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Keywords = solar proton events (SPEs)

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14 pages, 5863 KiB  
Technical Note
Magnetosphere-Ground Responses and Energy Spectra Analysis of Solar Proton Event on 28 October 2021
by Fang Zhang, Zhenxia Zhang, Dali Zhang, Xinqiao Li, Zhiqiang Ding, Lu Wang, Shujie Li, Zhenghua An and Jilong Zhang
Remote Sens. 2025, 17(1), 15; https://doi.org/10.3390/rs17010015 (registering DOI) - 25 Dec 2024
Abstract
Among the coronal mass ejections (CMEs) and solar proton events (SPEs) frequently observed by near-Earth spacecraft, the SPE that occurred on 28 October 2021 stands out as a remarkable research event. This is due to the infrequency of reported ground-level enhancements it induced. [...] Read more.
Among the coronal mass ejections (CMEs) and solar proton events (SPEs) frequently observed by near-Earth spacecraft, the SPE that occurred on 28 October 2021 stands out as a remarkable research event. This is due to the infrequency of reported ground-level enhancements it induced. The CSES (China seismo-electromagnetic satellite) is equipped with high-energy particle detectors, namely, HEPP and HEPD, capable of measuring protons within an energy range of 2 MeV to 143 MeV. These detectors provide valuable opportunities for studying solar activity. By utilizing the Monte Carlo method to simulate the pile-up effect and accounting for the detector’s dead time, with the assistance of real-time incident counting rates, we successfully corrected the spectra in the 10–50 MeV range. The energy spectrum is important for understanding solar proton events. We used the data from the HEPP (high-energy particle package) and HEPD (high-energy particle detector) to obtain the total event-integrated spectrum, which possessed good continuity. Additionally, we compared the observations from the CSES with those from the NOAA satellite and achieved reasonable agreement. We also searched for ground-based responses to this solar activity in China and discovered Forbush decreases detected by the Yang Ba Jing Muon Telescope experiment. In conclusion, the HEPP and HEPD can effectively combine to study solar activity and obtain a smooth and consistent energy spectrum of protons across a very wide energy range. Full article
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<p>Space weather index from 26 October to 5 November 2021. (<b>a</b>) The solar wind dynamic pressure Pd (nPa). (<b>b</b>) Geomagnetic index Kp. (<b>c</b>) The equatorial ring current index Dst (nT). (<b>d</b>) The magnetic field component Bz (nT). (<b>e</b>) The sunspot number. (<b>f</b>) The velocity of solar wind (km/s).</p>
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<p>The evolution of proton fluxes observed by HEPP-L onboard CSES from 26 October to 5 November. The panels are the evolution of proton fluxes from HEPP-L for 2–6 MeV, 6–10 MeV, 10–14 MeV, and 14–20 MeV.</p>
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<p>The evolution of proton fluxes observed by HEPD onboard CSES from 26 October to 5 November. The panels are the evolution of proton fluxes from HEPD for 45–58 MeV, 58–87 MeV, 87–110 MeV, 110–143 MeV, and above 143 MeV.</p>
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<p>The evolution of proton fluxes observed by HEPP-H onboard CSES from 26 October to 5 November. The (<b>a</b>–<b>d</b>) panels are the evolution of proton fluxes from HEPP-H for 10–20 MeV, 20–30 MeV, 30–40 MeV, and 40–55 MeV.</p>
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<p>The evolution of proton flux (L = 6, 50 MeV) energy observed by HEPP-H, HEPD, and NOAA from 26 October to 5 November.</p>
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<p>The data are detected by HEPP-L (blue dots), HEPP-H (red dots), and HEPD (green dots) and fitted by Weibull (green line), Ellison–Ramaty (blue line), and Band (red line). (<b>a</b>) The original total event-integrated spectrum from 28 October to 1 November. (<b>b</b>) The corrected total event-integrated spectrum. (<b>c</b>) The correction factors for different energies.</p>
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<p>The upper panel is the fit to corrected total event-integrated spectrum, and the below panel is the relative deviation for different fit functions.</p>
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<p>The corrected total event-integrated spectrum by correct factors from 28 October to 1 November. The data are detected by HEPP-L (blue dots), HEPP-H (red dots), and HEPD (green dots) and fitted by Weibull (green line), Ellison–Ramaty (blue line), and Band (red line). Panels from top to bottom correspond to different average interval times of 8, 9, 11 and 12 μs from top panels to bottom panels used in simulations.</p>
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<p>The fluxes variation detected by Yang Ba Jing Muon Telescope from 26 October to 7 November.</p>
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<p>The evolution of proton fluxes of GOES from 26 October to 4 November.</p>
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11 pages, 1242 KiB  
Article
Mesospheric Ozone Depletion during 2004–2024 as a Function of Solar Proton Events Intensity
by Grigoriy Doronin, Irina Mironova, Nikita Bobrov and Eugene Rozanov
Atmosphere 2024, 15(8), 944; https://doi.org/10.3390/atmos15080944 - 6 Aug 2024
Viewed by 1795
Abstract
Solar proton events (SPEs) affect the Earth’s atmosphere, causing additional ionization in the high-latitude mesosphere and stratosphere. Ionization rates from such solar proton events maximize in the stratosphere, but the formation of ozone-depleting nitrogen and hydrogen oxides begins at mesospheric altitudes. The destruction [...] Read more.
Solar proton events (SPEs) affect the Earth’s atmosphere, causing additional ionization in the high-latitude mesosphere and stratosphere. Ionization rates from such solar proton events maximize in the stratosphere, but the formation of ozone-depleting nitrogen and hydrogen oxides begins at mesospheric altitudes. The destruction of mesospheric ozone is associated with protons with energies of about 10 MeV and higher and will strongly depend on the intensity of the flux of these particles. Most studies investigating the impact of SPEs on the characteristics of the middle atmosphere have been based on either simulations or reanalysis datasets, and some studies have used satellite observations to validate model results. We study the impact of SPEs on cold-season ozone loss in both the northern and southern hemispheres using Aura MLS mesospheric ozone measurements over the 2004 to 2024 period. Here, we show how strongly SPEs can deplete polar mesospheric ozone in different hemispheres and attempt to evaluate this dependence on the intensity of solar proton events. We found that moderate SPEs consisting of protons with an energy of more than 10 MeV and a flux intensity of more than 100 pfu destroy mesospheric ozone in the northern hemisphere up to 47% and in the southern hemisphere up to 33%. For both hemispheres, the peak of winter ozone loss was observed at about 76 km. In the northern hemisphere, maximum winter ozone loss was observed on the second day after a solar proton event, but in the southern hemisphere, winter ozone depletion was already detected on the first day. In the southern hemisphere, mesospheric ozone concentrations return to pre-event levels on the ninth day after a solar proton event, but in the northern hemisphere, even on the tenth day after a solar proton event, the mesospheric ozone layer may not be fully recovered. The strong SPEs with a proton flux intensity of more than 1000 pfu lead to a maximum winter ozone loss of up to 85% in the northern hemisphere, and in the southern hemisphere winter, ozone loss reaches 73%. Full article
(This article belongs to the Special Issue Cosmic Rays, Ozone Depletion and Climate Change)
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<p>Results of superposed epoch analysis of Aura MLS ozone altitudinal profiles over 60–80 NH before and after SPEs, which are summarized in <a href="#atmosphere-15-00944-t001" class="html-table">Table 1</a>.</p>
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<p>Results of superposed epoch analysis of Aura MLS ozone altitudinal profiles over 60–80 SH before and after SPEs, which are summarized in <a href="#atmosphere-15-00944-t002" class="html-table">Table 2</a>.</p>
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<p>Northern hemisphere ozone depletion (in %) after SPEs compared to the average ozone concentration observed before SPEs, which are summarized in <a href="#atmosphere-15-00944-t001" class="html-table">Table 1</a>. The ozone profile for each day is obtained using superposed epoch analysis of Aura MLS ozone altitudinal profiles for 60–80 NH after moderate SPEs with a proton flux intensity of more than 100 pfu.</p>
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<p>Northern hemisphere ozone depletion (in %) after SPEs compared to the average ozone concentration observed before SPEs, which are summarized in <a href="#atmosphere-15-00944-t001" class="html-table">Table 1</a>. The ozone profile for each day is obtained using superposed epoch analysis of Aura MLS ozone altitudinal profiles for 60–80 NH after strong SPEs with a proton flux intensity of more than 1000 pfu.</p>
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<p>Southern hemisphere ozone depletion (in %) after SPEs compared to the average ozone concentration observed before SPEs, which are summarized in <a href="#atmosphere-15-00944-t002" class="html-table">Table 2</a>. Each day ozone profile—results superposed epoch analysis of Aura MLS ozone altitudinal profiles for 60–80 SH after solar proton events. Moderate SPEs—with a proton flux intensity of more than 100 pfu.</p>
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<p>Southern hemisphere ozone depletion (in %) after SPEs compared to the average ozone concentration observed before SPEs, which are summarized in <a href="#atmosphere-15-00944-t002" class="html-table">Table 2</a>. Each day ozone profile—results superposed epoch analysis of Aura MLS ozone altitudinal profiles for 60–80 SH after SPE. Strong solar proton events—with a proton flux intensity of more than 1000 pfu.</p>
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10 pages, 1639 KiB  
Article
Radioprotection for Astronauts’ Missions: Numerical Results on the Nomex Shielding Effectiveness
by Filomena Loffredo, Emanuele Vardaci, Davide Bianco, Antonio Di Nitto and Maria Quarto
Life 2023, 13(3), 790; https://doi.org/10.3390/life13030790 - 15 Mar 2023
Cited by 1 | Viewed by 1756
Abstract
Space missions with humans expose the crews to ionizing radiation, mainly due to the galactic cosmic radiation (GCR). All radiation protection programs in space aim to minimize crews’ exposure to radiation. The radiation protection of astronauts can be achieved through the use of [...] Read more.
Space missions with humans expose the crews to ionizing radiation, mainly due to the galactic cosmic radiation (GCR). All radiation protection programs in space aim to minimize crews’ exposure to radiation. The radiation protection of astronauts can be achieved through the use of shields. The shields could serve as a suit to reduce GCR exposure and, in an emergency, as a radiation shelter to perform necessary interventions outside the space habitat in case of a solar proton event (SPE). A space radiation shielding that is suitable for exploration during space missions requires particular features and a proper knowledge of the radiation type. This study shows the results of numerical simulations performed with the Geant4 toolkit-based code DOSE. Calculations to evaluate the performance of Nomex, an aramidic fiber with high mechanical resistance, in terms of dose reduction to crews, were performed considering the interaction between protons with an energy spectrum ranging from 50 to 1100 MeV and a target slab of 20 g/cm2. This paper shows the properties of secondary products obtained as a result of the interaction between space radiation and a Nomex target and the properties of the secondary particles that come out the shield. The results of this study show that Nomex can be considered a good shield candidate material in terms of dose reductions. We also note that the secondary particles that provide the greatest contribution to the dose are protons, neutrons and, in a very small percentage, α-particles and Li ions. Full article
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<p>The galactic cosmic rays’ composition.</p>
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<p>A schematic view of the geometry of the experimental setup used in the simulation. (<b>left</b>) GCR spectrum; (<b>right</b>) a 20 g/cm<sup>2</sup> thick Nomex target and the tissue-equivalent ionization chamber at 1.5 cm from the Nomex target [<a href="#B18-life-13-00790" class="html-bibr">18</a>].</p>
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<p>(<b>a</b>) Energy spectrum for the secondary products in the Nomex target normalized to the total yield; (<b>b</b>) computed atomic and mass numbers (Z, A) of the secondary products produced in proton–Nomex interaction for the GCR proton energy spectrum; (<b>c</b>) computed atomic numbers and event frequency of the secondary products produced in the proton–Nomex interaction for the GCR proton energy spectrum. The three clusters of high (1), middle (2), and low (3) masses are highlighted; (<b>d</b>) computed atomic number and energy (Z, E) of the secondary particles produced in the proton–Nomex interaction for the GCR proton energy spectrum [<a href="#B18-life-13-00790" class="html-bibr">18</a>].</p>
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<p>(<b>a</b>) Energy spectrum for the secondary products, normalized to the total yield that leaves the target and arrives at the ionization chamber; (<b>b</b>) computed atomic and mass numbers (Z, A) of the secondary particles that leave the target and arrive at the ionization chamber; (<b>c</b>) computed atomic numbers and event frequency of the secondary particles that leave the target and arrive at the ionization chamber; (<b>d</b>) computed atomic number and energy (Z, E) of the secondary particles that leave the target and arrive at the ionization chamber [<a href="#B18-life-13-00790" class="html-bibr">18</a>].</p>
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<p>Energy spectra for the main secondary products that leave the target and arrive at the ionization chamber. Each spectrum is independently normalized to the total yield (y).</p>
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18 pages, 3743 KiB  
Article
Response of Arabidopsis thaliana and Mizuna Mustard Seeds to Simulated Space Radiation Exposures
by Ye Zhang, Jeffrey T. Richards, Alan H. Feiveson, Stephanie E. Richards, Srujana Neelam, Thomas W. Dreschel, Ianik Plante, Megumi Hada, Honglu Wu, Gioia D. Massa, Grace L. Douglas and Howard G. Levine
Life 2022, 12(2), 144; https://doi.org/10.3390/life12020144 - 19 Jan 2022
Cited by 9 | Viewed by 3731
Abstract
One of the major concerns for long-term exploration missions beyond the Earth’s magnetosphere is consequences from exposures to solar particle event (SPE) protons and galactic cosmic rays (GCR). For long-term crewed Lunar and Mars explorations, the production of fresh food in space will [...] Read more.
One of the major concerns for long-term exploration missions beyond the Earth’s magnetosphere is consequences from exposures to solar particle event (SPE) protons and galactic cosmic rays (GCR). For long-term crewed Lunar and Mars explorations, the production of fresh food in space will provide both nutritional supplements and psychological benefits to the astronauts. However, the effects of space radiation on plants and plant propagules have not been sufficiently investigated and characterized. In this study, we evaluated the effect of two different compositions of charged particles-simulated GCR, and simulated SPE protons on dry and hydrated seeds of the model plant Arabidopsis thaliana and the crop plant Mizuna mustard [Brassica rapa var. japonica]. Exposures to charged particles, simulated GCRs (up to 80 cGy) or SPEs (up to 200 cGy), were performed either acutely or at a low dose rate using the NASA Space Radiation Laboratory (NSRL) facility at Brookhaven National Lab (BNL). Control and irradiated seeds were planted in a solid phytogel and grown in a controlled environment. Five to seven days after planting, morphological parameters were measured to evaluate radiation-induced damage in the seedlings. After exposure to single types of charged particles, as well as to simulated GCR, the hydrated Arabidopsis seeds showed dose- and quality-dependent responses, with heavier ions causing more severe defects. Seeds exposed to simulated GCR (dry seeds) and SPE (hydrated seeds) had significant, although much less damage than seeds exposed to heavier and higher linear energy transfer (LET) particles. In general, the extent of damage depends on the seed type. Full article
(This article belongs to the Special Issue Space Radiobiology)
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<p>Particle tracks simulated within the volume of one cell. (<b>A</b>) A single 300 MeV/n Ti particle track with numerous secondary particles within a cell; (<b>B</b>) 250 MeV/n H particle tracks generated within a cell; (<b>C</b>) simulated GCR1 mixed irradiation field within a cell; and (<b>D</b>) simulated GCR2 irradiation field within a cell.</p>
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<p>Effect of 300 MeV/n Ti particles on seed germination, viability, and morphological measurements. (<b>A</b>) Tables of seeds number with percentages of viability, germination, cotyledon deformation, and absence of measurable roots by experimental group. (<b>B</b>) Root length distribution (small circles) in seedlings from control and Ti irradiated seeds. Multiple instances of zero root length are plotted with small jitter so that they can be distinguished. Estimates of 75th percentile root length (orange bars) are shown with 95% confidence limits (dashed lines). (<b>C</b>) Comparative histograms of root-length distributions. (<b>D</b>) Examples of cotyledon deformation. * Indicates <span class="html-italic">p</span> &lt; 0.05 compared to controls.</p>
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<p>Effect of 250 MeV/n protons on root length in seedlings grown from control and irradiated Arabidopsis seeds. (<b>A</b>) <span class="html-italic">Arabidopsis</span> seed number and germination rate. (<b>B</b>) Root length distribution (small circles) in seedlings from control and irradiated seeds. Multiple instances of zero root length, including non-germinated seeds are plotted with small random jitter so that they can be distinguished. Estimates of median root length (orange bars) are shown with 95% confidence limits (dashed lines). (<b>C</b>) Comparative histograms of root-length distributions in plants from germinated seeds. * Indicates <span class="html-italic">p</span> &lt; 0.05 compared to controls.</p>
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<p>Effect of GCRs on root length in seedlings from control and irradiated <span class="html-italic">Arabidopsis</span> seeds. (<b>A</b>) <span class="html-italic">Arabidopsis</span> seed number and germination rate. (<b>B</b>) Root length distribution (small circles) in seedlings from control and Ti irradiated seeds. Multiple instances of zero root length (including non-germinated seeds) are plotted with small random jitter so that they can be distinguished. Estimates of median root length (orange bars) are shown with 95% confidence limits (dashed lines). (<b>C</b>) Comparative histograms of root-length distributions in plants from germinated seeds.</p>
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<p>The effect of GCR-2 scenario on root length reduction in seedlings developed from control and irradiated dry seeds. (<b>A</b>) <span class="html-italic">Arabidopsis</span> seed number and germination rate. (<b>B</b>) Root length distribution (small circles) in <span class="html-italic">Arabidopsis</span> seedlings from control and irradiated seeds. Estimates of median root length (orange bars) are shown with 95% confidence limits (dashed lines). Multiple instances of zero root length (including non-germinated seeds) are plotted with small jitter so that they can be distinguished. (<b>C</b>) Mizuna seed number and germination rate. (<b>D</b>) Cotyledon deformation rate in Mizuna seedlings. (<b>E</b>) Root length distribution (small circles) in mizuna seedlings from control and irradiated seeds. Estimates of median root length (orange bars) are shown with 95% confidence limits (dashed lines). Multiple instances of zero root length (including non-germinated seeds) are plotted with small jitter so that they can be distinguished. * Shows <span class="html-italic">p</span> &lt; 0.05 compared to controls.</p>
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<p>The effect of SPE scenarios on root length reduction in seedlings developed from control and irradiated imbibed seeds. (<b>A</b>) <span class="html-italic">Arabidopsis</span> seed number and germination rate. (<b>B</b>) Root length distribution (small circles) in <span class="html-italic">Arabidopsis</span> seedlings from control and irradiated seeds. Estimates of median root length (orange bars) are shown with 95% confidence limits (dashed lines). Multiple instances of zero root length (including non-germinated seeds) are plotted with small jitter so that they can be distinguished. (<b>C</b>) Mizuna seed number and germination rate. (<b>D</b>) Cotyledon deformation rate in Mizuna seedlings. (<b>E</b>) Root length distribution (small circles) in mizuna seedlings from control and irradiated seeds. Multiple instances of zero root length (including non-germinated seeds) are plotted with small jitter so that they can be distinguished. Estimates of median root length (orange bars) are shown with 95% confidence limits (dashed lines). * Indicates <span class="html-italic">p</span> &lt; 0.05 compared to controls.</p>
Full article ">Figure 6 Cont.
<p>The effect of SPE scenarios on root length reduction in seedlings developed from control and irradiated imbibed seeds. (<b>A</b>) <span class="html-italic">Arabidopsis</span> seed number and germination rate. (<b>B</b>) Root length distribution (small circles) in <span class="html-italic">Arabidopsis</span> seedlings from control and irradiated seeds. Estimates of median root length (orange bars) are shown with 95% confidence limits (dashed lines). Multiple instances of zero root length (including non-germinated seeds) are plotted with small jitter so that they can be distinguished. (<b>C</b>) Mizuna seed number and germination rate. (<b>D</b>) Cotyledon deformation rate in Mizuna seedlings. (<b>E</b>) Root length distribution (small circles) in mizuna seedlings from control and irradiated seeds. Multiple instances of zero root length (including non-germinated seeds) are plotted with small jitter so that they can be distinguished. Estimates of median root length (orange bars) are shown with 95% confidence limits (dashed lines). * Indicates <span class="html-italic">p</span> &lt; 0.05 compared to controls.</p>
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<p>A plot of estimated ratios (treatment to control) of median root length (proton and CGR) or 75th percentiles (Ti) along with 95% confidence intervals showing that the <span class="html-italic">Arabidopsis</span> seedlings from irradiated seeds generally have shortened root length. Larger uncertainties for Ti exposure reflect the smaller sample size as well as the failure of many seeds to germinate or produce measurable roots. * Indicates <span class="html-italic">p</span> &lt; 0.05 compared to controls.</p>
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9 pages, 845 KiB  
Article
Radiation Risks in Cis-Lunar Space for a Solar Particle Event Similar to the February 1956 Event
by Fahad A. Zaman and Lawrence W. Townsend
Aerospace 2021, 8(4), 107; https://doi.org/10.3390/aerospace8040107 - 14 Apr 2021
Cited by 2 | Viewed by 2947
Abstract
Solar particle events (SPEs) can pose serious threats for future crewed missions to the Moon. Historically, there have been several extreme SPEs that could have been dangerous for astronauts, and thus analyzing their potential risk on humans is an important step towards space [...] Read more.
Solar particle events (SPEs) can pose serious threats for future crewed missions to the Moon. Historically, there have been several extreme SPEs that could have been dangerous for astronauts, and thus analyzing their potential risk on humans is an important step towards space exploration. In this work, we study the effects of a well-known SPE that occurred on 23 February 1956 on a mission in cis-Lunar space. Estimates of the proton fluence spectra of the February 1956 event were obtained from three different parameterized models published within the past 12 years. The studied geometry consists of a female phantom in the center of spherical spacecraft shielded by aluminum area densities ranging from 0.4 to 40 g cm2. The effective dose, along with lens, skin, blood forming organs, heart, and central nervous system doses, were tallied using the On Line Tool for the Assessment of Radiation In Space (OLTARIS), which utilizes the High Z and Energy TRansport code (HZETRN), a deterministic radiation transport code. Based on the parameterized models, the results herein show that thicknesses comparable to a spacesuit might not protect against severe health consequences from a February 1956 category event. They also show that a minimum aluminum shielding of around 20 g cm2 is sufficient to keep the effective dose and critical organ doses below NASA’s permissible limits for such event. In addition, except for very thin shielding, the input models produced results that were within good agreement, where the doses obtained from the three proton fluence spectra tended to converge with slight differences as the shielding thickness increases. Full article
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<p>Proton fluence spectra for the February 1956 event generated using BF10, BF18, and U20.</p>
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<p>The effective dose from U20, BF18, and BF10 February 1956 event spectra for various aluminum thicknesses. NASA’s permissible limits for 1-year mission for 30, 40, and 50-year old females are included in the plot. The dose limit for 60-year old is above the maximum obtained effective dose values.</p>
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<p>The skin dose from U20, BF18, and BF10 February 1956 event spectra for various aluminum thicknesses. NASA’s permissible career, 1-year, and 30-day skin dose limits are included in the plot.</p>
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<p>The heart dose from U20, BF18, and BF10 February 1956 event spectra for various aluminum thicknesses. NASA’s permissible 1-year and 30-day heart dose limits are included in the plot. The career limit (100 cGy-Eq) is above the maximum obtained dose values.</p>
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<p>The lens dose from U20, BF18, and BF10 February 1956 event spectra for various aluminum thicknesses. NASA’s permissible 1-year and 30-day lens dose limits are included in the plot. The career limit (400 cGy-Eq) is above the maximum obtained dose values.</p>
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<p>The BFO dose from U20, BF18, and BF10 February 1956 event spectra for various aluminum thicknesses. NASA’s permissible 1-year and 30-day BFO dose limits are included in the plot.</p>
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<p>The CNS dose from U20, BF18, and BF10 February 1956 event spectra for various aluminum thicknesses. NASA’s permissible 30-day lens dose limits are included in the plot. Note that the maximum obtained dose values are below the 30-day limit.</p>
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11 pages, 705 KiB  
Article
Possible Associations between Space Weather and the Incidence of Stroke
by Jone Vencloviene, Ricardas Radisauskas, Abdonas Tamosiunas, Dalia Luksiene, Lolita Sileikiene, Egle Milinaviciene and Daiva Rastenyte
Atmosphere 2021, 12(3), 334; https://doi.org/10.3390/atmos12030334 - 5 Mar 2021
Cited by 5 | Viewed by 4463
Abstract
The aim of our study was to detect the possible association between daily numbers of ischemic strokes (ISs) and hemorrhagic strokes (HSs) and space weather events. The daily numbers of ISs, subarachnoid hemorrhages (SAHs), and intracerebral hemorrhages (ICHs) were obtained from Kaunas Stroke [...] Read more.
The aim of our study was to detect the possible association between daily numbers of ischemic strokes (ISs) and hemorrhagic strokes (HSs) and space weather events. The daily numbers of ISs, subarachnoid hemorrhages (SAHs), and intracerebral hemorrhages (ICHs) were obtained from Kaunas Stroke Register during the period of 1986 to 2010. We used time- and season-stratified multivariate Poisson regression. We analyzed data of 597 patients with SAH, 1147 patients with ICH, and 7482 patients with IS. Strong/severe geomagnetic storms (GSs) were associated with an increase in the risk of SAH (by 58%) and HS (by 30%). Only GSs occurring during 6:00–12:00 UT were associated with the risk of IS. Low geomagnetic activity (GMA) was associated with the risk of ICH, HS, and IS (Rate Ratios with 95% CI were 2.51 (1.50–4.21), 2.33 (1.50–3.61), and 1.36 (1.03–1.81), respectively). The days of ≥ X9 class solar flare (SF) were associated with a 39% higher risk of IS. The risk of HS occurrence was greater than two times higher on the day after the maximum of a strong/severe solar proton event (SPE). These results showed that GSs, very low GMA, and stronger SFs and SPEs may be associated with an increased risk of different subtypes of stroke. Full article
(This article belongs to the Special Issue The Impacts of Space Weather on Human Health)
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<p>Univariate associations between GS occurring at different times (UT) and the risk of stroke (Rate ratio with 95% CI).</p>
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<p>Associations between stroke occurrence and space weather variables in a time-stratified multivariate model since 1995 (RR adjusted for month, the day of the week, air temperature, change in atmospheric pressure, relative humidity, and low GMA). * days of the maximum of strong/severe SPE.</p>
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18 pages, 1110 KiB  
Article
Associations between Space Weather Events and the Incidence of Acute Myocardial Infarction and Deaths from Ischemic Heart Disease
by Vidmantas Vaičiulis, Jonė Venclovienė, Abdonas Tamošiūnas, Deivydas Kiznys, Dalia Lukšienė, Daina Krančiukaitė-Butylkinienė and Ričardas Radišauskas
Atmosphere 2021, 12(3), 306; https://doi.org/10.3390/atmos12030306 - 26 Feb 2021
Cited by 8 | Viewed by 7239
Abstract
The effects of charged solar particles hitting the Earth’s magnetosphere are often harmful and can be dangerous to the human organism. The aim of this study was to analyze the associations of geomagnetic storms (GSs) and other space weather events (solar proton events [...] Read more.
The effects of charged solar particles hitting the Earth’s magnetosphere are often harmful and can be dangerous to the human organism. The aim of this study was to analyze the associations of geomagnetic storms (GSs) and other space weather events (solar proton events (SPEs), solar flares (SFs), high-speed solar wind (HSSW), interplanetary coronal mass ejections (ICMEs) and stream interaction regions (SIRs)) with morbidity from acute myocardial infarction (AMI) and mortality from ischemic heart diseases (IHDs) during the period 2000–2015 in Kaunas (Lithuania). In 2000–2015, 12,330 AMI events (men/women n = 6942/5388) and 3742 deaths from IHD (men/women n = 2480/1262) were registered. The results showed that a higher risk of AMI and deaths from IHD were related to the period of 3 days before GS—a day after GS, and a stronger effect was observed during the spring–autumn period. The strongest effect of HSSW was observed on the day of the event. We found significant associations between the risk of AMI and death from IHD and the occurrence of SFs during GSs. We also found a statistically significant increase in rate ratios (RRs) for all AMIs and deaths from IHD between the second and fourth days of the period of ICMEs. Full article
(This article belongs to the Special Issue The Impacts of Space Weather on Human Health)
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<p>(<b>A</b>) The monthly variation in the daily mean sunspot number, solar wind speed, and the Ap index; (<b>B</b>) the annual rate of the days of interplanetary coronal mass ejections (ICMEs), solar proton events (SPEs), X-class solar flares (SFs), and high-speed plasma streams (HSPSs).</p>
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<p>The effect of geomagnetic storm (the period of 3 days before GS, days of GS, and 1 day after GS) on the risk of AMI by different seasons. * <span class="html-italic">p</span> &lt; 0.05.</p>
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<p>The superposed epoch analyses of the rate ratios for AMI and death from IHD with the key days being the GSs (<b>A</b>), SPEs (<b>B</b>), ICMEs (<b>C</b>), and HSPSs (<b>D</b>) (RRs with 95% CI in the multivariate model). Zero corresponds to the day of the onset of the stormy period, the period of ICME, HSPS, and SPE. * <span class="html-italic">p</span> &lt; 0.05.</p>
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<p>The superposed epoch analyses of the rate ratios for AMI and death from IHD with the key days being the GSs (<b>A</b>), SPEs (<b>B</b>), ICMEs (<b>C</b>), and HSPSs (<b>D</b>) (RRs with 95% CI in the multivariate model). Zero corresponds to the day of the onset of the stormy period, the period of ICME, HSPS, and SPE. * <span class="html-italic">p</span> &lt; 0.05.</p>
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4014 KiB  
Review
Space Radiation: The Number One Risk to Astronaut Health beyond Low Earth Orbit
by Jeffery C. Chancellor, Graham B. I. Scott and Jeffrey P. Sutton
Life 2014, 4(3), 491-510; https://doi.org/10.3390/life4030491 - 11 Sep 2014
Cited by 306 | Viewed by 37761
Abstract
Projecting a vision for space radiobiological research necessitates understanding the nature of the space radiation environment and how radiation risks influence mission planning, timelines and operational decisions. Exposure to space radiation increases the risks of astronauts developing cancer, experiencing central nervous system (CNS) [...] Read more.
Projecting a vision for space radiobiological research necessitates understanding the nature of the space radiation environment and how radiation risks influence mission planning, timelines and operational decisions. Exposure to space radiation increases the risks of astronauts developing cancer, experiencing central nervous system (CNS) decrements, exhibiting degenerative tissue effects or developing acute radiation syndrome. One or more of these deleterious health effects could develop during future multi-year space exploration missions beyond low Earth orbit (LEO). Shielding is an effective countermeasure against solar particle events (SPEs), but is ineffective in protecting crew members from the biological impacts of fast moving, highly-charged galactic cosmic radiation (GCR) nuclei. Astronauts traveling on a protracted voyage to Mars may be exposed to SPE radiation events, overlaid on a more predictable flux of GCR. Therefore, ground-based research studies employing model organisms seeking to accurately mimic the biological effects of the space radiation environment must concatenate exposures to both proton and heavy ion sources. New techniques in genomics, proteomics, metabolomics and other “omics” areas should also be intelligently employed and correlated with phenotypic observations. This approach will more precisely elucidate the effects of space radiation on human physiology and aid in developing personalized radiological countermeasures for astronauts. Full article
(This article belongs to the Special Issue Response of Terrestrial Life to Space Conditions)
Show Figures

Figure 1

Figure 1
<p>The interplanetary space environment showing the toxic combination of galactic cosmic radiation (GCR) and (largely) proton radiation due to solar particle events (SPEs). Figure courtesy of NASA/JPL-Caltech.</p>
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<p>Relative abundance of GCR nuclei from hydrogen (Z = 1) to iron (Z = 26) [<a href="#B1-life-04-00491" class="html-bibr">1</a>].</p>
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<p>Energetic SPEs affecting low Earth orbit (LEO) space missions since 1991 are plotted as a function of the solar cycle. Shown here are events (red circles) that have been measured since 1991 to 2013 and include Solar Cycle 22 (partially), 23 and 24 (partially). Energetic solar events contain a higher fluence of &gt;100 MeV protons that can penetrate typical spacecraft shielding and significantly impact the health of astronauts.</p>
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<p>Select health effects due to space radiation exposures.</p>
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<p>Examples of two complex aberrations involving three or more chromosomes observed post-mission in astronauts. Chromosomes were hybridized with painting probes for chromosome 1 (red), chromosome 2 (green) and chromosome 4 (yellow). All other chromosomes were counterstained with DAPI (blue). Adapted from Cucinotta <span class="html-italic">et al.</span> [<a href="#B29-life-04-00491" class="html-bibr">29</a>] and republished with permission from <span class="html-italic">Radiation Research</span>.</p>
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<p>Acute radiation outcomes: (<b>a</b>) Blood cell counts (lymphocytes) following exposure to SPE-like gamma and proton radiation in a mouse model. Graph adapted from Romero-Weaver <span class="html-italic">et al.</span> [<a href="#B69-life-04-00491" class="html-bibr">69</a>]. (<b>b</b>) WBC counts in a mini-pig model following exposure to SPE-like electron and proton radiation. The WBC counts did not return to normal levels at the 30-day time point, with proton radiation exposure having the more detrimental effect. Graph adapted from Ann Kennedy [<a href="#B70-life-04-00491" class="html-bibr">70</a>] and reproduced with permission from <span class="html-italic">Life Sciences in Space Research</span>.</p>
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