An Introduction to CMEs and Energetic Particles

Energetic particle observations in the interplanetary medium provide fundamental information about the origin, development and structure of coronal mass ejections. This paper reviews the status of our understanding of the ways in which particles are energised at the Sun in association with CMEs. This understanding will remain incomplete until the relationship between CMEs and flares is determined and we know the topology of the associated magnetic fields. The paper also discusses the characteristics of interplanetary CMEs that may be probed using particle observations.     

Coronal Observations of CMEs

CMEs have been observed for over 30 years with a wide variety of instruments. It is now possible to derive detailed and quantitative information on CME morphology, velocity, acceleration and mass. Flares associated with CMEs are observed in X-rays, and several different radio signatures are also seen. Optical and UV spectra of CMEs both on the disk and at the limb provide velocities along the line of sight and diagnostics for temperature, density and composition. From the vast quantity of data we attempt to synthesize the current state of knowledge of the properties of CMEs, along with some specific observed characteristics that illuminate the physical processes occurring during CME eruption. These include the common three-part structures of CMEs, which is generally attributed to compressed material at the leading edge, a low-density magnetic bubble and dense prominence gas. Signatures of shock waves are seen, but the location of these shocks relative to the other structures and the occurrence rate at the heights where Solar Energetic Particles are produced remains controversial. The relationships among CMEs, Moreton waves, EIT waves, and EUV dimming are also cloudy. The close connection between CMEs and flares suggests that magnetic reconnection plays an important role in CME eruption and evolution. We discuss the evidence for reconnection in current sheets from white-light, X-ray, radio and UV observations. Finally, we summarize the requirements for future instrumentation that might answer the outstanding questions and the opportunities that new space-based and ground-based observatories will provide in the future.     

The Hydrogen Exospheric Density Profile Measured with ASPERA-3/NPD

We have evaluated the Lyman-α limb emission from the exospheric hydrogen of Mars measured by the neutral particle detector of the ASPERA-3 instrument on Mars Express in 2004 at low solar activity (solar activity index = 42, F_10.7=100). We derive estimates for the hydrogen exobase density, n _H = 10¹⁰ m^?3, and for the apparent temperature, T > 600 K. We conclude that the limb emission measurement is dominated by a hydrogen component that is considerably hotter than the bulk temperature at the exobase. The derived values for the exosphere density and temperature are compared with similar measurements done by the Mariner space probes in the 1969. The values found with Mars Express and Mariner data are brought in a broader context of exosphere models including the possibility of having two hydrogen components in the Martian exosphere. The present observation of the Martian hydrogen exosphere is the first one at high altitudes during low solar activity, and shows that for low solar activity exospheric densities are not higher than for high solar activity.     

Dynamics of Coronal Loop Oscillations Recent Improvements and Computational Aspects

We will discuss the observed, heavily damped transversal oscillations of coronal loops. These oscillations are often modeled as transversal kink oscillations in a cylinder. Several features are added to the classical cylindrical model. In our models we include loop curvature, longitudinal density stratification, and highly inhomogeneous radial density profiles. In this paper, we will first give an overview of recently obtained results, both analytically and numerically. After that, we shed a light on the computational aspects of the modeling process. In particular, we will focus on the parallellization of the numerical codes.     

Ground penetrating radar VIY-2

VIY-2 ground penetrating radar (GPR) with unique sounding possibilities and use simplicity is presented at this paper. VIY-2 GPR combines all units (synchronizer, transmitting and receiving modules, powering, and antenna system) into single case. The VIY-2 GPR communicates with computer via standard interface RS232 or USB1.0. Technical solutions utilized by the VIY-2 GPR reduce deployment time and simplify surveying process. The VIY-2 GPR design features and its components interaction are considered at this paper. Some field results are also presented here. The VIY-2 GPR design concept allows reducing the data acquisition time,, optimizing the time-varying gain control function, applying depth-stacking dependence, controlling the surveying window position and interference reducing by pulse repetition frequency randomizing.     

Track-before-detect procedures for early detection of moving target from airborne radars

In this paper we present a family of track-before-detect (TBD) procedures for early detection of moving targets from airborne radars. Upon a sectorization of the coverage area, the received echoes are jointly processed in the azimuth-range-Doppler domain and in the time domain through a Viterbi-like algorithm that exploits the physically admissible target transitions between successive illuminations, in order to collect all of the energy back-scattered during the time on target (TOT). A reduced-complexity implementation is derived assuming, at the design stage, that the target does not change resolution cell during the TOT in each scan. The constant false alarm rate (CFAR) constraint is also englobed in the proposed procedures as well as the possibility of working with quantized data. Simulation results show that the proposed algorithms have good detection and tracking capabilities even for high target velocities and low quantization rates.     

Rocket berthing to an asteroid: Design problems

The results of research in a process of a probe rocket berthing to an asteroid are presented. Control laws were obtained as solutions of three problems, namely berthing considering transient processes in a rocket engine, fastest berthing with regard to fuel consumption and berthing in a scheduled time considering fuel consumption. A program trajectory obtained at solving of the first problem is suitable for mathematical modeling of berthing with the feedback control law and stabilization of angular motion. The solutions of the problems are reduced to simple formulas for controlling parameters calculation in the corresponding structures of control laws. The results can be applied in designing promising space vehicles intended for berthing to other space objects.     

Analysis of geometrically nonlinear shells of revolution based on the finite element method with the vector interpolation of desired quantities

In this paper, we present an algorithm for geometrically nonlinear finite element analysis of the shells of revolution. Use is made of the most proper algorithms for vector interpolation of displacements through the nodal unknowns and an efficient algorithm for obtaining the stress-strain increment relation at a step of loading. By comparing the results of analyzing a geometrically nonlinear shell of revolution obtained on the basis of the ANSYS software with the scalar interpolation of displacements with those obtained on the basis of an author-developed finite element, it has been shown that application of the FEM vector displacement interpolation leads to increasing the accuracy of the finite element solutions in analyzing the stress-strain state of the geometrically nonlinear shells.     

Isotopic Criteria for Identification of Organic Carbon on Earth and Meteorites

Contrary to the often stated view, an enrichment of organic material in the light isotope is not a conclusive evidence of its life-related origin. The β¹³C - σ¹³C correlation is a special feature of biological systems. Therefore it can be used as a criterion for identification of organic carbon. A survey of the available isotopic data for organic compounds in meteorites shows that they do not comply with the β¹³C - σ¹³C correlation. The prevalence of amino and hydroxy acids in purines and sugars found in carbonaceous meteorites indicates that condensation of HCN and HCHO passed through cyanohydrin reaction, while biological evolution proceeds through formation of adenosine triphosphate (ATP). This, in addition to the isotope criterion, indicates that the organic compounds in carbonaceous chondrites are not life-related substances. This revised version was published online in August 2006 with corrections to the Cover Date.