bluuebunny/crossref_metadata_2025_split huggingface dataset:
Concluding remarks, session 1: Instabilities and irregularities
Authors: Reid George C. 
Published: February 2008

The topic of instabilities and irregularities is a comparatively recent field, in which a great deal of insight has been developed through interdisciplinary contacts between ionospheric and plasma physicists. Historically, the landmark year for the opening of the field was 1963, which saw the independent development by Farley [1963] and Bunemann [1963] of the theory of the two‐stream instability (now generally accepted as the cause of the Type I electro jet irregularities), and the development by Simon [1963] and Hoh [1963], in a laboratory‐plasma context, of what is now variously known as the gradient‐drift, crossfield, or E×B instability (which is becoming accepted as the source of Type II irregularities). In all fairness, however, it is worth remembering that Martyn [1959] had earlier published a qualitative description of the gradient‐drift instability and its possible application to ionospheric spread‐F.Since 1963, a great deal of effort has gone into studying the application of these instabilities to the E region, particularly in the equatorial electro jet, but also more recently in the auroral electro jet, where conditions are much more complicated. As shown by several of the papers presented at this conference, we have come a long way since the early days, when only linear theory was available and all one could do was to predict thresholds for the instability. Unfortunately, as is usual when knowledge increases, the picture has also become somewhat fuzzier and less distinct than it was: even the distinction between the instabilities is not as clear as it was, since essentially the same equations are used to describe both, and the irregularities they create feed back on each other. It is also now clear that much of the time we are in fact seeing secondary irregularities, at least at the frequencies commonly used in radar observations. These irregularities are generated as nonlinear consequences of the growth of the primary irregularities, which may for the most part be visible only at much lower radio frequencies, such as those used by ionosondes.
Analysis of mode conversion phenomena in a non‐uniform parallel plate wave guide (Summary)
Authors: Henrot Denis M. , Wait James R. 
Published: February 2008

A coupled mode analysis of a parallel plate wave guide with non‐uniform impedance boundaries is presented. Closed form solutions for the first order estimates of the modal amplitude coefficients are obtained assuming small variations. An analytical comparison with an exact mode‐matching solution in the case of a stepwise change of the lower wall impedance is given and verified numerically. As an extension of the method, a wave guide with perfectly conducting but rough walls is analyzed. The possibility of selective mode coupling is pointed out.Full article is available on microfiche. Order from American Geophysical Union, 2000 Florida Avenue, N.W., Washington, D. C. 20009. Document S81‐002; $1.00. Payment must accompany order.
Remarks upon professor Rücker's paper and Wilde's magnetarium
Authors: Bauer L. A. 
Published: February 2008

I am constrained to add a few remarks upon the foregoing paper and the interpretation to be put upon the results derived from the “Magnetarium.” Professor Rücker admits that Wilde's results must be received with great caution, and that the conditions under which the experiments were performed are open to legitimate criticism. As I have already had occasion in another connection to point out some of the errors to which “the Magnetarium” results are liable, I shall not enter again upon this matter, but simply accept Wilde's observational results as correct, and endeavor to show what interpretation is to be put upon them.As Professor Rücker states, “The magnetic field of the earth may be regarded as that primarily due to a uniformly magnetized globe disturbed by some secondary causes.” Furthermore, the result of recent investigations has been that this field originates practically from causes within the earth's crust, and can be referred to a potential. The total magnetic potential on the earth's surface can then be represented by the following terms:V = Vs + V′s + Vu; Vs = Vp + Ve; V′s = V′p + V′e.
The physical decomposition of the permanent magnetic field of the United States—No. 1. the assumed normal magnetization and the characteristics of the primary resulting residual field
Authors: Bauer L. A. , Hazard D. L. 
Published: February 2008

In the March (1899) issue of the JOURNAL, L. A. Bauer published a paper entitled, “The Physical Decomposition of the Earth's Permanent Magnetic Field,” and in that paper were developed the principles and formulae upon which the decomposition was based. The present paper is an application of these principles and formulae for a special portion of the Earth, namely, the United States of America.This investigation is based upon the series of magnetic charts constructed by Mr. C. A. Schott for the year 1900, and published in Appendix No. 1, Coast and Geodetic Survey Reports for 1896, and 1897. These charts give us the best possible representation of the distribution of the magnetic elements in the United States up to the date of the construction of the charts.
Beobachtungen über die electricitätszerstreuung an der steilen Südküste der Krim
Authors: Rachmanow Von George 
Published: February 2008

In diesem Frühling unternahm ich eine Excursion an die Südküste der Krim, um daselbst in verschiedener Seehöhe Beobachtungen über die Electricitätszerstreuung mit einem Apparat nach Elster und Geitel auszuführen. Hier will ich vorläufig einige besonders interessante Daten mittheilen.Ich bezeichne mit q das Verhältniss,
wo a− die Zerstreuung der negativen und a+ die der positiven Electricität bedeutet. Meine Beobachtungen ergaben folgende Werthe für q.
Report on the magnetic observations made at the magnetic observatory at Pola, Austria, during the time of the total solar eclipse of May 17, 18, 1901
Authors: Kesslitz Wilhelm 
Published: February 2008

“Mit Beziehung auf Ihre (T. M., Vol. v, p. 166) Einladung zur Vornahme simultaner erdmagnetischer Beobachtungen am 17. Mai von 14h bis 21h Greenwicher Zeit, wird Ihnen hiemit eine Zusammenstellung der Curven‐Ablesungen vom Magnetographen in Pola u. zw. von Minute zu Minute und die Aufzeichungen des Thermographen Richard für jede 5te Minute des obgenannten Zeit‐Intervalles übersendet.Die magnetischen Curven nehmen in dieser Zeit einen ganz normalen Verlauf und zeigen keinerlei Störungen.
Report on the magnetic observations made at the University of Groningen during the total solar eclipse of May 17, 18, 1901
Authors: Haga W. 
Published: February 2008

At the request of Dr. van Rijckevorsel, I have made in the laboratory of the University of Groningen, during the night between 17–18 May, observations of the variations of declinations and of the horizontal intensity.The laboratory is quite free from iron, and lies in a garden far from the railway, canals, and frequented streets. In Groningen there are no electric car lines nor electric plants, hence we are undisturbed by stray or “vagabundirende” currents.
Zur Bibliographie von W. Gilbert's “De Magnete”
Authors: Hellmann G. 
Published: February 2008

Vor einiger Zeit frug ein Fachgenosse bei mir an, welche Ausgabe von William Gilbert's grundlegendem Werke “De Magnete” die seltenste sei. Ich habe diese Frage nicht ohne weiteres beantworten können, sondern erst einige Nachforschungen darüber anstellen müssen, deren Ergebniss ich wegen der grossen Wichtigkeit und Seltenheit des Buches hier auch weiteren Kreisen mittheilen will.Zunächst mochte ich betonen, dass es nur drei Ausgaben von Gilbert's Werkgiebt: London 1600, Stettin (Sedini) 1628 und 1633. Die beiden letzten wurden von dem Stettiner Assessor Wolfgang Lochmann besorgt, einem grossen Verehrer der Gilbert'schen Lehren, die damals im Ausland mehr Anklang fanden, als in England selbst.
Ueber die meteorologische Natur der variationen des Erdmagnetismus
Authors: Nippoldt A. 
Published: February 2008

Wenn man die Curven unserer Magnetographen betrachtet und von augenscheinlich gestörten Tagen absieht, so zeigt sich uns aufs deutlichste, dass wir es hier mit einem sehr gesetzmässigen Vorgange zu thun haben; dennoch wissen wir über die Quelle dieser Gesetzmässigkeit noch sehr wenig. Die von Schuster geschaffene und von Bezold so eingehend discutierte Theorie der täglichen Variationen, zeigt zwar, dass man ein System magnetischer Kräfte construieren kann, innerhalb dessen die Erde rotiert, und das die genannten Variationen erzeugen konnte, allein damit verlegt sich die Frage nur und lautet jetzt: Wodurch entsteht ein solches System?Dass es ein rein magnetisches ist, ist unwahrscheinlich, denn die Atmosphäre enthält keine Bestandteile, die genügend magnetisierbar sind, und sie ist doch der Sitz dieser Kräfte. Zwar wäre ein cosmisches Feld denkbar, allein der Verlauf der Kraftlinien trägt doch einen unverkennbar irdischen Character. Daher muss man annehmen, dass das Feld electrischer Natur ist. Dann aber hängen dessen Ströme von der Leitfähigkeit der Luft ab und mithin unter anderem sehr wahrscheinlich von ihrem meteorologischen Zustande. Sie können ausserdem noch in Richtung und Intensität dadurch variieren, dass jene Ursachen variieren, welche die Ströme hervorgerufen haben. Diese Ursachen können ebenfalls terrestrischer Natur, aber auch cosmischen respective solaren Ursprungessein, etwa in der Art der Theorien von Birkeland1 Arrhenius2 und Bigelow,3 die alle darin übereinstimmen, dass sie electrisierte Teilchen von der Sonne ausgehen und zum Teil die Erde treffen lassen. Es sei übrigens hier bemerkt, dass schon vor anderthalb Jahrhunderten Mairan in seinem Traité de l'aurore boréale, p. 455, Paris 1754, zur Erklärung der regelmässigen Variationen angenommen hat, dass von der Sonne feine Teilchen ausströmen, die die magnetische Nadel beeinflussen.
Vorschläge für die Ausführung electrischer Beobachtungen während der bevorstehenden Sonnenfinsterniss
Authors: Elster J. , Geitel H. 
Published: February 2008

Die Frage, ob Beobachtungen der electrischen Eigenschaften der Atmosphäre während einer totalen Sonnenfinsterniss mit Sicherheit wertvolle Aufschlüsse über die Natur der atmosphärischen Electricität versprechen, ist, unserer Meinung nach, nur mit Vorbehalt bejahend zu beantworten, nichtsdestoweniger erscheint es geboten, die bevorstehende Finsterniss nicht ungenützt vorübergehen zu lassen.1 Man ist leider noch nicht im Besitze einer vollständigen Theorie, aus der sich voraussagen liesse, welche Erscheinungen in der Zone der Verfinsterung zu erwarten sind und deren Voraussage daher an den Beobachtungen als richtig oder unrichtig erwiesen werden könnte.Zwar ist bekannt, dass Gase, während sie vom Lichte durchstrahlt werden, eine Ionisierung erfahren können, indem Ionen sowohl im Innern des Gases selbst auf Kosten der absorbierten Lichtenergie gebildet werden, als auch besonders in der Nähe der begrenzenden festen Körper, die während der Bestrahlung negative Electronen aussenden. Aber diese Wirkungen sind für die atmosphärische Luft und für diejenigen festen Stoffe, aus denen die Erdoberfläche besteht, nur für Licht von sehr kleinen Wellenlängen nachgewiesen, die dem Sonnenlichte an der Erdoberfläche fast oder völlig fehlen.
Le projet du levé magnétique de l'Empire Russe et les travaux magnétiques executés en Russie en 1910
Authors: Rykatchew M. 
Published: February 2008

Dans mon rapport à la Commission magnétique du Comité Météorologique International, publié dans le Rapport de cette Commission,1 j'ai communiqué le plan du levé magnétique de l'Empire Russe, projeté par la Commission Magnétique, nommée près de l'Académie Impériale des Sciences de St. Pétersbourg. Cette Commission consiste des représentants de l'Académie des Sciences, de l'Observatoire Physique Central Nicolas, des différents ressorts et Institutions, des Sociétés scientifiques, des Universités et des autres établissements et personnes privées, qui ont bien voulu prendre part à l'entreprise.Le projet du levé magnétique avec le devis a été présenté à l'Académie, laquelle dans sa séance du 13/26 octobre l'a approuvé. Désirant faire tout ce qui est dans son pouvoir pour soutenir cette entreprise elle a décidé d'assigner de son coté pour le levé magnétique 10,000 rb. par an depuis 1912 durant 10 années si elle reçoit le crédit qu'elle demande pour les entreprises scientifiques de l'Académie. Ce don considérable et la bonne volonté des autres institutions et personnes, qui voulent bien prendre part dans nos travaux, nous donne l'espoire que nous parviendrons au but.
The magnetic survey of Australia
Authors: Bauer L. A. 
Published: February 2008

Australia is at present the largest land area in which so comparatively few magnetic observations have been made. With the exception of the portion of Victoria, of which a magnetic survey embracing about 235 points was carried out by the indefatigable Neumayer, between 1858 and 1864, the preliminary magnetic survey of Tasmania by McAulay and Hogg in 1901, and some isolated observations along the coasts, such magnetic results as exist in the interior are confined, well‐nigh exclusively, to compass observations by surveyors.If it be remembered that the total area involved is over three‐fourths that of entire Europe, and is practically equal to that of the United States (exclusive of Alaska), it will readily be appreciated that there remains here an important field for magnetic exploration. And the importance does not arise merely from purely scientific considerations, but from practical ones as well—navigation, surveying, and exploration of the great interior reaches. The prevalence of local disturbances at some of the ports of call is well known, and mention should be made here of the remarkable local disturbances revealed at Port Walcott on the northwest coast, by the admirable work of H. M. S. Penguin, 1890–93.
The physical theory of the Earth's magnetic and electric phenomena: 4. Continued
Authors: Bauer L. A. 
Published: February 2008

53. I am grateful to Dr. Steiner for his helpful discussion of the question raised in Nos. III and IV as to whether the Earth is chiefly an electromagnet, due possibly to negative electric currents circulating overhead in the same general direction as that of the Earth's rotation. It may be recalled that this was advanced merely as a working hypothesis in order to ascertain just what conclusions would thereby be implied and how far the hypothesis might assist in explaining the phenomena found in my paper, PD No. II. (Terr. Mag. v. 6, pp. 13–24). The facts of the latter paper will receive fuller treatment in a subsequent number; they appear to be related in some manner to the Earth's rotation.Steiner agrees with me that the portion of the Earth's magnetism which heretofore was thought almost universally could only be due to internal agencies, can be produced, at least theoretically, equally as well by external electric currents. He is also in agreement with me as to the direction in which these exernal currents would have to circulate around the Earth, viz., from west to east, if negative, and the reverse, if positive. In other words, the direction of the external currents would be precisely the same as that of internal currents supposed capable of causing the Earth's magnetism. If Nos. III and IV accomplish nothing beyond the general recognition of these two facts—that the electric currents may be external ones, and that their direction may be at the same time the same as the supposed internal ones—I shall feel abundantly repaid for the labor bestowed. Given the possibility of an external source, a variety of questions stimulating further research immediately arises.
Halley's observations of the magnetic declination, 1698–1700
Authors: Ault J. P. , Wallis W. F. 
Published: February 2008

The spelling of the ports visited by Halley's ship, the Paramour Pink, was modernized. It was thought desirable, however, to retain Halley's dates as given by him, which apply to the old style calendar; to refer them to the new style calendar, it would be necessary to add 10 days in 1698–99 and 11 days in 1700.The latitudes and longitudes, given in the columns headed “Halley's noon position”, are those as published in Halley's journal, all his reckoning being made from noon to noon. The latitude usually results from “a good observation” at noon and the longitude is obtained by reckoning from the previous noon position, except in a very few cases as described in the footnotes.
Bemerkungen zu einem Gewitter in San Carlos de Ancud
Authors: Knoche Walter 
Published: February 2008

Am 25.–26. Oktober 1912 rief ein ausserordentlich heftiges Gewitter in San Carlos de Ancud (Hauptstadt der Inselprovinz Chiloé) die grösste Aufregung unter seinen Bewohnern hervor, da Chile in seinen bewohnten Teilen ein ausserordentlich gewitterarmes Land ist. So beobachteten unter 33 meteorologischen Stationen im Jahre 1911, 13 kein, 12 ein, 3 zwei, 2 drei, 2 vier und nur 1 (Santiago) sieben Gewitter und Wetterleuchten (ohne die stillen Entladungen tiber den Anden zu zählen); hierzu kommt, dass die beobachteten Gewitter, z. B. alle sieben in Santiago, meist sehr unbedeutender Natur waren.Das Gewitter, welches ausser in Nordchiloé auch in der Provinz LLanquihue beobachtet wurde, ist nun dadurch interessant, dass es im Seminario Conciliar yon Ancud mittelst Registrierappkrats. aufgezeichnet wurde. P. Galceran, der Direktor des Seminars, hatte die Freundlichkeit, uns die Registrierstreifen einzuschicken und eine kurze Beschreibung des Apparats zu liefern. Derselbe besteht aus einem Branlyschen Kohärer; der Kohärerstrom (⅓V) schliesst durch ein Relais (mit Klopfer) den Batteriestrom einer Art Morsetelegraph. Die Erdung ist vorzüglich durch Anschluss an den aus Stahlwerk bestehenden Kirchturm erreicht. An diesen ist, gut isoliert, die Antenne yon 80 m Länge bis zur Höhe yon 40 m geführt. Den Ablauf des Registrierstreifens besorgt ein Uhrwerk, mir der sehr grossen Geschwindigkeit von 3.60 m pro 1 Stunde oder 6 cm pro 1 Minute oder 1 mm in der Sekunde. Bei etwa 5 Entladungen in der Sekunde hört die Auflösungsfähigkeit dieses Apparates ftir die Entladungen auf, die. dann einen ununterbrochenen Streifen bilden. Es kamen stellenweise tatsächlich, derartige zusammenhängende Partieen trotz der schnellen Abwicklung vor, die längste 6 sec andauernd, mir einem Minimum also von 30 Entladungen während dieser Zeit.
Activity of the Earth's magnetism
Authors: Hazard D. L. 
Published: February 2008

At the request of the International Commission for Terrestrial, Magnetism, the “activity” of the Earth's magnetism has been computed for each day of the year 1915 from the records of the Cheltenham Magnetic Observatory, using the method proposed by the late Dr. Bidlingmaier and explained by him in the publication of the results of the Wilhelmshaven observations for 1911.This method takes the variability of the Earth's magnetism as a measure of its activity, that is, its departure, from moment to moment, from its undisturbed state. As we have not as yet data for determining this undisturbed state, the activity for a day is derived from the departures from the daily mean. This is divided into two parts, namely: the departure of the hourly means from the daily mean and the departure of the individual values in each hour from the mean value for that hour.
The magnetic storm of May 13–16, 1921, at Observatorio del Ebro, Tortosa, Spain
Authors: Rodes Father Luis 
Published: February 2008

On May 13, 1921, at 13h 10m, there began the most violent magnetic storm registered at this observatory since 1910. The first movement was a very sudden one: towards east in declination, and a decrease in the horizontal intensity, followed by a rapid change to an increase. The oscillation of the vertical component was so rapid that its initial direction could not be determined.At 19h 18m of May 13 there occurred again sudden jumps in the three elements; there next followed very rapid oscillations, generally of a short amplitude, until the next day, May 14, at 16h 15m, when the general character of the former perturbation was reproduced with a maximum intensity between 22h 15m, May 14, and 8h, May 15, during which time the curves left the photographic sheet several times; the H‐component particularly remained off the sheet from 3h to 11h, May 15, and 8h to 10h, May 16.
The magnetic character of the year 1920
Authors: van Dijk G. 
Published: February 2008

The annual review of the “Caractère magnétique de chaque jour” for 1920 has been drawn up in the same manner as for the preceding years. Thirty‐nine observatories contributed to the quarterly reviews, 36 of them having sent complete data.Table II of the annual review, containing the mean character of each day and each month, the list of calm days and the days recommended for reproduction, are reprinted here.
Report on magnetic observations made by the National Observatory of Mexico during the total solar eclipse of September 10, 1923
Authors: Gallo Joaquin 
Published: February 2008

In accordance with the plan outlined1 by the Department of Terrestrial Magnetism of the Carnegie Institution of Washington, special magnetic declination observations were made at Yerbanis, Durango, in the path of totality, on September 10, 1923, by Sr. Ingeniero Rosendo O. Sandoval, in charge of the Magnetic Department of the National Observatory.Using Dover magnetometer, No. 126, eye‐readings were made every minute from 17h 28m to 24h 02m, G. M. T. The results are given in Table 1. The geographic position of Yerbanis is as follows: latitude, 24° 44′ North; longitude, 104° 10′ West of Greenwich.
The computation of tabular quantities
Authors: Neumann Frank 
Published: February 2008

There is one phase of magnetic work which, although only of secondary importance as compared with its theoretical problems, is nevertheless of real practical importance to those who have in hand the preparation and publication of the results of magnetic observatory observations. It may be of interest to describe some of the methods which have recently been found effective in facilitating the preparation of the magnetic observatory results for the five observatories of the Coast and Geodetic Survey. Reference will be made only to the computation of the hourly values of the magnetic elements and to the diurnal variation tables.The hourly values of declination, horizontal and vertical intensities are, of course, computed by simply adding the converted hourly magnetogram scalings to constant base‐line values and applying corrections for temperature when necessary. There are several ways in which this may be done, depending largely on the facilities at hand and on the preferences of individual computers. The system to be described here includes the use of an addition table and a special copyholder, and these, when used in conjunction with a touch system adding and tabulating machine, enable computers with even very limited experience to attain a high degree of speed and accuracy. When it is realized that as many as three or four thousand tabular quantities might be computed in the course of a day, the reason for great attention to detail becomes very evident.
Principal magnetic storms recorded at the Huancayo Magnetic Observatory, July to December, 1925
Authors: Booth R. T. 
Published: February 2008

(Latitude, 12° 02.′7S.; Longitude, 75° 20′.4W. or 5h 01m.W. of Greenwich.)During the quarter ending September 30, 1925, the only marked magnetic storm was the sudden commencement at 2h 17m September 20, 1925, in which the horizontal intensity increased about 92γ within the space of a minute or two and the vertical intensity and declination showed corresponding sudden commencements.