bluuebunny/crossref_metadata_2025_split huggingface dataset:
Principal magnetic storms and earthquakes at the Watheroo Magnetic Observatory, October to December 1925
Authors: Johnston H. F. 
Published: February 2008

(Lat., 30° 19′.1S.; Long., 115° 52′.6 or 7h 44mE. of Greenwich.)October 21‐25, 1925. This protracted disturbance of moderate severity is the only one tabulated as a magnetic storm during October though the month as a whole was greatly disturbed. The storm was characterized by bays and peaks, the most prominent of which occurred on October 21 at 14h. 2 and 19h. 8, on October 22 at 14h. 5 and 19h. 7, and on October 24 at 8h. 2. At 8h on October 24 there was quite a violent disturbance in vertical intensity, causing a change of 80γ in 17 minutes; the disturbance in horizontal intensity was not marked, and the declination changed 13′ westward in the same period.
Principal magnetic storms recorded at the Huancayo Magnetic Observatory for January to March, 1926
Authors: Goddard Richard H. 
Published: February 2008

(Latitude, 12° 02′.7S.; longitude, 75° 20′.4W or 5h 01m W. of Greenwich.)January 13, 1926. This is not strictly a magnetic storm. There are two sudden commencements of interest. The first began at 19h 40m and in ten minutes the H trace had dropped 71γ. There followed a period of normalcy and at 20h 39m another sudden commencement in which the H decreased 85γ in twelve minutes, when it left the sheet and apparently continued its abrupt downward movement for some minutes, returning to registration approximately 30 minutes after leaving the sheet.
Ueber die Ursache der Schwankungen des luftelektrischen Potentialgefaelles
Authors: Gockel Von A. 
Published: February 2008

Inhaltsangabe.—In einer früheren Arbeit hat der Verfasser die Frage untersucht, ob der Zusammenhang zwischen Sonnentätigkeit und den Aenderungen des elektrischen Erdfeldes ein direkter sein kann, vermittelt durch eine von der Sonne ausgehende Strahlung oder ein indirekter hervorgerufen dadurch, dass die Sonnenflecken die meteorologischen Faktoren und damit die Leitfähigkeit der Atmosphäre ändern. Die erstere Auffassung scheint die wahrscheinlichere.Der Potentialgradient hängt ab von 2 unabhängigen Variabein, dem Luft‐Erdstrom und der Leitfähigkeit. Der erstere ist durch kosmische, die letztere durch meteorologische Faktoren beeinflusst. Wo sich die Leitfähigkeit der Atmosphäre wenig ändert, folgt der Verlauf des P. G. dem des Stromes. Dieser hat eine regelnlässige tägliche, jährliche und säkulare Schwankung. Der Zusammenhang tritt am deutlichsten hervor in der Arktis, der Antarktis und auf den Ozeanen. An andern Orten, an denen die Leitfähigkeit stark schwankt, wird der Verlauf des Luft‐Erdestromes ein unregelmässiger. Die 24 Stundenwelle des Potentialgradienten ist hauptsächlich durch den kosmischen Faktor beeinflusst, der sich nach Universalzeit ändert; die 12‐stündige durch Aenderungen der Leitfähigkeit, also meteorologische Vorgänge, die von der Lokalzeit abhängen.Abstract.—In a previous paper the author investigated the problem whether the relation existing between solar activity and variations of the Earth's electric field, caused by radiation proceeding from the Sun, is a direct relation or whether, because of the fact that sunspots produce changes in meteorological factors which in turn affect the conductivity of the atmosphere, the relation is an indirect one. It would appear that the former assumption is the more probable.The potential gradient depends upon two independent variables, the airearth current and the conductivity. The former is influenced by cosmic factors and the latter by meteorological. In the event where the conductivity of the atmosphere varies little, the course of the potential gradient follows that of the current. This current has a regular diurnal and annual variation and changes in the course of a sunspot cycle. This relation is most clearly evident in the Arctic and Antarctic regions and on Oceans. In other places where the conductivity varies strongly, the course of the air‐earth current becomes irregular. The 24‐hour wave of the potential gradient is influenced chiefly by the cosmic factor; this factor varies with universal time. The 12‐hour wave is caused by the variations of the conductivity and also of other meteorological occurrences which are dependent on local time.
Direct scaling of absolute magnetic values
Authors: McFarland W. N. 
Published: February 2008

The operation of a magnetic observatory has for its object the eventual tabulation of the results in some form which will be convenient for the purposes of the investigator. The successful operation of the magnetograph, however, by no means completes the labor necessary for the attainment of this end. Several routine processes have to be maintained in order that the resulting records may be controlled, including absolute observations of the magnetic elements, and the determination of scale values of the magnetogram, all of which must be done at regular intervals.The computer's work begins after the magnetogram has been developed and dried. The adjustment of the base‐line and scale‐value observations, while basic for proper carrying out of the rest of the program, is not long or laborious, but the measurement of the magnetograms and the subsequent reduction to the final absolute values which are printed, while simple in method, is both laborious and monotonous on account of the large number of operations of the same character which must be completed before the final values are obtained.
Micromagnetic oscillations as observed at the magnetical section of the Observatory of Irkutsk (Zouy), 1925
Authors: Pödder Arnold 
Published: February 2008

Sensitive magnetographs reveal frequently on disturbed, as on quite calm, days waves of a peculiar type, which are characterized by their small period and which are not perceptibly connected with the Sun's activity. Some days they are very weak, but on other days their amplitudes reach very considerable values.From the data of the special records of the Eschenhagen magnetograph at Zouy it can be concluded that two very different types of these waves exist:Type I.—Very regular periodical vibrations of the magnet continuing over many hours or even days; the periods are well defined and vary in the limits of from 5 to 14 seconds approximately;Type II.—Comparatively irregular vibrations having, however, a pronounced periodical character with considerably longer periods of a mean value of 34 seconds.
Swinging ship for the precise determination of deviations in magnetically‐disturbed harbors
Authors: Peters William J. 
Published: February 2008

In the ordinary method of swinging ship, the vessel is held on the selected headings successively as for example, E, SE, S, SW, W, NW, N, and NE and on the swing with the other helm the order is reversed, NE, N, NW, W, SW, S, SE, and E. When the region is magnetically disturbed and the highest precision is sought there are two points to be considered.a. In making a swing under ideal working conditions, that is perfectly calm weather, absolutely smooth water, with no current, and spending the same amount of time at uniform speed on each heading the vessel's course throughout the swing will describe a regular polygon as in Figure 1 in which the vessel on port swing, heads E from D to E, SE from E to F, etc., and on the starboard helm NW from F to E and W from E to D, etc. If the swings with both helms are made under these ideal conditions at the same speed and spending the same amount of time on each heading, the vessel will pass over the same bottom on opposite headings of the two swings, and the results for any two opposite headings of the two swings would be strictly comparable as regards irregular distribution of the local disturbance. This statement would not, however, hold for any other headings.
Considerations on measures for magnetic activity
Authors: Weinberg Boris 
Published: February 2008

I would like to point out at first that the very name “magnetic activity” is ill chosen because there is no doubt that the aperiodic magnetic variations are due to some agency differing from terrestrial magnetism itself, for instance, to changes in Earth's currents or to atmospheric‐electric currents, or to currents of electrons emitted by the Sun, etc. Therefore from the physical standpoint we must try to find a measure for the intensity, A, of this very agency, its mean value Ā being the real cause of the variability of magnetic force, for instance, the agency being some current it is the intensity of the current.If we do not wish to be influenced by the words it would be more adequate to speak about magnetic variability, but not about magnetic activity, reserving the word activity for the action of the agency causing these phenomena. This activity being beyond our means of observation we are obliged to estimate its amount according to the variations of the observed values of magnetic element at a number of stations.
Watheroo Magnetic Observatory July, 1928
Authors: Johnston H. F. 
Published: February 2008

(Latitude 30° 19′.1 S.; longitude 115° 52′.6 or 7h 44m E. of Gr.)July 7, 1928—This was a severe magnetic storm. Between 22h and 23h (G.M.T.) on July 7 the magnetic elements began to depart markedly from the normal curve, and within an hour all three elements showed large and rapid fluctuations. From 23h.5 on July 7 to 7h on the following day was the period of greatest severity of the storm, the oscillations of all three elements being so rapid as to scarcely leave a record on the photographic trace. The declination was especially disturbed and the H‐trace was greatly depressed during the last half of the period.
Magnetic storms observed by the international polar expeditions 1882–1883
Authors: Bastamoff S. 
Published: February 2008

Magnetic disturbances have been under investigation for many years. Recent expeditions, equipped with the most accurate instruments, have disclosed much that is characteristic of these phenomena. However, an examination of the earlier observations of terrestrial magnetism can furnish interesting material and particularly fruitful in this respect are the investigations of 1882–1883, for this was the only instance in the history of such researches that general and special observations were made in a complete network of stations surrounding the north magnetic pole and in its vicinity.For these stations there were no self‐recording magnetographs. The instrumental precision was not great and there were other deficiencies. Still the published material is vast and may serve as an inexhaustible source for conclusions and generalizations. Up to the present time only a partial study of this material has been made and the final results of the gigantic enterprise have not yet been attained, because of the large scale of the undertaking. In the present paper several results are considered which I regard, on the basis of hourly magnetic observations, as belonging preponderantly to the so‐called magnetic storms.
Preliminary note on the origin of the permanent magnetic fields of the Sun and Earth
Authors: Gunn Ross 
Published: February 2008

The writer's studies of the effects produced by ions as they are caused to execute long free‐paths and spiral about an impressed magnetic field by thermal agitation have led to interesting conclusions regarding the magnetic condition of the Sun and Earth. Such long free‐path phenomena take place only in the rarified atmosphere of the bodies. A calculation of the currents flowing in the atmosphere of the Sun and Earth as‐a result of an observed radial inhomogeneity in the magnetic field shows that the currents are inadequate to account for the observed magnetic moments, even though they flow in the correct direction.A further study of the effects produced by ions moving under thermal agitation in a magnetic field and executing short free‐paths has led to a group of phenomena which are of great interest in the problem of the origin of the magnetic fields of the Sun and Earth. Ion‐drifts which can give rise to currents have been found to result under the following conditions: (a) When a magnetic gradient exists which has a component perpendicular to the impressed magnetic field; (b) when an electric or gravitational field exists which has a component perpendicular to the impressed magnetic field. In each case the direction of the ion‐drift is at right‐angles to both the magnetic field and the gradient.
The mobility‐spectrum of atmospheric ions—principles of measurements and results
Authors: Israël H. , Schulz L. 
Published: February 2008

In the first part of the work, the methods of determining the “ionic spectrum,” that is, the percentage‐distribution of the ions for different mobilities, are discussed. The principle of the measurements consists in obtaining a current‐potential characteristic of a condenser through which air containing ions is passed. The ionic spectrum is obtained by forming a second differential quotient of the characteristic. Three different methods are described and their “resolving‐power” is discussed: The double‐condenser method, the method of the subdivided condenser, and the analysis according to Benndorf.In the second part the ionic spectra as determined to date at twelve different stations are assembled. Since the revolving‐power of the double‐condenser method is limited, only four rather large mobility‐regions are at present differentiated. Apart from very large local differences, which cannot yet be cleared up individually, there appears an annual variation in the composition of the spectra, such that the spectral center of gravity lies at the smaller mobilities in winter and at the larger in summer. Increase of humidity has obviously the effect of enlarging the ions or of diminishing their mobility through the accretion of water‐vapor by them. A consideration of the separate representative mobilities of the various spectra shows that these are related as 1 : 2 : 3 or 1 : 2 : 4. This simple relationship suggests that perhaps the ions are of equal size but with one, two, or more elementary charges.
PROVISIONAL SOLAR AND MAGNETIC CHARACTER‐FIGURES, MOUNT WILSON OBSERVATORY, JANUARY, FEBRUARY, AND MARCH, 1934
Authors: Nicholson Seth B. , Sternberg Elizabeth E. 
Published: February 2008

The diurnal range in H at Mount Wilson exceeded 100y on February 9, February 16, and March 5, but the variations on these days were not classed as magnetic storms.Thirteen spot‐groups were observed in the first quarter of 1934, five belonging to the waning cycle and eight to the new cycle. The increasing activity of the new cycle in the high solar latitudes indicates that the phase of minimum activity is probably past.
HUANCAYO MAGNETIC OBSERVATORY JANUARY TO MARCH, 1934
Authors: Cairns J. E. I. 
Published: February 2008

(Latitude 12° 02′.7 S.; longitude, 75° 20′.4 or 5h 01m W. of Gr.)March 4‐8—A disturbance, which lasted from March 4 to 8, was not of a very marked nature, the principal characteristic being the rapid oscillatory‐motions of relatively small amplitude. The disturbance began quietly on March 4 at 10h 20m G.M.T., with oscillations of small amplitude. As the maximum was approached at 14h the violence of the motions increased but not so strongly as not to record. The normal minimum was reached by a succession of descending bays at 21h 27m March 4 and was lower than usual. Disturbed conditions, the principal characteristics of which were lowered ordinates and oscillatory‐motions, particularly around the time of maximum and minimum, then persisted until March 7. The maximum of March 7 was considerably flattened and the minimum thereby obscured.
Critical‐frequency observations of the E‐layer at the Huancayo Magnetic Observatory
Authors: Wells H. W. 
Published: February 2008

This paper describes the nature and characteristics of the reflections from the E‐layer of the ionosphere as observed at the Huancayo Magnetic Observatory, and gives a comparison of the results obtained with similar investigations in the higher latitudes.It is shown that no marked critical frequencies are in evidence, and that the transition from the E‐region to an upper ionized layer, or vice versa, is a gradual process with little evidence of the long retardations which are frequently observed in the higher latitudes. There is, however, a definite and smooth diurnal variation of estimated maximum ionization which peaks around noon. The results indicate that the refractive index of the electromagnetic waves returned from the region of the maximum ionization of the E‐layer is complex and that dissipation is appreciable. Epstein's conclusion, that if the collisional frequency is large, part of the energy will be reflected and part transmitted, is borne out by these observations. It may be noted that this appears to be the necessary condition for the qualitative fulfilment of the so‐called “atmospheric‐dynamo” theory of diurnal variation of the Earth's magnetic field.
The magnetic character of the year 1933 and the numerical magnetic character of days, 1933
Authors: van Dijk G. 
Published: February 2008

The annual review of the “Caractère magnétique de chaque jour” for 1933 has been drawn up in the same manner as for preceding years. Forty‐nine observatories contributed to the quarterly tables, forty‐eight of them sent complete data.Table II (reproduced as Table 1 below) of the annual review, contains the mean character of each day for each month. The lists of calm days and disturbed days, and the days recommended for reproduction are also reprinted here as Table 2.
Summary of some auroral height‐measurements and observations at Chesterfield, Canada
Authors: Currie B. W. 
Published: February 2008

The Aurora‐Borealis investigations of the Canadian International Polar‐Year party located at Chesterfield Inlet, (63° 20′ north, 90° 42′ west), comprised single‐station visual observations, single‐station photographs of the brighter displays, and double‐station photographs for height‐measurements. To date height‐measurements have been made on 200 of the parallactic photographs, and a study has been made of the visual observations on nights without cloud.The secondary auroral station was located south of Chesterfield on the coast of Hudson Bay. It was established during September, 1932, when it was possible to travel along the coast by boat. A sod shelter, Figure 1, was built, and a supply of food and kerosene left there for future use. The position of this station relative to the Chesterfield station was determined the following spring by triangulation and stadia‐rod surveys over the Bay ice. The values obtained were: Length of base‐line, 33.14 km; azimuth from north, +173° 39′.
Watheroo Magnetic Observatory April to June, 1935
Authors: Parkinson W. C. 
Published: February 2008

(Latitude 30° 19′.1 S., longitude 115° 52′.6 or 7h 43m.5 E. of Gr.)May 1–2—This moderate disturbance began May 1 at 12h 47m, G. M. T., with a sudden commencement. Horizontal intensity increased 15 gammas in five minutes, vertical intensity decreased five gammas, and declination 0′.5 in the same interval. The disturbance ended May 2 at approximately 2h.
The fundamental theorem of applied geophysics
Authors: Löwy H. 
Published: February 2008

In all methods of geophysical prospecting, the attempt is made to ascertain the depth and extent of deposits (ore, oil, ground‐water) by means of certain measurements made on the Earth's surface. The question as to whether and under what conditions such an analysis may be made in a unique manner constitutes the fundamental problem of applied geophysics.The problem requires a separate solution for each method. In 1927, I published a solution for the electrodynamical method. As for the other geophysical methods, in the absence of a solution, recourse is had to a rule formulated by Professor A. O. Rankine as follows: “Underground structures, agreeable to the geophysicist's experience, have to be taken as hypotheses, and tested by calculation and comparison with the data provided by surface‐observations.” It is a very laborious and uncertain procedure. Even if one, by good luck, succeeds in divining a hypothetical underground structure which is in ideal agreement as respects the calculated and observed values, yet there is no certainty that this corresponds with reality. The physical values at the surface are uniquely determined by the underground structure but the inverse theorem—namely, that the underground structure may be uniquely ascertained from physical measurements made at the surface—does not necessarily follow. Indeed, it is not upon physics nor upon mathematics (however imposing some of the displays of the latter) but upon geology that the successful interpretation of geophysical measurements usually depends. The hypothetical structure must be “agreeable to the geologist's experience.” This is, according to Rankine “the geologist's selection rule.” It signifies no guide in the terra incognita, but, on the contrary, the exclusion of it. Until the fundamental problem is solved, the geophysicist will be obliged to work only in geologically known country.
The American character‐figure CA as a measure of magnetic activity of the Earth
Authors: McNish A. G. , Ludy A. K. 
Published: February 2008

A close relationship between radio‐transmission conditions and irregular fluctuations of the Earth's magnetic field has been recognized for some time. The nature of this relationship may be briefly stated as follows: At times when the variations of the Earth's magnetism are of a regular character transmission over long distances is generally good on all frequencies, but when the variations are irregular—that is, during magnetic “storms”—communication over high‐latitude paths is unsatisfactory or altogether impossible on the higher frequencies.In efforts to understand this relationship better, numerous investigators have made correlations of radio conditions and magnetic storminess. Various measures of storminess have been used—sometimes the daily range of magnetic change at a single station, sometimes a subjective estimate of storminess as assigned by the observer‐in‐charge of a magnetic station. Such measures are not fully adequate as they only partially represent the conditions at a single point on the Earth. Magnetic storms affect the entire Earth although local conditions may vary considerably.
On the lunar‐diurnal variation in the earth‐currents
Authors: Egedal J. 
Published: February 2008

In examining earth‐potentials at Jersey Marc Dechevrens twenty years ago found variations of tidal type, and in examining ordinary earth‐current observations the author demonstrated a lunar influence on the earth‐current potential‐gradient at Ebro, Spain, for the hours 10 to 11 a.m. In the following a complete determination of the lunar‐diurnal variation of the earth‐current potential‐gradient will be mentioned and discussed.The observational data—The data used for the present determination of the lunar‐diurnal variation of the earth‐current potential‐gradient are taken from the earth‐current observations made at Ebro in the period January 1 to December 21, 1910 (12 lunations). Only the data designated N→S, giving the potential‐gradient in a direction 25° west of north, have been examined.
The unusual aurora of March 30, 1937
Authors: Harradon H. D. 
Published: February 2008

On the night of March 30, 1937, a remarkable auroral display was visible over a large part of North America.Dr. E. H. Bramhall, of the University of Alaska, describes the phenomenon as observed by him at College, Alaska, as follows: “The unusual feature of the aurora was the blood‐red glow of considerable intensity. At 22h 45m, March 30, 150° west meridian time (8h45m GMT, March 31), I observed such a glow in the area from east to 20° south of east, and from the horizon to 20° altitude simultaneously with active rayed bands of unusual color in the same region and in the south and west. In the zenith there remained a partial corona with intense bands towards east and northwest; in fact in all parts of the sky except due north there was evident some activity. At 23h (9h GMT, March 31) a similar blood‐red glow developed in the south in the region of a very active rayed band. At 23h 10m (9h 10m GMT, March 31) the red was only faintly visible although the activity in all directions was still great.”