scholarly journals Solar and Interplanetary Dynamics (Symposium Summary)

1980 ◽  
Vol 91 ◽  
pp. 547-552 ◽  
Author(s):  
M. Kuperus
Keyword(s):  
Solar Atmosphere ◽  
Interplanetary Medium ◽  
Temporal Variations ◽  
Magnetic Structures ◽  
Solar Observations ◽  
The Earth ◽  
The Subject ◽  
Physical Phenomena ◽  
Made In

Solar and interplanetary dynamics comprises dynamic and plasma-physical phenomena in the solar atmosphere, the corona and the interplanetary medium in the broadest sense. In this symposium, however, one has essentially tried to restrict the subject matter to the study of the propagation of a disturbance, produced in the solar atmosphere, through the corona and the interplanetary medium. In studying solar and interplanetary dynamical phenomena we find ourselves in the unique position, with respect to other astrophysical disciplines, to be able to relate solar observations obtained with the highest possible spectral, spatial and time resolution with in situ measurements made in the interplanetary medium. It has now turned out that the two fundamental questions to be answered are:a) How does the medium in between the sun and the earth and beyond the earth's orbit, the socalled heliosphere, look like? Does a basic undisturbed heliosphere actually exist, and is one able to model its observed magnetic structures and plasma motions with their spatial and temporal variations?b) How and where in the solar atmosphere are the disturbances generated and what are the characteristic time scales, geometries and energies involved?

scholarly journals Géomorphologie : géographie globale – géographie totale – associations internationales

2005 ◽  
Vol 8 (16) ◽  
pp. 199-218 ◽  
Author(s):  
Louis-Edmond Hamelin
Keyword(s):  
United States ◽  
Subject Matter ◽  
International Association ◽  
The United States ◽  
Physical Sciences ◽  
Geographical Union ◽  
International Geographical ◽  
The Earth ◽  
The Subject ◽  
Made In

The great advances that geomorphology has made in recent years make necessary a critical re-examination of the relationships between this science and the field of geography. Is geomorphology truly geographical ? And if not, how can it become so ? Geomorphology has its roots in geology and was, of course, not designed to meet the specific needs of geographers. Under the leadership of W. M. Davis, geographers eventually adopted the study of geomorphology but did Utile to adapt it to particular purposes of their discipline. Most geographers can never aspire to true excellence in geomorphology because of their generally inadequate training in the physical sciences. We have found that most geographers tend to fall into one of four groups : 1. Those who consider themselves to be geomorphologists (about one-fourth of all geographers) ; 2. Those who just try to be informed in geomorphology ; 3. Those who ignore the existence of geomorphology ; 4. The « complete » geographer who practices a « functional » geomorphology. It also appears that the majority of geographers do not consider land-man relations to be their principal field of interest. The definition that we as geographers give to geography tends to sanction the kind of geography that we are capable of doing. For example, the classical géographie globale, which is characterized by an explanatory description of a complex of physical and human eclectic elements, does not normally require either a « complete » or a genetic geomorphology ; also, complex techniques of geomorphological investigation are not essential. Of greater importance is a geomorphology'-which is functional to geography and which will help us to understand better man's distribution and activities on the surface of the earth. This partial or « functional » geomorphology has achieved its greatest development in France (as an integral part of géographie globale) and is practised by a large number of geographers. Géographie totale, an expression which refers more to the subject matter of this geography than to its methodology, is an ensemble of specialized yet inter-related disciplines (one of which is geomorphology). This pluralistic geography daims many more adherents than does géographie globale. Géographie totale allows us to study all aspects of what is now called geomorphology (but which may eventually be termed « cosmomorphology  »). This new geomorphology is based on geophysical laws and is strictly quantitative. It is an integral part of the physical sciences but this does not mean that it is automatically divorced from man. Scientists of both the United States and the U. S. S. R. are actively engaged in this new geomorphology. We believe that it would be mutually advantageous for both the « functional » and the « complete » geomorphologists to group themselves into a new international association. To achieve this end we urge that the structures of the international Geographical Union be modified or that an « International Association of Geomorphology » be founded.

VI. The Sun as a Star

1988 ◽  
Vol 20 (1) ◽  
pp. 102-106
Author(s):  
L.E. Cram
Keyword(s):  
Time Scales ◽  
Spatial Extent ◽  
The Sun ◽  
Distinguishing Characteristic ◽  
X Ray ◽  
Spatially Resolved ◽  
Solar Observations ◽  
The Earth ◽  
The Subject

Studies of the global (spatially unresolved) output from the sun are important for two main reasons: (1) the global solar output directed towards the earth plays a central role in solar-terrestrial relations, and (2) global solar observations form a link between (neccessarily) global observations of stars and the more refined spatially resolved observations which are available for the sun. This report covers both aspects (insofar as they concern the sun), using the time-scales of various phenomena as a basic distinguishing characteristic. Note that certain studies of spatially unresolved solar output have not been discussed, since they are actually directed toward the investigation of phenomena of strictly limited spatial extent [e.g. radiospectrograph observations (e.g. Wiehl et al. 1985) and studies of X-ray bursts (e.g. Thomas et al. 1985)]. Collections of relevant papers may be found in De Jager and Svestka (1985) and Labonte et al. (1984), while a review of germane stellar work is available in Baliunas and Vaughan (1985) and solar-terrestrial work in Donnelly and Heath (1985). A comprehensive summary of the subject by Hudson will appear soon in Review of Geophysics and Planetary Physics.

scholarly journals Simultaneous Observations of Large Enhancement In the Flux of PSR 0950+08 Over a 200 km Baseline at 103 MHz

1996 ◽  
Vol 160 ◽  
pp. 477-478
Author(s):  
A.D. Bobra ◽  
Harish Chandra ◽  
Hari Om Vats ◽  
P. Janardhan ◽  
G.D. Vyas ◽  
...  
Keyword(s):  
Solar Wind ◽  
Interplanetary Medium ◽  
Temporal Variations ◽  
X Rays ◽  
Physical Research Laboratory ◽  
X Ray ◽  
The Earth ◽  
Wind Velocities ◽  
Electro Magnetic ◽  
Galactic Radio

Interplanetary Scintillation (IPS) is a diffraction phenomenon in which coherent electro-magnetic radiation, from a distant radio source, passes through the solar wind, which is a turbulent refracting medium, and suffers scattering. This results in random temporal variations of the signal intensity (scintillation) at the Earth. IPS observations to monitor the interplanetary medium (IPM), to measure solar wind velocities in the directions of a number of compact extra-galactic radio sources and to estimate the angular diameters of their compact components have been carried out for many years at 103 MHz using the IPS facility (Alurkar et al. 1989) of the Physical Research Laboratory (PRL), Ahmedabad, India. Over a period of approximately 10 years of such observations, it has been seen that PSR 0950+08 has always remained well within the noise level. We observed a sudden enhancement in its flux (Deshpande et al. 1994) on 29 July, 1992. The ionospheric observations which are being carried out on a regular basis at PRL using an ionosonde also recorded a steep increase in the absorption index Fmin, which is an indicator of the excess ionization produced due to X-rays. During this period, the Sun was exceptionally quiet, thereby raising the question about the origin of the X-ray flux responsible for the observed steep rise in Fminduring the transit of PSR 0950+08.

scholarly journals COMMISSION 12: SOLAR RADIATION AND STRUCTURE

2008 ◽  
Vol 4 (T27A) ◽  
pp. 104-123
Author(s):  
Valentin Martínez Pillet ◽  
Alexander Kosovichev ◽  
John T. Mariska ◽  
Thomas J. Bogdan ◽  
Martin Asplund ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Internal Structure ◽  
Solar Atmosphere ◽  
The Sun ◽  
Magnetic Structures ◽  
Structure And Dynamics ◽  
In Parenthesis ◽  
Magnetic Network ◽  
Made In

Commission 12 encompasses investigations on the internal structure and dynamics of the Sun, mostly accessible through the techniques of local and global helioseismology, the quiet solar atmosphere, solar radiation and its variability, and the nature of relatively stable magnetic structures like sunspots, faculae and the magnetic network. A revision of the progress made in these fields is presented. For some specific topics, the review has counted with the help of experts outside the Commission Organizing Committee that are leading and/or have recently presented relevant works in the respective fields. In this cases the contributor's name is given in parenthesis.

scholarly journals SOHO – an Observatory to Study the Solar Interior and the Solar Atmosphere

1990 ◽  
Vol 123 ◽  
pp. 277-284
Author(s):  
A.I. Poland ◽  
V. Domingo
Keyword(s):  
Solar Wind ◽  
Solar Atmosphere ◽  
Joint Venture ◽  
Solar Interior ◽  
Lagrangian Point ◽  
Heliospheric Observatory ◽  
Heating Mechanism ◽  
The Earth ◽  
Soho Spacecraft

AbstractThe Solar and Heliospheric Observatory, Soho, is a joint venture of ESA and NASA. The main objectives of Soho are: a) the study and understanding of solar coronal phenomena; and b) the study of the solar structure and interior dynamics from its core to the photosphere. The primary goals of the coronal and solar wind studies are to understand the coronal heating mechanism and its expansion into the solar wind.These goal will be achieved both by remote sensing of the solar atmosphere with high resolution spectrometers and telescopes and by “in situ” measurement of the composition and energy of the resulting solar wind and the energetic particles that propagate through it. The structure and interior dynamics will be studied by helio-seismological methods and the measurement of solar irradiance variations. The Soho spacecraft will be three-axis stabilized and located in a halo orbit around the L1 Lagrangian point (approximately 1% of the distance from the Earth to the Sun). It is currently scheduled for launch in July 1995.

A DENSITY DETERMINATION BY UNDERGROUND GRAVITY MEASUREMENTS IN MICHIGAN

Geophysics ◽  
1963 ◽  
Vol 28 (4) ◽  
pp. 663-664
Author(s):  
George B. Secor ◽  
Howard J. Meyer ◽  
William J. Hinze
Keyword(s):  
Sedimentary Rocks ◽  
Michigan Basin ◽  
Established Method ◽  
Density Determination ◽  
The Earth ◽  
Gravity Measurements ◽  
Made In

The in situ density of an 1,100‐ft section of Paleozoic sedimentary rocks in the southeastern portion of the Michigan Basin was determined by the established method of observing the change in gravity over a known vertical interval within the earth. The measurements were made in and adjacent to the Detroit Mine (Sec. 33, T2S, R11E) of the International Salt Company in Detroit, Michigan, which is the only deep shaft mine in the Southern Peninsula of Michigan.

scholarly journals XVII. On the curvature of the Indian arc

1860 ◽  
Vol 10 ◽  
pp. 648-650
Keyword(s):  
Appreciable Effect ◽  
Present Communication ◽  
The Earth ◽  
The Subject ◽  
The Mean ◽  
Calculated Amplitude ◽  
Made In

This communication completes the series of the author’s papers on the subject of the Indian Arc. He commences by recapitulating the chief results of his former calculations, and adverting to the attempt which he made in his former papers to explain the difficulty which those calculations brought to light, namely, that the amplitudes of the arcs from Kaliana to Kalianpur and from Kalianpur to Damargida, determined geodetically, were so little in excess as they proved to be of the same amplitudes determined astronomically,—a difficulty which he endeavoured to get over by attributing to the Indian Arc a curvature different from that corresponding to the mean meridian of the earth. In the present communication, introducing the condition that the length of the chord of the arc must be the same in both the ellipses, the local and the mean, drawn through the stations at the extremities of the arc, he demonstrates that no change in the curvature of the arc, within reasonable and indeed within wide limits, can have any appreciable effect on the calculated amplitude.

Rendez vous with Saturn's rings

1984 ◽  
Vol 75 ◽  
pp. 743-759 ◽  
Author(s):  
Kerry T. Nock
Keyword(s):  
Solar Energy ◽  
Electric Propulsion ◽  
Power Source ◽  
Propulsion System ◽  
Low Thrust ◽  
Ring Plane ◽  
The Earth ◽  
Total Impulse ◽  
Saturn's Rings

ABSTRACTA mission to rendezvous with the rings of Saturn is studied with regard to science rationale and instrumentation and engineering feasibility and design. Future detailedin situexploration of the rings of Saturn will require spacecraft systems with enormous propulsive capability. NASA is currently studying the critical technologies for just such a system, called Nuclear Electric Propulsion (NEP). Electric propulsion is the only technology which can effectively provide the required total impulse for this demanding mission. Furthermore, the power source must be nuclear because the solar energy reaching Saturn is only 1% of that at the Earth. An important aspect of this mission is the ability of the low thrust propulsion system to continuously boost the spacecraft above the ring plane as it spirals in toward Saturn, thus enabling scientific measurements of ring particles from only a few kilometers.

Direct Observations of the Epitaxial Growth of Sputtered Ag on Si

1973 ◽  
Vol 31 ◽  
pp. 122-123
Author(s):  
J. S. Maa ◽  
Thos. E. Hutchinson
Keyword(s):  
Epitaxial Growth ◽  
Film Growth ◽  
Ion Beam ◽  
Ion Beam Sputtering ◽  
Microscopy Technique ◽  
Direct Observations ◽  
In Situ Electron Microscopy ◽  
Beam Sputtering ◽  
The Subject

The growth of Ag films deposited on various substrate materials such as MoS2, mica, graphite, and MgO has been investigated extensively using the in situ electron microscopy technique. The three stages of film growth, namely, the nucleation, growth of islands followed by liquid-like coalescence have been observed in both the vacuum vapor deposited and ion beam sputtered thin films. The mechanisms of nucleation and growth of silver films formed by ion beam sputtering on the (111) plane of silicon comprise the subject of this paper. A novel mode of epitaxial growth is observed to that seen previously.The experimental arrangement for the present study is the same as previous experiments, and the preparation procedure for obtaining thin silicon substrate is presented in a separate paper.

“The heart above the ruins”: Miriam Waddington’s Poetry, the Spanish Civil War, and Jewish Canadian Literature

1969 ◽  
Vol 26 ◽  
Author(s):  
Emily Robins Sharpe
Keyword(s):  
Human Rights ◽  
World War Ii ◽  
Civil War ◽  
Spanish Civil War ◽  
World War ◽  
Canadian Literature ◽  
The Earth ◽  
The Holocaust ◽  
The Subject ◽  
War Consequences

The Jewish Canadian writer Miriam Waddington returned repeatedly to the subject of the Spanish Civil War, searching for hope amid the ruins of Spanish democracy. The conflict, a prelude to World War II, inspired an outpouring of literature and volunteerism. My paper argues for Waddington’s unique poetic perspective, in which she represents the Holocaust as the Spanish Civil War’s outgrowth while highlighting the deeply personal repercussions of the war – consequences for women, for the earth, and for community. Waddington’s poetry connects women’s rights to human rights, Canadian peace to European war, and Jewish persecution to Spanish carnage.

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