Investigation of the Electron Density Variation During the 21 August 2017 Solar Eclipse
Abstract This paper presents a comparison of modeled and measured electron densities for the 21 August 2017 solar eclipse across the USA. The location of the instrument was (43.81°N, 247.32°E) where the maximum obscuration of 99.6% occurred at 17.53 hr UT on 21 August. The solar apparent time was 9....
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| Format: | Article |
| Language: | English |
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Wiley
2018-02-01
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| Series: | Geophysical Research Letters |
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| Online Access: | https://doi.org/10.1002/2017GL076572 |
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| author | B. W. Reinisch P. B. Dandenault I. A. Galkin R. Hamel P. G. Richards |
| author_facet | B. W. Reinisch P. B. Dandenault I. A. Galkin R. Hamel P. G. Richards |
| author_sort | B. W. Reinisch |
| collection | DOAJ |
| description | Abstract This paper presents a comparison of modeled and measured electron densities for the 21 August 2017 solar eclipse across the USA. The location of the instrument was (43.81°N, 247.32°E) where the maximum obscuration of 99.6% occurred at 17.53 hr UT on 21 August. The solar apparent time was 9.96 hr, and the duration of the eclipse was 2.7 hr. It was found that if it is assumed that there are no chromosphere emissions at totality, ~30% coronal emission remaining at totality gave the best fit to the electron density variation at 150 km. The 30% coronal emission estimate has uncertainties associated with respect to uncertainties in the solar spectrum, the measured electron density, and the amount of chromosphere emissions remaining at totality. The agreement between the modeled and measured electron densities is excellent at 150 km with the assumed 30% coronal emission at totality. At other altitudes, the agreement is very good, but the altitude profile would be improved if the model peak electron density (NmF2) decayed more slowly to better match the data. The minimum NmF2 in the model occurs ~10 min after totality when it decreases to 0.55 from its noneclipse value. The minimum of the NmF2 data occurs between 6 and 10 min after totality but is ~15% larger. The total electron content decreases to 0.65 of its preeclipse value. These relative changes agree well with those predicted by others prior to the eclipse. |
| format | Article |
| id | doaj-art-754a251663d44ddf9c8aa1a3e38288bb |
| institution | DOAJ |
| issn | 0094-8276 1944-8007 |
| language | English |
| publishDate | 2018-02-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geophysical Research Letters |
| spelling | doaj-art-754a251663d44ddf9c8aa1a3e38288bb2025-08-20T03:09:42ZengWileyGeophysical Research Letters0094-82761944-80072018-02-014531253126110.1002/2017GL076572Investigation of the Electron Density Variation During the 21 August 2017 Solar EclipseB. W. Reinisch0P. B. Dandenault1I. A. Galkin2R. Hamel3P. G. Richards4Lowell Digisonde International Lowell MA USAApplied Physics Laboratory Johns Hopkins University Laurel MD USASpace Science Laboratory University of Massachusetts Lowell MA USALowell Digisonde International Lowell MA USADepartment of Physics and Astronomy George Mason University Fairfax VA USAAbstract This paper presents a comparison of modeled and measured electron densities for the 21 August 2017 solar eclipse across the USA. The location of the instrument was (43.81°N, 247.32°E) where the maximum obscuration of 99.6% occurred at 17.53 hr UT on 21 August. The solar apparent time was 9.96 hr, and the duration of the eclipse was 2.7 hr. It was found that if it is assumed that there are no chromosphere emissions at totality, ~30% coronal emission remaining at totality gave the best fit to the electron density variation at 150 km. The 30% coronal emission estimate has uncertainties associated with respect to uncertainties in the solar spectrum, the measured electron density, and the amount of chromosphere emissions remaining at totality. The agreement between the modeled and measured electron densities is excellent at 150 km with the assumed 30% coronal emission at totality. At other altitudes, the agreement is very good, but the altitude profile would be improved if the model peak electron density (NmF2) decayed more slowly to better match the data. The minimum NmF2 in the model occurs ~10 min after totality when it decreases to 0.55 from its noneclipse value. The minimum of the NmF2 data occurs between 6 and 10 min after totality but is ~15% larger. The total electron content decreases to 0.65 of its preeclipse value. These relative changes agree well with those predicted by others prior to the eclipse.https://doi.org/10.1002/2017GL076572Electron density during solar eclipseSolar irradiance changesMeasurements and modelsNeutral winds and ionosphere peak height |
| spellingShingle | B. W. Reinisch P. B. Dandenault I. A. Galkin R. Hamel P. G. Richards Investigation of the Electron Density Variation During the 21 August 2017 Solar Eclipse Geophysical Research Letters Electron density during solar eclipse Solar irradiance changes Measurements and models Neutral winds and ionosphere peak height |
| title | Investigation of the Electron Density Variation During the 21 August 2017 Solar Eclipse |
| title_full | Investigation of the Electron Density Variation During the 21 August 2017 Solar Eclipse |
| title_fullStr | Investigation of the Electron Density Variation During the 21 August 2017 Solar Eclipse |
| title_full_unstemmed | Investigation of the Electron Density Variation During the 21 August 2017 Solar Eclipse |
| title_short | Investigation of the Electron Density Variation During the 21 August 2017 Solar Eclipse |
| title_sort | investigation of the electron density variation during the 21 august 2017 solar eclipse |
| topic | Electron density during solar eclipse Solar irradiance changes Measurements and models Neutral winds and ionosphere peak height |
| url | https://doi.org/10.1002/2017GL076572 |
| work_keys_str_mv | AT bwreinisch investigationoftheelectrondensityvariationduringthe21august2017solareclipse AT pbdandenault investigationoftheelectrondensityvariationduringthe21august2017solareclipse AT iagalkin investigationoftheelectrondensityvariationduringthe21august2017solareclipse AT rhamel investigationoftheelectrondensityvariationduringthe21august2017solareclipse AT pgrichards investigationoftheelectrondensityvariationduringthe21august2017solareclipse |