On the relationship of the polar cap current system to the north-south component of the interplanetary magnetic field

1979 ◽  
Vol 84 (A6) ◽  
pp. 2567 ◽  
Author(s):  
James L. Horwitz ◽  
S.-I. Akasofu
1982 ◽  
Vol 60 (3) ◽  
pp. 349-356 ◽  
Author(s):  
J. S. Murphree ◽  
C. D. Anger ◽  
L. L. Cogger

Optical images of the polar cap region at both 5577 and 3914 Å obtained from 1400 km above the earth have been used to study the relationship between polar cap and oval aurora during periods when the interplanetary magnetic field is strongly northward, i.e., B2 > 3.5 nT. When this rather rare condition occurs, the distinction between the two types of aurora is no longer as clear as depicted on the basis of statistical definitions of the auroral oval. Diffuse, weak emission can fill in the region between the auroral oval and discrete auroral features in the polar cap. The polar cap discrete features can appear very similar to auroral oval arcs in intensity, intensity ratio, and structure. Even more striking are the situations where discrete polar cap features merge with oval auroras. From this study it is concluded that under conditions of large positive B2 the region of closed magnetic field lines can expand poleward to occupy much of the high latitude region.


2019 ◽  
pp. 42-44
Author(s):  
I.V. GUSAROV ◽  
V.A. OSTAPENKO ◽  
T.V. NOVIKOVА

Впервые в мире создана популяция зубров на территории 60 градусов северной широты. В новых климатических условиях разведения и сохранения зубров определены и проанализированы факторы существования вида на севере Европейской части РФ. Выявлены признаки, динамика численности, которые являются составной частью системы, предназначенной для управления биоразнообразием. Интродукция, являясь процессом введения в экосистему нехарактерных для нее видов, может усиливать изменения биоценозов как положительно, так и отрицательно. Насколько быстро и успешно проходит процесс адаптации заселенного вида, и усматривается его влияние на окружающую среду зависит дальнейшее существование зубров и в целом биоразнообразия. В статье обсуждаются вопросы взаимоотношения зубров с другими видами копытных и хозяйственной деятельностью человека, а также дальнейшим использованием зубров в сельскохозяйственном производстве. Пластичность зубров, выявление изменений и их анализ при вселении видов в новые условия обитания необходимы не только для определения развития или деградации биоценозов и в целом экосистемы, но и прогноза социально-экономических последствий интродукции как одного из методов сохранения редких и исчезающих видов фауны.For the first time in the world, a bison population has been created in an area of 60 degrees north latitude. In the new climatic conditions of breeding and preservation of bison, the factors of the species existence in the north of the European part of the Russian Federation are identified and analyzed. The signs, dynamics of abundance, which are an integral part of the system designed to manage biodiversity are identified, since the preservation of biological diversity on the planet is one of the main problems of our time. Introduction, being the process of introducing non-typical species into an ecosystem, can enhance changes in biocenoses, both positively and negatively. The question posing sounds especially when it comes to such a large hoofed animal as the European bison. How quickly and successfully the process of adaptation of the universe takes place and its environmental impact is seen depends on the continued existence of bison and biodiversity in general. The article discusses the relationship of bison with other types of ungulates and human activities, as well as the further use of bison in agricultural production. How these issues will be resolved positively depends on the future of these animals. Thus, the plasticity of bison, the identification of changes and their analysis, with the introduction of species into new habitat conditions is necessary not only to determine the development or degradation of biocenoses and the ecosystem as a whole, but also to predict the socio-economic consequences due to the introduction as one of the methods of preserving rare and endangered species of fauna.


Author(s):  
Debi Angelina Br. Barus

This study aims to determine the relationship of work values with the Batak Toba ethnic. This research was conducted at the Mobile Brigade Unit of the North Sumatra Regional Police. The subjects in this study were 45 people. This study uses a quantitative description approach. The results of the study are to find that hamoraon, hagabeon and hasangapon (3H) are in line with the principle of the work value of Brimob members. 3H is the peak achievement of individual Toba Batak ethnic work value in the mobile brigade unit of the North Sumatra regional police. Keyword: Work value, Batak Toba Etnic   Penelitian ini bertujuan untuk mengetahui hubungan nilai kerja dengan etnis Batak Toba. Penelitian ini dilakukan di Satuan Brigade Mobile Kepolisian Daerah Sumatera Utara. Subjek dalam penelitian ini adalah 45 orang. Penelitian ini menggunakan pendekatan kuantitatif deskripsi. Hasil penelitian adalah menemukan bahwa hamoraon, hagabeon dan hasangapon (3H) sejalan dengan prinsip nilai kerja pada satuan anggota Brimob. 3H merupakan puncak pencapaian dari nilai kerja individu yang beretnis Batak Toba di satuan brigade mobile kepolisian daerah Sumatera Utara. Kata Kunci: Nilai kerja, Etnis Batak Toba


2000 ◽  
Vol 18 (8) ◽  
pp. 887-896 ◽  
Author(s):  
P. T. Jayachandran ◽  
J. W. MacDougall

Abstract. Central polar cap convection changes associated with southward turnings of the Interplanetary Magnetic Field (IMF) are studied using a chain of Canadian Advanced Digital Ionosondes (CADI) in the northern polar cap. A study of 32 short duration (~1 h) southward IMF transition events found a three stage response: (1) initial response to a southward transition is near simultaneous for the entire polar cap; (2) the peak of the convection speed (attributed to the maximum merging electric field) propagates poleward from the ionospheric footprint of the merging region; and (3) if the change in IMF is rapid enough, then a step in convection appears to start at the cusp and then propagates antisunward over the polar cap with the velocity of the maximum convection. On the nightside, a substorm onset is observed at about the time when the step increase in convection (associated with the rapid transition of IMF) arrives at the polar cap boundary.Key words: Ionosphere (plasma convection; polar ionosphere) - Magnetospheric physics (solar wind - magnetosphere interaction)


1961 ◽  
Vol 39 (2) ◽  
pp. 350-366 ◽  
Author(s):  
B. K. Bhattacharyya

The characteristics of the magnetic field components at Agincourt have been calculated for a current system produced by an electric dipole located in the region of auroral activity near Ottawa. It is noted that, irrespective of the orientation of the dipole, the horizontal magnetic field component rotates in the clockwise and anticlockwise senses for motion of the dipole towards the east and the west respectively, when the dipole is situated in the north half of the sky as seen from the observing station.Next, the magnetograms obtained at Agincourt have been studied at those times of the night when auroral activity was recorded in the all-sky camera photographs at Springhill near Ottawa. It is noted that the horizontal magnetic field describes a loop during a particular phase of auroral activity because of its gradual growth and decay. The distributions of clockwise and anticlockwise rotations with respect to local time are found to be very similar in many respects to those of auroral motions to the east and west respectively. The sense of rotation of the loop is predominantly anticlockwise in the early part of the night and clockwise in the late hours of the night.It is found that eastward and westward orientations of the dipole are the most probable ones. The direction of movement and the initial location of the predominant auroral form in the sky are found to tally well with those of the dipole deduced from a study of the magnetograms.It seems that there is a time sequence relationship between successive phases of auroral activity and changes of characteristics of the loops described by the horizontal magnetic field vector. The area of a loop and the maximum magnitude of the field vector in the loop appear to be related to the brightness and horizontal extent of the auroral forms.


2017 ◽  
Vol 61 (2) ◽  
pp. 379-402
Author(s):  
ANDREW MCKENZIE-MCHARG

AbstractIn 1789 in Leipzig, a slim pamphlet of 128 pages appeared that sent shock waves through the German republic of letters. The pamphlet, bearing the title Mehr Noten als Text (More notes than text), was an ‘exposure’ whose most sensational element was a list naming numerous members of the North German intelligentsia as initiates of a secret society. This secret society, known as the German Union, aimed to push back against anti-Enlightenment tendencies most obviously manifest in the policies promulgated under the new Prussian king Frederick William II. The German Union was the brainchild of the notorious theologian Carl Friedrich Bahrdt (1741–92). But who was responsible for the ‘exposure’? Using material culled from several archives, this article pieces together for the first time the back story to Mehr Noten als Text and in doing so uncovers a surprisingly heterogeneous network of Freemasons, publishers, and state officials. The findings prompt us to reconsider general questions about the relationship of state and society in the late Enlightenment, the interplay of the public and the arcane spheres and the status of religious heterodoxy at this time.


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