scholarly journals Drift Effects and the Cosmic Ray Density Gradient in a Solar Rotation Period: First Observation with the Global Muon Detector Network (GMDN)

2008 ◽  
Vol 681 (1) ◽  
pp. 693-707 ◽  
Author(s):  
Y. Okazaki ◽  
A. Fushishita ◽  
T. Narumi ◽  
C. Kato ◽  
S. Yasue ◽  
...  
Keyword(s):  
Density Gradient ◽  
Solar Rotation ◽  
Rotation Period ◽  
Cosmic Ray ◽  
Muon Detector ◽  
Ray Density

PERIODICAL FLUCTUATION STUDIES OF COSMIC-RAY DIURNAL VARIATIONS DURING THE QUIET-SUN PERIOD 1962–64

1967 ◽  
Vol 45 (8) ◽  
pp. 2733-2748 ◽  
Author(s):  
Masahiro Kodama
Keyword(s):  
Diurnal Variation ◽  
Solar Minimum ◽  
Counting Rate ◽  
Solar Rotation ◽  
Rotation Period ◽  
Cosmic Ray ◽  
Diurnal Variations ◽  
Statistical Studies ◽  
Periodic Fluctuations ◽  
Recurrence Tendency

Statistical studies of periodic fluctuations of the cosmic-ray diurnal variation have been performed, using neutron and meson component data obtained by the high-counting-rate cosmic-ray monitors at Deep River. The data cover an interval from May 1962 to October 1964, a period of descending solar activity ending near the solar minimum. It is shown that a 27-day recurrence tendency of the amplitude of the diurnal variation occasionally appears as well as shorter recurrent variations, ranging from one-half to one-sixth of the solar rotation period. The correlations of these fluctuations with some typical solar and terrestrial indices are examined in order to search for possible origins of the shorter recurrent variations. A possible connection with the Kp index exists.

Energy Changes of Cosmic Rays

1978 ◽  
Vol 3 (3) ◽  
pp. 233-234
Author(s):  
L. J. Gleeson ◽  
G. M. Webb
Keyword(s):  
Cosmic Rays ◽  
Solar System ◽  
Density Gradient ◽  
Cosmic Ray ◽  
Integral Form ◽  
Rate Of Change ◽  
Number Density ◽  
Ray Density ◽  
The Mean

Recently (Gleeson (1972), Quenby (1973), Gleeson and Webb (1974, 1978)) it has been shown that the mean rate of change of momentum of cosmic rays reckoned for a volume fixed in the solar system iswhere G = (1/Up)(∂Up/∂r)si the cosmic-ray density gradient with Up, the differential number density with respect to momentum p at position r. (cf also the integral form of (1) by Jokipii and Parker 1967).

scholarly journals CONSTRAINTS ON THE COSMIC-RAY DENSITY GRADIENT BEYOND THE SOLAR CIRCLE FROMFERMIγ-RAY OBSERVATIONS OF THE THIRD GALACTIC QUADRANT

2010 ◽  
Vol 726 (2) ◽  
pp. 81 ◽  
Author(s):  
M. Ackermann ◽  
M. Ajello ◽  
L. Baldini ◽  
J. Ballet ◽  
G. Barbiellini ◽  
...  
Keyword(s):  
Density Gradient ◽  
Cosmic Ray ◽  
The Third ◽  
Ray Density

scholarly journals ERRATUM: “CONSTRAINTS ON THE COSMIC-RAY DENSITY GRADIENT BEYOND THE SOLAR CIRCLE FROM FERMI γ-RAY OBSERVATIONS OF THE THIRD GALACTIC QUADRANT” (2011, ApJ, 726, 81)

2013 ◽  
Vol 772 (2) ◽  
pp. 154 ◽  
Author(s):  
M. Ackermann ◽  
M. Ajello ◽  
L. Baldini ◽  
J. Ballet ◽  
G. Barbiellini ◽  
...  
Keyword(s):  
Density Gradient ◽  
Cosmic Ray ◽  
The Third ◽  
Ray Density ◽  
Γ Ray

scholarly journals The 30 cm radio flux as a solar proxy for thermosphere density modelling

2017 ◽  
Vol 7 ◽  
pp. A9 ◽  
Author(s):  
Thierry Dudok de Wit ◽  
Sean Bruinsma
Keyword(s):  
Solar Rotation ◽  
Rotation Period ◽  
Density Variation ◽  
Temperature Model ◽  
Radio Flux ◽  
Model Bias ◽  
Solar Forcing ◽  
Radio Emissions ◽  
Solar Uv ◽  
Density Modelling

The 10.7 cm radio flux (F10.7) is widely used as a proxy for solar UV forcing of the upper atmosphere. However, radio emissions at other centimetric wavelengths have been routinely monitored since the 1950 s, thereby offering prospects for building proxies that may be better tailored to space weather needs. Here we advocate the 30 cm flux (F30) as a proxy that is more sensitive than F10.7 to longer wavelengths in the UV and show that it improves the response of the thermospheric density to solar forcing, as modelled with DTM (Drag Temperature Model). In particular, the model bias drops on average by 0–20% when replacing F10.7 by F30; it is also more stable (the standard deviation of the bias is 15–40% smaller) and the density variation at the the solar rotation period is reproduced with a 35–50% smaller error. We compare F30 to other solar proxies and discuss its assets and limitations.

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