bluuebunny/crossref_metadata_2025 huggingface dataset:
Solar and Magnetic Data, October to December, 1943, Mount Wilson Observatory
Authors: Nicholson Seth B. , Mulders Elizabeth Sternberg
Published: February 2008

During the magnetic storm of October 24 to November 1 the only sunspot‐group visible was Mount Wilson No. 7621, a group of the old cycle, which was 82° east at. the beginning of the storm, 29° west at the end, and reached the west limb on. November 5. The polarities of the group were regular.

When this group reappeared at the east limb on November 20 (then numbered 7626), it was closely accompanied by a new group, No. 7625, also of the old cycle but with irregular polarities, which declined and disappeared while crossing the disk, being last seen on November 30. Group 7626 reached the west, limb on December 2. Its passage across the disk was accompanied by a magnetic storm (November 19 to 29); this was also true of the two immediately preceding passages (as No. 7621 mentioned above, and as No. 7617, for which see Terr. Mag., 48, 245, 1943).
Apia Observatory, July to September, 1943
Authors: Sapsford H. Bruce
Published: February 2008

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

August 8–9—The trace was slightly disturbed during the first week of August. Activity became more intense on August 8 and an unusual maximum occurred at 15h 51m GMT. The intensity of H then decreased steadily, reaching a minimum at 02h 00m, August 9, after which the trace gradually returned to normal; The range in H was 140 gammas. The maximum vertical intensity was recorded at 15h 24m, August 8, and the minimum at 01h 02m, August. 9, the range being 31 gammas. There were slight fluctuations in declination during the disturbed periods.
Magnetic Observatory, Hermanus, July to September, 1943
Authors: Ogg A.
Published: February 2008

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

July 2–14—Following micropulsations at 08h GMT, July 2, and forty‐five minutes later H increased, westerly declination increased, and Z increased numerically. The magnetograms remained comparatively smooth (except for micropulsations from 19h 51m to 20h 24m) until 22h 54m, when there was an abrupt change accompanied by micropulsations. The disturbances continued for about ten hours. Micropulsations appeared again from 22h 45m, July 3, to 01h 20m, July 4. The traces remained smooth until a gradual‐commencement storm began at 09h 54m, July 4. H increased 12 gammas in five minutes. The storm continued until 01h 30m, July 14. The period of greatest intensity was from 09h 54m, July 4, to 06h 00m, July 5. During this period there were three K‐indices of value 5 and four K‐indices of value 4. During the rest of the storm the maximum K‐index was 4.
Francis John Welsh Whipple, 1876–1943
Authors: Simpson G. C.
Published: February 2008

Dr. Francis John Welsh Whipple, whose death at the age of 67 years occurred on September 25, 1943, was primarily a mathematician and as an undergraduate took a very high place in the Mathematical School at Cambridge. After a short period as mathematical master at one of Britain's best known public schools, where he himself had been trained as a boy, he entered the London Meteorological Office in 1912. For 13 years his work was mainly concerned with meteorological instruments and climatology; but on the retirement of Dr. Charles Chree, Whipple was appointed to succeed him as Superintendent of Kew Observatory, a position held by his father 50 years previously.

Whipple was highly qualified for his new position: his scientific ability and knowledge were of the highest order, and he possessed, what is lacking in so many first‐rate scientists, interest in other people's work and readiness to devote his own time and thought to their problems. It is therefore not surprising that under his lead the scientific work at Kew Observatory was expanded and his staff of young men produced an outturn of scientific work which is memorable in the history of even such a celebrated Observatory as Kew.
Tucson Magnetic Observatory, January to March, 1944
Authors: Nelson J. H.
Published: February 2008

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

January 10–17—A magnetic storm of moderate intensity, but of long duration, began about 20h GMT, January 10. There were no outstanding characteristics of the storm other than that of generally rough magnetic weather. The end of the storm was difficult to identify, but the activity became less disturbed about the end of the Greenwich day, January 17.
Evaluation and Interpretation of the Columnar Resistance of the Atmosphere
Authors: Gish O. H.
Published: February 2008

The term columnar resistance is used by the writer instead of the more explicit but unwieldy phrase, namely: The electrical resistance of a vertical column of atmosphere having unit cross‐sectional area and extending from the Earth's surface to a specified altitude. This term and the conception, which it denotes, facilitate the discussion and interpretation of some aspects of atmospheric electricity. For example, the observation that the density of the electric current, which flows from air to earth in fair weather, is on the average, considerably smaller in the vicinity of large cities than over open country or over the oceans, may be attributed to a greater columnar resistance of the atmosphere over urban areas—a fourfold to fivefold increase is indicated for some places. Some impurities introduced into the air in various ways, such as by the burning of coal or other substances, increase the resistivity of the air thus polluted.
A Survey of Methods of Constructing Magnetic Charts
Authors: Bernstein Arthur
Published: February 2008

This survey of some of the literature on methods of representing the distribution of magnetic phenomena over the Earth's surface was undertaken primarily to provide a background for a study of the problem of improvement of methods of constructing world magnetic charts. In every case what was sought was a description of the method used in locating isomagnetic lines on charts, that is, of the scheme of interpolation used. With few exceptions, works written in English only were examined. Since the number of reports of magnetic surveys which include some description, however meager, of the method of interpolation is quite large, and since the number of different modes of construction is small, relatively few such reports have been abstracted.
Huancayo Magnetic Observatory, April to June, 1944
Authors: Ledig Paul G.
Published: February 2008

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

April 2—A moderate magnetic disturbance began with a small but sharp downward movement in H at 05h 37m GMT, April 2, which was followed by an irregular decrease to a deep bay at 09h 10m. This was followed by a sharp peak thirty minutes later and another even deeper bay just before 12h. After this time there was only mild disturbance during the daily maximum period and small irregular movements for the rest of the day. D and Z showed the effect of the disturbance largely by greater ranges than normal for the day. PAUL G. LEDIG, observer‐in‐Charge
Tucson Magnetic Observatory, July to September, 1944
Authors: Nelson J. H.
Published: February 2008

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

August 2–3—A rather severe storm began about 12h GMT, August 2. Between 12h and 22h the activity was rapid and of small amplitude. Following this period there were large variations in D and H, continuing until about 11h, August 3, at which time the storm ended quite suddenly. Ranges: D, 22′; H, 183 gammas; Z, 51 gammas.
Harmonic Analysis of the Annual Variation of Magnetic Declination and Horizontal Intensity at Oslo, 1843–1930
Authors: Wasserfall K. F.
Published: February 2008

Introduction—With reference to the author's work in reducing old data at Oslo for 1843–1930 [see 1 of “References” at end of paper] it will have been noted that the annual variation of the magnetic horizontal intensity (H) was of special interest because it was necessary in correcting numerous abrupt changes of unknown cause in base‐line values—changes not ascertainable from the absolute determinations. The reduction of the series in magnetic declination (D) required similar discussion of the annual variation in that element. In view of the importance of the annual variations it was deemed worth while to make harmonic analyses for them.

Material—The data used for the harmonic analyses are given in Tables 1 to 3 for D and 4 to 6 for H. For purposes of comparison the calculated harmonic constants for annual variations of the element at Rude Skov Observatory are added to each Table for the epoch 1920–30.
Tucson Magnetic Observatory, January to March, 1945
Authors: Nelson J. H.
Published: February 2008

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

January 28–30—A magnetic storm of moderate intensity began at 14h 55m GMT, January 28, with a small (6‐gamma) increase in H. During the first eight hours of the storm the activity was of short period and small amplitude. From 00h to 09h, January 29, there were moderately large swings in both D and H. Then the disturbance was mud until the end of the storm at 06h, January 30, Ranges: D, 14′; H, 145 gammas.
The Fifthieth Year of the Journal
Authors: Heck N. H.
Published: February 2008

It has rarely happened that two men have made outstanding contributions to a branch of earth science over a continuous, period of 50 years. These men are Bauer and Fleming. The contributions to terrestrial magnetism and electricity cover a wide range but not the least important is the founding and unbroken publication of the Journal of Terrestrial Magnetism and Atmospheric Electricity as an International publication. Bauer showed great vision and Fleming recognized the continuing need of a medium available to all students of the subject with its many and constantly increasing manifestations, and both made important personal contributions.

Some years ago a newspaper writer listed the JOURNAL among magazines with queer names. If the writer could be confronted with the contribution to the war effort of these apparently abstruse subjects he would not repeat his mistake.
The one‐hundred‐and‐tenth anniversary (1938) of the Kazan Magnetic Observatory
Authors: Pushkin N. F.
Published: February 2008

Kazan is one of the places on the Earth where regular magnetic observations began a long time ago. The first observations of declination were made here by Shopp in 1761. The declination at that time was westerly and amounted to 2° 25′. Later determinations of declination were made in 1805 by Schubert.
Watheroo Magnetic Observatory April to June, 1945
Authors: Parkinson W. C.
Published: February 2008

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

April 1—A short but sharp disturbance began at 04h 57m GMT, April 1, with a small sudden commencement shown in all three elements. The value of H began to decrease immediately afterwards and reached a minimum value at 09h 48m. The maximum activity during the disturbance occurred between 12h 20m and 13h 20m when there was a double peak of considerable dimensions in all three elements. After 14h 00m the traces gradually resumed their normal values and the disturbance came to an end at 18h 00m. Ranges: H, 100 gammas; D, 20′.8; Z, 115 gammas.
Scattering of radio waves from great virtual distances
Authors: Harang Leiv
Published: February 2008

Summary—Using a pulse‐transmitter of high power, scattered reflections corresponding to virtual reflection‐distances of 500 to 2,500 km have been obtained.

The test‐frequencies used (10–11 Mc/sec) were usually greater than the critical penetration‐frequencies of the F2‐layer. Records on a fixed frequency over a number of days have been taken in order to study the diurnal variation and dependence on geomagnetic activity and aurora. Four different phases in the diurnal variation have been recorded. During the two day‐phases it has been shown that the scattered reflections cannot come in vertically as they are not cut off by the F‐layer.

During the two night‐phases the echoes are reflected from scattering areas lying in or near the zenith at heights of 500 to 800 km. Small geomagnetic disturbances increased the scattering at these heights. Stronger perturbations were accompanied by scattering from heights down to 100 to 200 km.
Note on methods of determining the direction of auroral arcs from a single station
Authors: Harang Leiv
Published: February 2008

Observations have shown that the mean direction of auroral arcs and its diurnal variation are quantities which can be accurately determined and which further are characteristic for the place of observation. It should be of special significance, therefore, to secure reliable series of observations from places in both hemispheres for both geographical and secular studies of the mean directions of the arcs. The determination of the direction of the arcs is best made by measurement of the heights by means of parallactic photographs and plots of singular points of the lower border on a map. Unfortunately the possibilities for parallactic photography are limited, chiefly because the telephone‐lines seldom are available in the afternoon hours when the most splendid and quiet arcs frequently appear.
Sitka Magnetic Observatory July to September, 1945
Authors: Campbell Joel B.
Published: February 2008

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

July 1–2—A storm began at 00h GMT, July 1, and increased in intensity between 03h and 11h of the same date. After 11h, July 1, the storm continued moderately until 03h, July 2. The maximum K‐index recorded during the storm was 6.
Apia Observatory April to September, 1945
Authors: Sapsford H. Bruce
Published: February 2008

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

April 1—The H‐trace became disturbed at 05h 00m GMT, April 1, and fluctuated until 13h 12m on the same day, when the trace became normal. A maximum occurred at 05h 03m and a minimum at 08h 36m. The range in horizontal intensity during the storm was 106 gammas. D and Z were only slightly disturbed.
American magnetic character‐figure, CA, three‐hour‐range indices, K, and mean K‐indices, KA, for October to December, 1945, and summary for year 1945
Authors: Scott W. E.
Published: February 2008

Summaries of American URSI broadcasts have appeared regularly in this Journal since the issue for December, 1930.

As set forth in this Journal for June, 1937, “The Department of Terrestrial Magnetism and the United States Coast and Geodetic Survey with the cooperation of the United States Army and the United States Navy communication‐services and several amateur radio stations have undertaken to supply the American character‐figure based upon the reports of the seven American‐operated observatories—those of the Department of Terrestrial Magnetism at Huancayo in Peru and at Watheroo in Western Australia, and those of the United States Coast and Geodetic Survey at Cheltenham (Maryland), Honolulu (Hawaii), San Juan (Puerto Rico), Sitka (Alaska), and Tucson (Arizona).” This character‐figure is being designated CA, and its values for the first twelve, the second twelve, and all twenty‐four hours of each Greenwich day for October to December, 1945, are given in Table 1.
Mean K‐indices from thirty magnetic observatories and preliminary international character‐figures for 1944
Authors: Scott W. E.
Published: February 2008

K‐indices have been received at the Department of Terrestrial Magnetism from 30 magnetic observatories for the year 1944. Owing to difficulties of communication or stress of other scientific activities due to the world conflict, the records are not complete from all. Those contributing were, in order of geomagnetic latitude: Godhavn; Ivigtut; College; Lerwick; Dombås; Meanook; Sitka; Eskdalemuir; Rude Skov; Agincourt; Abinger; Srednikan; Yakutsk; Cheltenham; Zaimishche; Vyssokaya Dubrava; Zuy; San Fernando; Tucson; Dusheti; Tashkent (Keles); San Juan; Honolulu; Huancayo; Apia; Pilar; Hermanus; Watheroo; Toolangi; and Amberley. A newly contributing observatory is Pilar in Argentina, which has adopted 300γ as the lower limit of a K‐index of 9.
Resumption of full activities of International Union of Geodesy and Geophysics
Authors: Winterbotham H. S. J. L.
Published: February 2008

I have the honor to inform you that the International Union of Geodesy and Geophysics is about to resume its full activities. The Executive Committee, which has just met in Oxford, sends its hearty greetings, and desires me to give you the following information.

In the first place the Committee has made the following appointments, subject to the final approval of the next General Assembly:To be President of the UnionProfessor B. Helland‐HansenTo be General Secretary of the UnionDr. J. M. StaggNote. Owing to the continued absence of Dr. Stagg on duty in Germany, correspondence should be addressed to me until further notice.
Cause and effect in region F2 of the ionosphere
Authors: Bannon J. , Wood F. W.
Published: February 2008

For both hemispheres in the neighborhood of latitude 35° the behavior of region F2 of the ionosphere has been examined. It has been found that:

(1) There are great differences in the graphs of monthly mean noon values of maximum electron‐density (
) for Washington, Wuchang, and Tokio in the north, but only small differences for Watheroo, Mount Stromlo, Wellington, and Christchurch in the south.

(2) For all stations for which data are available, midnight
is in step with the Sun, being a maximum in summer and a minimum in winter.

(3) Noon values of
correlate with values of
cos½
(where
is the monthly mean Wolf sunspot‐number, and
is the local zenith‐angle of the Sun at noon on the 15th day of the month) to give correlation‐coefficients (ρ) equal to 0.50, 0.60, and 0.25 for Mount Stromlo, Watheroo, and Washington, respectively.

(5) Midnight values of the annual mean maximum electron‐density (
) for Washington are linearly related to annual mean sunspot‐numbers (
). This follows from the fact that noon values of
bear a linear relationship to midnight values of
. In 1937 about 90 per cent of
for Washington was due to sunspots.

(6) The noon values of monthly mean equivalent heights show very great seasonal fluctuations. The midnight values are comparatively steady.

(7) In the Northern Hemisphere the graph of
cos½
for the period 1934‐40 is, for the most part, in step with the Sun, whereas in the Southern Hemisphere it shows no relation to solar altitude.

It has been concluded that:

(a) There is a variation, in the composition of region F2, from place to place over the Earth's surface.

(b) The annual effect found by Berkner and Wells may be due to the variation in composition of region F2, and to the differences in
cos½
in the two hemispheres.

(c) The annual effect has not a sidereal cause.

(d) As far as annual mean values of maximum electron‐density are concerned, the transition from noon to midnight is not influenced by the number of sunspots.

(e) If the thermal‐expansion hypothesis is correct, midnight temperatures are probably low, and do not vary much throughout the year. Summer‐noon temperatures are very much higher than temperatures at midnight.
The meeting of the Executive Committee of the International Union of Geodesy and Geophysics, in Oxford, December 10–14, 1945
Authors: Winterbotham H. S. J. L.
Published: February 2008

Foreword

Papers laid before the Committee

(1) Report on the Proceedings of the Seventh (Washington) General Assembly

(2) Report of the General Secretary for the war period

(3) Notes on Administration

(4) Balance Sheet of Union Funds for the period January 1, 1939, to November 30, 1945

(5) Recommendations on the future administration of the Union, made by the British National Committee in February 1945

(6) Provisional Agenda.

The position in the autumn of 1945
Low‐level reflections observed at Christmas Island
Authors: Peavey R. C.
Published: February 2008

Observations of ionospheric reflections at heights significantly below normal E‐layer heights were made at Christmas Island Ionospheric Station during a series of manual multifrequency measurements made during June 11–30, 1945. The measurements were made after slight alteration of apparatus to reduce recovery‐time of ground pulse and to increase the gain of the receiver. Echoes were observed only during daylight hours and were usually quite weak. Qualitative estimate of their strengths was attempted in the categories “very weak,” “weak,” “fair,” and “strong,” relative to local background noise.
Cheltenham Magnetic Observatory October to December, 1945
Authors: Hershberger John
Published: February 2008

(Latitude 38° 44′.0 N., longitude 76° 50′.5 or 5h 07m.4 W. of Gr.)

October 12–13—A minor disturbance, resulting in three K‐indices of 5, began about 06h GMT, October 12, and ended about 10h, October 13.
Huancayo Magnetic Observatory October to December, 1945
Authors: Ledig Paul G.
Published: February 2008

(Latitude 12° 02′.7 S., longitude 76° 20′.4 or 5h 01m.4 W. of Gr.)

October 12—A short disturbance was registered on October 12 beginning about 10h.5 GMT with moderate movements in H and marked only by several moderate peaks and bays. The range in H was over 218 gammas. The disturbance ended between 14h and 15h.
Circular letter to all adhering countries: International Union of Geodesy and Geophysics
Authors: Stagg J. M.
Published: February 2008

(President: Professor B. Helland‐Hansen; Acting General Secretary: Dr. J. M. Stagg)

(1) I have the honour to inform you that, following the recommendations of the emergency meeting of the Executive Committee of the International Union of Geodesy and Geophysics held at Oxford in December, 1945, arrangements have now been made to hold an Extraordinary General Assembly of the Union at Cambridge, England, from July 29 to August 2 or 3, 1946.
Alibag Magnetic Observatory January to March, 1946
Authors: Rao M. P.
Published: February 2008

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

January 3–4—A storm of great intensity suddenly commenced at 08h 07m GMT, January 3, raising H by 44 gammas and lowering Z by 2 gammas in about six minutes. After a period of slight disturbance H began to fall rapidly at 10h 30m and in about ninety minutes H diminished by 256 gammas, after which there were some rises and falls both in H and Z, which resulted in one K‐index of 8 and two K‐indices of 7. The storm ended at about 21h, January 4. Ranges: H, 278 gammas; Z, 43 gammas; D, 8′.7.
Adolf Schmidt, 1860–1944
Authors: Bartels J.
Published: February 2008

On October 17, 1944, Adolf Schmidt, to whom geomagnetism owes many outstanding contributions, an eminent collaborator of this Journal since its first issue, died at Gotha, Germany, after a long and progressing infirmity.

Adolf Friedrich Karl Schmidt was born at Breslau on July 23, 1860, as the son of an engineer. He studied, from 1878, mathematics, physics, and English at his home town; with a mathematical thesis, on Cremona transformations, he got his doctor's degree, in 1882. At Breslau Observatory he helped in the magnetic readings for the First International Polar Year, 1882–83; he is therefore one of the few scientists who took an active interest in both Polar Years, since he attended, by special invitation of Dr. la Cour, the meeting of the International Polar Year Commission, for 1932–33, at Copenhagen in May 1933. He was teacher and professor in the Gymnasium Ernestinum at Gotha until 1902, when he was called to direct the Potsdam Magnetic Observatory. He lectured in Berlin University, and the rare title of ordinary honorary professor was conferred on him in 1907. He retired in 1929 and returned to Gotha.
Periodicity of geomagnetic activity
Authors: Ogg A.
Published: February 2008

In a paper published in this Journal [51, 75–83, (1946)], which dealt chiefly with the correlation of the three‐hour‐range indices (K) at Hermanus with those at seven American‐operated observatories,. I drew attention to the question of the periodicity of the geomagnetic activity.

Periodograms which were published indicated in one group of K‐indices periodicities of 9, 18, and 27 days, and in another group periodicities of 14 and 28 days. However, from the method, which was adopted in the search for periodicity, a high correlation‐ratio for 18 and 27 days did not prove 18‐ and 27‐day periods, if there existed a nine‐day period in the group.
The radial stability of the geomagnetic ring‐current (Second paper)
Authors: Ferraro V. C. A.
Published: February 2008

An exact solution is given of an idealised problem, approximately treated by S. Chapman and the writer in an earlier paper dealing with the radial stability of a geomagnetic ring, in which the ring is replaced by an electrically neutral uniform cylindrical current‐sheet whose axis is parallel to the magnetic axis of the Earth. The conclusions of that paper are substantiated, and though it is shown that the sheet is in reality unstable, the rate at which instability sets in is so slow that the sheet may well be considered to be stable. This rate is, moreover, comparable with the rate of decrease of intense and moderate magnetic storms.
Sitka Magnetic Observatory July to September, 1946
Authors: Cleven Merril L.
Published: February 2008

(Latitude 57° 03′.0 N., longitude 135° 20′.1 or 9h 01m3 W. of Gr.)

July 14—A brief minor disturbance beginning rather suddenly at 13h30m GMT, was characterized by a change of 520 gammas in H. The displacement of all three elements continued for about an hour, and a K‐index of 7 was recorded for this period.
Huancayo Magnetic Observatory April to September, 1946
Authors: Ledig Paul G.
Published: February 2008

(Latitude 12° 02′.7 S., longitude 76° 20′.4 or 5h 01m4 W. of Gr.)

April 22–24—Along but moderate magnetic storm began on April 22 at 06h 58m GMT with a sharp increase in H of 43 gammas in four minutes, and was followed for about 26 hours by minor disturbances characterized by small, rapid peaks and bays. A general increase in H began at 09h 20m, April 23, with somewhat larger but still rapid peaks and bays, coming up to a low maximum at the usual midday period and then followed by a long, jagged decline lasting all afternoon and ending with a minimum of 298 gammas below the base‐line at 23h 42m. After this the storm gradually died out with moderate, slow peaks and bays during a slow increase in H for another twelve hours on April 24. D and Z showed only mild activity during only the daylight hours of April 22 and 23.
Hermanus Magnetic Observatory July to September, 1946
Authors: van Wijk A. M.
Published: February 2008

(Latitude 34° 25′.2 S., longitude 19° 13′.5 or 1h 16m9 E. of Gr.)

July 3—A minor disturbance began with a small “sudden commencement” at 0lh 21m GMT, July 3, and continued until about 17h.
Committee on Geophysical Sciences of the Joint Research and Development Board (U.S.A.)
Authors: Piggot C. S.
Published: February 2008

The first and organizational meeting of the Committee on Geophysical Sciences of the Joint Research and Development Board was recently held in Washington, D.C. This Committee was established by the Joint Research and Development Board to assist the Board in carrying out the provisions of its Charter in those departments of scientific research lying within the geophysical sciences. These include the following:

Physics of the upper atmosphere in the region where cosmic rays and ultra‐violet light are of considerable significance and in which long‐range rockets and possibly jet‐planes will attain great speeds.
Sitka Magnetic Observatory October to December, 1946
Authors: Campbell Joel B.
Published: February 2008

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

October 26–27—A moderately disturbed period began rather slowly at about 04h GMT, October 26, and was characterized by long‐period oscillations until about 15h of the same date when activity nearly ceased. However, at about 23h there appeared short‐period, low‐amplitude oscillations which soon became superposed on rather large bays. A maximum of disturbance was reached between 08h and 15h GMT, October 27, when K‐indices of 9, 8, and 7 were recorded. The traces for several days following this moderately severe storm showed signs of slighter disturbances.
Terrestrial influences in the lunar and solar tidal motions of the air
Authors: Wulf Oliver R. , Nicholson Seth B.
Published: February 2008

Tidal motions in the atmosphere have been the subject of much study including both the tide produced by the Moon and also the tide‐like motion produced by the Sun in which thermal as well as gravitational effects enter. In discussing the lunar atmospheric tide, Chapman [see 1 of “References” at end of paper], to whom a considerable part of our knowledge of this subject is due, has emphasized the importance of peculiarities that manifest themselves in the behavior of such a relatively simple effect. The lunar effect is simple, in contrast to the solar, because it is purely gravitational in origin, free from direct thermal influences which are important in the latter. Complexities that appear in the lunar tide must apparently be due to the atmosphere itself and its lower boundary, the surface of the Earth.
Diurnal variations of computed electric currents in the high atmosphere
Authors: Sucksdorff E.
Published: February 2008

This investigation is based on the supposition that the observed departures of the geomagnetic force from a mean value are caused by infinite electric line‐currents, or at least very narrow ones, which flow across the meridian. It has been done according to a simple trigonometric method.

The departures of the components of the magnetic force in a vertical geographic meridian plane through the station are expressed by ΔX and ΔZ. The ratio (ΔX/ΔZ) = tan α in which α stands for the angle between the resultant vector and the downward direction, which is the same as the elevation‐angle of the supposed line‐current in the meridian plane above the horizon. Thus the direction towards the current is determined. From the positive or negative sign of ΔX and ΔZ it can be concluded whether the current flows to the north or south of the station and whether its direction is eastward or westward.
Needs of Geophysical Service in Austria
Authors: Toperczer M.
Published: February 2008

As leader of the Geophysical Service in Austria, I now take the opportunity to enter into communication with colleagues in countries which have not been devastated by the war. I turn to you with the request for your assistance in scientific connections, and, if possible, I add the request for support of my coworkers in a material sense.

As a direct result of the war the Geophysical Service here has been especially hard hit in its installations. It has suffered the loss of almost all of its difficultly replaceable special equipment. The magnetic base‐station was completely destroyed. We also lack all the recent scientific literature.
Apia Observatory October, 1946, to March, 1947
Authors: Beagley J. W.
Published: February 2008

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

October 8–10—A mild disturbance emerged at 17h 24m GMT, October 8, and continued until 00h 13m, October 10. Movement was irregular. A negative bay during the second three‐hour period, October 9, gave the maximum K‐index 5,
Watheroo Magnetic Observatory January to March, 1947
Authors: Wood F. W.
Published: February 2008

(Latitude 30° 19′.1 S., longitude 115° 52′.6 or 7h 48m.5 E. of Gr.)

January 4–5—A sudden commencement was recorded at 11h 18m GMT, January 4. The horizontal intensity increased by 41 gammas in one minute, west declination decreased by 1′ and then increased by 4′, while the vertical intensity showed a sudden decrease of 3 gammas followed by an increase of 16 gammas. H dropped fairly sharply by 69 gammas in the next hour, whereas D and Z recovered their original values within about ten minutes of the commencement. For the next eleven hours all elements showed large irregular movements without departing appreciably from normal values. From 22h 30m, January 4, until 04h, January 5, conditions were quiet. Moderately disturbed conditions prevailed again from 04h onward, with small, rapid fluctuations at first followed by large, slow swings which died away by about 22h, January 5. At this stage the elements were practically normal again. However, conditions were a little unsettled for a further period of about twenty hours. Ranges: D, 14′; H, 83 gammas; Z, 86 gammas.
Polar radio disturbances during magnetic bays
Authors: Wells H. W.
Published: February 2008

Comparison of ionospheric and magnetic records at College Observatory, College, Alaska, shows very definite ionospheric effects during magnetic bays. High absorption producing partial to complete radio blackouts was coincident with each of 69 significant magnetic bays which were examined for the period January to September, 1942. The radio absorption is limited to duration of the magnetic bay, thereby establishing a direct relationship which is unusual in magnetic‐ionospheric investigations.

Strong absorption of radio waves associated with complete disappearance of all signals is often encountered in the polar regions. This condition is known to become more pronounced during periods of magnetic and ionospheric disturbance. Continuous operation of the Observatory at College, Alaska, near the zone of maximum auroral and magnetic activity, has revealed important information concerning ionospheric characteristics and radio wave‐propagation in polar regions. College Observatory was established in 1941 by the Department of Terrestrial Magnetism of the Carnegie Institution of Washington, in cooperation with the University of Alaska. It was operated by the Carnegie Institution of Washington until 1946 with support of the National Defense Research Committee, Navy Department, and the Wave Propagation Committee of the Joint Communications Board. Since 1946 operation was continued by the University of Alaska under contract with the Central Radio Propagation Laboratory of the National Bureau of Standards. The general program includes continuous ionospheric recordings over a wide range of frequencies, signal‐intensity recordings on high‐frequency broadcasting stations, magnetic observations, auroral studies, and special direction‐finder operations.
Graphs of the induced magnetic moment and shielding effect of a spherical shell in a uniform magnetic field
Authors: Tuckerman Bryant
Published: February 2008

This paper presents graphs of well‐known formulas for the induced magnetic moment and shielding effect of a spherical shell of constant permeability introduced into a uniform magnetic field. The problem is of interest in the theory of the deviations and compensation of the magnetic compass, and in the shielding of electromagnetic instruments from external magnetic fields.

Barlow [see 1 of “References” at end of paper] in an experimental investigation of the deviations of a compass produced by spherical balls and shells, concluded, “... the tangents of the deviation are proportional to the cubes of the diameters, or as the 3/2 power of the surface, whatever may be the weight and thickness... . This law, however, I have since found to have its limits; ... the magnetic fluid requires a certain thickness of metal, exceeding 1/30 inch, in order effectually to develop itself, and to act with its maximum of effect.” The latter conclusion was based on work with ten‐inch spheres.
Geomagnetic data in China at Zô‐Sè and Tsingtao Magnetic Observatories
Authors: Burgaud M.
Published: February 2008

Tables 1 and 2 give the geomagnetic elements so far as recorded in 1943 and 1944 and so observed with absolute instruments for three months in 1945 and 1946 and for the first five months of 1947.
Hermanus Magnetic Observatory
Authors: van Wijk A. M.
Published: February 2008

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

April 2–3—Small crochet‐type deflections on the D‐ and Z‐traces at 10h 15m.5 GMT, April 2, were followed by abrupt changes in all three elements at 15h 01m.5, April 3. The mild disturbance which ensued, died away at about 24h, April 3.
Notes on the Aurora Australis
Authors: Thomsen I. L.
Published: February 2008

Before 1933 very little was known concerning the appearance of the Aurora Australis as seen from New Zealand, except from odd newspaper reports and the casual remarks passed by residents of the southern half of the South Island. Certainly very little, if anything, was ever published in scientific transactions. The general feeling of the scientific world at large, was that if one wished to study aurora in the Southern Hemisphere it was necessary to make a trip to the Antarctic. Up to the time of the Byrd Antarctic Expedition of 1929, most of our knowledge of the Aurora Australis had been obtained from the printed reports of Antarctic expeditions, commencing with Cook in 1773.
K‐indices and sudden commencements, July to September, 1947, at Abinger
Authors: Jones H. Spencer
Published: February 2008

I enclose the list of K‐indices of geomagnetic activity at Abinger for July to September, 1947, in Table 1.

In view of the interest which is now attached to “Sudden‐Commencement” phenomena, I append in Table 2 a list of the times at which these characteristic movements have appeared on the Abinger traces during the same period. The time is “Universal Time” (UT = GMT). An asterisk (*) indicates that the movement, though abrupt, was not characteristically “sudden.”
Mean K‐indices from thirty magnetic observatories and preliminary international character‐figures, C, for 1946
Authors: Scott W. E.
Published: February 2008

K‐indices have been received at the Department of Terrestrial Magnetism from 31 magnetic observatories for the year 1946. The records are not complete from all, but the average number reporting was 30. Those contributing (arranged in order of geomagnetic latitude) were as follows: Godhavn; College; Lerwick; Dombås; Sitka; Eskdalemuir; Rude Skov; Agincourt; Witteveen; Abinger; Srednikan; Yakutsk; Cheltenham; Zaimishche; Vyssokaya Dubrava; Moscow; Zuy; San Fernando; Tucson; Dusheti; Tashkent (Keles); San Juan; Honolulu; Alibag (the lower limit for a K‐index 9 is 300γ at Alibag); Huancayo; Apia; Pilar; Hermanus; Watheroo; Toolangi; and Amberley. No reports were received for 1946 from Sodankylä, Slutsk, Chambon‐la‐Forêt, Zô‐Sè, and Kuyper.
Summary of the year's work, to June 30, 1947, Department of Terrestrial Magnetism, Carnegie Institution of Washington
Authors: Tuve M. A. , Harradon H. D.
Published: February 2008

This first year of post‐war operations marks a major change in the activities of the Department, with the completion of the observatory and field‐party work of the world magnetic survey.

Much of our effort in the past has been concerned with obtaining and interpreting large numbers of observations on the magnetic and electric conditions of the Earth. During the first two decades after 1904 the Department was occupied with a world survey of the Earth's magnetic and electric fields, using the Galilee and the Carnegie to cruise all the oceanic areas, and organizing parties on land to occupy thousands of stations scattered over every continent and in the Arctic and Antarctic. At the end of World War I plans were inaugurated for establishing a number of observatories, to be located at the special sites needed to round out at least a rough approximation of a world coverage, in order to make systematic studies of the variations of the Earth's magnetic and electric fields and other related quantities, particularly in relation to solar effects and magnetic storms. Only two of the list of projected observing stations were established, one at Huancayo, Peru, and the other at Watheroo, Western Australia, but these were fortunately the most vital locations needed for a reasonable world picture. Largely by reason of the extensive and accurate observations made at these stations, comprehensive treatments of the daily, yearly, and sunspot‐cycle effects on the electrical currents in the upper atmosphere and in the Earth's crust have been made during the past 20 years, and many new facts brought out, especially in relation to magnetic storms and other aspects of solar activity. The addition of new analytical procedures based on the technique of observing echoes from radio‐pulse transmitters, first demonstrated by the Department's laboratory group in 1925, gave quantitative information of great significance, and this work was expanded into world‐wide activities of the Armed Services of many nations and all agencies concerned with radio communication. Numerous other cooperative activities, concerned with seismology, meteorology, cosmic and auroral rays, and other solar disturbances have fitted naturally into this program. The original planning for this observatory‐program contemplated the integration of our stations into the scientific life of their local areas, and the expected transfer of our activities to local sponsors at the end of 25 years.
Watheroo Magnetic Observatory July to September, 1947
Authors: Wood F. W.
Published: February 2008

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

(Latitude 30° 19′.1 S., longitude 115° 52′.6 or 7h 43m.5 E. of Gr.)
The production of the E‐layer
Authors: Hoyle F. , Bates D. R.
Published: February 2008

Difficulties in the current theory of the formation of the E‐layer are summarized. Consideration is given to the possibility that it is produced by the high‐energy photons that are thought to be emitted by the solar corona. The energy‐distribution needed is investigated, and it is found that it is sufficient that there be a photon‐group either at about 325 e‐V or at about 1300 e‐V. However only the former would give detailed agreement with observation; the latter would not be fully satisfactory owing to the effects of secondary emission in the Earth's atmosphere. The general requirements are consistent with the predictions of solar theory.
Zô‐Sè Observatory July to December, 1947
Authors: Burgaud M.
Published: February 2008

(Latitude 31° 05′.8 N., longitude 121° 11′.2 or 8h 04m.8 E. of Gr.)

July 17—A preliminary beginning, at 10h 37m GMT, July 17, was followed by a second greater one, amounting to 70 γ, at 17h 50m. The disturbance was a moderate one, lasting one day. Maximum range was 160 γ andwas recorded during the first three hours of the perturbation.
Hermanus Magnetic Observatory July to December, 1947
Authors: van Wijk A. M.
Published: February 2008

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

July 16–18—Bays of K‐index 3 began abruptly on all three traces at 01h 08m GMT, July 16. These were followed by small “twitches” in the records at 10h 38m, July 17, and finally by a storm of considerable intensity, beginning with a sudden commencement at 17h 49m (H, 56 γ). During the first two hours of the disturbance, small irregular oscillations were super‐imposed on the larger movements. The seventh three‐hour period of July 17 yielded a K‐index of 8. The ranges of the storm were as follows: D, 26′.2; H and Z, 217 γ. While recovery commenced soon after H had reached its minimum value at 15h 11m, July 18, it would be difficult to say exactly when the storm ended, as small disturbances continued almost without interruption until the end of the month.
Magneto‐ionic measurements at high latitudes
Authors: Scott James C. W.
Published: February 2008

Measurements of F2‐layer critical frequencies for z‐, o‐, and x‐modes at Clyde River Baffin Land, on the assumption of the law

math image

indicate large diurnal and seasonal variations in the magnetic field. Superimposed on these periodic changes a drop of 20 per cent in apparent field occurred in February, 1946, which persisted through September. The variation of gyro‐frequency with height is greater than would be expected from the inverse‐cube law and the law

is not confirmed.
“True”‐reading magnetic compasses
Authors: May W. E.
Published: February 2008

On one occasion, during the late war, a young officer in command of a British motor torpedo boat demanded that the Naval Store Officer should supply him with a compass in which the card was mounted askew on the needles so that it should read true instead of magnetic. He appears to have overlooked the fact that the variation differed through about 5° in the area of his possible operations and probably thought that his idea was revolutionary. Actually, the idea has often been proposed and sometimes adopted.

Already, by the Fifteenth Century it was known that the compass‐needle did not point truly to the North Pole but erred by an angle which later became known as the variation. The navigators of the day were not very clever at mathematics and someone hit upon the idea of off‐setting the needles from the fleur‐de‐lys, which indicated the north point of the card, by the amount of this variation. The idea seems to have caught on among the compass‐makers of the northern and western coasts of Europe but, unfortunately, the variation not being the same everywhere, all did not adopt the same angle of slew or “set of the compassé” as it was called [see 1 of “Authorities quoted” at end of paper]. It followed that, if compasses made in different localities were used together, the ignorant sailor might be confused by the difference between them.
Alexander Ogg, 1870–1948
Authors: van Wijk A. M.
Published: February 2008

The death occurred in Johannesburg on February 24, 1948, of the well‐known South African scientist and geomagnetician, Dr. Alexander Ogg

As a result of some fifty years of research work of first‐rate importance, Dr. Ogg enjoyed a world‐wide reputation as a physicist. In the country of his adoption his outstanding services were widely acclaimed, and it was said of him in 1936, on the occasion of his retirement from the chair of Physics at the University of Cape Town, that to him more than any single man did South Africa owe the extent and high quality of physical research which is being carried out in the Union.
List of geomagnetic observatories and thesaurus of values—VIII
Authors: Fleming J. A. , Scott W. E.
Published: February 2008

The International Association of Terrestrial Magnetism and Electricity at the Stockholm Assembly in August 1930 appointed a Committee to consider existing and desirable distribution of magnetic and electric observatories and the better coordination of work and publications of existing observatories. That Committee submitted reports at subsequent assemblies of the Association in 1933 (Lisbon), 1936 (Edinburgh), and 1939 (Washington) which are published in Bulletins 9, 10, and 11 of the Association. At the Lisbon Assembly it recommended that there be prepared and published a second and revised edition of the “Liste des observatoires magnétiques” of 1910 to include not only detailed information regarding organization, history, geographic position, elevation above sea‐level, instrumentation, publications, personnel, and special remarks for each observatory, but also a complete thesaurus of annual values of the geomagnetic elements. An up‐to‐date summary of finally corrected annual values for both existing and discontinued observatories is much needed for international services, unification of publications, and centralization of magnetic data.
Thunderstorm electricity
Authors: Workman E. J.
Published: February 2008

A recent article by G. C. Simpson [Terr. Mag. 53, 27–33 (1948)] described the remarkable “mirror‐image effect.” The effect is illustrated by curves which show that the current from a needle point placed 8.4 meters above the ground at Kew Observatory was negative (that is, a negative potential‐gradient existed) when the charge on precipitation particles reaching the ground was positive, and vice versa.

Much less refined measurements made by investigators from the New Mexico School of Mines, Research and Development Division, in the spring of 1947 at the top of Sandia Mountain (altitude 10,700 feet) near Albuquerque, New Mexico, yielded similar results. A Wilson electrometer connected to the inner surface of an Erlenmeyer flask having the neck removed and the inner surface sputtered with a transparent but electrically conducting surface of gold was used for the measurement of particle charges. A generating‐voltmeter‐type field meter was used for potential‐gradient measurements. Only qualitative field measurements were sought.