Spectral Analysis of Short-Period K Indices at Huancayo Geomagnetic Observatory
First published: 2016
Brief summary
Wavelet spectral analysis of geomagnetic K-index data reveals annual harmonic cycles (182.6, 365, 730 days) and solar-rotation-linked periods (6.8-27 days) that vary in strength between solar cycles.
Article
Spectral Analysis of Short-Period K Indices at Huancayo Geomagnetic Observatory is a preprint published by arXiv in 2016. It focuses on wavelet spectral analysis of geomagnetic K-index data reveals annual harmonic cycles (182.6, 365, 730 days) and solar-rotation-linked periods (6.8-27 days) that vary in strength between solar cycles.
The analysis focuses on 182.6, 365, 730 days (annual harmonics). It also considers 6.8, 9.0, 13.5, 27.0 days (solar rotation harmonics). It also considers wavelet spectral analysis of observatory data. This gives the cycle claim a specific numerical and evidential setting rather than presenting periodicity only as a visual impression.
The article reports the following result: The manifestation of periods of 182.6, 365 and 730 days corresponding to harmonics of the seasonal annual cycle is observed, along with predominant periods of 6.8 and 9.0 days linked to solar activity. The interpretation is strongest when it survives red-noise modelling, uneven sampling, spectral-window effects and correction for the number of frequencies searched.
For cycles researchers, the article brings together geomagnetic k-index, solar rotation harmonics, annual cycles, wavelet analysis. It is relevant to the detection and interpretation of periodic signals in astronomical observations, where sampling, red noise and instrumental effects can imitate or obscure genuine cycles.
Because it is a preprint, the work should be read alongside later peer-reviewed publications and independent replications. It remains useful because the proposed cycle, dataset and analytical approach are stated clearly enough to be scrutinised.
Source details and credits
- Source / publisher: arXiv
- Source type: Preprint
- URL type: PDF
- Credits: arXiv
- URL: https://arxiv.org/pdf/1610.03047