Coronal holes, solar wind streams, and geomagnetic activity during the new sunspot cycle

Details Coronal holes, solar wind streams, and geomagnetic activity during the new sunspot cycle Coronal holes, solar wind streams, and geomagnetic activity during the new sunspot cycle

Sep 1978

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1978soph...59..159h&link_type=abstract

Solar Physics, Volume 59, Issue 1, pp.159-173

Physics

12

Scientific paper

We have extended our previous study of coronal holes, solar wind streams, and geomagnetic disturbances from the declining phase (1973 1975) of sunspot cycle 20 through sunspot minimum (1976) into the rising phase (1977) of cycle 21. Using daily He I 10830 Å spectroheliograms and photospheric magnetograms, we found the following results:
(1)
As the magnetic field patterns changed, the solar atmosphere evolved from a structure having a few, large, long-lived, low-latitude coronal holes to one having numerous small, short-lived, high-latitude holes (in addition to the polar holes which persisted throughout this 5-year interval).
(2)
The high-latitude holes recurred with a synodic rotation period of 28 29 days instead of the 27-day period already known to be characteristic of low-latitude holes.
(3)
During 1976 1977 many coronal holes were intrinsically ‘weak’ in the sense that their average intensities did not differ greatly from the intensity of their surroundings. Such low-contrast holes were rare during 1973 1975. An updated Bartels display of the occurrence of holes, wind speed, and geomagnetic activity summarizes the evolution of their characteristics and interrelations as the sunspot cycle has progressed. Long-lived, low-latitude holes have become rare but remain terrestrially effective. The more common high-latitude holes are effective only when the Earth lies at a relatively high heliographic latitude in the same solar hemisphere.

Affiliated with

Also associated with

No associations

Rating

Coronal holes, solar wind streams, and geomagnetic activity during the new sunspot cycle 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 Coronal holes, solar wind streams, and geomagnetic activity during the new sunspot cycle, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Coronal holes, solar wind streams, and geomagnetic activity during the new sunspot cycle will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-943445