摘要:

Annual sunspot numbers since 1700 and the known maxima and minima since 1610 show a similarity of pattern from century to century. This suggests that the mean cycle is approximately 11‐1/9 years.The records of sunspots and aurorae enable magnitudes and dates of sunspot maxima since at least A.D. 300 to be estimated. The constancy of the mean cycle over long periods enables the number of missing maxima to be calculated, and, using certain general principles, a table of minima complete since at least 200 B.C. can be established. A 78‐year cycle appears to exist in the length of the sunspot cycle and an irregular cycle of about 200 to 205 years may exist in auroral intensity. A characteristic pattern in even centuries enables some predictions to be made for the next 50 years. Intervals between intense maxima in the range 200 to 1,000 years apart show clusters at certain values; these values are close to multiples of 11.11. Intervals between well‐dated maxima since A.D. 300 are often slightly less than such multiples, for example, 554 instead of 555; from B.C. 200 to A.D. 300, intervals are slightly greater. In classical and early medieval times the cycle was thus slightly less. The variability of the sunspot cycle is only apparent. The fundamental rhythm of 11.1 years (together with the 78‐year cycle) is constant through the centuries; temporary aberrations are partly due to variations in sunspot intensity, inasmuch as active cycles tend to become “early” and weak cy

ISSN:0148-0227    

DOI:10.1029/JZ060i002p00127

年代:1955

数据来源: WILEY

摘要:

Magnetograph records for February and March 1934 from Little America and College‐Fairbanks (Alaska) were examined for conspicuous disturbance movements with respect to their parallelism in time of occurrence. The study, although based on only a few available records, is unique, in that the two stations lie in about the same geographical meridian and each is located in respective northern and southern auroral zones. It was found that the time difference between the occurrences at the two stations is often small (a matter of minutes or less

ISSN:0148-0227    

DOI:10.1029/JZ060i002p00147

年代:1955

数据来源: WILEY

摘要:

Considerations suggesting the existence of an interplanetary magnetic field are presented. Such a field would not exceed about 5×10−8gauss, and its presence can explain the observed cutoff in the primary cosmic‐ray momentum spectrum. A field existing within the earth's orbit can account for all or part of the observed solar‐terrestrial time delays in aurorae and magnetic storms. The time required for the formation of a magnetic field pervading the solar system is less than 103years, and its lifetime against decay is probably more than 101

ISSN:0148-0227    

DOI:10.1029/JZ060i002p00155

年代:1955

数据来源: WILEY

摘要:

The observed delay of about 24 hours between the meridian passage of a sunspot or flare and the onset of an associated magnetic storm or aurora is shown to originate in the magnetic deflection of the ion streams involved. If a solar magnetic dipole is exclusively responsible, its moment must be between 6×1027and 1029gauss cm3. If an interplanetary magnetic field is involved, its magnitude is about 4×10−8gauss. Should both fields act, which is likely, then the above figures represent max

ISSN:0148-0227    

DOI:10.1029/JZ060i002p00161

年代:1955

数据来源: WILEY

摘要:

Geomagnetic works have been conducted on Volcano Mihara since its great eruption in 1950. As a result of repeated magnetic surveys marked changes in the geomagnetic field have been found. A continuous recording also proves the occurrence of anomalous changes in geomagnetic declination in connection with development and subsidence of the volcanic activity. It seems likely that the main parts of the geomagnetic changes thus found are caused by the demagnetization and magnetization within the volcano, which is composed of basaltic rocks containing a large amount of magnetite. Geomagnetic studies will be useful for inferring the internal state of certain volcanoes and sometimes even for the prediction of their eruptions.

ISSN:0148-0227    

DOI:10.1029/JZ060i002p00165

年代:1955

数据来源: WILEY

摘要:

A correlation method requiring six values of the correlation coefficient is developed. Expressions for the drift velocity, fading velocity, and characteristic velocity are obtained from a correlation theory extended to include an elliptical contour in the horizontal plane.The physical significance of the derived velocities is considered. Preliminary data indicate that the correlation ellipse exhibits a preferred orientation and that fading associated with random changes is as important as fading associated with a drifting pattern.

ISSN:0148-0227    

DOI:10.1029/JZ060i002p00173

年代:1955

数据来源: WILEY

摘要:

The effect of pressure on the ionic conductivity of peridot is measured and its influence on the electrical conductivity and temperature of the earth's mantle discussed.

ISSN:0148-0227    

DOI:10.1029/JZ060i002p00187

年代:1955

数据来源: WILEY

摘要:

The ambient positive‐ion composition of the upper atmosphere in the range 8 to 49 atomic mass units (AMU) was measured between 93 and 219 km by means of a Bennett radio‐frequency mass spectrometer. The experiment was flown in the Navy Viking 10 rocket, launched from White Sands Proving Ground, Las Cruces, New Mexico, at 10h00mMST, May 7, 1954. The most prominent ion peaks found between 93 and 124 km on the ascent were at 16, 26, 30, and 32 AMU. Other less prominent peaks occurred at 12, 18, 19, 21, 23, 38, and 45 AMU. From 124 to 219 km, ions of 16 and 32 AMU persisted. The results of this investigation are to be considered preliminary and need further verification, not only because the data were obtained from only one flight, but also because of complications introduced by a charge acquired by the rocket and by the evolution of gas from the roc

ISSN:0148-0227    

DOI:10.1029/JZ060i002p00193

年代:1955

数据来源: WILEY

摘要:

Simultaneous measurements of the 5577A line and the 3914A line in the aurorae are described. The measurements were made with a scanning photoelectric photometer. The 3914A line was present toward the north during the entire period of observation. The 3914A line usually showed a larger increase relative to the night‐sky background than did the 5577A line. In a pulsating aurora, the 3914A line showed many small pulsations, whose period was 1 to 2 seconds, in addition to the large pulsation

ISSN:0148-0227    

DOI:10.1029/JZ060i002p00205

年代:1955

数据来源: WILEY

摘要:

A source of variable 22.2‐Mc/sec radiation has been detected with the large “Mills Cross” antenna of the Carnegie Institution of Washington. The source is present on nine records out of a possible 31 obtained during the first quarter of 1955. The appearance of the records of this source resembles that of terrestrial interference, but it lasts no longer than the time necessary for a celestial object to pass through the antenna pattern. The derived position in the sky corresponds to the position of Jupiter and exhibits the geocentric motion of Jupiter. There is no evident correlation between the times of appearance of this phenomenon and the rotational period of the planet Jupiter, or with the occurrence of solar activity. There is evidence that most of the radio energy is concentrated at frequencies lower than 38 M

ISSN:0148-0227    

DOI:10.1029/JZ060i002p00213

年代:1955

数据来源: WILEY