Magnetospheric effects on cosmic rays during the magnetic storm of March 2015

Cosmic ray variations of magnetospheric origin during the magnetic storm on 17th of March 2015 were studied. Cosmic ray intensity data were obtained from the neutron monitor database (NMDB) and the data of the Dst index were taken from World Data Center for Geomagnetism, Kyoto. The global survey method was employed for the calculation of changes in the cutoff rigidities throughout the storm. A correlation analysis between the Dst index and the calculated cutoff rigidity variations was performed for each cosmic ray station. The most essential decrease in cutoff rigidities occured when the Dst index was around the value of -234nT. A latitudinal distribution of the cutoff rigidities was acquired, showing that the maximum effect took place at mid-latitude stations with rigidities around 8-10GV. During the examined event the maximum change in cutoff rigidity was observed at Athens station where the decrease of the cutoff rigidity reached the value of 1.07GV. Furthermore, corrections of cosmic ray intensity due to the magnetospheric effect were calculated using the derived cutoff rigidities showing a discperancy with the observed values at mid- and low- latitude stations

The updated GLE alert system by ANEMOS

Ground level enhancements (GLEs) of cosmic radiation are the result of solar energetic particles (SEPs) arriving at the Earth, potentially causing major damage to technological systems, but also posing a threat for human health. Intense SEPs, such as the GLE events, can influence the radiation exposure of aircrafts and consequently increase the radiation dose on human crew, but also have an impact on satellites and affect the design of space missions, i.e electronic devices onboard the satellite platforms etc. Therefore, predicting such events is challenging and one of the most important aspects of space weather research. In this work the updated GLE Alert++ System of the Athens Neutron Monitor Station (A.Ne.Mo.S.) implemented by the Athens Cosmic Ray Group of the National and Kapodistrian University of Athens (NKUA) is being presented. Moreover, the innovations of the updated system in relation to the previous version of the GLE Alert Plus are introduced. Finally, the most recent and the first of solar cycle 25 GLE event, GLE73, is discussed. This event was registered by several stations of the worldwide ground-based neutron monitor network. An accurate alert was issued successfully by the ESA R-ESC federated product GLE Alert Plus, as well as by the updated GLE Alert++ System of the NKUA/A.Ne.Mo.S. It should be emphasized that GLE Alert++ signal by NKUA/A.Ne.Mo.S. was issued 45 minutes earlier than the one issued by GOES satellites

Atmospheric cosmic ray induced ionization and radiation affecting aviation

Cosmic radiation is a major factor of ionization of the Earth’s atmosphere. Both solar and galactic cosmic rays, which depend on solar activity and geomagnetic field, affect the radiation exposure in the atmosphere. Several models have been created for the estimation of the ionization and radiation dosimetry. In this work, as regards the ionization rate computations the CRAC:CRII model by the University of Oulu (https://cosmicrays.oulu.fi/CRII/CRII.html) was used, while for the estimation of the ambient equivalent dose rate (dH*(10)/dt) we used the validated software DYASTIMA / DYASTIMA-R by the University of Athens (http://cosray.phys.uoa.gr/index.php/applications/dyastima). Both tools are of great importance as they allow us to calculate the respective quantities all over the globe, at the entire atmosphere and for different time periods and solar cycle phases. The study concerns the last two solar cycles 23 and 24 (1996–2019) and specific flight levels of commercial aviation (FL310, FL350 and FL390). The dependance of CRII and dH*(10)/dt on geomagnetic cut-off rigidity, solar activity, cosmic ray intensity, as well as the altitude inside the atmosphere, affect the radiation exposure of the air crew members and frequent flyers, which make the results very interesting for the aviation industr

Derivation of relativistic SEP properties through neutron monitor data modeling

The Ground Level Enhancement (GLE) data recorded by the worldwide Neutron Monitor (NM) network are useful resources for space weather modeling during solar extreme events. The derivation of Solar Energetic Particles (SEPs) properties through NM-data modeling is essential for the study of solar-terrestrial physics, providing information that cannot be obtained through the exclusive use of space techniques; an example is the derivation of the higher-energy part of the SEP spectrum. We briefly review how the application of the Neutron Monitor Based Anisotropic GLE Pure Power Law (NMBANGLE PPOLA) model (Plainaki et al. 2010), can provide the characteristics of the relativistic SEP flux, at a selected altitude in the Earth's atmosphere, during a GLE. Technically, the model treats the NM network as an integrated omnidirectional spectrometer and solves the inverse problem of the SEP-GLE coupling. As test cases, we present the results obtained for two different GLEs, namely GLE 60 and GLE 71, occurring at a temporal distance of ~ 11 years

Human Physiological Parameters Related to Solar and Geomagnetic Disturbances: Data from Different Geographic Regions

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

Human Physiological Parameters Related to Solar and Geomagnetic Disturbances: Data from Different Geographic Regions

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

The Updated Version of the A.Ne.Mo.S. GLE Alert System: The Case of the Ground-Level Enhancement GLE73 on 28 October 2021

A ground-level enhancement (GLE) event is a sudden increase in cosmic ray intensity originated by solar sources and recorded by ground-based detectors. GLEs are invariably associated with large solar flares that can release and accelerate solar particles at high energies. The minimum kinetic energy of particles reaching the Earth’s surface is >433 MeV at sea level and about 300 MeV/n at high-mountain altitude of about 3000 m a.s.l. Even though these abrupt events linked to solar activity are quite rare, they can have a great impact on technological systems and human health when recorded. Therefore, the accurate and effective prognosis of such events is of great importance. In this paper, an overview of the most recently recorded GLE event and the first of solar cycle 25, i.e., GLE73, as well as a post-event analysis is presented. GLE73 was detected on 28 October 2021 and was associated with the active region AR12887 on the central part of the solar disk, which produced an X1.0 solar flare. The event was registered by several stations of the worldwide ground-based neutron monitor network. An accurate alert was issued successfully by the ESA R-ESC federated product GLE Alert Plus, as well as the updated GLE Alert++ System of the Athens Neutron Monitor Station (A.Ne.Mo.S.). It should be emphasized that the GLE Alert++ signal by NKUA/A.Ne.Mo.S. was issued 45 min earlier than the one issued by GOES. A short description and the advantages of this last system are provided

The Updated Version of the A.Ne.Mo.S. GLE Alert System: The Case of the Ground-Level Enhancement GLE73 on 28 October 2021

A ground-level enhancement (GLE) event is a sudden increase in cosmic ray intensity originated by solar sources and recorded by ground-based detectors. GLEs are invariably associated with large solar flares that can release and accelerate solar particles at high energies. The minimum kinetic energy of particles reaching the Earth’s surface is >433 MeV at sea level and about 300 MeV/n at high-mountain altitude of about 3000 m a.s.l. Even though these abrupt events linked to solar activity are quite rare, they can have a great impact on technological systems and human health when recorded. Therefore, the accurate and effective prognosis of such events is of great importance. In this paper, an overview of the most recently recorded GLE event and the first of solar cycle 25, i.e., GLE73, as well as a post-event analysis is presented. GLE73 was detected on 28 October 2021 and was associated with the active region AR12887 on the central part of the solar disk, which produced an X1.0 solar flare. The event was registered by several stations of the worldwide ground-based neutron monitor network. An accurate alert was issued successfully by the ESA R-ESC federated product GLE Alert Plus, as well as the updated GLE Alert++ System of the Athens Neutron Monitor Station (A.Ne.Mo.S.). It should be emphasized that the GLE Alert++ signal by NKUA/A.Ne.Mo.S. was issued 45 min earlier than the one issued by GOES. A short description and the advantages of this last system are provided

Radiation Exposure in the Lower Atmosphere during Different Periods of Solar Activity

In recent years, there has been a huge increase in air travel, both for business and leisure. For this reason, entities such as the European Commission and the International Committee on Radiological Protection have provided several recommendations for the radiation protection of aviation crews and frequent flyers, as well as highlighted the need for accurate tools for radiation assessment in the atmosphere. With a focus on the most frequent commercial flying altitudes, this work has performed dosimetry calculations in the lower atmosphere of Earth for different values of cut-off rigidity, covering the recent solar cycles 23 and 24. Results are based on Monte Carlo simulations performed with the validated Geant4 software application Dynamic Atmospheric Shower Tracking Interactive Model Application (DYASTIMA) and its extension, DYASTIMA-R