cosmic ray intensity
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Atmosphere ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1613
Author(s):  
Helen Mavromichalaki ◽  
Maria-Christina Papailiou ◽  
Maria Gerontidou ◽  
Svetla Dimitrova ◽  
Karel Kudela

It is well known that the various manifestations of space weather can influence a wide range of human activities, from technological systems to human health. Various earlier, as well as more recent multi-disciplinary heliobiological and biometeorological studies have revealed that the human organism is sensitive to environmental physical activity changes and reacts to them through variations of the physiological parameters of the human body. This paper constitutes an overview of the National and Kapodistrian University of Athens investigations in regard to the possible effect of solar, geomagnetic, and cosmic ray activity on human physiological parameters. The Athens Cosmic Ray and Solar Physics Groups collaborated with scientific teams from different countries, statistically processing and analyzing data related to human physiological parameters (such as mean heart rate, arterial systolic, and diastolic pressure), or the number of incidents of different types of cardiac arrhythmias and so forth, in relation to data concerning and describing geomagnetic activity (geomagnetic indices Ap and Dst) and variations in cosmic ray intensity (Forbush decreases and cosmic ray intensity enhancements). In total, four projects were carried out concerning data from different geographical regions (Baku, Azerbaijan; Kosice, Slovakia; Tbilisi, Georgia; Piraeus, Greece), covering different time periods and time scales (daily data or yearly data), and referring to different groups of individuals (selected healthy persons or random persons). The studies concluded with interesting results concerning the possible influence of geomagnetic and cosmic ray activity on the human physiological state.


Physics World ◽  
2021 ◽  
Vol 34 (10) ◽  
pp. 3iii-3iii

Researchers have discovered that radiation doses in aeroplanes during periods of increased cosmic-ray intensity at ground level do not pose a threat to health.


2021 ◽  
Vol 922 (2) ◽  
pp. 219
Author(s):  
M. Nakanotani ◽  
G. P. Zank ◽  
L.-L. Zhao

Abstract Particle acceleration behind a shock wave due to interactions between magnetic islands in the heliosphere has attracted attention in recent years. The downstream acceleration may yield a continuous increase of particle flux downstream of the shock wave. Although it is not obvious how the downstream magnetic islands are produced, it has been suggested that current sheets are involved in the generation of magnetic islands due to their interaction with a shock wave. We perform 2D hybrid kinetic simulations to investigate the interaction between multiple current sheets and a shock wave. In the simulation, current sheets are compressed by the shock wave and a tearing instability develops at the compressed current sheets downstream of the shock. As the result of this instability, the electromagnetic fields become turbulent and magnetic islands form well downstream of the shock wave. We find a “post-cursor” region in which the downstream flow speed normal to the shock wave in the downstream rest frame is decelerated to ∼ 1V A immediately behind the shock wave, where V A is the upstream Alfvén speed. The flow speed then gradually decelerates to 0 accompanied by the development of the tearing instability. We also observe an efficient production of energetic particles above 100 E 0 during the development of the instability some distance downstream of the shock wave, where E 0 = m p V A 2 and m p is the proton mass. This feature corresponds to Voyager observations showing that the anomalous cosmic-ray intensity increase begins some distance downstream of the heliospheric termination shock.


2021 ◽  
Author(s):  
Prithvi Raj Singh ◽  
A. I. Saad Farid ◽  
Y. P. Singh ◽  
A. K. Singh ◽  
Ayman A. Aly

Abstract To study the solar rotational oscillation on daily averaged time series of solar activity proxies: sunspot number (SSN), modified coronal index (MCI), solar flare index (FI), and cosmic ray intensity (CRI) are subjected to Lomb/Scargle periodogram, and continuous wavelet transform. For this purpose, we have used data of all the considered parameters from 2012 to 2015, which covers the maximum phase including the polarity reversal period of the solar cycle 24. Both spectral analysis techniques are carried out to study the behavior of 27-days on the time scale of the synodic period and to follow their evolution throughout the epoch. Further, we have used R package RobPer (least square regression) techniques and obtained a significant true period ~27 days is present in this study. It is noted that the ~27-day period of solar activity parameters and cosmic rays is much prominent during the examined period.


Solar Physics ◽  
2021 ◽  
Vol 296 (8) ◽  
Author(s):  
Alexander Mishev ◽  
Stepan Poluianov

AbstractCosmic rays, high-energy subatomic particles of extraterrestrial origin, are systematically measured by space-borne and ground-based instruments. A specific interest is paid to high-energy ions accelerated during solar eruptions, so-called solar energetic particles. In order to build a comprehensive picture of their nature, it is important to fill the gap and inter-calibrate ground-based and space-borne instruments. Here, we focus on ground-based detectors, specifically neutron monitors, which form a global network and provide continuous recording of cosmic ray intensity and its variability, used also to register relativistic solar energetic particles. The count rate of each neutron monitor is determined by the geomagnetic and atmospheric cut-offs, both being functions of the location. Here, on the basis of Monte Carlo simulations with the PLANETOCOSMICS code and by the employment of a new verified neutron monitor yield function, we assessed the atmospheric cut-off as a function of the altitude, as well as for specific stations located in the polar region. The assessed in this study altitude profile of the atmospheric cut-off for primary cosmic rays builds the basis for the joint analysis of strong solar proton events with different instruments and allows one to clarify recent definitions and related discussions about the new sub-class of events, so-called sub-ground-level enhancements (sub-GLEs).


2021 ◽  
Author(s):  
Mikhail Krainev ◽  
Mikhail Kalinin ◽  
Boris Gvozdevsky ◽  
O.P.M. Aslam ◽  
Donald Ngobeni ◽  
...  

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