Long term variations in the Extreme UV corona: the EIT/SoHO perspective

Since the start of the SoHO mission, EIT -the Extreme ultraviolet Imaging Telescope- offers a global view of the solar corona over the whole rising phase of the current activity cycle. Such a dataset is unprecedented. We give here the current results of an on-going investigation over the entire EIT archive. In the Fe XV images (2 MK), the on-disk and off-disk intensity distributions have been evaluated, and their evolution is described. Additionally, we developed an image processing technique that extracts the smallest detectable features. The cosmic ray hits are statistically disentangled from the solar point-like phenomena, and the trends in both rates are assessed.

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Solar Modulation Effects in Terrestrial Production of Carbon-14

Radiocarbon ◽

10.1017/s0033822200009413 ◽

1980 ◽

Vol 22 (2) ◽

pp. 133-158 ◽

Cited By ~ 185

Author(s):

Giuliana Castagnoli ◽

Devendra Lal

Keyword(s):

Solar Activity ◽

Cosmic Ray ◽

Solar Modulation ◽

Carbon 14 ◽

Cosmic Ray Modulation ◽

The Earth ◽

Secular Variations ◽

Galactic Cosmic Ray ◽

Long Term Variations

This paper is concerned with the expected deviations in the production rate of natural 14C on the earth due to changes in solar activity. We review the published estimates of the global production rates of 14C due to galactic and solar cosmic ray particles, and present new estimates of the expected secular variations in 14C production, taking into account the latest information available on galactic cosmic ray modulation and long-term variations in solar activity.

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LONG-TERM BALLOON COSMIC RAY EXPERIMENT: RESULTS OF ANALYSIS OF ENERGETIC ELECTRON PRECIPITATION EVENTS

International Journal of Modern Physics A ◽

10.1142/s0217751x05030260 ◽

2005 ◽

Vol 20 (29) ◽

pp. 6843-6845 ◽

Cited By ~ 7

Author(s):

V. S. MAKHMUTOV ◽

G. A. BAZILEVSKAYA ◽

Y. I. STOZHKOV ◽

A. K. SVIRZHEVSKAYA ◽

N. S. SVIRZHEVSKY

Keyword(s):

Energetic Electron ◽

Cosmic Ray ◽

Activity Cycle ◽

Solar Activity Cycle ◽

Electron Precipitation ◽

Occurrence Rate ◽

Balloon Experiment ◽

Semiannual Variation ◽

Precipitation Events

More than 500 energetic Electron Precipitation Events were observed in the Earth's Northern and Southern polar atmosphere during a long-term cosmic ray balloon experiment. The results of analysis of these events allow to show (1) distribution of occurrence rate of EPEs within solar activity cycle, (2) semiannual variation in the EPE occurrence, (3) interplanetary and geomagnetic conditions related to the EPEs in the atmosphere.

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Wavelet analysis of long-term variations in neutron monitor, sunspot number and interplanetary magnetic field data

NMDB@Home 2020 - Cosmic ray studies with neutron detectors ◽

10.38072/2748-3150/p5 ◽

2021 ◽

pp. 39-42

Author(s):

Fraser Baird ◽

Alexander MacKinnon

Keyword(s):

Magnetic Field ◽

Field Data ◽

Solar Magnetic Field ◽

Cosmic Ray ◽

Negative Polarity ◽

Neutron Monitors ◽

Magnetic Field Data ◽

First Time ◽

Long Term Variations

For the first time, based on the experimental data of AMS-02, a three-parameter spectrum of variations of ga - lactic cosmic rays was obtained in the range of rigidity 1- 20 GV, to which neutron monitors are most sensitive. It was found that during the period of negative polarity of the solar magnetic field, a power-law spectrum of va - riations is observed with a strong exponential decay in the region of high rigidity. When the polarity changes to positive at the beginning of the new 24th solar cycle, the spectrum of cosmic ray variations becomes purely po- wer-law. The transition to the experimentally obtained spectrum of variations will make it possible to remove a number of uncertainties and increase the accuracy of the analysis of data from the ground network of detectors. This will make it possible to retrospectively obtain fluxes of galactic protons with an average monthly resolution for the period of the space era based on ground-based monitoring.

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