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 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.

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.

Simulating effects of the 774 AD solar proton event on atmospheric electricity

2021 ◽  
Author(s):  
Stergios Misios ◽  
Mads F. Knudsen ◽  
Christoffer Karoff
Keyword(s):  
Atmospheric Electricity ◽  
Circulation Model ◽  
High Energy ◽  
Solar Proton ◽  
Solar Proton Event ◽  
Proton Event ◽  
Atmospheric Conditions ◽  
Global Circulation Model ◽  
Fair Weather ◽  
Particle Radiation

<p>High energy cosmic rays of galactic and solar origin, natural radioactivity, lighting in thunderstorms and electrified shower clouds, produce ion clusters and charge the whole atmosphere causing a ubiquitous potential difference between the ionosphere and the surface. This Global Electric Circuit (GEC) allows the flow of charges to the surface in the fair-weather regions of the globe. Here, we simulate the effect of highly energetic particle radiation, in particular the 774 AD solar proton event, on the GEC with the aid of the global circulation model EMAC/MESSy. The simulations assume pre-industrial atmospheric conditions and the coupling of aerosol and atmospheric electricity schemes allows for ion-ion and ion-aerosol capture reactions. We discuss effects in fair weather current and atmospheric conductivity at different latitudinal bands. </p>

scholarly journals Multiradionuclide evidence for an extreme solar proton event around 2,610 B.P. (∼660 BC)

2019 ◽  
Vol 116 (13) ◽  
pp. 5961-5966 ◽  
Author(s):  
Paschal O’Hare ◽  
Florian Mekhaldi ◽  
Florian Adolphi ◽  
Grant Raisbeck ◽  
Ala Aldahan ◽  
...  
Keyword(s):  
Ice Core ◽  
Ice Cores ◽  
Solar Proton ◽  
Solar Proton Event ◽  
Proton Event ◽  
Production Rates ◽  
Cosmogenic Radionuclides ◽  
Solar Event ◽  
Carbon 14 ◽  
Order Of Magnitude

Recently, it has been confirmed that extreme solar proton events can lead to significantly increased atmospheric production rates of cosmogenic radionuclides. Evidence of such events is recorded in annually resolved natural archives, such as tree rings [carbon-14 (14C)] and ice cores [beryllium-10 (10Be), chlorine-36 (36Cl)]. Here, we show evidence for an extreme solar event around 2,610 years B.P. (∼660 BC) based on high-resolution10Be data from two Greenland ice cores. Our conclusions are supported by modeled14C production rates for the same period. Using existing36Cl ice core data in conjunction with10Be, we further show that this solar event was characterized by a very hard energy spectrum. These results indicate that the 2,610-years B.P. event was an order of magnitude stronger than any solar event recorded during the instrumental period and comparable with the solar proton event of AD 774/775, the largest solar event known to date. The results illustrate the importance of multiple ice core radionuclide measurements for the reliable identification of short-term production rate increases and the assessment of their origins.

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