| Autor: | Blanca Mendoza, Jose F. Valdés Galicia, Alejandro Lara, D. Maravilla |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
Physics
Solar phenomena Astrophysics::High Energy Astrophysical Phenomena Astronomy Coronal hole Astronomy and Astrophysics Coronal loop Corona Nanoflares Solar wind Space and Planetary Science Physics::Space Physics Coronal mass ejection Astrophysics::Solar and Stellar Astrophysics Interplanetary magnetic field |
| Zdroj: | Solar Physics. 203:27-38 |
| ISSN: | 0038-0938 |
| Popis: | We use observations of the green corona low-brightness regions to construct a time series of a polar coronal hole area from 1939 to 1996, covering 5 solar cycles. We then perform a power-spectral analysis of the monthly data time series. Several persistent significant periodicities appear in the spectra, which are related with those found in solar magnetic flux emergence, geomagnetic storm sudden commencements and cosmic-ray flux at Earth. Of particular importance are the peak at around 1.6–1.8 yr recently found in cosmic-ray intensity fluctuations, and the peak at around 1 yr, also identified in coronal hole magnetic flux variations. Additional interesting features are the peaks close to 5 yr, 3 yr and the possible peak at around 30 yr, that were also found in other solar and interplanetary phenomena. Our results stress the physical connection between the solar magnetic flux emergence and the interplanetary medium dynamics, in particular the importance of coronal hole evolution in the structuring of the heliosphere. |
| Databáze: | OpenAIRE |
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