The solar wind control of the equatorial ionosphere dynamics during geomagnetic storms

The interplanetary magnetic field, geomagnetic variations, virtual ionosphere height h′F, and the critical frequency foF2 data during the geomagnetic storms are studied to demonstrate relationships between these phenomena. We study 5-min ionospheric variations using the first Western Pacific Ionosphere Campaign (1998–1999) observations, 5-min interplanetary magnetic field (IMF) and 5-min auroral electrojets data during a moderate geomagnetic storm. These data allowed us to demonstrate that the auroral and the equatorial ionospheric phenomena are developed practically simultaneously. Hourly average of the ionospheric foF2 and h′F variations at near equatorial stations during a similar storm show the same behavior. We suppose this is due to interaction between electric fields of the auroral and the equatorial ionosphere during geomagnetic storms. It is shown that the low-latitude ionosphere dynamics during these moderate storms was defined by the southward direction of the B_z-component of the interplanetary magnetic field. A southward IMF produces the Region I and Region II field-aligned currents (FAC) and polar electrojet current systems. We assume that the short-term ionospheric variations during geomagnetic storms can be explained mainly by the electric field of the FAC. The electric fields of the field-aligned currents can penetrate throughout the mid-latitude ionosphere to the equator and may serve as a coupling agent between the auroral and the equatorial ionosphere.     

Observation of fast variations of the helium-ion abundance in the solar wind

This paper describes the results of studying the helium component of the solar-wind ion-flux measurement by the BMSW instrument on the Spektr-R satellite with a time resolution of 3 s. In contrast to most previous works that presented values averaged over large (hourly average or daily average) intervals, we have shown that the relative helium-ion abundance in the solar wind experiences considerable (by a few percent and even 10%) variations on such short intervals as 10 seconds or even several seconds.     

The hemispheric asynchrony of polar faculae during solar cycles 19–22

We investigate the north–south (N–S) asynchrony of the polar faculae and compare it with the hemispheric asynchrony of solar activity at low latitudes. We find that, (1) both the solar activity at high and low latitudes do not synchronously occur in the northern and southern hemispheres, there is phase shifts between the two hemispheres; (2) the N–S asynchrony of the polar faculae is a function of latitudes, implying that the asynchrony of the polar faculae between the two hemispheres is related to the hemispheric asymmetry and latitudinal distribution of the polar faculae.     

A multiple type-II burst associated with a coronal transient and its MHD simulation

A large coronal transient took place on 8 May 1981. The transient was related to an M7.7/2B flare and was associated with at least two coronal type II bursts. The velocities of the type II bursts were in the range 1100–1800 kms^?1, in excess of the transient velocity of 500–1000 kms^?1. Two dimensional positions of the type II radio sources are available from both the Clark Lake and the Culgoora Radio Observatories. We carry out two dimensional MHD simulations of the event, taking into account the observed velocity, position, and size of the type II bursts. We simulate the multiple shocks observed during the event and their interaction, and discuss some results of the simulation.     

Up-to-date observations of space energetic particles made by the Chinese satellite Fengyun-1 (B).

This paper presents the observational results of space energetic particles obtained by the Cosmic Ray Composition Monitor (CRCM) onboard the Chinese satellite, Fengyun-1(B). These results, including those of a few solar proton events, the geomagnetically trapped particles and the anomalous cosmic ray components, were obtained from 3 September 1990 to 15 February 1991. The observed elements include H, He, C, N, O and Fe of energies from 4-23 MeV/u. It was found that the proton fluxes of the inner Radiation Belt (IRB) increased obviously during the period of solar proton event (SPE). A few kinds of heavy ions (Z > or = 6) were also detected in the IRB. As to the anomalous cosmic ray component (ACRC), in addition to C, N and O, anomalous iron particles were also recorded.     

The application of space imagery to geology and mineral exploration in the USSR — A case history

A short history of the application of space images to geology and mineral exploration in the U.S.S.R. is given with special emphasis to circular features observed on small scale and low-resolution pictures within the Precambrian terrain. These features are believed to correspond to the oldest basins of volcano-sedimentary deposition or, in other words, to primary cells of basic proto-crust. Metallogenic significance of circular features is also discussed. Remote sensing in oil-gas field exploration and in the study of recent tectonics are also dealt with.     

Architectures and GPS/INS integration: impact on missionaccomplishment

The GPS (Global Positioning System) signal contains information which, when properly combined with information from INS and other sensors, provides exceptionally high accuracy position, velocity, attitude, and time measurements. These ten elements of information (three each in position, velocity, and attitude, and one in time) are common, in various combinations, to most avionics functions. When viewed from a system perspective, this high-precision information can be thought of as an integration basis, or a reference set, which offers opportunities for reconfiguration of the offensive, defensive, communication, navigation, and other sensors. Various integration architectures for fusion of these sensors can inherently enhance, enable, or severely limit these potential mission capabilities. The choice of integration architecture, can directly and profoundly affect performance, cost of integration, cost of ownership, and exploitation of much greater mission capability. This is illustrated by an example     

Results of ZARNITZA-2, a rocket experiment on artificial electron beam injection in the ionosphere

The rocket experiment ZARNITZA-2 on artificial electron beam injection in the ionosphere was carried out on September 11, 1975. Great attention was paid to the study of phenomena occurring in the near-rocket region. The results of the experiment are discussed in terms of a beam plasma discharge.