methods of discovering and tracking small space debris fragments at high orbits were developed and tested. About 40 of 150 detected unknown objects of magnitudes 15–20.5 were tracked during many months. A series of dedicated 22-cm telescopes with large field of view for GEO survey tasks is in process of construction. 7 60-cm telescopes will be modernized in 2007.