Time changes of the attenuation coefficients for cosmic-ray neutron monitors

1968 ◽  
Vol 46 (10) ◽  
pp. S1041-S1043 ◽  
Author(s):  
F. Bachelet ◽  
E. Dyring ◽  
N. Iucci ◽  
G. Villoresi
Keyword(s):  
Regression Analysis ◽  
Solar Cycle ◽  
Sea Level ◽  
Time Variation ◽  
Cosmic Ray ◽  
Neutron Monitors ◽  
Attenuation Coefficients ◽  
Daily Data ◽  
Independent Estimate ◽  
Time Changes

The time variation of the attenuation coefficients is synoptically studied by regression analysis on reduced and filtered daily data of 21 IGY neutron monitors from 1957 to 1965 and 11 IQSY supermonitors from 1964 to 1966. For the sea-level IGY monitors at high latitude a typical peak-to-peak amplitude of 4% is found for the solar-cycle change, in agreement with an independent estimate of the effect. The supermonitor results show, as expected, no relevant time variation in the period studied and smaller differences than the IGY monitors among stations of similar geophysical conditions.Attenuation coefficients obtained by mobile monitor measurements in 1967 are also presented.

The relation between latitude and solar-cycle variations in the neutron-monitor mass-absorption coefficient

1968 ◽  
Vol 46 (10) ◽  
pp. S1087-S1089 ◽  
Author(s):  
Miriam A. Forman
Keyword(s):  
Solar Cycle ◽  
Absorption Coefficient ◽  
Sea Level ◽  
Neutron Monitor ◽  
Mass Absorption Coefficient ◽  
Cutoff Rigidity ◽  
Neutron Monitors ◽  
Solar Cycle Variation ◽  
Mass Absorption ◽  
Pressure Altitude

The differential mass-absorption coefficient for rigidities between 2 and 15 GeV/c for IGY-type neutron monitors at sea level and at 500 mm Hg pressure altitude has been calculated from the variation of the neutron-monitor intensity and mass-absorption coefficient with cutoff rigidity. Combined with six sea-level surveys of neutron-monitor intensity between 1954 and 1962, and assuming no time variation in the neutron-monitor mass-absorption coefficient above 15 GeV/c cutoff, the calculated differential mass-absorption coefficient implies a solar-cycle variation of about 0.04%/mm Hg at 2 GeV/c cutoff rigidity at sea level.

scholarly journals The Upper Limiting Primary Rigidity of the Cosmic Ray Solar Anisotropy

1965 ◽  
Vol 18 (5) ◽  
pp. 451 ◽  
Author(s):  
RM Jacklyn ◽  
JE Humble
Keyword(s):  
Diurnal Variation ◽  
Sea Level ◽  
Free Space ◽  
Daily Variation ◽  
Cosmic Ray ◽  
Neutron Monitors ◽  
Annual Average ◽  
Average Value

A method of determining the upper limiting rigidity of the solar diurnal variation of the cosmic ray primaries in free space is described. It involves a comparision of the response to the anisotropy of neutron monitors at sea level and of meson telescopes underground. Making use of the model for the free-space first harmonic proposed by Radio, McCracken, and Venkatesan, the annual average value for the upper limiting rigidity (Ru) in 1958 is estimated to have been 95 GV with an error of estimate of about 10-20 GV. Changes in the observed annual mean daily variation between 1958 and 1962 indicate that Ru may have decreased by about 20-40 GV over this period, but a more refined analysis is needed to confirm this.

Synoptic study of the attenuation coefficients for the cosmic-ray neutron monitors of the IGY network from 1957 to 1965

1967 ◽  
Vol 52 (1) ◽  
pp. 106-123 ◽  
Author(s):  
F. Bachelet ◽  
E. Dyring ◽  
N. Iucci ◽  
G. Villoresi
Keyword(s):  
Cosmic Ray ◽  
Neutron Monitors ◽  
Attenuation Coefficients

scholarly journals Galactic cosmic ray decreases associated with non-interacting magnetic clouds in the 23rd solar cycle

2013 ◽  
Vol 8 (S300) ◽  
pp. 483-484
Author(s):  
J. J. Masías-Meza ◽  
S. Dasso
Keyword(s):  
Solar Cycle ◽  
Cosmic Ray ◽  
Total Sample ◽  
Magnetic Clouds ◽  
Neutron Monitors ◽  
Interplanetary Coronal Mass Ejections ◽  
23Rd Solar Cycle ◽  
Preliminary Study ◽  
Galactic Cosmic Ray ◽  
Selection Of

AbstractSudden Galactic Cosmic Ray (GCR) intensity decreases are related to the passage of Interplanetary Coronal Mass Ejections (ICMEs). These phenomena are also known as Forbush Decreases (FDs). The deepest FDs are associated with the passage of Magnetic Clouds (MCs). In this preliminary study we select “non-interacting” MCs associated with FDs observed from ground Neutron Monitors in the period 1996-2009, with the aim of reducing the complexity and the number of parameters involved in the GCR-MC interactions. We introduce a method to determine properties of the “ejecta component” of the FD. We analyze properties of the ejecta component in combination with properties of MCs. From the resulting selection of events, we find that those FDs containing ejecta components show stronger correlations with MC parameters than our total sample of events.

Characteristics of Cosmic Ray Diurnal Variation from Deep River Neutron and Meson Data and Temperature Effects

1972 ◽  
Vol 50 (12) ◽  
pp. 1323-1331 ◽  
Author(s):  
S. P. Agrawal ◽  
A. G. Ananth ◽  
U. R. Rao
Keyword(s):  
Solar Cycle ◽  
Diurnal Variation ◽  
Temperature Effects ◽  
Cosmic Ray ◽  
Cutoff Rigidity ◽  
Neutron Data ◽  
Neutron Monitors ◽  
Temperature Coefficients ◽  
Extensive Analysis ◽  
Yield Values

From an extensive analysis of Deep River meson data for over 5 years, new temperature coefficients have been derived for correcting the meson data. It is shown that meson data corrected using new coefficients yield values of diurnal and semidiurnal anisotropy consistent with those obtained from neutron monitors. Using the temperature-corrected meson and neutron data, the upper cutoff rigidity beyond which the diurnal variation ceases is shown to vary with solar cycle showing a minimum of about 35 GV during the Quiet Solar Year of 1965, and a maximum of ≈ 125 GV during 1968–1969.

Multiplicity measurements on the IGY and NM64 neutron monitors

1968 ◽  
Vol 46 (10) ◽  
pp. S1057-S1060 ◽  
Author(s):  
F. Bachelet ◽  
E. Dyring ◽  
N. Iucci
Keyword(s):  
Multiplicity Distribution ◽  
Neutron Monitors ◽  
Attenuation Coefficients ◽  
Preliminary Results ◽  
Time Changes ◽  
The Individual

Preliminary results are given of the analysis of the continuous recordings of the detected multiplicity distribution obtained at the Uppsala IGY monitor and at the Rome supermonitor in the first months of 1967. The relative frequencies and the attenuation coefficients of the individual multiplicities as measured at both monitors are compared. The time changes of the multiplicity distribution on the occasion of substantial primary spectral variations are studied.

scholarly journals Signs of geoeffective space weather events in cosmic rays during the first half of the solar cycle 24

2021 ◽  
pp. 119-124
Author(s):  
Agnieszka Gil ◽  
Renata Modzelewska ◽  
Szczepan Moskwa ◽  
Agnieszka Siluszyk ◽  
Marek Siluszyk ◽  
...  
Keyword(s):  
Solar Cycle ◽  
Space Weather ◽  
Transmission Lines ◽  
Cosmic Ray ◽  
Neutron Monitors ◽  
Time Intervals ◽  
Forbush Decreases ◽  
Solar Cycle 24 ◽  
Cycle 24 ◽  
Galactic Cosmic Ray

Solar originating events are continually evident in galactic cosmic ray (GCR) flux registered at the ground by neutron monitors. We analyze time intervals of sporadic Forbush decreases (Fd) observed by neutron monitors (NM) during the first half of solar cycle 24. We consider NMs data, as well as, solar, heliospheric and geoma - gnetic activity parameters, around those periods, using different mathematical tools. Subsequently, an impact of space weather phenomena on energy infrastructure is well known, in the further step we consider logs from one of the Polish transmission lines operators during the time intervals of Fds. Based on the data from the Ins- titute of Meteorology and Water Management-Polish National Research Institute we exclude from the analysis the weather-related failures. We found that the increase in the superposed averaged number of failures appears around Forbush decreases.

scholarly journals Experimental spectrum of the cosmic ray variations within rigidity range of 1-20 GV in the Earth’s orbit by the data of AMS-02

2021 ◽  
pp. 31-38
Author(s):  
Anatoly V. Belov ◽  
Raisa T. Gushchina ◽  
Victor Yanke ◽  
Liudmila Trefilova ◽  
Pavel G. Kobelev ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Experimental Data ◽  
Solar Cycle ◽  
Cosmic Rays ◽  
Solar Magnetic Field ◽  
Cosmic Ray ◽  
Experimental Spectrum ◽  
Negative Polarity ◽  
Neutron Monitors ◽  
First Time

For the first time, based on the experimental data of AMS-02, a three-parameter spectrum of variations of ga - lactic cosmic rays was obtained in the range of rigidity 1- 20 GV, to which neutron monitors are most sensitive. It was found that during the period of negative polarity of the solar magnetic field, a power-law spectrum of va - riations is observed with a strong exponential decay in the region of high rigidity. When the polarity changes to positive at the beginning of the new 24th solar cycle, the spectrum of cosmic ray variations becomes purely po- wer-law. The transition to the experimentally obtained spectrum of variations will make it possible to remove a number of uncertainties and increase the accuracy of the analysis of data from the ground network of detectors. This will make it possible to retrospectively obtain fluxes of galactic protons with an average monthly resolution for the period of the space era based on ground-based monitoring.

scholarly journals A Solar Cycle of Cosmic Ray Fluxes for 2006-2014: Comparison between PAMELA and Neutron Monitors

2018 ◽  
Vol 123 (6) ◽  
pp. 4479-4487 ◽  
Author(s):  
Sergey A. Koldobskiy ◽  
Gennady A. Kovaltsov ◽  
Ilya G. Usoskin
Keyword(s):  
Solar Cycle ◽  
Cosmic Ray ◽  
Neutron Monitors
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