bluuebunny/crossref_metadata_2025 huggingface dataset:
A new experimental method for study of the upper atmosphere
Authors: Tuve M. A. , Johnson E. A. , Wulf O. R.
Published: February 2008

The idea of utilizing the light scattered from a powerful searchlight‐beam directed to high altitudes has frequently been suggested for exploring the upper atmosphere. Examination of this possibility was made here some years ago, and no doubt elsewhere at earlier dates, but, in addition to technical difficulties connected with instrumental sensitivity, the background level of the light of the night sky constitutes a fundamental limitation. The light scattered from a powerful searchlight‐beam in the absence of clouds or dust (molecular scattering only) would be submerged in this background luminosity even for altitudes which are reached by instrument‐carrying balloons. However, an audacious suggestion was made in 1930 by E. H. Synge,1 who proposed to concentrate the beams from an assemblage of several hundred searchlights (for example, with the help of the military authorities) on a common volume of the upper air. Utilizing a 36‐inch mirror in conjunction with the photo‐cell at the receiver, Synge calculated that with one hundred large searchlights it should be possible to measure the light scattered by the atmosphere (cloud‐free) at a height of 30 km with an accuracy of possibly one per cent. The stimulus of this large‐scale proposal led one of us (M.A.T.) shortly thereafter to discuss the problem at a meeting of the Washington Atomic‐Physics Colloquium and to point out that by using a modulated searchlight‐beam, thereby placing an “identification‐tag” on the scattered light it is desired to observe, a method of wholly new possibilities emerged from the older idea. Not only does this make available the convenience of resonance‐instruments for high‐sensitivity observations (alternating‐current amplification), but the background limit is no longer the total light of the night sky entering the receiver but only that Fourier component of the (variable) sky‐light which has the same frequency as the searchlight‐modulation. On this basis it was suggested that the use of a single modulated searchlight, with a 36‐inch receiving mirror, gave promise of making accessible to examination the unexplored levels of the atmosphere at heights above 30 km.
American URSI broadcasts of cosmic data October to December, 1935
Authors: Ennis C. C.
Published: February 2008

The data for terrestrial magnetism, sunspots, solar constant, and auroræ are the same as given in previous tables.

The first three columns of the Table give (1) the magnetic character according to the scale 0–2 of the International Commission of Terrestrial Magnetism and Atmospheric Electricity, (2) the type featuring the day other than normal by the letters b, p, o and i for days marked by bay, rapid pulsations, long‐period oscillations, and irregular oscillations, respectively, and (3) the hour and minute of Greenwich mean time marking the beginning of a storm, the end of the storm being indicated in the footnote to the Table. The next two columns give the data relating to sunspots: (1) the number of groups of spots and (2) the total number of spots. It is to be noted that sunspot‐numbers such as those from Zürich can be obtained from the number of groups and spots given in the Table by the formula N=k (10g + s), where k for Mount Wilson is about 0.7.
Harmonic analysis by means of linear combinations of ordinates (Concluded)
Authors: Labrouste H. , Labrouste Mrs.
Published: February 2008

Multiple combinations and curve definitions

§20. We have seen that simple and compound combinations permit suppressing or reducing greatly certain sine‐waves while they amplify others, but they are generally insufficient to isolate the diverse elementary components which are present in a curve.Multiple combinations (or combinations of combinations), that is, a succession of combinations, must be used: The first one, made on the given curveC, gives a transformed curveC′, the second one, made onC′ gives a new transformed curveC′′, etc. We represent them by a symbolical product, so as to bring under notice the fact that the magnification‐factor is equal to the product of the magnification‐factors of the successive combinations and that it is possible to interchange the order of the combinations in the same way as it is possible to interchange the order of the factors in a product.
The New Observatory at San Miguel, Argentina
Authors: Puig Ignacio
Published: February 2008

On December 12, 1935, a cosmic‐physical Observatory was inaugurated in the San Miguel District, on the Pacific Railway Line about 30 kilometers from the center of Buenos Aires. The President of the Republic together with the Ministers of Public Instruction and of Agriculture were present on that occasion.

The new Observatory, although belonging to the Society of Jesus and directed by its members, has been founded through the initiative of the National Council of Observatories and is invested with an official character.
On the auroral spectrograms taken at Chesterfield, Canada, during 1932–33
Authors: Currie B. W. , Edwards H. W.
Published: February 2008

This is a study of 693 spectrograms of the auroral and the night‐sky light that were taken at Chesterfield during the International Polar Year. The spectrograms had been obtained with successive exposures of about 1.5 hours throughout each night. In addition to presenting spectrographic pictures of the variations in auroral activity throughout each night they showed the effect of twilight and of moonlight on the auroral radiations.

The radiations that appeared on the spectrograms are identified with reasonable certainty, and their frequencies of occurrence are computed. Evidence is presented to show that the radiations from the upper atmosphere at Chesterfield are characteristically auroral at all times, and that the green‐line luminescence of the night‐sky at lower latitudes does not occur continuously at Chesterfield. A comparison is made between the frequencies of occurrence and the intensities of the two red‐radiations on moonlight nights and on dark nights to show the effect of moonlight on these radiations. Similar effects are shown to occur during twilight‐periods.

The possibility of using spectrographic observations to deduce auroral character‐numbers is indicated. The mean nightly variation in the intensity of the aurora for 30 clear nights is deduced from the apparent changes in the intensity of 5577Å, of 3914Å, and of all the radiations appearing on the spectrograms, and is compared with the mean nightly variation as deduced from the visual observations. The appearance of the radiation 3578Å (as an indicator of bright, active aurora), is used to find the mean nightly variation in auroral activity during the winter. The mean nightly variation in auroral activity is compared with the mean diurnal ranges of the earth‐potential and of the magnetic declination used as indicators of earth‐current and magnetic activity, respectively.
The new San Miguel cosmophysical observatory
Authors: Puig Ignacio
Published: February 2008

On December 12, 1935, the new cosmophysical observatory at San Miguel, about 30 kilometers from Buenos Aires, Argentina, was formally inagurated in the presence of the President of the Republic and other officials (see Plate 3 in which the lower view was made during the inaugural ceremonies, December 12, 1935). The National Committee on Observatories extended its patronage and has invested the Observatory with an official character although it is the property of a private organization—the Society of Jesus.

The complete program of this Observatory is similar to that of the Observatory of the Ebro in Spain. It embraces the study of solar and cosmic phenomena and their relations with terrestrial phenomena, particularly those of magnetism and electricity. The work will be distributed among three sections—Geophysical, Electrometeorological, and Astrophysical. The Geophysical Section will investigate terrestrial magnetism, earth‐currents, and earthquakes; the Electrometeorological Section will investigate Hertzian waves, electrical potential, ionization, and radioactivity of the atmosphere; the Astrophysical Section will concern itself with phenomena connected with solar activity and cosmic rays.
Solar and magnetic character‐figures, Mount Wilson Observatory April, May, and June, 1936
Authors: Nicholson Seth B. , Sternberg Elizabeth E.
Published: February 2008

The bright hydrogen eruption of April 8 which was simultaneously accompanied by a major radio fade‐out occurred in a group situated in latitude north 20° and longitude west 8°. The horizontal intensity at Mount Wilson decreased suddenly by 12 gammas at 16h 45m, GCT. No magnetic storm followed and it is quite probable that the relation between this solar eruption and the disturbance in the Earth's magnetic field is very different from that which exists between solar activity and ordinary magnetic storms.1

An oscillation of about 120 gammas occurred between 5h and 6h April 18. Irregular oscillations from April 19 to 24 were probably caused by an active region in the southern hemisphere which crossed the central meridian from April 21 to 23.
Auroral display at Fortine, Montana
Authors: Davies F. T.
Published: February 2008

A brilliant auroral display on the night of April 17, 1936, at Fortine, Montana, is reported by W. Weydemeyer. In addition to, and quite separate from, an auroral display along the northeast horizon, a brilliant narrow, homogeneous band appeared between 22h and 23h 23m, local time. The band moved slowly from a northwest‐to‐east to a northwest‐to‐southwest position during this interval, the highest point being south of the zenith. A. W. Johnson and J. F. Fait reported a bright band across the sky from west to east at Conrad and Lytle, Montana, respectively. Bright auroras were seen at Helena, Montana, by W. E. Maughan but not the distinctive band. The bright band must have extended for a distance of at least 200 miles at approximately latitude 48° north and between longitudes 111° and 116° west. Earth‐current records at Tucson, Arizona, at the time of occurrence of this band, show exceptional disturbance.
Magnetic station at Cape Chelyuskin
Authors: Harradon H. D.
Published: February 2008

In view of the importance of continued registrations of the magnetic elements in the arctic regions, it is pleasing to note in a recent number of the Bulletin of the Arctic Institute that the Polar Station established by that Institute on Cape Chelyuskin in 1932 was considerably enlarged in 1934, the staff consisting of 32 men under the direction of I. D. Papanin. In addition to dwelling‐houses and technical buildings, there were erected a pavilion for variation‐instruments with a room for absolute control‐measurements, a pavilion for atmospheric‐electric observations, and a number of other buildings for meteorological, hydrological, and other purposes.

The atmospheric‐electric investigations were conducted by V. I. Gerassimivich who had specialized in that work. During the winter of 1934–35, he succeeded in obtaining a continuous record of the potential gradient using a Benndorf recording‐electrometer in which a number of alterations has been made to adapt it to polar conditions. The necessary absolute determinations were made for control of the registrations. A second Benndorf instrument was arranged for continuous registration of the electric conductivity of the atmosphere.
Sitka Magnetic Observatory April to June, 1936
Authors: Burke R. G.
Published: February 2008

(Latitude 57° 03′.0 N., longitude 135° 20′.1 or 9h 0lm.3 W. of Gr.)

April 18–22—This storm was a drawn‐out disturbance but of no great violence at any one time. It began at 2h GMT, April 18, and ended about 17h, April 22, with extremes ranging from the beginning to the end, of 88′.6 in D, 980 gammas in H, and 594 gammas in Z. There were irregular pulsations and bays throughout with more disturbed periods from 4h to 8h on April 18, from 12h to 16h on April 20, and from 7h on April 21 to 17h on April 22.
Tucson Magnetic Observatory April to June, 1936
Authors: Joyce J. Wallace
Published: February 2008

(Latitude 32° 14′.8 N., longitude 110° 50′.1 or 7h 23m.3 W. of Gr.)

April 17–24—A moderate disturbance began gradually at about 21h GMT April 17. At 5h April 18, H and D, and to a lesser degree, Z, went to sudden peaks and then subsided again all within a little over an hour. During this short interval, the following ranges were recorded: Horizontal intensity, 133 gammas; vertical intensity, 19 gammas; declination, 16′. The remainder of the storm was a series of very long, gradual bays, with intervals of superimposed short‐period activity. Total ranges were: Horizontal intensity, 176 gammas; vertical intensity, 59 gammas; declination 24′. The storm ended about 7h April 24.
Note on magnetic conditions June 18–20, 1936
Authors: Johnston H. F.
Published: February 2008

This short description of magnetic conditions existing during the total solar eclipse of June 19, 1936, is based upon a radio report from Watheroo Magnetic Observatory, upon magnetograms from the Huancayo Magnetic Observatory, both operated by the Department of Terrestrial Magnetism of the Carnegie Institution of Washington, and upon copies of magnetograms from the observatories at Cheltenham, Tucson, San Juan, and Honolulu kindly furnished by the United States Coast and Geodetic Survey.

The total eclipse of June 19, 1936 began at 2h.9 GMT, and ended at 7h.9. A magnetic disturbance blanketed the total eclipse‐period. It began at 9h.7, June 18, and lasted until approximately 7h June 20. This magnetic disturbance was a magnified reappearance of a minor disturbance which had affected the magnetic elements at various multiples of 27 days previously, namely, March 24–28, April 21–25, and May 18–22.
Coulomb wave‐functions in repulsive fields
Authors: Wicher E. R.
Published: February 2008

The calculations of Yost, Wheeler, and Breit1 for the solution of the radial equation in inverse‐square repulsive fields are extended to the case L = 2.
Sitka Magnetic Observatory July to September, 1936
Authors: Hershberger John
Published: February 2008

(Latitude 57° 03′.0 N., longitude 135° 20′.1 or 9h 01m.3 W. of Gr.)

July 2—A storm began about 7h 30m GMT, July 2, although the elements had been slightly disturbed for some hours previous to this time. East declination increased 42′ in about half an hour, and the vertical intensity decreased nearly 300 gammas in less than an hour, while the horizontal intensity gradually decreased 824 gammas in five hours. All the elements fluctuated moderately until about 11h, when the oscillations became quite violent, continuing so until 16h, During the next hour they resumed their normal values, and by 17h the storm was over. Ranges: Declination, 115′; horizontal intensity, 824 gammas; vertical intensity, 669 gammas.
Apia Observatory April to September, 1936
Authors: Baird H. F.
Published: February 2008

(Latitude 13° 48′.4 S., longitude 171° 46′.5 or 11h 27m.1 W. of Gr.)

June 18–20—A fairly intense magnetic disturbance seems to have commenced with a sudden rise in H of only 6 gammas at 9h 40m GMT, June 18. The H‐trace was then slightly disturbed rising gradually to a maximum at 18d 20h 15m and then declining slowly until 18d 23h 10m when a sudden fall of 29 gammas in H introduced a very disturbed trace. H then fell rapidly to a minimum at 19d 07h 40m rising again gradually and remaining disturbed throughout June 19 and 20. D and Z also showed very disturbed traces over the period. The total range of the disturbance in H was 218 gammas.
Huancayo Magnetic Observatory July to October, 1936
Authors: Torreson O. W.
Published: February 2008

(Latitude 12° 02′.7 S., longitude 75° 20′.4 or 5h 01m.4 W. of Gr.)

July 2—A brief disturbance occurred July 2 with an abrupt movement in H and Z but not in D. H decreased 41 gammas in seven minutes while Z decreased seven gammas in the same interval. The disturbance is chiefly notable for the depressed values of H between 9h and 17h GMT, the minimum in H for the day occurring about the middle of this period at 13h 34m with the low value of H of approximately 29450 gammas. D and Z were somewhat more variable than usual during this disturbance.
The distribution of atmospheric ozone in equilibrium with solar radiation and the rate of maintenance of the distribution
Authors: Wulf Oliver R. , Deming Lola S.
Published: February 2008

In two earlier articles the authors have shown that if atmospheric ozone is considered as existing in a photochemical steady state depending on solar radiation, calculations involving certain assumptions regarding the absorption‐coefficients yield a distribution of the ozone with height which is sufficiently similar to the distribution that is deduced from experimental observations to suggest that the photochemical picture is adequate to account for atmospheric ozone. At the end of the first paper the disturbance of the steady state by atmospheric circulation was briefly discussed, and it was pointed out that the known variations in the existing vertical ozone path over any point on the Earth's surface might be explained as due to such disturbance. In order to estimate the quantitative importance of circulation in the photochemical picture, it is necessary to have some idea of the rates at which the steady state is maintained at the various heights. It is one of the purposes of the present paper to estimate the approximate values of these rates.
Comparisons between the horizontal‐intensity values at the Observatories Copenhagen (Rude Skov) and Lovö (Stockholm)
Authors: Åslund Sven
Published: February 2008

The standards in horizontal intensity (H) at Rude Skov and Lovö were compared in March, 1937, using the QHM‐instruments 3, 5, and 7, kindly placed at the disposal of the Lovö Observatory, Hydrographic Service, Stockholm, by the courtesy of the International Association of Terrestrial Magnetism and Electricity. The instruments were sent by mail between the two observatories and their constants were determined at Rude Skov. The observations with the QHM‐instruments were made during several days at Lovö. The summary of the results is given below.
The determination of the magnetic inclination with an earth‐inductor
Authors: Egedal J.
Published: February 2008

The method used at the Rude Skov Observatory to obtain more accurate determinations of the magnetic inclination is described, and the need in general of accurate determinations of the inclination is emphasized.
Progress of magnetic survey in the Union of South Africa
Authors: Ogg A.
Published: February 2008

At the request of the International Commission for the Polar Year 1932–33, Dr. A. Ogg, Professor of Physics at the University of Cape Town, established in August, 1932, a Magnetic Observatory at Cape Town. The Observatory had to be built near the Physics Department of the University, although it was realized that the suburban electric railways would have a disturbing influence. As the work of the Observatory had to be controlled by the staff of the Physics Department there was no alternative. Grants from the Department of the Interior made it possible to continue the Observatory from April, 1934, to April, 1937, with B. Gotsman as Observer.
Sitka Magnetic Observatory, October to December 1937
Authors: Gebhardt Robert E.
Published: February 2008

(Latitude 57° 03′.0 N., longitude 135° 20′.l or 9h 01m.3 W. of Gr.)

September 30–October 1—A slight magnetic disturbance began abruptly at 13h 46m GMT, September 30, with a sudden increase of 40 gammas in H and a decrease of 8′ in east declination. The elements were mildy disturbed with short‐period vibrations superimposed on irregular oscillations until about 24h GMT, October 1. Ranges: D, 62′; H, 437 gammas; Z, 437 gammas.
Watheroo Magnetic Observatory, October to December 1937
Authors: Green J. W.
Published: February 2008

(Latitude 30° 19′.1 S., longitude 115° 52′.6 or 7h 43m.5 E. of Gr.)

October 1—See “Note on solar eruption of October 1, 1937” under Letters to Editor in this issue.
Some atmospheric‐electric observations at Poona
Authors: Sil J. M.
Published: February 2008

A continuous record of the Earth's electric field has been obtained at Poona since September 1930. Since 1935 arrangements were also made to take systematic measurements of the conductivity as well as of the dust, nuclei, and ionic contents of the air simultaneously at some appointed hour. In this preliminary report, all observations cover a period from 1935 to 1937 except those on potential‐gradient which are from September 1930 to November 1937.

Poona is a rocky place, situated on a plateau formed on the eastern side of the chain of mountains, called the Western Ghats. Its position is latitude 18° 30′ north, longtitude 73° 53′ east, and its height above mean sea‐level is 1830 feet. It is not an industrial center. During afternoons in summer, a cool sea‐breeze blows from the Arabian Sea and raises a fairly good amount of dust. During the monsoon season (July to September) the sky is almost overcast on most of the days although it rains only occasionally. During September and October there are frequent thunderstorms. During winter (November to February) a strong inversion of temperature occurs almost every evening, followed sometimes by moderate haze or fog in the early morning. Considering the above it will be clear that the number of undisturbed days in a year is very small and observations extending over a long period, therefore, are necessary for the collection of sufficiently reliable data.
American URSI broadcasts of cosmic data, January to March 1938, with American magnetic character‐figure CA, February to April 1938
Authors: Johnston H. F.
Published: February 2008

The data for terrestrial magnetism, sunspots, and solar constant are the same as given in previous tables.

The first three columns of the Table give (1) the magnetic character according to the scale 0–2 of the International Commission of Terrestrial Magnetism and Atmospheric Electricity, (2) the type featuring the day‐other than normal by the letters b, p, o, and i for days marked by bay, rapid pulsations, long‐period oscillations, and irregular oscillations, respectively, and (3) the hour and minute of Greenwich mean time marking the beginning of a storm, the end of the storm being indicated in the foot‐note to the Table. The next two columns give the data relating to sunspots: (1) the number of groups of spots and (2) the total number of spots. It is to be noted that sunspot‐numbers such as those from Zürich can be obtained from the number of groups and spots given in the Table by the formula N= k (10g + s), where the mean value of k for Mount Wilson was 0.53 during 1936; during 1937 this value varied from 0.47 to 0.66 with an average value of 0.53.
Provisional solar and magnetic character‐figures, Mount Wilson Observatory, January, February, and March 1938
Authors: Nicholson Seth B. , Mulders Elizabeth Sternberg
Published: February 2008

A very large group crossed the Sun's disk between January 12 and 24 in latitude 17° north. It was comparable in size with the two largest groups of 1937, which crossed the central meridian on July 28 and October 4, respectively. A very bright chromospheric eruption occurred in this group on January 20 between 18h and 21h, GMT. Large prominences of the fountain‐like spot‐type were observed over the spot at the west limb on January 24.
Asymmetrical characteristics of the Earth's magnetic disturbance‐field
Authors: Vestine E. H.
Published: February 2008

Asymmetries in the Earth's magnetic disturbance‐field are considered in relation to the asymmetries in the Earth's main field, using data of 32 stations. The auroral‐zone curve of terrestrial magnetism, in north polar regions, is elongated in a direction roughly parallel to the elongation of Hsoclinic curves. It agrees roughly with the curve of maximum auroral frequency, as given by Fritz, except in regions where his auroral data were scanty. The curve appears to undergo regionally a small diurnal oscillation.

The amplitude of the disturbance diurnal variation (SD) is approximately symmetrical with respect to the geographical equator in low latitudes, is zonal‐symmetrical with respect to the auroral zone, and has a zero vertical component near the north pole given by the eccentric dipole. No change in amplitude with longitude has been detected, and it is concluded that induced earth‐currents in the oceans contribute little to SD.

The local time‐phase of the mainly sinusoidal variation SD shows a range of about four hours with longitude. But if in defining time the geographic north pole be replaced by the north pole given by the eccentric dipole, then at the auroral zone there is no significant variation in time‐phase with longitude. This suggests that the auroral zone has a controlling and initiating influence over the world‐wide electric currents responsible for SD.

Average asymmetries in the geographical distribution of magnetic disturbance and aurora are compared. The average force‐vectors for the daily means of disturbance are perpendicular to the average directions of homogeneous auroral arcs, to a high degree of approximation, in polar regions.

The SD electric current‐system of magnetic storms proposed by Chapman shows good general agreement with the extensive data here considered. Certain changes are suggested whereby the fit with observation may be improved.
Preliminary results of magnetic measurements at the “North Pole” station
Authors: Fedorov E.
Published: February 2008

We took magnetic measurements with the aid of a theodolite and also diurnal series of measurements of the magnetic variations using special visual magnetometers. A total of 55 measurements of declination and of horizontal intensity and 36 measurements of inclination were made.

Up to the middle of November, 1937, 14 diurnal series of measurements of variation were made, but later the ice‐floe began to turn around hindering the use of the variometers. As a result of measurement of the variations it was observed that the declination had an average diurnal value at about 6h, 13h, and 0h, GMT; between 6h and 13h the deviation was to the east, between 13h and 0h to the west, and between 0h and 6h a little to the east; these characteristics persisted in all cases. The amplitude ranged from 2° on quiet days to 10° on disturbed days. The horizontal intensity had an average diurnal value at about 6h, 10h, and 18h; a small maximum was observed from 6h to 10h, a large minimum from 10h to 18h, and a large maximum from 18h to 6h. In the main this character persisted. The amplitude ranged from 150 to 500 gammas.
Sitka Magnetic Observatory, April to June 1938
Authors: Gebhardt Robert E.
Published: February 2008

(Latitude 57° 03′.0 N., longitude 135° 20′.1 or 9h 01m.3 W. of Gr.)

April 13–15—A moderate magnetic storm began gradually at about 11h 42m GMT, April 13, with an increase in the horizontal intensity and decreases in the vertical intensity and east declination. The storminess gradually increased with short‐period vibrations superimposed on a long‐period motion. At 05h 26m, April 14, there was a sudden decrease in the horizontal intensity of 600 gammas accompanied by similar changes in the vertical intensity and declination. After 09h, April 14, the storm gradually subsided; the traces reaching normal values at 04h, April 15. Ranges: D, 102′; H, 1285 gammas; Z, 371 gammas.
Data for absolute storminess for the polar station Gjöahavn for the year of 1904
Authors: Wasserfall K. F.
Published: February 2008

Roald Amundsen took a set of Eschenhagen variation‐instruments for use on the Gjöa Expedition during 1903 to 1906 and at his base station Gjöahavn (latitude 68° 37′.6 north and longitude 95° 54′.8 west). That station was occupied from November 1903 to May 1905; hence almost complete hourly data for D, H, and V could be published for that period.

When the results from the expedition were published,1 there was no opportunity to undertake special studies of the variation of the magnetic elements, because the data collected were so abundant that publication had to be limited to the hourly values for the three elements D, H, and V. It has seemed, however, worth while to make further use of these valuable data and the present paper represents one of the special variation‐studies based thereon.
An alternating‐current apparatus for measuring small magnetic moments
Authors: Johnson E. A. , McNish A. G.
Published: February 2008

A method of measuring the moments of small magnetic dipoles is described. The dipole to be measured is rotated inside of a fixed coil, and the voltage induced in the coil is measured by means of an alternating‐current amplifier. The limiting sensitivity is computed from the calculated signal‐voltage and the thermal agitation in the input‐circuit. In the practical application the theoretical sensitivity is approximately obtained and moments of 3×10−7 CGS unit can be detected and with a specimen 1.5 cm on a side 8×10−8 CGS unit/cc can be detected. The method has been applied to the measurement of the polarization in sedimentary deposits.
Provisional solar and magnetic character‐figures, Mount Wilson Observatory July, August, and September, 1938
Authors: Mulders Elizabeth Sternberg , Nicholson Seth B.
Published: February 2008

The storm of July 15–17 and that of August 11 were probably associated with the very large and active group which crossed the central meridian on July 15.1 and again on August 10.9.

The storms of September 26 and 27–28 were probably associated with two active groups which crossed the central meridian on September 25.6 and 28.0.
Annual variation of the critical frequencies of the ionized layers at Tromsö during 1938
Authors: Harang Leiv
Published: February 2008

In previous notes the monthly means of the critical frequencies of the ionized layers for preceding years have been given. Regular observations were usually taken on six days during the week at 10h, 12h, and 14h local time. At Tromsö, situated near the auroral zone, the conditions of the ionosphere are strongly influenced by magnetic storms and the echoes are often lacking during disturbed periods, or more or less irregular and scattered echoes appear which sometimes make a precise critical‐frequency determination difficult.

Figure 1 shows the annual variation of the noon‐values of the critical frequencies for the ., , and E‐layers.
Giant pulsations recorded at Sodankylä during 1914–1938
Authors: Sucksdorff E.
Published: February 2008

Giant pulsations (GP) are a special kind of regular oscillations which at times appear in magnetic and earth‐current records1. They are registered as very characteristic and easily recognized series of sinusoidal waves; specimens of such registrations are reproduced in Figures 1, 2 and 32. The period of these oscillations remains constant in general throughout individual registrations and the amplitude shows generally a certain regularity also—either it develops continually to a maximum, decreasing thereafter (this may happen repeatedly), or the amplitude remains on the whole constant during a considerable part of the time of the pulsations. During the 25 years from 1914 to 1938 there were recorded 150 pulsations of this kind at Sodankyla or in other words, on the average, six pulsations every year.
Watheroo Magnetic Observatory April to June, 1939
Authors: Parkinson W. C.
Published: February 2008

April 16–19—The disturbance began with movements in all elements at 21h 29m GMT, April 16. During a period of five minutes D moved easterly 1″.8 and the numerical value of Z decreased 10 gammas; in a period of four minutes H increased 16 gammas. The period until 01h 57m, April 17, was comparatively undisturbed, at which time there was a typical sudden commencement in all elements; D moved easterly 2″.8, H increased 32 gammas, and the numerical value of Z decreased 14 gammas. The traces were then moderately disturbed until 24h, April 17, followed by a disturbance of milder character until 22h, April 19. Ranges: D, 22″.O; H, 282 gammas; Z, 195 gammas.
The magnetic character of the year 1938, review of the years 1928–1938, and numerical magnetic character of days 1938
Authors: van Dijk G.
Published: February 2008

The annual review of the “Caractère magnétique de chaque jour” for 1938 has been drawn up in the same manner as for the preceding years 1, moreover it contains a review of the collaboration of the observatories during the years 1928 to 1938.

In 1938, sixty–one observatories contributed to the quarterly tables; 46 of them sent complete data.
Provisional solar and magnetic character‐figures, Mount Wilson Observatory April to September, 1939
Authors: Mulders Elizabeth Sternberg , Nicholson Seth B.
Published: February 2008

The storm of April 17 began 24 hours after a large active sunspot‐group had crossed the central meridian in latitude north 13°. The group first appeared on April 12 and developed rapidly in size. A red auroral display was seen on Mount Wilson on April 17 while this storm was in progress.

A bright chromospheric eruption of intensity 3 began at 16h 47m GMT, April 21, in a spot‐group north 28°, east 60°. Starting at 16h 54m, H decreased 39 gammas in 21 minutes. The time of its recovery is uncertain because of a slight disturbance which lasted throughout the day. A very well‐marked radio fade‐out was observed at the Huancayo Magnetic Observatory, beginning at 16h 54m, with a complete fade‐out from 16h 56m to 17h 49m.
American URSI broadcasts of cosmic data, with american magnetic character‐figure CA July to September, 1939
Authors: Johnston H. F.
Published: February 2008

The data for terrestrial magnetism, sunspots, and solar constant are the same as given in previous tables.

The first three columns of Table 1 give (1) the magnetic character according to the scale 0–2 of the International Commission of Terrestrial Magnetism and Atmospheric Electricity, (2) the type featuring the day other than normal by the letters b, p, o, and i for days marked by bay, rapid pulsations, long‐period oscillations, and irregular oscillations, respectively, and (3) the hour and minute of Greenwich mean time marking the beginning of a storm, the end of the storm being indicated in the foot‐note to the Table.
Cheltenham Magnetic Observatory October to December, 1939
Authors: Ludy Albert K.
Published: February 2008

October 3–4—A mild disturbance began gradually about 07 h GMT, October 3. It reached its peak between 02 h and 06 h, October 4, during which interval all three elements had their greatest ranges. Ranges: D, 63′; H, 211 gammas; Z, 203 gammas.

October 6—An interval of moderate activity occurred between 05 h and 11 h GMT, October 6. Ranges: D, 22′; H, 123 gammas; Z, 126 gammas.
The ionosphere at Huancayo, Peru, July to September, 1939
Authors: Wells H. W.
Published: February 2008

This report on ionospheric conditions is in continuation of those published in preceding issues of this Journal submitting results of continuous multifrequency ionospheric recordings at the Huancayo Magnetic Observatory, Department of Terrestrial Magnetism, Carnegie Institution of Washington. The current data for the months July, August, and September, 1939, are obtained from recordings for each hour of the day and for every day of the month except for short intervals necessary for maintenance of the equipment.
The local variation of atmospheric potential‐gradient measured at Taihoku, Formosa, Japan
Authors: Ogasahara K.
Published: February 2008

In spite of the importance of the study of atmospheric electricity in tropical regions, there are practically few data of observations and many problems remaining still unsolved.

Formosa is an island extending over the north temperate and the tropical zones, and under both continental and marine meteorological influences it shows a special feature in weather‐type, for example, the Island is very often made the battle‐field of a polar continental airmass (Siberian) and a tropical marine air‐mass (Pacific Ocean) coming into collision to give rise to a great disturbance in the atmospheric‐ electric field there.
Report on work in terrestrial magnetism and electricity in U.S.S.R. during 1936–1939
Authors: Lazarev P. P. , Leuschin N. I. , Nikolsky N. N. , Pushkov N. V. , Trubyatchinsky N. N.
Published: February 2008

(I) Observatories and institutions—The work in terrestrial magnetism and electricity is done at many observatories and institutions. The fields covered by the principal ones are as follows:

(1) Institute of Theoretical Geophysics of the Academy of Sciences of U.S.S.R., Moscow—Investigational and experimental work in magnetism of rocks and ionosphere
American URSI broadcasts of cosmic data, with American magnetic character‐figure CA, October to December, 1939, and summary of CA for year 1939
Authors: Johnston H. F.
Published: February 2008

The data for terrestrial magnetism, sunspots, and solar constant are the same as given in previous tables.

The three columns for each month in Table 1 give (1) the magnetic character according to the scale 0–2 of the International Commission of Terrestrial Magnetism and Atmospheric Electricity, (2) the type featuring the day other than normal by the letters b, p, o, and i for days marked by bay, rapid pulsations, long‐period oscillations, and irregular oscillations, respectively, and (3) the hour and minute of Greenwich mean time marking the beginning of a storm, the end of the storm being indicated in the foot‐note to the Table.
Apia Observatory October to December, 1939
Authors: Sapsford H. Bruce
Published: February 2008

October 2–3—From 09h GMT, October 2, the H‐trace became disturbed and failed to rise to the usual maximum at about 23h. A steady decline in value commenced shortly after 01h, October 3, and a minimum value of approximately 34700 gammas was recorded at 03h 44m. Z was similarly affected but D was only very slightly disturbed. After the minimum value on October 3 the trace slowly returned to normal.
The ionosphere at Watheroo, Western Australia, October to December, 1939
Authors: Parkinson W. C. , Prior L. S.
Published: February 2008

The information contained in this report is similar in character to that supplied for previous months. Table 1, as before, gives the mean hourly values of minimum virtual height and critical frequency of the o wave‐component for the ionospheric regions for each hour during October, November, and December 1939, over those periods of the day when these values are scaled. It also includes mean hourly values of the lowest frequency recorded, fmin, when this frequency exceeded the lower limit of the frequency‐sweep, namely, 16.0 to 0.516 megacycles per second. Figure 1 gives the data of Table 1 in graphical form.
Alibag Magnetic Observatory October to December, 1939
Authors: Rangaswami M. R.
Published: February 2008

(Latitude 18° 38′.3 N., longitude 72° 52′.3 or 4h 51m.5 E. of Gr.)

October 3–4—A moderate disturbance began at 09h 00m GMT, October 3, with a sudden commencement which was not large. H attained its minimum value at 19h 16m, October 3. The disturbance ended at about 05h.5, October 4. Ranges: D, 4.′1; H, 168 gammas; Z, 27 gammas.
Geomagnetic tides in horizontal intensity at Huancayo
Authors: Bartels J. , Johnston H. F.
Published: February 2008

Following an introductory survey of the main features of the solar and lunar daily variations, S and L, in horizontal intensity, H, in January at Huancayo, days with conspicuous lunar influences, geomagnetic tides, are discussed. A separation of S and L on such “big‐L‐days” is attempted. Daily ranges A in H are then introduced for the study of the intensity of S and, thereby, of the solar wave‐radiation W. Up to international character‐figures C=1.1, A is found independent of changes in the solar corpuscular radiation P.

Various methods for studying L are compared. Lunar semimonthly waves in the ranges A are computed and discussed in their change with season and sunspot‐cycle. In the months November to March, when L is larger than in the rest of the year, L and S increase, in their effects on A, proportionally to each other from sunspot‐minimum to sunspot‐maximum, but around June, when L is small, it does not participate in the change of S with the sunspot‐cycle. The day‐to‐day variability of S and L is studied in some detail; S and L fluctuate rather independently of each other, and the relative fluctuations of L seem to be greater than those of S. The elimination of the lunar effect AL is described; (A − AL) = As is proposed as a measure for W.

A more extensive summary, including some results to be described in Part II, has been published elsewhere [see 4 of “References” at end of paper].
Notes on Isomagnetic Charts: V—The Occurrence of Local Dip‐ Poles
Authors: Chapman S.
Published: February 2008

Summary—It is shown that local magnetic dip‐poles occur in pairs or groups of pairs, and the nature of the isomagnetic lines and magnetic meridians is illustrated in the simpler cases, It is also shown that a local magnetic disturbance due to a single magnetic pole, if sufficiently intense, can produce one pair of dip‐poles, and that if the disturbance is due to the field of a sufficiently intense local dipole, there may be either one or two local pole‐pairs, according to the orientation of the dipole. If the dipole‐field is due to magnetization induced in a roughly spherical mass of magnetite or iron pyrites, by the existing normal field, the necessary susceptibility of the mineral, if it is to produce local dip‐poles, is shown to depend on the ratio of its radius to its depth, and on the local value of the normal horizontal intensity H. A classification of pie‐pairs according to this value of H and the distance between the poles of a pole‐pair is suggested.
Final Relative Sunspot‐Numbers for 1940
Authors: Brunner W.
Published: February 2008

Table 1 contains the final sunspot‐numbers for 1940, for the whole disk of the Sun, based on observations made at the Zürich Observatory, supplemented by series furnished by other cooperating observatories for days (indicated by asterisks) on which no observations were possible at Zürich.

Table 2 gives the yearly means of the relative numbers, R, since the last minimum 1933 and the number of days without spots.
Ionospheric Recordings During Magnetic Storm of March 1, 1941
Authors: Wells H. W.
Published: February 2008

Examination of automatic multifrequency ionospheric records obtained at the Kensington Experimental Station of the Department of Terrestrial Magnetism, Carnegie Institution of Washington, during the intense magnetic storm of March 1, 1941, reveals that the ionized regions of the Earth's outer atmosphere were greatly disturbed, and that the period of greatest disturbance corresponds to that of greatest magnetic activity.

Commencement of the ionospheric disturbance was associated with the development of an ionized region between the normal levels of the E‐ and F‐regions. Virtual height of this region was 160 km at 06h 15m GMT. By 06h 30m its maximum ion‐density had increased threefold and its virtual height had fallen to normal E‐region levels at 130 km. Radio reflections from this region were returned by the normal process of magnetoionic double refraction. Both ordinary and extraordinary wave‐components were recorded, and reflection‐coefficients were not high. Apparently the condition was not one of simple sporadic E‐region ionization.
Cheltenham Magnetic Observatory, January to March, 1941
Authors: Ludy Albert K.
Published: February 2008

January 16–21—On January 16 at 20h 30m GMT, a disturbance of mild proportions began and continued until the end of January 21. The greatest, K‐number during this interval was 5 which occurred eight times in the five days.

January 23–28—The field again became disturbed on January 23 and continued so until January 28. During this time there were three K‐numbers as great as 5.
Polarization‐Studies of Echoes Reflected from the Abnormal E‐Layer Formed during Geomagnetic Storms
Authors: Harang Leiv
Published: February 2008

The effect of geomagnetic storms and auroras on the ionosphere at high latitudes in the vicinity of the auroral zone may be summarized as follows: (a) Slight magnetic disturbances and faint auroras are accompanied by an increase of the ionization in the region of the E‐layer. Owing to this abnormal ionization the echoes reflected from the E‐region may be followed even up to 9 or 12 Mc/sec. This increased ionization sometimes screens off the F‐echoes completely, in other cases the strongly ionized layer formed in the E‐region is so thin that a considerable part of the energy penetrates the layer and reflections from the F‐region are obtained simultaneously, (b) Strong magnetic storms and great auroras are accompanied by complete cessation of the echoes on all frequencies over certain time‐intervals. This absorption‐effect is usually ascribed to the formation of an increased ionization at the lower boundary of the E‐layer, which causes increased absorption of the radio waves.
The rate of ion‐production at any height in the Earth's atmosphere: II—The Fourier expression for its daily variation
Authors: Chapman Sydney , Mian A. Majid
Published: February 2008

Summary—Part II: The daily variation in the rate of ion‐production at any level in any latitude at any season may be expressed in the form of a Fourier's series. For the equinoxes, when the Earth's curvature is neglected, the coefficients may be calculated in terms of integrals that can conveniently be represented approximately by index‐sums, as in Part I. At other seasons, however, and when the Earth's curvature is taken into account, the Fourier coefficients can probably be calculated most conveniently in terms of the Legendre coefficients determined in Part I.
HermanusMagnetic Observatory, October to December, 1941
Authors: Ogg A.
Published: February 2008

(Latitude 34° 25′.2 S., longitude 19° 13′.5 or 1h 16m.9 E. of Gr.)

October 2—There were small disturbances during the period 17h to 24h GMT, October 2.
Magnetic Observatory, Elisabethville, Belgian Congo
Authors: Heinrichs G.
Published: February 2008

The Elisabethville Observatory (latitude 11° 39′.5 south, longitude 27° 28′.1 east) was established for the Second International Polar Year of January 1, 1933, to January 1, 1934. Operation was discontinued until 1938 when the present Observer took charge. It was then found that the D‐ and H‐variometers could be put in operation but that the Z‐variorneter was so rusted that repairs were necessary; this explains the lack of vertical‐intensity values for 1938 in Table 1.
Solar and magnetic data, April to June, 1942, Mount Wilson Observatory
Authors: Nicholson Seth B. , Mulders Elizabeth Sternberg
Published: February 2008

No magnetic storms were recorded at Mount Wilson in April, May, or June, 1942.

Sunspot‐group No. 7397, with which magnetic storms had been associated in February and March, was last seen at the west limb of the Sun on April 3. Small disturbances in the Earth's magnetic field on April 1‐4 may have resulted from activity associated with this group.
Notes on the lunar geomagnetic tide: I—Its mathematical and graphical representations, and their significance
Authors: Chapman Sydney
Published: February 2008

Summary—This paper supplements and comments on a recent valuable discussion of the geomagnetic tide or lunar daily geomagnetic variation L by J. Bartels and H. F. Johnston; this referred particularly to the geomagnetic tide in Huancayo horizontal magnetic force, but also extended the existing notation for L, and illustrated L by means of two new types of harmonic‐dial diagram. The present paper is general in that it does not discuss results for L for any particular station or element; its chief novel feature is a further mode of representing L for any element and station, throughout half a lunation or any greater interval (ignoring seasonal changes), by means of a surface or by plane contour‐lines representing the surface. The relations between various aspects of L hitherto considered, by Chambers, Broun, Figee, Bartels, Johnston, and others, are elucidated with reference to this surface.