scholarly journals Radiation dose of aircrews during a solar proton event without ground-level enhancement

2015 ◽  
Vol 33 (1) ◽  
pp. 75-78 ◽  
Author(s):  
R. Kataoka ◽  
Y. Nakagawa ◽  
T. Sato
Keyword(s):  
Radiation Dose ◽  
Solar Energetic Particle ◽  
Ground Level ◽  
Solar Proton ◽  
Significant Enhancement ◽  
Radiation Hazard ◽  
Proton Event ◽  
Ground Level Enhancement ◽  
Air Shower ◽  
Open Question

Abstract. A significant enhancement of radiation doses is expected for aircrews during ground-level enhancement (GLE) events, while the possible radiation hazard remains an open question during non-GLE solar energetic particle (SEP) events. Using a new air-shower simulation driven by the proton flux data obtained from GOES satellites, we show the possibility of significant enhancement of the effective dose rate of up to 4.5 μSv h−1 at a conventional flight altitude of 12 km during the largest SEP event that did not cause a GLE. As a result, a new GOES-driven model is proposed to give an estimate of the contribution from the isotropic component of the radiation dose in the stratosphere during non-GLE SEP events.

THE GROUND-LEVEL ENHANCEMENT OF 2012 MAY 17: DERIVATION OF SOLAR PROTON EVENT PROPERTIES THROUGH THE APPLICATION OF THE NMBANGLE PPOLA MODEL

2014 ◽  
Vol 785 (2) ◽  
pp. 160 ◽  
Author(s):  
Christina Plainaki ◽  
Helen Mavromichalaki ◽  
Monica Laurenza ◽  
Maria Gerontidou ◽  
Anastasios Kanellakopoulos ◽  
...  
Keyword(s):  
Ground Level ◽  
Solar Proton ◽  
Solar Proton Event ◽  
Proton Event ◽  
Ground Level Enhancement

scholarly journals Enhancement of stratospheric aerosols after solar proton event

1996 ◽  
Vol 14 (11) ◽  
pp. 1119-1123 ◽  
Author(s):  
O. I. Shumilov ◽  
E. A. Kasatkina ◽  
K. Henriksen ◽  
E. V. Vashenyuk
Keyword(s):  
Considerable Increase ◽  
Ground Level ◽  
Solar Proton ◽  
Stratospheric Aerosol ◽  
Nucleation Mechanism ◽  
Solar Proton Event ◽  
Proton Event ◽  
Aerosol Layer ◽  
Event Type ◽  
Lidar Measurements

Abstract. The lidar measurements at Verhnetulomski observatory (68.6°N, 31.8°E) at Kola peninsula detected a considerable increase of stratospheric aerosol concentration after the solar proton event of GLE (ground level event) type on the 16/02/84. This increase was located at precisely the same altitude range where the energetic solar protons lost their energy in the atmosphere. The aerosol layer formed precipitated quickly (1–2 km per day) during 18, 19, and 20 February 1984, and the increase of R(H) (backscattering ratio) at 17 km altitude reached 40% on 20/02/84. We present the model calculation of CN (condensation nuclei) altitude distribution on the basis of an ion-nucleation mechanism, taking into account the experimental energy distribution of incident solar protons. The meteorological situation during the event was also investigated.

scholarly journals Ionization effect of solar particle GLE events in low and middle atmosphere

2010 ◽  
Vol 10 (12) ◽  
pp. 30381-30404 ◽  
Author(s):  
I. G. Usoskin ◽  
G. A. Kovaltsov ◽  
I. A. Mironova ◽  
A. J. Tylka ◽  
W. F. Dietrich
Keyword(s):  
Middle Atmosphere ◽  
Ground Level ◽  
Solar Proton ◽  
Energy Spectra ◽  
Wide Energy Range ◽  
Ground Level Enhancement ◽  
Direct Ionization ◽  
Ionization Effect ◽  
The World ◽  
Wide Energy

Abstract. Using a new reconstruction of the solar proton energy spectra for Ground Level Enhancement (GLE) events, based on fits to measurements from ground-based and satellite-borne instruments covering a wide energy range, we quantitatively evaluate the possible ionization effects in the low and middle atmosphere for 58 out of the 66 GLE events recorded by the world-wide neutron monitor network since 1956. The ionization computations are based on the numerical 3-D CRAC:CRII model. A table of the ionization effect caused by the GLE events at different atmospheric heights is provided. It is shown that the direct ionization effect is negligible or even negative, due to the accompanying Forbush decreases, in all low- and mid-latitude regions. The ionization effect is important only in the polar atmosphere, where it can be dramatic in the middle and upper atmosphere (above 30 km) during major GLE events.

scholarly journals Radiation Dose Nowcast for the Ground Level Enhancement on 10-11 September 2017

Space Weather ◽  
2018 ◽  
Vol 16 (7) ◽  
pp. 917-923 ◽  
Author(s):  
Ryuho Kataoka ◽  
Tatsuhiko Sato ◽  
Shoko Miyake ◽  
Daikou Shiota ◽  
Yûki Kubo
Keyword(s):  
Radiation Dose ◽  
Ground Level ◽  
Ground Level Enhancement

scholarly journals Ionization effect of solar particle GLE events in low and middle atmosphere

2011 ◽  
Vol 11 (5) ◽  
pp. 1979-1988 ◽  
Author(s):  
I. G. Usoskin ◽  
G. A. Kovaltsov ◽  
I. A. Mironova ◽  
A. J. Tylka ◽  
W. F. Dietrich
Keyword(s):  
Middle Atmosphere ◽  
Ground Level ◽  
Solar Proton ◽  
Energy Spectra ◽  
Wide Energy Range ◽  
Ground Level Enhancement ◽  
Direct Ionization ◽  
Ionization Effect ◽  
The World ◽  
Wide Energy

Abstract. Using a new reconstruction of the solar proton energy spectra for Ground Level Enhancement (GLE) events, based on fits to measurements from ground-based and satellite-borne instruments covering a wide energy range, we quantitatively evaluate the possible ionization effects in the low and middle atmosphere for 58 out of the 66 GLE events recorded by the world-wide neutron monitor network since 1956. The ionization computations are based on the numerical 3D CRAC:CRII model. A table of the ionization effect caused by the GLE events at different atmospheric heights is provided. It is shown that the direct ionization effect is negligible or even negative, due to the accompanying Forbush decreases, in all low- and mid-latitude regions. The ionization effect is important only in the polar atmosphere, where it can be dramatic in the middle and upper atmosphere (above 30 km) during major GLE events.

scholarly journals The virtual enhancements − solar proton event radiation (VESPER) model

2018 ◽  
Vol 8 ◽  
pp. A06 ◽  
Author(s):  
Sigiava Aminalragia-Giamini ◽  
Ingmar Sandberg ◽  
Constantinos Papadimitriou ◽  
Ioannis A. Daglis ◽  
Piers Jiggens
Keyword(s):  
Time Series ◽  
Radiation Effects ◽  
Solar Energetic Particle ◽  
Solar Proton ◽  
Galactic Cosmic Rays ◽  
Solar Proton Event ◽  
Proton Event ◽  
Proton Radiation ◽  
Virtual Time ◽  
Trapped Radiation

A new probabilistic model introducing a novel paradigm for the modelling of the solar proton environment at 1 AU is presented. The virtual enhancements − solar proton event radiation model (VESPER) uses the European space agency's solar energetic particle environment modelling (SEPEM) Reference Dataset and produces virtual time-series of proton differential fluxes. In this regard it fundamentally diverges from the approach of existing SPE models that are based on probabilistic descriptions of SPE macroscopic characteristics such as peak flux and cumulative fluence. It is shown that VESPER reproduces well the dataset characteristics it uses, and further comparisons with existing models are made with respect to their results. The production of time-series as the main output of the model opens a straightforward way for the calculation of solar proton radiation effects in terms of time-series and the pairing with effects caused by trapped radiation and galactic cosmic rays.

scholarly journals Northern Hemisphere atmospheric influence of the solar proton events and ground level enhancement in January 2005

2011 ◽  
Vol 11 (3) ◽  
pp. 7715-7755 ◽  
Author(s):  
C. H. Jackman ◽  
D. R. Marsh ◽  
F. M. Vitt ◽  
R. G. Roble ◽  
C. E. Randall ◽  
...  
Keyword(s):  
Northern Hemisphere ◽  
Atmospheric Chemistry ◽  
Reasonable Agreement ◽  
Climate Model ◽  
Michelson Interferometer ◽  
Ground Level ◽  
Solar Proton ◽  
Ground Level Enhancement ◽  
Time Period ◽  
Solar Proton Events

Abstract. Solar eruptions in early 2005 led to a substantial barrage of charged particles on the Earth's atmosphere during the 16–21 January period. Proton fluxes were greatly increased during these several days and led to the production of HOx (H, OH, HO2) and NOx (N, NO, NO2), which then caused the destruction of ozone. We focus on the Northern polar region, where satellite measurements and simulations with the Whole Atmosphere Community Climate Model (WACCM3) showed large enhancements in mesospheric HOx and NOx constituents, and associated ozone reductions, due to these solar proton events (SPEs). The WACCM3 simulations show enhanced short-lived OH throughout the mesosphere in the 60–82.5° N latitude band due to the SPEs for most days in the 16–21 January 2005 period, in reasonable agreement with the Aura Microwave Limb Sounder (MLS) measurements. Mesospheric HO2 is also predicted to be increased by the SPEs, however, the modeled HO2 results are somewhat larger than the MLS measurements. These HOx enhancements led to huge predicted and MLS-measured ozone decreases of greater than 40% throughout most of the northern polar mesosphere during the SPE period. Envisat Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) measurements of hydrogen peroxide (H2O2) show increases throughout the stratosphere with highest enhancements of about 60 pptv in the lowermost mesosphere over the 16–18 January 2005 period due to the solar protons. WACCM3 predictions indicate H2O2 enhancements over the same time period of more than twice that amount. Measurements of nitric acid (HNO3) by both MLS and MIPAS show an increase of about 1 ppbv above background levels in the upper stratosphere during 16–29 January 2005. WACCM3 simulations show only minuscule HNO3 changes in the upper stratosphere during this time period. Polar mesospheric enhancements of NOx are computed to be greater than 50 ppbv during the SPE period due to the small loss rates during winter. Computed NOx increases, which were statistically significant at the 95% level, lasted about a month past the SPEs. The SCISAT-1 Atmospheric Chemistry Experiment Fourier Transform Spectrometer NOx measurements and MIPAS NO2 measurements for the polar Northern Hemisphere are in reasonable agreement with these predictions. An extremely large ground level enhancement (GLE) occurred during the SPE period on 20 January 2005. We find that protons of energies 300 to 20 000 MeV, not normally included in our computations, led to enhanced lower stratospheric odd nitrogen concentrations of less than 0.1% as a result of this GLE.

SOLAR MODULATION OF ATMOSPHERIC COSMIC RADIATION: COMPARISON BETWEEN IN-FLIGHT AND GROUND-LEVEL MEASUREMENTS

2005 ◽  
Vol 20 (29) ◽  
pp. 6690-6692
Author(s):  
R. H. A. ILES ◽  
G. C. TAYLOR ◽  
J. B. L. JONES
Keyword(s):  
Radiation Dose ◽  
Radiation Exposure ◽  
Cosmic Radiation ◽  
Collaborative Study ◽  
Solar Energetic Particle ◽  
Ground Level ◽  
National Physical Laboratory ◽  
Civil Aviation ◽  
Solar Modulation ◽  
Eu Directive

January 2000 saw the start of a collaborative study involving the Mullard Space Science Laboratory, Virgin Atlantic Airways, the Civil Aviation Authority and the National Physical Laboratory in a program to investigate the cosmic radiation exposure to aircrew. The study has been undertaken in view of EU Directive 96/291 (May 2000) which requires the assessment of the level of radiation exposure to aircrew. The project's aims include validation of radiation dose models and evaluation of space weather effects on atmospheric cosmic radiation levels, in particular those effects not accounted for by the models. Ground level measurements are often used as a proxy for variations in cosmic radiation dose levels at aircraft altitudes, especially during Forbush Decreases (FDs) and Solar Energetic Particle (SEP) events. Is this estimation realistic and does the ground level data accurately represent what is happening at altitude? We have investigated the effect of a FD during a flight from Hong Kong to London Heathrow on the 15th July 2000 and compared count rate and dose measurements with simultaneous variations measured at ground level. We have also compared the results with model outputs.

scholarly journals GROUND LEVEL ENHANCEMENT IN THE 2014 JANUARY 6 SOLAR ENERGETIC PARTICLE EVENT

2014 ◽  
Vol 790 (1) ◽  
pp. L13 ◽  
Author(s):  
N. Thakur ◽  
N. Gopalswamy ◽  
H. Xie ◽  
P. Mäkelä ◽  
S. Yashiro ◽  
...  
Keyword(s):  
Energetic Particle ◽  
Solar Energetic Particle ◽  
Ground Level ◽  
Solar Energetic Particle Event ◽  
Ground Level Enhancement ◽  
Particle Event
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