On the diurnal variation coefficients of the nucleonic component of cosmic rays

1978 ◽  
Vol 45 (3) ◽  
pp. 243-274
Author(s):  
M. F. Tolba ◽  
S. A. Wahab ◽  
A. M. Salem
Keyword(s):  
Cosmic Rays ◽  
Diurnal Variation ◽  
Nucleonic Component

Radial and Latitudinal Gradients in Galactic Cosmic Rays

1994 ◽  
Vol 11 (2) ◽  
pp. 170-174 ◽  
Author(s):  
D. L. Hall ◽  
J. E. Humble ◽  
M. L. Duldig
Keyword(s):  
Cosmic Rays ◽  
Diurnal Variation ◽  
Galactic Cosmic Rays ◽  
Latitudinal Gradients ◽  
Solar Cycles ◽  
Neutron Monitors ◽  
Field Reversal ◽  
Muon Telescope ◽  
Surface Muon ◽  
Underground Muon

AbstractWe have deduced the yearly averaged value of the solar diurnal variation as observed by a surface muon telescope and three underground muon telescopes over the years 1957 to 1985. This has allowed us to examine the temporal variation in both the latitudinal gradient Gz and the product of the parallel mean free path and the radial gradient of galactic cosmic rays during three consecutive solar cycles. The median rigidities of the primary particles being detected by the telescopes are 50 GV in the case of the surface muon telescope and greater than 150 GV in the case of the underground muon telescopes. We have compared our results with those of a similar study made from observations of the solar diurnal variation by neutron monitors and an ion chamber, which have median rigidities of response between 17 and 70 GV (Bieber and Chen 1991a). The product has a solar magnetic cycle dependence and our values are lower than those observed by neutron monitors, in agreement with the Bieber and Chen observation that reverses after a solar magnetic field reversal, in accordance with drift theories.

The North–South Anisotropy and the Radial Density Gradient of Galactic Cosmic Rays at 1 AU

1995 ◽  
Vol 12 (2) ◽  
pp. 153-158 ◽  
Author(s):  
D. L. Hall ◽  
M. L. Duldig ◽  
J. E. Humble
Keyword(s):  
Cosmic Rays ◽  
Diurnal Variation ◽  
Density Gradient ◽  
Cosmic Ray ◽  
Ecliptic Plane ◽  
Galactic Cosmic Rays ◽  
Radial Density ◽  
Sidereal Time ◽  
Direction Parallel ◽  
The North

AbstractThe radial density gradient (Gr) of Galactic cosmic rays in the ecliptic plane points outward from the Sun. This indicates an increasing density of cosmic ray particles beyond the Earth’s orbit. Due to this gradient and the direction of the Sun’s interplanetary magnetic field (IMF) above and below the IMF wavy neutral sheet, there exists an anisotropic flow of cosmic ray particles approximately perpendicular to the ecliptic plane (i.e. in the direction parallel to BIMF × Gr). This effect is called the north–south anisotropy (ξNS) and manifests as a diurnal variation in sidereal time in the particle intensity recorded by a cosmic ray detector. By analysing the yearly averaged sidereal diurnal variation recorded by five neutron monitors and six muon telescopes from 1957 to 1990, we have deduced probable values of the average rigidity spectrum and magnitude of ξNS. Furthermore, we have used determined yearly amplitudes of ξNS to infer the magnitude of Gr for particles with rigidities in excess of 10 GV.

Dependence on Latitude of the Amplitude of the Diurnal Variation of Cosmic Rays

Nature ◽  
1960 ◽  
Vol 187 (4743) ◽  
pp. 1099-1100 ◽  
Author(s):  
ARNE ELD SANDSTRÖM ◽  
ERIC DYRING ◽  
STIG LINDGREN
Keyword(s):  
Cosmic Rays ◽  
Diurnal Variation

On the Interpretation of the Diurnal Variation of Cosmic Rays

Tellus ◽  
1954 ◽  
Vol 6 (1) ◽  
pp. 73-83 ◽  
Author(s):  
E. A. BRUNBERG ◽  
A. DATTNER
Keyword(s):  
Cosmic Rays ◽  
Diurnal Variation

On the Absorption of Nucleonic Component in Cosmic Rays

1948 ◽  
Vol 74 (12) ◽  
pp. 1878-1879 ◽  
Author(s):  
G. Bernardini ◽  
G. Cortini ◽  
M. Manfredini
Keyword(s):  
Cosmic Rays ◽  
Nucleonic Component

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°.

scholarly journals Scaling Features of Diurnal Variation of Galactic Cosmic Rays

Solar Physics ◽  
2021 ◽  
Vol 296 (8) ◽  
Author(s):  
Renata Modzelewska ◽  
Agata Krasińska ◽  
Anna Wawrzaszek ◽  
Agnieszka Gil
Keyword(s):  
Time Series ◽  
Solar Cycle ◽  
Cosmic Rays ◽  
Diurnal Variation ◽  
Hurst Exponent ◽  
Solar Minimum ◽  
Galactic Cosmic Rays ◽  
Solar Cycles ◽  
Scaling Features ◽  
Hurst Exponents

AbstractWe analyze the scaling properties of the diurnal variation of galactic cosmic rays (GCRs) in Solar Cycle 24 and the solar minima between Solar Cycles 23/24 and 24/25 for 2007 – 2019 based on the count rates of the Oulu, Newark, Hermanus, and Potchefstroom neutron monitors. The scaling features of the GCR diurnal variation are studied by evaluating the Hurst exponent, a quantitative parameter used as an indicator of the state of the randomness of a time series. We estimate the Hurst exponents for GCR diurnal-variation parameters amplitude and phase using structure-function and detrended-fluctuation-analysis methods. Results show that the Hurst exponents for the GCR diurnal variation vary in the range from $\approx0.3$ ≈ 0.3 to $\approx0.9$ ≈ 0.9 , with a general tendency of being systematically above 0.5. It suggests that the GCR diurnal variation reveals a more persistent structure than Brownian motion. However, the time series of GCR diurnal-variation amplitude and phase evolve from a more persistent structure in the solar minimum between Solar Cycles 23/24 in 2007 – 2009 to a more random character in and near the solar maximum 2012 – 2014. This observation seems to be in agreement with the general configuration of the heliosphere through the 11-year solar-activity cycle. Moreover, the temporal profile of the Hurst exponent for GCR diurnal amplitude and phase around the beginning of the solar minimum between Solar Cycles 24/25 (2018 – 2019) differs from the solar minimum between Solar Cycles 23/24 in 2007 – 2009, suggesting a dependence on solar-magnetic polarity. These findings could shed more light on GCR particle transport in the turbulent heliosphere over the solar cycle.

A WORLD-WIDE STUDY OF THE DAILY VARIATION OF THE NUCLEONIC COMPONENT OF COSMIC RAYS

1960 ◽  
Vol 38 (8) ◽  
pp. 1011-1026 ◽  
Author(s):  
J. Katzman ◽  
D. Venkatesan
Keyword(s):  
Diurnal Variation ◽  
Phase Angle ◽  
World Wide ◽  
Pressure Effect ◽  
Cosmic Ray ◽  
Mean Amplitude ◽  
Short Term ◽  
Nucleonic Component ◽  
The Mean ◽  
Considerable Spread

The semidiurnal component of the nucleonic intensity at Ottawa, Canada, is essentially a pressure effect for the 5-year period, 1955 to 1959. The diurnal variation is composed of the component due to pressure, and a component that may be attributed to an anisotropy of the primary cosmic-ray particles. The results are confirmed by a comparative study of the data from 15 stations between the geomagnetic latitudes 83 °N. and 73 °S.A world-wide barometric coefficient of −0.72% per mb was obtained from the semidiurnal component and this coefficient was used to correct the diurnal component at all the stations. The average corrected diurnal variation during the period of study common to all stations, August 1957 to October 1958, is 0.27% and occurs at 14 h 16 m solar time. There is considerable spread in both amplitude and phase angle amongst the various stations. The root mean square differences from the mean amplitude is ±0.05% and from the mean phase angle is ±10° (40 minutes in time). The difficulty of drawing definite conclusions about the anisotropy from short-term studies of individual stations is pointed out.

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