Astronomy and Astrophysics – Astrophysics
Scientific paper
Oct 2001
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2001jgr...10621599m&link_type=abstract
Journal of Geophysical Research, Volume 106, Issue A10, p. 21599-21610
Astronomy and Astrophysics
Astrophysics
25
Interplanetary Physics: Cosmic Rays, Interplanetary Physics: Energetic Particles, Solar, Interplanetary Physics: Solar Cycle Variations, Solar Physics, Astrophysics, And Astronomy: Corona
Scientific paper
A total of 125 large fluence solar proton events identified from the nitrate deposition in ice core from Greenland for the period 1561-1950 are examined in an exploratory study of the geophysical information that will be available from such data in the future. These data have been augmented with ionospheric and satellite data for the period 1950-1994. There were five periods in the vicinity of 1610, 1710, 1790, 1870, and 1950, when large >30 MeV proton events with fluence greater than 2×109cm-2 were up to 8 times more frequent than in the era of satellite observation. There is a well-defined Gleissberg (approximately 80 year) periodicity in the large fluence proton events, with six well-defined minima, two in close association with the Maunder and Dalton minima in sunspot number. The present ``satellite'' era is recognized as a recurrence of this series of minima. Comparison of the total solar proton production for the five Gleissberg cycles since 1580 shows that the cycle 1820-1910 was the most active followed by the cycle 1580-1660. The present Gleissberg cycle is one of the least effective in the production of solar proton events at Earth. It is shown that the solar and solar proton event data both indicate that the Maunder Minimum ended about 1700, 16 years before the commonly accepted date of 1716. It is proposed that the delayed ``switch on'' of aurorae after the Maunder Minimum is due to the changing nature of the solar corona from ``Maunder Minimum'' conditions to the more active conditions of the Gleissberg cycle, and a physical mechanism is proposed in which variations in the coronal densities modulate the efficiency of solar proton event production throughout the Gleissberg cycle. The ``streaming limited fluence'' for >30 MeV protons is estimated to be 6-8×109cm-2, and the rapid decrease in the probability of occurrence of solar proton events observed in the vicinity of this fluence is proposed to be due to this effect.
Dreschhoff Gisela A. M.
McCracken K. G.
Shea Margaret Ann
Smart Don Frederick
No associations
LandOfFree
Solar cosmic ray events for the period 1561-1994: 2. The Gleissberg periodicity does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Solar cosmic ray events for the period 1561-1994: 2. The Gleissberg periodicity, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Solar cosmic ray events for the period 1561-1994: 2. The Gleissberg periodicity will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1002438