35 research outputs found

    Intershock observations during STIP intervals 17 and 18

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    The Prognoz-10/Intercosmos satellite (Intershock Project) carried out observations from Earth orbit from 26 April 1985 until 11 November 1985, covering STIP Intervals XVII and XVIII. Data obtained during the systematic measurements in the course of STIP Interval XVII and part of XVIII are presented; i.e., hourly averages of the solar wind velocity, temperature and ion concentration, ion flux changes (10 to the -1 to 10 to the -3 Hz), plasma wave parameters, energetic particles flux, magnetic fields, etc. Special attention is paid to solar wind distrubances causing abrupt and large effects on the shape of the bow shock (i.e., on 2 May 1985 and 14 September 1985). Generally, the observation period was very close to a minimum of solar activity and was quiet without significant interplanetary shocks

    Sharp changes of solar wind ion flux and density within and outside current sheets

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    Analysis of the Interball-1 spacecraft data (1995-2000) has shown that the solar wind ion flux sometimes increases or decreases abruptly by more than 20% over a time period of several seconds or minutes. Typically, the amplitude of such sharp changes in the solar wind ion flux (SCIFs) is larger than 0.5x10^8 cm^-2 s^-1. These sudden changes of the ion flux were also observed by the Solar Wind Experiment (SWE), on board the WIND spacecraft, as the solar wind density increases and decreases with negligible changes in the solar wind velocity. SCIFs occur irregularly at 1 AU, when plasma flows with specific properties come to the Earth's orbit. SCIFs are usually observed in slow, turbulent solar wind with increased density and interplanetary magnetic field strength. The number of times SCIFs occur during a day is simulated using the solar wind density, magnetic field, and their standard deviations as input parameters for a period of 5 years. A correlation coefficient of ~0.7 is obtained between the modelled and the experimental data. It is found that SCIFs are not associated with coronal mass ejections (CMEs), corotating interaction regions (CIRs), or interplanetary shocks; however, 85% of the sector boundaries are surrounded by SCIFs. The properties of the solar wind plasma for days with 5 or more SCIF observations are the same as those of the solar wind plasma at the sector boundaries. One possible explanation for the occurrence of SCIFs (near sector boundaries) is magnetic reconnection at the heliospheric current sheet or local current sheets. Other probable causes of SCIFs (inside sectors) are turbulent processes in the slow solar wind and at the crossings of flux tubes.Comment: 33 pages, 8 figures, 6 tables, Solar Physics 2011, in pres

    КОНБВРУКЦИЯ Π”ΠΠ’Π§Π˜ΠšΠžΠ’ ΠŸΠžΠ’ΠžΠšΠžΠ’ ΠšΠžΠ‘ΠœΠ˜Π§Π•Π‘ΠšΠžΠ™ ΠŸΠ›ΠΠ—ΠœΠ« НА ΠžΠ‘ΠΠžΠ’Π• Π¦Π˜Π›Π˜ΠΠ”Π Π ЀАРАДЕЯ

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    Important tasks of modern space research are the study and continuous observations of the processes of cosmic and meteorological Β«weatherΒ». One of the electronic devices for carrying out such researches is a plasma sensor based on Faraday cup. The purpose of the work was to develop a constructive variant of the Faraday cup with precision sensitive (selective) elements in the form of metal grid microstructures and a four-sector collector, which has no analogues in the world technology.For the formation of grid nickel microstructures, a process has been developed for creating a matrix of nanoporous anodic aluminum oxide by photolithography as a precision shape (template) for depositing nanostructured metal layers. Methods for conducting testing for mechanical (vibrational) and thermocyclic impact that satisfies the requirements for space instruments have been developed.The grid microstructures are formed in a unified technological cycle with the production of ring-holders along the perimeter of the grid, with a square 20 Γ— 20 ΞΌm2Β section of the web and square cells with a size of 1 Γ— 1 mm2. The transparency of each of the grids was more than 90 % for the normal incidence of light. Dimensions of holders and grid microstructures: internal diameters (34, 47, 60) Β± 0.1 mm, external diameters of rings (42, 55, 68) Β± 0.1 mm, respectively. The weight of one grid was less than 50 mg.The test results demonstrated the operability of the developed grid microstructures with multiple thermocyclic actions from –50 to +150 Β°C and vibrational and static overloads specific for space flights. Instruments for plasma measurements in the near of the Earth and in the interplanetary space will comprise six sensors with different angular orientations. This will make it possible to detect ions of cosmic plasma in a solid angle of about 180Β°.Π’Π°ΠΆΠ½Ρ‹ΠΌΠΈ Π·Π°Π΄Π°Ρ‡Π°ΠΌΠΈ соврСмСнных космичСских исслСдований ΡΠ²Π»ΡΡŽΡ‚ΡΡ ΠΈΠ·ΡƒΡ‡Π΅Π½ΠΈΠ΅ ΠΈ Π½Π΅ΠΏΡ€Π΅Ρ€Ρ‹Π²Π½Ρ‹Π΅ наблюдСния процСссов космичСской ΠΈ мСтСорологичСской Β«ΠΏΠΎΠ³ΠΎΠ΄Ρ‹Β». Одним ΠΈΠ· элСктронных ΠΏΡ€ΠΈΠ±ΠΎΡ€ΠΎΠ² для провСдСния Ρ‚Π°ΠΊΠΈΡ… исслСдований являСтся Π΄Π°Ρ‚Ρ‡ΠΈΠΊ ΠΏΠ»Π°Π·ΠΌΡ‹ Π½Π° основС Ρ†ΠΈΠ»ΠΈΠ½Π΄Ρ€Π° ЀарадСя. ЦСль Ρ€Π°Π±ΠΎΡ‚Ρ‹ состояла Π² Ρ€Π°Π·Ρ€Π°Π±ΠΎΡ‚ΠΊΠ΅ конструктивного Π²Π°Ρ€ΠΈΠ°Π½Ρ‚Π° Ρ†ΠΈΠ»ΠΈΠ½Π΄Ρ€Π° ЀарадСя с ΠΏΡ€Π΅Ρ†ΠΈΠ·ΠΈΠΎΠ½Π½Ρ‹ΠΌΠΈ Ρ‡ΡƒΠ²ΡΡ‚Π²ΠΈΡ‚Π΅Π»ΡŒΠ½Ρ‹ΠΌΠΈ (ΡΠ΅Π»Π΅ΠΊΡ‚ΠΈΡ€ΡƒΡŽΡ‰ΠΈΠΌΠΈ) элСмСнтами Π² Π²ΠΈΠ΄Π΅ мСталличСских сСточных микроструктур ΠΈ чСтырСхсСкторным ΠΊΠΎΠ»Π»Π΅ΠΊΡ‚ΠΎΡ€ΠΎΠΌ, Π½Π΅ ΠΈΠΌΠ΅ΡŽΡ‰Π΅Π³ΠΎ Π°Π½Π°Π»ΠΎΠ³ΠΎΠ² Π² ΠΌΠΈΡ€ΠΎΠ²ΠΎΠΉ Ρ‚Π΅Ρ…Π½ΠΈΠΊΠ΅.Для формирования сСточных Π½ΠΈΠΊΠ΅Π»Π΅Π²Ρ‹Ρ… микроструктур Ρ€Π°Π·Ρ€Π°Π±ΠΎΡ‚Π°Π½ процСсс создания с ΠΏΠΎΠΌΠΎΡ‰ΡŒΡŽ Ρ„ΠΎΡ‚ΠΎΠ»ΠΈΡ‚ΠΎΠ³Ρ€Π°Ρ„ΠΈΠΈ ΠΌΠ°Ρ‚Ρ€ΠΈΡ†Ρ‹ ΠΈΠ· нанопористого Π°Π½ΠΎΠ΄Π½ΠΎΠ³ΠΎ оксида алюминия ΠΊΠ°ΠΊ ΠΏΡ€Π΅Ρ†ΠΈΠ·ΠΈΠΎΠ½Π½ΠΎΠΉ Ρ„ΠΎΡ€ΠΌΡ‹ (шаблона) для осаТдСния наноструктурированных мСталличСских слоСв. Π Π°Π·Ρ€Π°Π±ΠΎΡ‚Π°Π½Ρ‹ ΠΌΠ΅Ρ‚ΠΎΠ΄Ρ‹ провСдСния тСстовых испытаний Π½Π° мСханичСскиС (Π²ΠΈΠ±Ρ€Π°Ρ†ΠΈΠΎΠ½Π½Ρ‹Π΅) ΠΈ тСрмоцикличСскиС воздСйствия, ΡΠΎΠΎΡ‚Π²Π΅Ρ‚ΡΡ‚Π²ΡƒΡŽΡ‰ΠΈΠ΅ трСбованиям ΠΊ космичСским ΠΏΡ€ΠΈΠ±ΠΎΡ€Π°ΠΌ.Π‘Π΅Ρ‚ΠΎΡ‡Π½Ρ‹Π΅ микроструктуры сформированы Π² Π΅Π΄ΠΈΠ½ΠΎΠΌ тСхнологичСском Ρ†ΠΈΠΊΠ»Π΅ с ΠΊΠΎΠ»ΡŒΡ†Π°ΠΌΠΈ-дСрТатСлями ΠΏΠΎ ΠΏΠ΅Ρ€ΠΈΠΌΠ΅Ρ‚Ρ€Ρƒ сСтки, с ΠΊΠ²Π°Π΄Ρ€Π°Ρ‚Π½Ρ‹ΠΌ 20 Γ— 20 ΠΌΠΊΠΌ2 сСчСниСм ΠΏΠΎΠ»ΠΎΡ‚Π½Π° ΠΈ ячСйками Ρ€Π°Π·ΠΌΠ΅Ρ€ΠΎΠΌ 1 Γ— 1 ΠΌΠΌ2. ΠŸΡ€ΠΎΠ·Ρ€Π°Ρ‡Π½ΠΎΡΡ‚ΡŒ ΠΊΠ°ΠΆΠ΄ΠΎΠΉ ΠΈΠ· сСток ΠΏΡ€ΠΈ Π½ΠΎΡ€ΠΌΠ°Π»ΡŒΠ½ΠΎΠΌ ΠΏΠ°Π΄Π΅Π½ΠΈΠΈ свСта составила Π±ΠΎΠ»Π΅Π΅ 90 %. Π“Π°Π±Π°Ρ€ΠΈΡ‚Π½Ρ‹Π΅ Ρ€Π°Π·ΠΌΠ΅Ρ€Ρ‹ Π΄Π΅Ρ€ΠΆΠ°Ρ‚Π΅Π»Π΅ΠΉ ΠΈ сСточных микроструктур: Π²Π½ΡƒΡ‚Ρ€Π΅Π½Π½ΠΈΠ΅ Π΄ΠΈΠ°ΠΌΠ΅Ρ‚Ρ€Ρ‹ (34, 47, 60) Β± 0,1 ΠΌΠΌ, внСшниС Π΄ΠΈΠ°ΠΌΠ΅Ρ‚Ρ€Ρ‹ ΠΊΠΎΠ»Π΅Ρ† (42, 55, 68) Β± 0,1 ΠΌΠΌ соотвСтствСнно. Масса ΠΎΠ΄Π½ΠΎΠΉ сСтки составила ΠΌΠ΅Π½Π΅Π΅ 50 ΠΌΠ³.Π Π΅Π·ΡƒΠ»ΡŒΡ‚Π°Ρ‚Ρ‹ испытаний продСмонстрировали Ρ€Π°Π±ΠΎΡ‚ΠΎΡΠΏΠΎΡΠΎΠ±Π½ΠΎΡΡ‚ΡŒ Ρ€Π°Π·Ρ€Π°Π±ΠΎΡ‚Π°Π½Π½Ρ‹Ρ… сСточных микроструктур ΠΏΡ€ΠΈ ΠΌΠ½ΠΎΠ³ΠΎΠΊΡ€Π°Ρ‚Π½Ρ‹Ρ… тСрмоцикличСских воздСйствиях ΠΎΡ‚ –50 Π΄ΠΎ +150 Β°Π‘ ΠΈ Π²ΠΈΠ±Ρ€Π°Ρ†ΠΈΠΎΠ½Π½Ρ‹Ρ… ΠΈ статичСских ΠΏΠ΅Ρ€Π΅Π³Ρ€ΡƒΠ·ΠΊΠ°Ρ…, Ρ…Π°Ρ€Π°ΠΊΡ‚Π΅Ρ€Π½Ρ‹Ρ… ΠΏΡ€ΠΈ космичСских ΠΏΠΎΠ»Π΅Ρ‚Π°Ρ…. Π’ составС ΠΏΡ€ΠΈΠ±ΠΎΡ€ΠΎΠ² для провСдСния ΠΏΠ»Π°Π·ΠΌΠ΅Π½Π½Ρ‹Ρ… ΠΈΠ·ΠΌΠ΅Ρ€Π΅Π½ΠΈΠΉ Π² окрСстности Π—Π΅ΠΌΠ»ΠΈ ΠΈ Π² ΠΌΠ΅ΠΆΠΏΠ»Π°Π½Π΅Ρ‚Π½ΠΎΠΌ пространствС Π±ΡƒΠ΄ΡƒΡ‚ ΠΈΡΠΏΠΎΠ»ΡŒΠ·ΠΎΠ²Π°Π½Ρ‹ ΡˆΠ΅ΡΡ‚ΡŒ Π΄Π°Ρ‚Ρ‡ΠΈΠΊΠΎΠ² с Ρ€Π°Π·Π»ΠΈΡ‡Π½ΠΎΠΉ ΡƒΠ³Π»ΠΎΠ²ΠΎΠΉ ΠΎΡ€ΠΈΠ΅Π½Ρ‚Π°Ρ†ΠΈΠ΅ΠΉ. Π­Ρ‚ΠΎ обСспСчит Π²ΠΎΠ·ΠΌΠΎΠΆΠ½ΠΎΡΡ‚ΡŒ фиксирования ΠΈΠΎΠ½ΠΎΠ² космичСской ΠΏΠ»Π°Π·ΠΌΡ‹ Π² тСлСсном ΡƒΠ³Π»Π΅ ΠΎΠΊΠΎΠ»ΠΎ 180Β°

    Solar wind correlations: Statistical and case studies

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    Recent work on solar wind plasma correlations using data from several widely-separated spacecraft (IMP 8, INTERBALL-I, WIND, and ISEE-3) has shown that, for 6-hour periods, the average plasma correlation is 0.7. The focus of these studies has been directed toward a statistical understanding of gross solar wind correlation behavior. In all correlations examined, lower average correlations are caused by the presence of many points from the low correlation subpopulation; nevertheless, data points from the high correlation population are still present. No single organizational factor has yet been found which adequately separates low-correlation periods from high-correlation periods. Some of the spread in correlations is due to the spatial orientations and dimensions of solar wind structures, and thus to the locatiohal alignments of the spacecraft being correlated, but this does not adequately explain all the good or poor correlations since sometimes three nearby spacecraft show poor correlations, while sometimes three widely-separated spacecraft show good correlations. Thus, in order to understand the underlying physics, detailed investigation of individual cases has been undertaken. These results will be important in assigning quality measures to space weather predictions using satellite measurements taken at L1, for example

    Correlation Dependencesdetermined By Simultaneous

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    Solar wind measurements on board several spacecraft were used to study the two-points correlations of the solar wind plasma structures. The factors having the most influence on the correlation level are the density variability and IMF cone angle. The characteristic length of large solar wind structures is estimated at 500--1000 R E

    Geosynchronous magnetic field responses to fast solar wind dynamic pressure enhancements: MHD field model

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    We performed global MHD simulations of the geosynchronous magnetic field in response to fast solar wind dynamic pressure (Pd) enhancements. Taking three Pd enhancement events in 2000 as examples, we found that the main features of the total field B and the dominant component Bz can be efficiently predicted by the MHD model. The predicted B and Bz varies with local time, with the highest level near noon and a slightly lower level around mid-night. However, it is more challenging to accurately predict the responses of the smaller component at the geosynchronous orbit (i.e., Bx and By). In contrast, the limitations of T01 model in predicting responses to fast Pd enhancements are presented
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