CHANGES IN THE DIURNAL HOUR OF MAXIMUM OF THE COSMIC-RAY INTENSITY

1961 ◽  
Vol 39 (10) ◽  
pp. 1477-1485
Author(s):  
J. Katzman
Keyword(s):  
Solar System ◽  
Interplanetary Space ◽  
Geomagnetic Latitude ◽  
Cosmic Ray ◽  
Cosmic Ray Intensity ◽  
Latitude Belt

The diurnal hour of maximum of the meson component changed progressively at Ottawa, Canada, from 10 hr 44 min to 14 hr 40 min during the period January 1955 to December 1960 while the nucleon component changed from 12 hr 12 min to 15 hr 16 min for the same period. This evidence favors the 22-year cycle in the diurnal hour of maximum that was first suggested by Thambyahpillai and Elliot, for stations within a geomagnetic latitude belt between 58.1° N. and 48.1° S. The diurnal hour of maximum at Churchill changed from 14 hr 40 min to 15 hr 24 min during the period April 1957 to December 1960 for the meson component and from 15 hr 12 min to 15 hr 52 min for the nucleon component. Although the change was for a later hour the indication of a 22-year cycle at Churchill is not impressive. At Resolute the diurnal hour of maximum is dominated by the varying magnetic masses in interplanetary space. It is shown that the anisotropy varies both in magnitude and direction depending on the conditions that exist in the solar system.

Two anisotropies of the cosmic-ray particles producing the cosmic-ray diurnal variation

1968 ◽  
Vol 46 (10) ◽  
pp. S828-S830
Author(s):  
Masatoshi Kitamura
Keyword(s):  
Cosmic Rays ◽  
Diurnal Variation ◽  
Interplanetary Space ◽  
Geomagnetic Latitude ◽  
Cosmic Ray ◽  
Diurnal Variations ◽  
Low Energy ◽  
The Other ◽  
Energy Spectra ◽  
Cosmic Ray Intensity

The solar diurnal variations of both meson and nucleon components of cosmic rays at sea level at geomagnetic latitude 57.5° and geomagnetic longitude 0° are analyzed by the model in which two anisotropies of cosmic-ray particles (one of them, Δj1, from about 20 h L.T. and the other, Δj2, from about 8 h L.T. in interplanetary space) produce the solar diurnal variation of the cosmic-ray intensity on the earth.When the energy spectra of Δj1 and Δj2 are represented by [Formula: see text] and [Formula: see text], respectively, where j0(E) is the normal energy spectrum of the primary cosmic rays, it is shown that the evaluation for m1 = 1, 2, m2 = 0 and the cutoffs at 8 and 10 BeV on the low-energy side of spectra of both Δj1 and Δj2 agree well with the observational results at Deep River.

Cosmic Ray Intensity in Interplanetary Space

Nature ◽  
1960 ◽  
Vol 186 (4721) ◽  
pp. 299-300 ◽  
Author(s):  
H. ELLIOT
Keyword(s):  
Interplanetary Space ◽  
Cosmic Ray ◽  
Cosmic Ray Intensity

The Accuracy of Radiocarbon Dates

Antiquity ◽  
1963 ◽  
Vol 37 (147) ◽  
pp. 213-219 ◽  
Author(s):  
W. F. Libby
Keyword(s):  
Magnetic Field ◽  
Solar System ◽  
Cosmic Ray ◽  
Average Life ◽  
Radiocarbon Dates ◽  
Cosmic Ray Intensity ◽  
Rapid Mixing ◽  
The Past ◽  
The Earth ◽  
The Magnetic Field

The first test of the accuracy of dates obtained by the radiocarbon technique was made by determining whether dates so obtained agreed with the historical dates for materials of known age (n. 1). The validity of the radiocarbon method continues to be an important question, especially in the light of the numerous results that have been accumulated and the greater precision of the technique during the past few years (n. 2).The radiocarbon content of the biosphere depends on three supposedly independent geophysical quantities: (i) the average cosmic ray intensity over a period of 8000 years (the average life of radiocarbon) as measured in our solar system but outside the earth's magnetic field (n. 1); (ii) the magnitude (but not the orientation, because of the relatively rapid mixing over the earth's surface) of the magnetic field in the vicinity of the earth, averaged over the same period (n. 1,3); and (iii) the degree of mixing of the oceans during the same period (n. 1). The question of the accuracy of radiocarbon dates therefore is of interest to geophysicists in general as well as to the archaeologists, geologists and historians who use the dates.Previous workers in this area (n. 1, 2) have reported some discrepancies, and it is the purpose here to consider the matter further.

Time variations of directional cosmic ray intensity at low latitudes - III. Interpretation of solar daily variation and changes of east-west asymmetry

1961 ◽  
Vol 263 (1312) ◽  
pp. 127-135 ◽  
Keyword(s):  
Energy Spectrum ◽  
Interplanetary Space ◽  
Daily Variation ◽  
Cosmic Ray ◽  
Local Source ◽  
Cosmic Ray Intensity ◽  
The Earth ◽  
Low Latitudes ◽  
Time Variations ◽  
East West

The daily variation of cosmic ray intensity at low latitudes can under certain conditions be associated with an anisotropy of primary radiation. During 1957-8, this anisotropy had an energy spectrum of variation of the form aϵ -0.8±0.3 and corresponded to a source situated at an angle of 112 ± 10° to the left of the earth-sun line. The daily variation which can be associated with a local source situated along the earth-sun line has an energy spectrum of variation of the form aϵ 0 . Increases in east-west asymmetry and the associated daily variation for east and west directions can be explained by the acceleration of cosmic ray particles crossing beams of solar plasma in the neighbourhood of the earth. For beams of width 5 x 10 12 cm with a frozen magnetic field of the order of 10 -4 G, a radial velocity of about 1.5 x 108 cm/s is required. The process is possible only if the ejection of beams takes place in rarefied regions of inter­ planetary space which extend radially over active solar regions. An explanation of Forbush, type decreases observed at great distances from the earth requires similar limitation on the plasma density and conductivity of regions of interplanetary space. The decrease of east-west asymmetry associated with world-wide decreases of intensity and with SC magnetic storms is consistent with a screening of the low-energy cosmic ray particles due to magnetic fields in plasma clouds.

scholarly journals 39. The anisotropy of primary cosmic radiation and the electromagnetic state in interplanetary space

1958 ◽  
Vol 6 ◽  
pp. 377-385
Author(s):  
V. Sarabhai ◽  
N. W. Nerurkar ◽  
S. P. Duggal ◽  
T. S. G. Sastry
Keyword(s):  
Experimental Data ◽  
Cosmic Rays ◽  
Cosmic Radiation ◽  
Interplanetary Space ◽  
Daily Variation ◽  
Cosmic Ray ◽  
The Sun ◽  
Cosmic Ray Intensity ◽  
Daily Variations ◽  
Primary Cosmic Radiation

Study of the anisotropy of cosmic rays from the measurement of the daily variation of meson intensity has demonstrated that there are significant day-today changes in the anisotropy of the radiation. New experimental data pertaining to these changes and their solar and terrestrial relationships are discussed.An interpretation of these changes of anisotropy in terms of the modulation of cosmic rays by streams of matter emitted by the sun is given. In particular, an explanation for the existence of the recently discovered types of daily variations exhibiting day and night maxima respectively, can be found by an extension of some ideas of Alfvén, Nagashima, and Davies. An integrated attempt is made to interpret the known features of the variation of cosmic ray intensity in conformity with ideas developed above.

Eisenmeteorite als Raumsonden für die Untersuchung des Intensitätsverlaufes der kosmischen Strahlung während der letzten Milliarden Jahre

1962 ◽  
Vol 17 (5) ◽  
pp. 422-432 ◽  
Author(s):  
H. Voshage
Keyword(s):  
Interplanetary Space ◽  
Cosmic Ray ◽  
Gas Production ◽  
Rare Gas ◽  
Rare Gases ◽  
Production Rates ◽  
Cosmic Ray Intensity ◽  
Long Time ◽  
History Of ◽  
Exposure Ages

The use of iron meteorites for the establishment of possible long-time variations (108 —109 years) of the cosmic ray intensity in interplanetary space is based upon the study of the production rates of nuclides which are formed by the interaction of cosmic ray particles with nuclei in meteorites. Mass spectrometric measurements of the isotopic composition of meteoritic potassium * are combined with data on cosmogenic rare gases and other elements to give K41-K40-exposure ages and rare gas production rates. The K41-K40-exposure ages are larger than the exposure ages obtained from the study of short-lived activities (e. g. Cl36, A39), by a factor 1.3 to 1.8. This result indicates that the cosmic ray intensity increased during the bombardment history of the meteorites. The data, for example, are consistent with the following assumptions: 1) The cosmic ray intensity was constant during most of the bombarding time and increased by a factor of about 1.5 only a few million years ago. 2) The intensity rose as I(t) =I0 e— γt with —1.1·10-9 ≦ γ ≦ —0.6 · 10-9 a–1. The consequences of this result for the interpretation of meteorite data are discussed.

Semidiurnal Anisotropy of Galactic Cosmic Ray Intensity

1971 ◽  
Vol 49 (1) ◽  
pp. 34-48 ◽  
Author(s):  
G. Subramanian
Keyword(s):  
Energy Spectrum ◽  
Counting Rate ◽  
Interplanetary Space ◽  
Cosmic Ray ◽  
Cosmic Ray Intensity ◽  
The Earth ◽  
Positive Exponent ◽  
Semidiurnal Variation ◽  
Using Data ◽  
Galactic Cosmic Ray

The semidiurnal variation of galactic cosmic ray intensity is investigated using data from mainly high counting rate neutron and meson monitors during 1964–1968. It is shown that in order to explain the observed semidiurnal variation it is necessary that an anisotropy of cosmic ray intensity be present in interplanetary space. The energy spectrum and the asymptotic latitude dependence of the anisotropy are then determined. The energy spectrum has a positive exponent close to + 1 for the power law in energy. The strength of the anisotropy decreases more rapidly than cosλ with increasing asymptotic latitude λ, both cos2λ and cos3λ being acceptable. The distribution of cosmic ray intensity in the range of heliolatitudes ± 7.25° at the orbit of the earth, obtained using data from the Ottawa neutron monitor, does not support the explanation of the semidiurnal variation based on the models of Subramanian and Sarabhai or Lietti and Quenby.

scholarly journals Prediction of galactic cosmic ray intensity variation for a few (up to 10-12) years ahead on the basis of convection-diffusion and drift model

2005 ◽  
Vol 23 (9) ◽  
pp. 3003-3007 ◽  
Author(s):  
L. I. Dorman
Keyword(s):  
Interplanetary Space ◽  
Intensity Variation ◽  
Cosmic Ray ◽  
Particle Energy ◽  
Cosmic Ray Intensity ◽  
Convection Diffusion ◽  
Drift Model ◽  
Galactic Cosmic Ray ◽  
Near Future

Abstract. We determine the dimension of the Heliosphere (modulation region), radial diffusion coefficient and other parameters of convection-diffusion and drift mechanisms of cosmic ray (CR) long-term variation, depending on particle energy, the level of solar activity (SA) and general solar magnetic field. This important information we obtain on the basis of CR and SA data in the past, taking into account the theory of convection-diffusion and drift global modulation of galactic CR in the Heliosphere. By using these results and the predictions which are regularly published elsewhere of expected SA variation in the near future and prediction of next future SA cycle, we may make a prediction of the expected in the near future long-term cosmic ray intensity variation. We show that by this method we may make a prediction of the expected in the near future (up to 10-12 years, and may be more, in dependence for what period can be made definite prediction of SA) galactic cosmic ray intensity variation in the interplanetary space on different distances from the Sun, in the Earth's magnetosphere, and in the atmosphere at different altitudes and latitudes.

Sign in / Sign up

Export Citation Format

Share Document