Ionospheric measurements of relative coronal brightness during the total solar eclipses of 11 August, 1999 and 9 July, 1945

Details Ionospheric measurements of relative coronal brightness during the total solar eclipses of 11 August, 1999 and 9 July, 1945 Ionospheric measurements of relative coronal brightness during the total solar eclipses of 11 August, 1999 and 9 July, 1945

Feb 2000

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2000angeo..18..182d&link_type=abstract

Annales Geophysicae, vol. 18, Issue 2, pp.182-190

Computer Science

Sound

9

Scientific paper

Swept-frequency (1-10 MHz) ionosonde measurements were made at Helston, Cornwall (50∘06'N, 5∘18'W) during the total solar eclipse on August 11, 1999. Soundings were made every three minutes. We present a method for estimating the percentage of the ionising solar radiation which remains unobscured at any time during the eclipse by comparing the variation of the ionospheric E-layer with the behaviour of the layer during a control day. Application to the ionosonde date for 11 August, 1999, shows that the flux of solar ionising radiation fell to a minimum of 25+/-2% of the value before and after the eclipse. For comparison, the same technique was also applied to measurements made during the total solar eclipse of 9 July, 1945, at Sörmjöle (63∘68'N, 20∘20'E) and yielded a corresponding minimum of 16+/-2%. Therefore the method can detect variations in the fraction of solar emissions that originate from the unobscured corona and chromosphere. We discuss the differences between these two eclipses in terms of the nature of the eclipse, short-term fluctuations, the sunspot cycle and the recently-discovered long-term change in the coronal magnetic field.

Affiliated with

Also associated with

No associations

Rating

Ionospheric measurements of relative coronal brightness during the total solar eclipses of 11 August, 1999 and 9 July, 1945 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 Ionospheric measurements of relative coronal brightness during the total solar eclipses of 11 August, 1999 and 9 July, 1945, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ionospheric measurements of relative coronal brightness during the total solar eclipses of 11 August, 1999 and 9 July, 1945 will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1492254