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Updated: Mar 16, 2026
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Scattering And Absorption of Light in Planetary Regoliths
Published on: July 1, 2019
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Using the ionospheric response to the solar eclipse on 20 March 2015 to detect spatial structure in the solar corona
C J Scott1, J Bradford2, S A Bell3
1Department of Meteorology, University of Reading, Earley Gate, PO Box 243, Reading RG6 6BB, UK chris.scott@reading.ac.uk.
Summary
During a 2015 solar eclipse, scientists studied the ionosphere's response above the UK. Coronal emission wavelengths best explained the observed ionospheric changes, linking solar disc activity to atmospheric effects.
Area of Science:
- Space Physics
- Atmospheric Science
- Solar Physics
Background:
- Total solar eclipses offer unique opportunities to study Earth's atmospheric layers.
- The ionospheric E-region's response to solar obscuration is crucial for understanding radio wave propagation.
- Previous studies often lacked high time resolution data for detailed ionospheric event analysis.
Purpose of the Study:
- To investigate the high time resolution (1-minute) decay and recovery of the Earth's ionospheric E-region during the 20 March 2015 solar eclipse.
- To compare the observed ionospheric obscuration with modeled solar extreme ultraviolet (EUV) and X-ray emissions.
- To identify which solar emission wavelengths most accurately represent the ionospheric response to eclipses.
Main Methods:
- Utilized high time resolution (1-minute) ionospheric data from Chilton, UK, during the 2015 solar eclipse.
- Re-created the eclipse using Solar Dynamics Observatory data to model incident solar radiation across nine EUV and X-ray wavelengths.
- Analyzed the obscuration of different solar emission wavelengths and their correlation with ionospheric E-region changes.
Main Results:
- The ionospheric E-region showed a maximum obscuration of 66% approximately at the time of maximum solar photosphere obscuration (88.88%).
- Solar wavelengths corresponding to coronal emissions (94, 211, and 335 Å) most effectively replicated the observed time-varying fraction of unobscured radiation in the ionosphere.
- Discrepancies between photospheric and ionospheric obscuration suggest localized solar emission sources are key.
Conclusions:
- The spatial distribution of solar EUV and X-ray emissions significantly influences the ionospheric E-region's response to solar eclipses.
- Coronal emission lines are critical drivers of the ionospheric changes observed during solar eclipses.
- This research provides a method for interpreting historical ionospheric eclipse data by considering specific solar emission distributions.
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