scholarly journals GLE # 67 Event on 2 November 2003: An Analysis of the Spectral and Anisotropy Characteristics Using Verified Yield Function and Detrended Neutron Monitor Data

Solar Physics ◽  
2021 ◽  
Vol 296 (5) ◽  
Author(s):  
Alexander L. Mishev ◽  
Sergey A. Koldobskiy ◽  
Leon G. Kocharov ◽  
Ilya G. Usoskin
Keyword(s):  
Neutron Monitor ◽  
Dynamical Evolution ◽  
Ground Level ◽  
High Energy ◽  
Yield Function ◽  
Angle Distribution ◽  
Ground Level Enhancement ◽  
Solar Particles ◽  
Monitor Data

AbstractDuring Solar Cycle 23 16 ground-level enhancement events were registered by the global neutron monitor network. In this work we focus on the period with increased solar activity during late October – early November 2003 producing a sequence of three events, specifically on ground-level enhancement GLE 67 on 2 November 2003. On the basis of an analysis of neutron monitor and space-borne data we derived the spectra and pitch-angle distribution of high-energy solar particles with their dynamical evolution throughout the event. According to our analysis, the best fit of the spectral and angular properties of solar particles was obtained by a modified power-law rigidity spectrum and a double Gaussian, respectively. The derived angular distribution is consistent with the observations where an early count rate increase at Oulu neutron monitor with asymptotic viewing direction in the anti-Sun direction was registered. The quality of the fit and model constraints were assessed by a forward modeling. The event integrated particle fluence was derived using two different methods. The derived results are briefly discussed.

Neutron monitor observations of high-energy solar particles during the new cycle

Solar Physics ◽  
1967 ◽  
Vol 2 (4) ◽  
Author(s):  
G.A. Baird ◽  
G.G. Bell ◽  
S.P. Duggal ◽  
M.A. Pomerantz
Keyword(s):  
Neutron Monitor ◽  
High Energy ◽  
Solar Particles

scholarly journals New neutron monitor altitude-dependent yield function and its application to an analysis of neutron-monitor data

2021 ◽  
Author(s):  
Sergey Koldobskiy ◽  
Alexander Mishev ◽  
Gennady Kovaltsov ◽  
Agnieszka Gil ◽  
Ilya Usoskin
Keyword(s):  
Neutron Monitor ◽  
Yield Function ◽  
Neutron Monitor Data ◽  
Monitor Data

scholarly journals SEP spectra derived from neutron monitor data and from EPHIN space detector data during recent GLEs and sub-GLEs

2021 ◽  
pp. 89-95
Author(s):  
Rolf Bütikofer ◽  
Patrick Kühl ◽  
Athanasios Papaioannou
Keyword(s):  
Neutron Monitor ◽  
Count Rate ◽  
Rate Increase ◽  
Angle Distribution ◽  
Pitch Angle Distribution ◽  
Heliospheric Observatory ◽  
Proton Intensity ◽  
Worldwide Network ◽  
Monitor Data ◽  
Modelling Approach

The Electron Proton Helium Instrument (EPHIN) aboard the Solar Heliospheric Observatory (SOHO) observed several SEP events with protons accelerated to energies E>500 MeV, whereas no neutron monitor (NM) of the worldwide network showed a significant increase in their counting rate. For instance, the SEP event on 8 November 2000 with maximum proton intensity at 500 MeV of >0.1 (cm2 s sr MeV)-1 is outstanding, as this maximum pro-ton flux is comparable with the GLEs on 14 July 2000 and on 15 April 2001 (max. count rate increase in 5-min data of 225% at South Pole NM). In a first step we applied a forward modelling approach of the SEP event on 8 November 2000, i.e. we computed the expected NM count rate increases for selected NM stations, utilizing as input para-meters the SEP spectra determined from EPHIN data as well as anticipated pitch angle distribution and apparent source direction. The simulated count rate increases for selected NM stations showed that this SEP event should have be seen as a clear GLE. To further understand this situation, we investigated in a next step recent GLEs and sub-GLEs. Consequently, a total of four SEP events were selected, two clearly identified GLEs and two sub-GLEs. We performed a “GLE analysis” based on the data of the worldwide network of NMs for each of the four SEP events and then compared the derived SEP spectra with the proton spectra as determined from EPHIN measurements.

THE HIGH-ENERGY IMPULSIVE GROUND-LEVEL ENHANCEMENT

2012 ◽  
Vol 761 (2) ◽  
pp. 101 ◽  
Author(s):  
K. G. McCracken ◽  
H. Moraal ◽  
M. A. Shea
Keyword(s):  
Ground Level ◽  
High Energy ◽  
Ground Level Enhancement

Improved Approach in the Coupling Function Between Primary and Ground Level Cosmic Ray Particles Based on Neutron Monitor Data

Solar Physics ◽  
2021 ◽  
Vol 296 (6) ◽  
Author(s):  
L. Xaplanteris ◽  
M. Livada ◽  
H. Mavromichalaki ◽  
L. Dorman ◽  
M. K. Georgoulis ◽  
...  
Keyword(s):  
Neutron Monitor ◽  
Cosmic Ray ◽  
Ground Level ◽  
Coupling Function ◽  
Neutron Monitor Data ◽  
Monitor Data

scholarly journals Role of the heliospheric current sheet in high energy proton transport through modelling of historic GLE events 

2021 ◽  
Author(s):  
Charlotte Waterfall ◽  
Silvia Dalla
Keyword(s):  
Current Sheet ◽  
Test Particle ◽  
Ground Level ◽  
High Energy ◽  
Heliospheric Current Sheet ◽  
Particle Model ◽  
The Earth ◽  
Monitor Data ◽  
Mev Protons

<p>The influence of the heliospheric current sheet (HCS) on the propagation of high energy solar protons is explored using 3D test particle modelling. The test particle model, which includes drift effects, is used to simulate specific past ground level enhancement (GLE) events which cover a range of HCS configurations. For example, the effects of a source location close to and far from the HCS for events both poorly and well-connected to Earth are examined. Similarly, the effect of the Earth’s location relative to the HCS is explored. The modelling is performed for high energy (300-1200 MeV) protons to represent the energetic conditions under which GLEs occur. The derived intensity profiles at 1AU are compared to observations from HEPAD onboard GOES, as well as STEREO (at locations away from Earth) and neutron monitor data. </p>

The Cosmic Ray Ground-level Enhancement of 24 October 1989

1994 ◽  
Vol 11 (1) ◽  
pp. 28-32 ◽  
Author(s):  
J. L. Cramp ◽  
J. E. Humble ◽  
M. L. Duldig
Keyword(s):  
Pitch Angle ◽  
Cosmic Ray ◽  
Ground Level ◽  
Model Fit ◽  
South Pole ◽  
Neutron Monitors ◽  
Ground Level Enhancement ◽  
Apparent Source ◽  
Worldwide Network ◽  
Monitor Data

AbstractThe cosmic ray ground-level enhancement (GLE) of 24 October 1989 was the last of a series of GLEs associated with the same solar active region. Intensity enhancements were observed by at least 31 neutron monitors in the worldwide network, with the largest increase (~200%) observed at South Pole, Antarctica around 20:30 UT. Using a least-squares model fit to all available neutron monitor data, spectra, apparent source directions and particle pitch angle distributions have been derived. The effect of disturbed geomagnetic conditions has also been taken into account.

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