21 research outputs found
Spatial variations of ionospheric conductivity and radar auroral amplitude in the eastward electrojet region during pre-substorm conditions
The dependence of auroral backscatter amplitude on different ionospheric parameters (conductivity, current density, electric field) is studied by means of data recorded by STARE (Scandinavian Twin Auroral Radar Experiment), the two-dimensional Scandinavian Magnetometer Array (SMA), and auroral all-sky cameras. The observations were made on 16 March 1978 during pre-substorm conditions in the region of the eastward polar electrojet. The paper shows that in this event the auroral backscatter amplitudes in the 140 MHz frequency band were controlled mainly by spatial variations in the electron density or conductivity inside the back-scatter volume. To a certain extent also a linear relationship between backscatter amplitude and ionospheric current density was found but it is regarded as a special case of a more general relationship between electron density and backscatter amplitude. A stable discontinuity in the Hall conductivity over the most equatorward auroral arc was deduced from the data: On the equatorward side the conductivity was 3-5 times higher than on the nearby poleward side. Our conclusions are discussed in the light of some previously published results on the same subject.
ARK: https://n2t.net/ark:/88439/y000016
Permalink: https://geophysicsjournal.com/article/262
 
The Earth: Plasma Sources, Losses, and Transport Processes
This paper reviews the state of knowledge concerning the source of magnetospheric plasma at Earth. Source of plasma, its acceleration and transport throughout the system, its consequences on system dynamics, and its loss are all discussed. Both observational and modeling advances since the last time this subject was covered in detail (Hultqvist et al., Magnetospheric Plasma Sources and Losses, 1999) are addressed
The Energetic Particle Detector (EPD) Investigation and the Energetic Ion Spectrometer (EIS) for the Magnetospheric Multiscale (MMS) Mission
Abstract The Energetic Particle Detector (EPD) Investigation is one of 5 fields-and-particles investigations on the Magnetospheric Multiscale (MMS) mission. MMS comprises 4 spacecraft flying in close formation in highly elliptical, near-Earth-equatorial orbits targeting understanding of the fundamental physics of the important physical process called magnetic reconnection using Earth’s magnetosphere as a plasma laboratory. EPD comprises two sensor types, the Energetic Ion Spectrometer (EIS) with one instrument on each of the 4 spacecraft, and the Fly’s Eye Energetic Particle Spectrometer (FEEPS) with 2 instruments on each of the 4 spacecraft. EIS measures energetic ion energy, angle and elemental compositional distributions from a required low energy limit of 20 keV for protons and 45 keV for oxygen ions, up to \u3e0.5 MeV (with capabilities to measure up to \u3e1 MeV). FEEPS measures instantaneous all sky images of energetic electrons from 25 keV to \u3e0.5 MeV, and also measures total ion energy distributions from 45 keV to \u3e0.5 MeV to be used in conjunction with EIS to measure all sky ion distributions. In this report we describe the EPD investigation and the details of the EIS sensor. Specifically we describe EPD-level science objectives, the science and measurement requirements, and the challenges that the EPD team had in meeting these requirements. Here we also describe the design and operation of the EIS instruments, their calibrated performances, and the EIS in-flight and ground operations. Blake et al. (The Flys Eye Energetic Particle Spectrometer (FEEPS) contribution to the Energetic Particle Detector (EPD) investigation of the Magnetospheric Magnetoscale (MMS) Mission, this issue) describe the design and operation of the FEEPS instruments, their calibrated performances, and the FEEPS in-flight and ground operations. The MMS spacecraft will launch in early 2015, and over its 2-year mission will provide comprehensive measurements of magnetic reconnection at Earth’s magnetopause during the 18 months that comprise orbital phase 1, and magnetic reconnection within Earth’s magnetotail during the about 6 months that comprise orbital phase 2
Inductive Electric Fields in the Magnetotail and Their Relation to Auroral and Substorm Phenomena
Qc 2012041
The Social Interaction between the Public Space and an Individual in the Shopping Mall
Pētījums aplūko publiskās telpas un indivīda sociālo mijiedarbību lielveikalā. Pētījumā izvirzīts apgalvojums, ka indivīda darbību lielveikalā nosaka tā specifiskā publiskās telpas organizācija un simbolika. Pētījuma novitāte ir projektētas telpas etnometodoloģiska studija, kas ļauj tieši aplūkot indivīdu darbības telpā. Novērojums veikts lielveikalos Spice un Olympia, kas atrodas Rīgā, Pārdaugavā. Novērojumu papildina materiālu analīze un autores ikdienas pieredze. Autore lielveikala apmeklējumu atspoguļo kā ceļojumu, kas sākas indivīda mājās ar lielveikala reklāmu un virtuālo telpu internetā. Ceļojums sākas ar tuvināšanos lielveikalam. Kā tipiski lielveikala apmeklējuma objekti aplūkoti ieeja, gaitenis, eskalators/kāpnes/lifts, telpa bērniem, kases zona un izeja. Lielveikalu kartes indivīdam ļauj plānot ceļojuma maršrutus.A statement is brought forward in the research that actions of an individual in a shopping mall are determined by specific organization and symbolic of its public space. Project’s novelty is an enthomethodological study of the projected space, which allows a direct observation of the actions of individuals in this space. Observation has been conducted in the shopping malls Spice and Olympia, located in Riga, Kurzemes suburb. Observations are supplemented by analysis of materials and author’s daily experience. Author reflects a visit to shopping mall as a journey that begins with a television advertisement at individual’s home or in a virtual internet space. As typical objects of visit in the shopping mall are - the entrance, the hallway, the escalator / stairway/ lift, space for children, the pay-box zone and the exit
Experimental data on electric field and electron density dependence of auroral E-region drift turbulence and radar backscatter
Haldoupis et al. (1982), Uspensky et al. (1983) and Starkov et al. (1983) have recently found that the 140 MHz backscatter amplitude in the auroral ionosphere depends mainly on the mean electron density (height-integrated conductivity) in the E–layer. A similar relationship for the 46 MHz band was also found by Leinonen et al. (in press, 1983). In principle, this can be explained by only a slight dependence of the relative level of E-region drift turbulence < (∆N/ N)2 > in the auroral ionosphere on ionospheric parameters, viz. electric field and mean electron density. However, up to now, quantitative evidence for such a backscatter amplitude — electron density relationship is restricted to the few events which have so far been analyzed. Therefore, the aim of this short note is to add some more data to that data set. Furthermore, we will compare measurements made in the evening and morning sectors, where the conditions for irregularity excitation might be different.
ARK: https://n2t.net/ark:/88439/y063050
Permalink: https://geophysicsjournal.com/article/196
 
Political responsibility in Latvia after renewal of independency
Darba tēma ir “Politiskais atbildīgums Latvijā pēc neatkarības atjaunošanas”. Bakalaura darba izpētes jautājums ir: Kādi faktori ietekmē Latvijas vadošo politiķu lēmumu uzņemties politisko atbildību? Tika apskatīta teorija par politiskā atbildīguma elementiem, noskaidrots politiķu viedoklis par politisko atbildību, kā arī veikta Latvijas likumdošanas izpēte .
Autore analizēja piecu faktoru: partija, citi politiķi, masu mediji, sabiedrība un politiķa morālā apziņa , to ietekmi uz politiķu lēmumu uzņemties politisko atbildību .
Tika secināts, ka noteicošie faktori, kas varētu ietekmēt politiķi uzņemties politisko atbildību ir masu mediju un sabiedrības spiediens.
Darbā tika izmantota mediju kontentanalīzes metode. Atslēgvārdi: politiskā atbildība, politiskā atskaitīšanās , faktori , politiķi. The theme of this paper is “Political responsibility in Latvia after renewal of independency”. The research question of this paper is: What factors influence politicians decision to take political responsibility? The author of the work has included theory of political responsibility, politicians views, legislative analysis.
The author analizyed five factors: political party, other politicians, the mass media, society, moral consciousness influence on the politicians decision to take political responsibility .
It was concluded that the main factors, what influence politicians decisions are the mass media and society pressure.
It was concluded using the gualitative research approach and the content analysis. Keywords: political accountability, political accountability, factors politicians
Spatial and temporal characteristics of impulsive structure of magnetospheric substorm
At least a dozen well-defined activations were recorded with high spatial resolution during the first 25 min of a substorm commencing at 1959 UT on 3 March 1976. The activations were determined by Pi1 and 2-type magnetic pulsations, magnetic variations and cosmic noise absorption. The activations exhibited differences in intensity, spatial extent and the accompanied auroral behaviour. In all cases but one an impulsive counterclockwise differential equivalent current vortex was observed superimposed on the continuously growing westward electrojet. The high-energy particle precipitation reached its maximum in these vortex regions. In cases where the activations observed on the ground occurred close to the footpoint of the IMP-J satellite, it registered simultaneously (within 2 min) burstlike enhancements of the high-energy particle fluxes. The satellite was at these times 37 RE away from the Earth in the plasma sheet boundary layer. Large, practically isotropic high-energy electron fluxes detected at the satellite during the substorm expansion suggested the existence of a large-scale magnetic loop structure in the far magnetotail. The results give evidence of a time-varying dissipation process operating in an impulsive manner in separate regions of the plasma sheet (within a few RE). According to the magnetic variations at mid-latitude, the intensity of the cross-tail current disruption (or the substorm current wedge) does not respond to these activations in the same impulsive manner, but seems to integrate their effects.
ARK: https://n2t.net/ark:/88439/y017215
Permalink: https://geophysicsjournal.com/article/221
 
Pi2 magnetic pulsations, auroral break-ups, and the substorm current wedge: A case study
The two-dimensional distribution of the characteristics of Pi2 magnetic pulsations observed by the Scandinavian Magnetometer Array (SMA) during the passage of a westward travelling surge on 11 November 1976 and during three sucessive auroral break-ups around magnetic midnight on 15 February 1977 have been studied in relation to the position of active aurora and the break-up current system. On both days the greatest Pi2 amplitudes were collocated with the region where the brightest auroras were observed. The sense of polarization of the horizontal disturbance vectors changed along longitudinal and meridional lines. The two-dimensional equivalent current system of the Pi2 pulsations resembled a circular current vortex around the location of the localized upward field-aligned currents and changed its direction from counterclockwise to clockwise and back to counterclockwise again within one Pi2 cycle. Our observations indicate that the generation of Pi2 pulsations is not directly connected to periodic fluctuations of the complete current system at substorm onset, but that the upward directed field-aligned currents at the western edge of this system play the most important role for the Pi2 generation.
ARK: https://n2t.net/ark:/88439/y071359
Permalink: https://geophysicsjournal.com/article/167