Документы 11 - 20 из 1378
11.

Количество страниц: 2 с.

Development of DPY currents and auroral convection electrojets during the growth phase of a substorm accocding to geomagnetic observations data : [тезисы докладов] / R. N. Boroev, A. V. Moiseyev, S. I. Solovyev, M. Engebretson, K. Yumoto // Physics of auroral phenomena : 26th annual seminar, 25-28 February 2003 : abstacts. – 2003. – P. 21.

12.

Количество страниц: 4 с.

By using data treatment results of mid-latitude geomagnetic variations, the significant increase of the local current system intensity with the eastern direction current system, arising near the meridian of expected substorm center ~10-30 min before the break-up onset, has been found. A comparison of longitudinal sizes of two current system, forming the substorm disturbance before and after the onset of the substorm expansion phase, has been carried out. The longitudinal size of the current loop of the substorm growth phase is nearly twice as small as azimuth scale of the substorm current wedge, and the current strength is as week as 2.7-12 times.

Boroyev, R. N. Local increase of field-aligned current intensity before a substorm onset / R. N. Boroyev, V. A. Velichko, D. G. Baishev // Proceedings of the Fifth International Conference on Substorms : 16-20 May 2000 Congress Centre of the Arctic and Antarctic Research Institute, St. Petersburg, Russia. − Noordwijk, Netherlands : European Space Agency, 2000. − P. 279-282.

13.

Количество страниц: 4 с.

The NE Siberia is known as a region with supreme finds of mammoth fauna and the Ice Age occupation sites preserved in permafrost. The frozen grounds contribute to preservation of the most unique paleontological, palaeobotanical and organic archaeological material exposed from the primary cryolithic geological layers of the late Pleistocene riverine valleys. Investigations carried out in the upper and middle reaches of the Kolyma River basin of the Republic of Sakha (Yakutia) in 2013–2018 brought new evidence on the natural habitats of the Paleolithic peopling of this region with the earliest findings 14C-dated >44 000 years ago. The field data allow the reconstruction of sequenced environmental conditions for the last tens of thousand of years and the modeling of human biological and cultural adaptation to the mid-Last Glacial and the extreme Last Glacial ecosystems within modern forest-tundra.
Северо-Восток Сибири известен как регион c важными находками мамонтовой фауны и стоянок древних людей последнего ледникового периода, сохраненных в вечной мерзлоте. Минусовые термические условия содействуют сохранению уникальных палеонтологических, палеоботанических и органических археологических материалов, краткосрочно вымытых на поверхность из первичных криолитических геологических слоев древних речных долин эпохи плейстоцена. Проведенные работы в бассейне верхнего и среднего течения реки Колыма в пределах Республики Саха (Якутия) в 2013–2018 гг. принесли новые, подтвержденные радиоуглеродными датами свидетельства обитания человека эпохи палеолита в этом регионе более чем 44 тыс. л. н. Данные полевых исследований позволяют провести реконструкцию природных условий последних десятков тысяч лет и моделирование биологической и культурной адаптации человека к экстремальным условиям последнего интергляциала и гляциала в поясах современной лесотундры.

The mid-last glacial habitats of the palaeolithic peopling of the Kolyma basin, Nortn-East Yakutia=Следы обитания человека эпохи палеолита в интергляциале бассейна Колымы, северо-восток Якутии / J. Chlachula, M. Yu. Cheprasov, T. F. Obada, S. E. Grigoriev // V Северный археологический конгресс, 11-14 декабря 2019, Ханты-Мансийск : тезисы докладов. – Екатеринбург ; Ханты-Мансийск : Альфа-Принт, 2019. – С. 58-60.

14.

Количество страниц: 3 с.

In the accompanying Papers 1 and 2 was fulfilled timing of the 20.11.05 super-storm. Were detected 4 various types of the magnetospheric disturbances observable at southward IMF, and presented a new model of the field-aligned currents density spatial distribution in the polar ionosphere. In this paper are described the ionospheric convection systems, characteristic for the above various types. Are mentioned the mesoscale spatial inhomogeneities, which are observed more or less regularly but have not been mentioned in the past literature.

Dynamics of the Ionospheric Convection Systems Observed during The Super-Storm on Nov. 20, 2003 / M. Foerster, V. M. Mishin, T. I. Saifudinova, A. D. Bazarzhapov, L. A. Sapronova, V. P. Golovkov, P. Stauning, J. Watermann, and S. I. Solovyev // Solar Extreme Events Fundamental Science and Applied Aspects Nor-Amberd, Armenia 26-30 September 2005 : proceedings of the Second International Symposium / edited by A. Chilingarian and G. Karapetyan. − Erevan : Cosmic Ray Division, Alikhanyan Physics Institute, 2006. − P. 83-85.

15.

Количество страниц: 4 с.

The results of the hydroxyl and oxygen molecules rotational temperature measurements during two observational seasons 1999-2001 at Maymaga station (φ=63°N;λ=129.50°E) are presented. The rotational temperatures of OH(6,2) and O2 (0,1) bands have been measured with the infrared spectrograph equipped by the cooled CCD registration system. It is shown that the amplitude of seasonal change of hydroxyl rotational temperature is greater than the molecular oxygen variation. OH temperatures have been systematically higher the O2 ones during winter. An abrupt decrease of the O2 intensity connected with the springtime transition of the atmospheric circulation is found in both time series. For the first time a change of the temperature vertical gradient sign caused by mesopause height displacemet to a higher (winter) level was shown in the data of August-September 2001.

Gavrilyeva, G. A. Measurements of the mesosphere temperature by two molecular emissions in Yakutsk (62°N, 129,5°E) / G. A. Gavrilyeva // Physics of auroral phenomena : proceedings of the 26th annual seminar, 25 - 28 February 2003. – 2003. – P. 198-201.

16.

Количество страниц: 14 с.

The spatial evolution of vortex-like flow structures induced by a negative sudden impulse (SI-) is studied on the basis of SuperDARN King Salmon HF radar (KSR) with other ground and satellite data. A large dip in the solar wind density induced a fairly large SI- with a SYM-H amplitude of ~40 nT. The SI-induced ionospheric flow signatures in the evening sector (MLT ~ 19 h) were observed by KSR as a westward flow associated with the preliminary impulse (PI) followed by a more intense eastward flow with the main impulse (MI) in the sub-auroral region on the magnetic latitude ~60-70 deg, consistent with the local ground magnetic field observations. Following the first PI-MI flow sequence, KSR saw a second and possibly third sequence of flow variation which were much smaller in flow amplitude than the first pair but showed qualitatively very similar flow variations and latitudinal/longitudinal propagation characterististics/ These observations can be interpreted as aftershocks of the first PI-MI; the same sequence of vortices and field-aligned currents were generated and then drifted anti-sunward with the same mechanism, namely the pumping motion of dayside magnetosphere. These results are qualitatively consistent with predictions suggested by recent numerical simulations.

Evolution of negative SI-induced ionospheric flows observed by SuperDARN King Salmon HF radar / T. Hori, A. Shinbori, N. Nishitani, T. Kikuchi, S. Fujita, T. Nagatsuma, O. Troshichev, K. Yumoto, A. Moiseyev, and K. Seki // Journal of Geophysical Research: Space Physics. – 1978. – 2012 (December), vol. 117, N 12. – P. A12223.
DOI: 10.1029/2012JA018093

17.

Количество страниц: 6 с.

This paper uses the plasma data from Cluster and TC-1 and geomagnetic data to study the geomagnetic signatures of current wedge produced by fast-flow braking in the plasma sheet. The three fast flows studied here occurred in a very quiet background and were accompanied by no (or weak) particle injections, thus avoiding the influences from other disturbances. All the geomagnetic signatures of a substorm current wedge can be found in geomagnetic signatures of a current system produced by the braking of fast flows, indicating that the fast flows can produce a complete current wedge which contains postmidnight downward and premidnight upward field-aligned currents, as well as a westward electrojet. The Pi2 precursors exist not only at high latitudes but also at midlatitudes. The starting times of midlatitude Pi2 precursors can be identified more precisely than those of high-latitude Pi2 precursors, providing a possible method to determine the starting time of fast flows in their source regions. The AL drop that a bursty bulk flow produces is proportional to its velocity and duration. In three cases, the AL drops are 200 nT, whether a substorm can be triggered depends mainly on the conditions of the braking regions before fast flows. The observations of solar wind before the three fast flows suggest that it is difficult for the fast flows to trigger a substorm when the interplanetary magnetic field Bz of solar wind is weakly southward.

Geomagnetic signatures of current wedge produced by fast flows in a plasma sheet / Jin-Bin Cao, Chunxiao Yan, Malcolm Dunlop, Henri Reme, Iannis Dandouras, Tielong Zhang, Dongmei Yang, Alexey Moiseyev, Stepan I. Solovyev, Z. Q. Wang, A. Leonoviche, N. Zolotukhina, and V. Mishin // Journal of Geophysical Research: Space Physics. – 1978. – 2010 (August), vol. 115, N 8. – P. A08205.

18.

Количество страниц: 4 с.

Long-lasting ground based measurements of a polarization jet (PJ) by the latitudinal chain of ionospheric stations in Yakutia (3 < L < 5; MLT = UT + 9 h) and by 5 subauroral Russian stations were analyzed. A number of cases were found when PJ was recorded simultaneously with energetic ion observations by AMPTE/CCE and INTERBALL 2. The data comparison shows that at least in the considered cases of strong magnetic substorms, PJ was accompanied by strong injection of ions with the energy of ~20-50 keV and intensity of ~10 cm-² c-¹ sr-¹keV-¹. Close to the injection region in the near midnight sector no ion dispersion was observed, but in the evening sector nose events were detected. In accordance with the mechanism suggested by Southwood and Wolf (JGR, 1978, 83, 5227) PJ was observed near the equatorial boundary of energetic ion penetration into the magnetosphere. Measurements by ionosonds at different longitudes show that the westward velocity of the frontt of PJ development is close to the gradient drift velocity of 20 keV ions (forming nose events). Thus, the physical mechanism of PJ formation due to energetic ion injection during a strong substorm burst is experimentally confirmed. Satellite measurements show that in the near midnight sector energetic ions reach the shell L=3.0 in 20-30 minutes after a substorm commencement with AE>500 nT.

Formation of polarization jet during injection of ions into the inner magnetosphere / V. L. Khalipov, Yu. I. Galperin, A. E. Stepanov, E. D. Bondar // Physics of auroral phenomena : proceedings of the 25th annual seminar, Apatity, 26 February – 1 March 2002. – 2002. – P. 43-46.
DOI: 10.1016/S0273-1177(03)00016-4

19.

Количество страниц: 4 с.

The geomagnetic manifestation of sudden impulse (SI) caused by a sharp decrease of the solar wind dynamic pressure due to the plasma density reduction is considered. The observational data of the magnetometer world network have been analysed. The propagation velocities of the SI signal in the meridional direction by using data of the horizontal component of geomagnetic field in the high-latitude region have been calculated. It is found that at a sharp decrease of the solar wind density the meridional propagation of the SI signal is in the northern direction. In this case, on the day side the propagation velocity is constant but there is a tendency of its increasing in the MLT morning sector. It has been established that the meridional propagation velocity of the SI signal at a sharp decrease of the solar wind density depends on the geomagnetic latitude, i.e. with the rise of latitude the velocity in the auroral zone decreases and in the polar cap it increases.

High-latitude peculiarities of the geomagnetic SI impulse propagation meridional velocity during sharp decrease of solar wind density / G. A. Makarov, D. G. Baishev, A. V. Moiseyev, S. I. Solovyev, V. A. Pilipenko, M. J. Engebretson, K. Yumoto // Proceedings of the Fifth International Conference on Substorms : 16-20 May 2000 Congress Centre of the Arctic and Antarctic Research Institute, St. Petersburg, Russia. − Noordwijk, Netherlands : European Space Agency, 2000. − P. 523-526.

20.

Количество страниц: 1 с.

Makarov, G. A. Propagation velocities of geomagnetic sudden impulses caused by sharp changes jf solar wind dinamic pressure at high latitudes / G. A. Makarov, V. Moiseev, and S. I. Solovyev // The First S-Ramp Conference, October 2-6, 2000: Sapporo, Japan. – Sapporo, 2000. – P. 122.