A STATISTICAL ANALYSIS OF THE BAROMETER COEFFICIENTS FOR COSMIC-RAY INTENSITIES

1962 ◽  
Vol 40 (6) ◽  
pp. 687-697 ◽  
Author(s):  
S. M. Lapointe ◽  
D. C. Rose
Keyword(s):  
Statistical Analysis ◽  
Sea Level ◽  
Neutron Monitor ◽  
Seasonal Variations ◽  
Geomagnetic Latitude ◽  
Cosmic Ray ◽  
Seasonal Fluctuations ◽  
Latitude Effect ◽  
Standard Neutron ◽  
The One

The data from all four Canadian cosmic-ray stations, Ottawa, Resolute, Churchill, and Sulphur Mountain, have been analyzed statistically with the help of an I.B.M. 650 computer over a period of three and a half years extending from the beginning of the I.G.Y. in July 1957 to the end of 1960. The barometer coefficients for triple and double coincidences in the international cubical telescope and for the nucleon intensity in the standard neutron monitor have been derived. A single correlation between intensity and pressure was used; two different ways of effecting this correlation were tried over a 6-month period. The results were compared and the best method was applied to the remaining three years. Monthly values were calculated, as were yearly values and also values for the 3-year period. The results reveal no significant seasonal variations in the barometer coefficients and no significant year-to-year variation. However, the seasonal fluctuations of the nucleon coefficient unsuspectedly follow those of the meson. A small latitude effect seems to be present. The nucleon coefficient at Sulphur Mountain, a high altitude station, is larger than the one at Ottawa (same geomagnetic latitude, sea level station).

THE VARIATION OF SEA LEVEL COSMIC RAY INTENSITY BETWEEN 1954 AND 1957

1958 ◽  
Vol 36 (7) ◽  
pp. 824-839 ◽  
Author(s):  
A. G. Fenton ◽  
D. C. Rose ◽  
K. B. Fenton
Keyword(s):  
Solar Activity ◽  
Sea Level ◽  
Geomagnetic Latitude ◽  
Cosmic Ray ◽  
High Solar Activity ◽  
General Level ◽  
Intensity Level ◽  
Cosmic Ray Intensity ◽  
Primary Cosmic Radiation ◽  
The One

Results from neutron monitors and meson telescopes at Ottawa (geomagnetic latitude 57° N.) and Resolute (geomagnetic latitude 83° N.) are presented for the years 1954–57, a period of increasing solar activity. The results indicate that the sea level meson intensity at these latitudes decreased by 5–6% between April 1954 and December 1957. During the same period the intensity of the nucleonic component at these stations decreased by over 22%. Investigation of the relative response of the two types of recorder to transient decreases during this period indicates that the long term change in the intensity level cannot be explained completely as an accumulation of shorter transient decreases, which become more frequent at times of high solar activity. It is concluded that the transient decreases are superimposed upon the longer term changes, each being produced by a separate modulation process but ultimately controlled by the general level of solar activity. Significant differences are found in the shape of transient decreases observed at the Canadian stations, both between different components at the one station and the same component at different stations. These may be interpreted as due to a varying energy dependence from one transient decrease to another, and to anisotropy in the primary cosmic radiation at these times.

AN APPARENT ANOMALY OF THE BAROMETRIC COEFFICIENT FOR THE NUCLEONIC COMPONENT OF COSMIC-RAY INTENSITY

1964 ◽  
Vol 42 (10) ◽  
pp. 1847-1856
Author(s):  
S. M. Lapointe
Keyword(s):  
Statistical Analysis ◽  
Pressure Coefficient ◽  
Geomagnetic Latitude ◽  
Cosmic Ray ◽  
Attenuation Length ◽  
Cosmic Ray Intensity ◽  
Simple Theoretical Model ◽  
Standard Neutron ◽  
Nucleonic Component ◽  
Barometric Coefficient

A statistical analysis, based on three and one-half years of observational data, previously published by Lapointe and Rose (1962), produced a larger barometric coefficient for the nucleonic intensity in the standard neutron monitor at Sulphur Mountain (altitude 2283 meters) than at Ottawa (same geomagnetic latitude, sea level station).To explain this apparent anomaly, a simple theoretical model is presented which reproduces the results of this statistical analysis. The model treats the nucleonic component as consisting of two distinct cascades of nucleons, one "hard", characterized by a greater attenuation length and smaller pressure coefficient, and one "soft", characterized by a shorter attenuation length and larger pressure coefficient. The validity of the model is discussed.

scholarly journals Observing the neutron component during thunderstorm activity at a mountain CR station

2019 ◽  
Vol 5 (3) ◽  
pp. 54-58
Author(s):  
Анна Луковникова ◽  
Anna Lukovnikova ◽  
Виктор Алешков ◽  
Viktor Aleshkov ◽  
Алексей Лысак ◽  
...  
Keyword(s):  
Field Strength ◽  
Sea Level ◽  
Neutron Monitor ◽  
Electromagnetic Interference ◽  
Count Rate ◽  
Cosmic Ray ◽  
Thunderstorm Activity ◽  
Signal Discrimination ◽  
Lightning Discharges ◽  
Neutron Component

During three summer months in 2015, the Cosmic Ray (CR) station Irkutsk-3000, located at 3000 m above sea level, measured the CR neutron component intensity with the 6NM64 neutron monitor, as well as the atmospheric electric field strength and the level of electromagnetic interference during lightning discharges. It is shown that the level of electromagnetic interference, when registered during lightning discharges, depends considerably on the fixed level of signal discrimination. During observations, we observed no effects of thunderstorm discharges at the neutron monitor count rate at the CR station Irkutsk-3000.

III. Cosmic-ray latitude survey in Western USA and Hawaii in summer, 1966

1969 ◽  
Vol 47 (19) ◽  
pp. 2057-2065 ◽  
Author(s):  
H. Carmichael ◽  
M. A. Shea ◽  
R. W. Peterson
Keyword(s):  
Sea Level ◽  
Neutron Monitor ◽  
Cosmic Radiation ◽  
Measuring Equipment ◽  
Cosmic Ray ◽  
Temperature Structure ◽  
Western Usa ◽  
Secular Variations ◽  
The Usa ◽  
Different Levels

A 3-NM-64 neutron monitor and a 2-MT-64 muon monitor were operated at 29 sites near sea level and on mountains on the western seaboard of the USA and in Hawaii in May, June, and July, 1966, in continuation of the latitude survey begun in 1965 and reported in papers I and II of this set of five papers. The original results and also the corrections for temperature structure of the atmosphere and for secular variations of the cosmic radiation are given in detail. While the overland equipment was at its highest altitude on Mt. Hood (2.4 GV) and on the summits of Mt. Palomar (5.7 GV) and Mt. Haleakela (13.3 GV), an airborne neutron monitor was operated at seven different levels between 3000 m and 12 000 m. The pressure-measuring equipment and also the neutron monitor in the aircraft were calibrated in terms of the overland instruments while the aircraft was at the same altitude as the overland equipment on the summit of Mt. Haleakela.

LATITUDE EFFECT OF THE COSMIC RAY NUCLEON AND MESON COMPONENTS AT SEA LEVEL FROM THE ARCTIC TO THE ANTARCTIC

1956 ◽  
Vol 34 (9) ◽  
pp. 968-984 ◽  
Author(s):  
D. C. Rose ◽  
K. B. Fenton ◽  
J. Katzman ◽  
J. A. Simpson
Keyword(s):  
Sea Level ◽  
Cosmic Ray ◽  
The Arctic ◽  
High Latitudes ◽  
Geomagnetic Equator ◽  
Northern Latitudes ◽  
Latitude Effect ◽  
Nucleonic Component ◽  
The Antarctic ◽  
Eccentric Dipole

Results are presented of cosmic ray measurements taken at sea level during 1954–55 from the Arctic to the Antarctic. The equipment consisted of a neutron monitor and a meson telescope. Latitude effects of 1.77 for the nucleonic component and 1.15 for the meson component were measured. The longitude effect at the equator was much less than expected on the basis of the geomagnetic eccentric dipole and the longitude effect at intermediate northern latitudes shows that the longitude of the effective eccentric dipole is considerably west of that of the geomagnetic eccentric dipole. In a previous paper by the same authors, the positions of the equatorial minima were combined with other published cosmic ray measurements to calculate a new cosmic ray geomagnetic equator. In this paper new coordinates are derived on the assumption that these equatorial coordinates apply to a new eccentric dipole, and, therefore, that the equatorial coordinates may be extended to high latitudes. When the complete results are plotted on these coordinates, it is found that an eccentric dipole representation of the earth's magnetic field is inconsistent with the combined observations at all latitudes.

Time and other Variations in the Intensity of Cosmic Ray Neutrons

1951 ◽  
Vol 6 (11) ◽  
pp. 592-598
Author(s):  
N. Adams ◽  
H. J. J. Braddick
Keyword(s):  
Cosmic Rays ◽  
Solar Flare ◽  
Diurnal Variation ◽  
Sea Level ◽  
Geomagnetic Latitude ◽  
Cosmic Ray ◽  
Temporal Variations ◽  
Neutron Production ◽  
Neutron Intensity

AbstractWe have measured the barometer coefficient of cosmic ray neutron production at sea level and find the value -9,25% ± 0,20/cmHg. We have shown that there is no diurnal variation of neutron production of amplitude greater than about 0,4 %. The effects of the large solar flare of November 19 th , 1949 on cosmic ray neutrons were much greater than on ionising cosmic rays at sea level; the maximum factor of increase was more than 5 and the intensity remained measurably above normal for about 12 hours. A small increase of neutron intensity is found, statistically, to be correlated with a number of recorded radio fade-outs. It is suggested that neutron measurements are particularly suitable for studying temporal variations of cosmic rays. The latitude increase of cosmic ray neutrons between geomagnetic latitude 54,5° and 56,5° was found to be about 2%. No certain increase was found between 56,5° and 59,5°.

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