155-day Periodicity in solar cycles 3 and 4 |
| |
| Authors: | JM Vaquero RM Trigo M Vázquez MC Gallego |
| |
| Institution: | 1. Departamento de Física Aplicada, Escuela Politécnica, Universidad de Extremadura, Cáceres, Spain;2. CGUL-IDL, Universidade de Lisboa, Lisbon, Portugal;3. Departamento de Eng. Civil da Universidade Lusófona, Lisbon, Portugal;4. Instituto de Astrofísica de Canarias, La Laguna 38200, Spain;5. Departamento de Astrofísica, Universidad de La Laguna, 38205 La Laguna, Spain;6. Departamento de Física, Universidad de Extremadura, Badajoz, Spain |
| |
| Abstract: | The near 155 days solar periodicity, so called Rieger periodicity, was first detected in solar flares data and later confirmed with other important solar indices. Unfortunately, a comprehensive analysis on the occurrence of this periodicity during previous centuries can be further complicated due to the poor quality of the sunspot number time series. We try to detect the Rieger periodicity during the solar cycles 3 and 4 using information on aurorae observed at mid and low latitudes. We use two recently discovered aurora datasets, observed in the last quarter of the 18th century from UK and Spain. Besides simple histograms of time between consecutive events we analyse monthly series of number of aurorae observed using different spectral analysis (MTM and Wavelets). The histograms show the probable presence of Rieger periodicity during cycles 3 and 4. However different spectral analysis applied has only confirmed undoubtedly this hypothesis for solar cycle 3. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
