Characteristics of magnetosheath plasma observed at low altitudes in the dayside magnetospheric cusps

Magnetosheath plasma penetrating to low altitudes in the dayside cusp region of the magnetosphere has been observed by the ISIS 1 soft particle spectrometer (SPS). The extent of these particle fluxes in local magnetic time and invariant latitude, their variation with magnetic activity, and their pitch angle distribution are given. Comparison between the SPS data and energetic particle data indicates that the boundary between open and closed field lines on the dayside is associated with a sharp drop in the outer zone keV electron fluxes. It is shown that these newly identified cusp fluxes provide the necessary energy to produce observed dayside auroral oval phenomena

The cyclotron energization through auroral wave experiments (CENTAUR 2B)

The CENTAUR 2B mission, a dual payload program, is in many aspects the same as the previous missions from Cape Perry and Norway in 1985. It was planned that these payloads would be launched from Andoya, Norway, Nov. 1989 from the Universal II launcher. The payloads are identical, but would have been launched at different azimuths as far north and as far west as possible. Particle experiments include the angular resolving energy analyzer (AREA), the fast ion mass spectrometer (FIMS), the spectrographic particle images (SPI), and finally, the differential ion flux probe (DIFP). SwRI was responsible for the scientific payload, which includes the power supplies, the power supply interfacing, the manipulating of the data from the instruments to format it for the telemetry system, all mechanical structure and restraint mechanisms, and the payload subskin. The status of the various components of this program is given

The relationships between high latitude convection reversals and the energetic particle morphology observed by the Atmosphere Explorer

Simultaneous measurements of the auroral zone particle precipitation and the ion convection velocity by Atmosphere Explorer show a consistent difference between the location of the poleward boundary of the auroral particle precipitation and the ion convection reversal. The difference of about 1.5 degrees of invariant latitude is such that some part of the antisunward convection lies wholly within the auroral particle precipitation region. The nature of the convection reversals within the precipitation region suggests that in this region the convection electric field is generated on closed field lines that connect in the magnetosphere to the low latitude boundary layer

Polar plasmas as observed by Dynamics Explorers 1 and 2

Plasma measurements from the Dynamics Explorer 1 and 2 satellites were used to characterize the polar cap environment. Analysis of numerous polar-cap passes indicate that, in general, three major regimes of plasma exist: (1) polar rain--electrons with magnetosheath-like energy spectra but much lower densities, most intense near the cusp and weakening toward the central polar cap; (2) polar wind--low energy upward flowing ions with both field-aligned and conical distributions; and (3) acceleration events--sporadic events consistent with the acceleration of electrons and positive ions by parallel electric fields. (1) to (3) were observed at high altitudes by Dynamics Explorer 1, while (1) and (3) were also observed at low altitudes by Dynamics Explorer 2. The plasma parameters associated with these plasma regimes are presented and discussed in terms of source and acceleration mechanisms

Report from magnetospheric science

By the early 1990s, magnetospheric physics will have progressed primarily through observations made from Explorer-class spacecraft, sounding rockets, ground based facilities, and shuttle based experiments. The global geospace science (GGS) element of the International Solar Terrestrial Physics program, when combined with contributions to the ESA Cluster mission and ground based and computer modeling programs, will form the basis for a major U.S. initiative in magnetospheric physics. The scientific objectives of the GGS program involve the study of energy transport throughout geospace. The Cluster mission will investigate turbulence and boundary phenomena in geospace, particularly at high latitudes on the dayside and in the region of the neutral sheet at geocentric distances of about 20 earth radii on the night side of the earth. The current state of knowledge is reviewed and the goals of these missions are briefly discussed

Dense ion clouds of 0.1 ? 2 keV ions inside the CPS-region observed by Astrid-2

International audienceData from the Astrid-2 satellite taken between April and July 1999 show several examples of dense ion clouds in the 0.1?2 keV energy range inside the inner mag-netosphere, both in the northern and southern hemispheres. These inner magnetospheric ion clouds are found predomi-nantly in the early morning sector, suggesting that they could have originated from substorm-related ion injections on the night side. However, their location and density show no cor-relation with Kp, and their energy-latitude dispersion is not easily reproduced by a simple particle drift model. There-fore, these ion clouds are not necessarily caused by substorm-related ion injections. Alternative explanations for the ion clouds are the direct solar wind injections and up-welling ions from the other hemisphere. These explanations do not, however, account for all of the observations

MemAerobics: a Cognitive Intervention to Improve Memory Ability and Reduce Depression in Older Adults

Numerous researchers have shown that older adults who participate in memory enhancement programs can improve their memory abilities. However, previous research has generally focused on young-old adults (i.e., under 75 years of age). We replicated these findings with an older assisted living facility population using a new program called MemAerobicsTM. This program could be used by other long-term care facilities to both improve and maintain residents\u27 overall wellness. Volunteers participated in one of two experimental conditions: either a cognitive enhancement intervention specifically designed to stimulate cognitive activity (known as MemAerobics) or a control group that did not participate in any extra activities. Before the intervention, all participants completed a battery of standardized tests designed to measure memory ability, beliefs in the efficacy in their memory, life satisfaction, and depression. After three-months of MemAerobics exercises, all participants were reassessed with the same measures to determine the magnitude and direction of changes as a function of their intervention group. The results indicated that MemAerobics participants experienced an increase in memory ability as well as a decrease in depressive symptoms

The effect of conjugate photoelectron impact ionization on the pre-dawn ionosphere

Theoretical calculations using photoelectron fluxes measured by a soft particle spectrometer on ISIS-2 as input data show that impact ionization by photoelectrons arriving from the sunlit conjugate region is insignificant in the ionization balance of the nighttime ionosphere.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/33780/1/0000033.pd